REVIEW | doi:10.20944/preprints202309.0487.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: protozoan infections; helminthiasis; infectious diseases; travel medicine; human migration; climate change; one health
Online: 7 September 2023 (10:49:03 CEST)
In a rapidly evolving global landscape characterized by increased international travel, migration, and ecological shifts, this study sheds light on the emergence of protozoal and helminthic infections targeting the central nervous system (CNS) within Europe. Despite being traditionally associated with tropical regions, these infections are progressively becoming more prevalent in non-endemic areas. By scrutinizing the inherent risks, potential outcomes, and attendant challenges, this study underscores the intricate interplay between diagnostic limitations, susceptibility of specific population subsets, and the profound influence of climate fluctuations. The contemporary interconnectedness of societies serves as a conduit for the introduction and establishment of these infections, warranting comprehensive assessment. This study emphasizes the pivotal role of heightened clinician vigilance, judicious public health interventions, and synergistic research collaborations to mitigate the potential consequences of these infections. Though rare, their profound impact on morbidity and mortality underscores the collective urgency required to safeguard the neurological well-being of the European populace. Through this multifaceted approach, Europe can effectively navigate the complex terrain posed by these emergent infections.
ARTICLE | doi:10.20944/preprints202309.0347.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: Fasciola hepatica; triclabendazole; anthelmintic-resistance; amino acid-substitution; binding-pocket; ligand-protein docking; protein 3D modeling.
Online: 6 September 2023 (10:24:35 CEST)
The expression of the Fasciola hepatica Carboxylesterase type B (CestB) gene is induced in response to the anthelmintic triclabendazole (TCBZ), resulting in a significant increase in enzymatic specific activity. Furthermore, the amino acid sequence of CestB exhibits variations that could lead to substantial amino acid substitutions at the ligand-binding site. These substitutions have the potential to affect the interaction between the ligand and the protein, as well as the catalytic properties of the enzyme. The objective of this study was to identify new CestB polymorphisms in TCBZ-resistant parasites using 3D modeling against the metabolically oxidized form of the anthelmintic TCBZSOX. Our aim was to observe the formation of TCBZSOX-specific binding pockets that could potentially explain the resistance to anthelmintic agents. We identified a CestB polymorphism in a TCBZ-resistant strain of parasites exhibiting three radical amino acid substitutions at positions 147, 215, and 243, resulting in the formation of a TCBZSOX-affinity pocket capable of binding the anthelmintic drug. Additionally, our 3D modeling analysis revealed that these amino acid substitutions also had an impact on the configuration of the CestB catalytic site, affecting the enzyme's interaction with chromogenic carboxylic ester substrates and altering its catalytic properties; however, the identified TCBZSOX-binding pocket was located far from the enzyme's catalytic site, making the enzymatic hydrolysis of TCBZSOX theoretically impossible. Nonetheless, the increased affinity for the anthelmintic may explain a drug-sequestration type of anthelmintic resistance and lays the foundation for the development of a molecular diagnostic tool for identifying anthelmintic resistance in F. hepatica.
ARTICLE | doi:10.20944/preprints202308.0628.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: imported schistosomiasis; diagnosis; LAMP; immunocromatographic rapid test; microscopy; Latent Class Analysis.
Online: 8 August 2023 (09:13:53 CEST)
Migratory flows and international travel are triggering an increase in imported cases of schistosomiasis in non-endemic countries, with serology being the recommended method for screening migrants. The present study aims to evaluate, for the first time, the LAMP technique on patients’ urine samples for the diagnosis of imported schistosomiasis in a non-endemic area in comparison to a commercial immunochromatographic test and microscopic examination of feces and urine. A prospective observational study was conducted in sub-Saharan migrants attending at the Tropical Medicine Unit, Almería, Spain. For schistosomiasis diagnosis, serum samples were tested using an immunochromatographic test (Schistosoma ICT IgG-IgM). Stool and urine samples were examined by microcopy. Urine samples were evaluated by combining three LAMP assays for the specific detection of Schistosoma mansoni and S. haematobium, and an assay for the genus Schistosoma. To evaluate the diagnostic accuracy of Schistosoma-LAMP in comparison to microscopy and Schistosoma ICT IgG-IgM test, a Latent Class Analysis (LCA) was performed. A total of 115 patients were included; 21 patients (18.3%) were diagnosed with schistosomiasis confirmed by microscopy, with S. haematobium being the most frequent species identified (18/115; 15.7%). The Schistosoma ICT IgG-IgM test resulted 100% positive and Schistosoma-LAMP was 61.9% positive, reaching as high as 72.2% for S. haematobium. The sensitivity and specificity estimated by LCA, respectively, were: 92% and 76% for Schistosoma ICT IgG-IgM, 68% and 44% for Schistosoma-LAMP and, 46% and 97% for microscopy. The Schistosoma-LAMP technique presented a higher sensitivity than microscopy for the diagnosis of imported urinary schistosomiasis, which could improve the diagnosis both in referral centers and in centers with limited experience or scarce resources and infrastructure.
ARTICLE | doi:10.20944/preprints202308.0488.v2
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: COVID-19; Receptor binding domain (RBD); natural infection; vaccination; neutralizing antibodies
Online: 8 August 2023 (07:11:22 CEST)
(1) Background: To fight for COVID-19 pandemic, immunity against SARS-CoV-2 should be achieved not only through natural infection but also vaccination. Controversies exist about the effect of COVID-19 vaccination on previously infected persons; (2) Methods: A prospective cohort was undergone to collect sera from unvaccinated survivors and vaccinated persons--with and without COVID-19 pre-infection. The sera were analyzed for the anti-Receptor Binding Domain (RBD) titers by ELISA and for the capacity to neutralize the pseudovirus of the Wuhan-Hu-1 strain by luciferase assays; (3) Results; Neither the antibody titers nor the neutralization capacity was significantly different between the three groups. However, the correlation between the antibody titers and the percentage of viral neutralization derived from sera of unvaccinated survivors was higher than that from vaccinated persons with pre-infection (Spearman correlation coefficient (r) = -0.8558; 95% CI, -0.9259 to -0.7288), p <0.0001 vs -0. 581; 95% CI, -0.7679 to -0.3028; p = 0.0002, respectively), indicating the capacity to neutralize the virus is better among the unvaccinated individuals. (4) Conclusions: Vaccines induced anti-RBD titers as high as the natural infection with lower neutralization capacity, and it did not boost the immunity in pre-infected persons.
ARTICLE | doi:10.20944/preprints202307.1592.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: Acinetobacter; pneumonia; community-acquired; tropical; infection; bacteramic
Online: 24 July 2023 (11:02:23 CEST)
Background: Community acquired Acinetobacter pneumonia (CAAP) typically presents with rapid progression to fulminant disease, and is complicated by high mortality. Australian epidemiological studies are few. Methods: We conducted a retrospective study on bacteraemic cases of CAAP over twenty years, (2000-2019) in North Queensland. Cases were selected on microbiologic, clinical, and radiographic parameters. Data on patient demographics were obtained, along with microbial, antibiotic, mortality, and climatic data. Results: 28 cases of CAAP were included. Nineteen (67.9%) were male, twenty-three (82.1%) were Indigenous Australians, and mean age was 45.9 years. Most presentations were of moderate to severe pneumonia, 25/28 (89.3%). 90% of cases had two or more risk factors. The strongest risk factors for CAAP were alcohol excess and tobacco use. No statistically significant difference in presenting severity, ICU admission or mortality was seen between dry and wet season disease. Dry season disease accounted for 35.7% of cases. Overall mortality was 28.6%. Early use of meropenem or gentamicin reduced mortality irrespective of presenting severity (mortality 17.6%) Non-targeted antibiotic therapy was associated with a non-significant difference in mortality of 44.4%. Conclusions: Early administration of targeted antibiotics can mitigate a high mortality rate. Choice of antibiotic therapy for community acquired pneumonia should be based upon severity, risk factors and clinical suspicion of CAAP rather than seasonality.
REVIEW | doi:10.20944/preprints202307.1020.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: Plasmodium vivax; Duffy Blood-Group System; Vivax malaria; Plasmodium Duffy antigen binding protein; prevalence
Online: 14 July 2023 (13:01:06 CEST)
The Duffy protein, a transmembrane molecule, functions as a receptor for various chemokines and facilitates attachment between the reticulocyte and the Plasmodium Duffy antigen-binding protein. Duffy expression correlates with the Duffy receptor gene for the chemokine, located on chromosome 1, and exhibits geographical variability worldwide. Traditionally, researchers have described the Duffy negative genotype as a protective factor against phenotypic malaria expression. However, recent studies suggest this microorganism's evolution potentially diminishes this protective effect. Nevertheless, there is currently insufficient global data to demonstrate this phenomenon. This study aimed to evaluate the relationship between the Duffy genotype/phenotype and the prevalence of Plasmodium vivax infection. The protocol for the systematic review was registered in PROSPERO as CRD42022353427 and involved reviewing published studies from 2012 to 2022. Medline, Web of Science, Scopus, and Scielo databases were consulted. Assessments of study quality were conducted using the STROBE and GRADE tools. A total of 34 studies were included, with Africa accounting for most recorded studies. The results varied significantly regarding the relationship between the Duffy genotype/phenotype and Plasmodium vivax invasion. Some studies predominantly featured the negative Duffy genotype yet reported no malaria cases. Other studies identified minor percentages of infections. Conversely, certain studies observed a higher prevalence (99%) of Duffy-negative individuals infected with Plasmodium vivax. In conclusion, no evidence of a gender-specific distribution of malaria between Duffy-negative men and women was found. However, evidence supports that the homozygous Duffy genotype positive for the A allele (FY*A/*A) is associated with a higher incidence of Plasmodium infection. Furthermore, the negative Duffy genotype does not confer protection against this disease.
CASE REPORT | doi:10.20944/preprints202306.0666.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: Blastomycosis; Blastomyces dermatitidis; Endemic Fungi; Axe Throwing; Occupational Exposure
Online: 9 June 2023 (04:32:25 CEST)
Blastomycosis is an endemic fungal disease seen prominently in the northern regions of North America, manifested as pulmonary disease, however also with dissemination to the skin, bones, and genitourinary tract. We describe a case of a patient in Southern California diagnosed with disseminated blastomycosis due to a novel occupational exposure of axe throwing.
ARTICLE | doi:10.20944/preprints202306.0269.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: Schistosoma mekongi; LAMP; Reservoir Animal; Domestic animal; Lao PDR; Mekong River;
Online: 5 June 2023 (08:25:55 CEST)
The prevalence of Schistosoma mekongi in humans in the Lao People’s Democratic Republic (Lao PDR) has been relatively well monitored and has decreased due to effective interventions such as preventative chemotherapy with mass drug administration of praziquantel and community awareness programs. However, the prevalence among potential domestic reservoir animals remains broadly unclear, except for a few villages in the endemic area. Therefore, we conducted S. mekongi surveys for the domestic animals that had contact with Mekong River water. We conducted a cross-sectional study of the domestic animals in the seven sentinel villages in the Khong and Mounlapamok Districts of Champasak Province in southern Lao PDR in 2018 by random sampling with a statistically reliable sample size. Stool samples of the five predominant domestic animal species, cattle (n = 160), pig (n = 154), buffalo (n = 149), dog (n = 143), and goat (n = 85), were collected and examined by experienced laboratory technicians using parasitological FECT method and the LAMP technique. The microscopic analysis did not detect any eggs of S. mekongi in the stool samples of any animal species. However, S. mekongi DNA was detected by the LAMP test in dog stool samples (0.7%; 1/143). Other helminth eggs were found during our microscopic analysis. These findings suggested that an intervention for S. mekongi infection should focus solely on human populations. However, periodic surveillance for S. mekongi infection among dogs should be conducted to monitor a possible resurgence of S. mekongi infection in the domestic animal population.
ARTICLE | doi:10.20944/preprints202303.0492.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: Malaria parasitaemia; Risk factors; Malaria Diagnosis; infectious mode in children
Online: 28 March 2023 (14:58:24 CEST)
Background: Malaria remains a serious public health concern worldwide, particularly in tropical and subtropical regions, and the leading causes of mortality and morbidity in children especially among those aged under five in developing countries. Malaria can be fatal if not promptly and accurately diagnosed, especially in children.This study was carried out to determine the level of malaria infection and its associated risk factors among febrile children.Methods: Blood samples were collected and analyzed from two- hundred (200) systematically selected febrile children aged 1-10 years old. assay of samples collected were carried out using standard methods.data were collected using a pretested structured questionnaire. Results: Results obtained from study subjects shows that, of the eighty-seven (87) infected subjects, 34 (39.1%) were aged 1-5 years, while 52 (59.8%) were within the range of 6 years and above.severity of infection showed 48 (55.2%) with scanty parasitic infection while 25 (28.7%) showed moderate infection, and 13 (14.9%) showed heavy infection.The association of age and level of parasitemia showed that 34 (58.8% ) subjects below 5 years, recorded scanty malaria compared to 14.7% with severe malaria within the age range.Considering gender, of the 33 infected female subjects, 45.5% had scanty malaria, 36.4% showed moderate malaria, while 18.2% had severe malaria, compared to the males subjects.Conclusion: This study reveals the prevalence of malaria infection with some level of severity among children at our study location.The need for prompt diagnosis and improved access to all malaria interventions becomes relevant,with a special focus on the high risk group.
ARTICLE | doi:10.20944/preprints202303.0388.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: tungiasis; Brazil; rapid assessment; epidemiology; neglected tropical disease
Online: 22 March 2023 (03:21:06 CET)
Tungiasis has been included in the WHO list of Neglected Tropical Diseases, but systematic data on the occurrence are scarce. We analyzed data on the occurrence of tungiasis in the 184 munici-palities of Ceará State in Northeast Brazil, based on an online open rapid assessment question-naire focused on health professionals and other key stakeholders. Questions included the occur-rence of tungiasis, severe cases, cases in animals and seasonal variations of the disease. There were in total 1,265 individual data entries available (1 to 104 per municipality) from all munici-palities of the state. A total of 181 (98.3%) of municipalities reported the occurrence of tungiasis in the past or currently, 120 (65.2%) reported current occurrence, 155 (84.2%) severe cases in the past or currently; and 47 (25.5%) reported severe cases currently. A total of 132 (71.7%) municipalities reported tungiasis in animals, most commonly in dogs (97), pigs (80), cats (50), horses (20), cattle (8) and goats (6). Most municipalities mentioned the seasonality of tungiasis (n=146; 79.3%). There was no report of any specific tungiasis control program. Our data show that tungiasis and severe tungiasis commonly occur in Ceará state and that tungiasis is a significant public health issue for both humans and animals. An integrated One Health approach is needed to reduce dis-ease burden, including human and animal health, and the environment.
ARTICLE | doi:10.20944/preprints202301.0089.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: Strongyloidiasis; Strongyloidesstercoralis; Strongyloidesratti; DNA-molecular techniques
Online: 5 January 2023 (02:09:06 CET)
Background: Strongyloidiasis, a neglected disease caused by intestinal nematodes of the genus Strongyloides, is endemic to tropical and subtropical areas such as Vietnam. The morphological diagnosis of larvae by Hara Mori culture technique and microscopicare are considered the standard diagnostic procedures in the endemic areas of Strongyloides spp. However, they could only identify the genus, not the species of Strongyloides. DNA-molecular techniques which are highly sensitive and more cost-effective have been increasingly utilized in detection of Strongyloides species. This study aims to determine prevalence and the species of Strongyloides among resident population in Duc Hoa district, Long An province, Southern Vietnam. Methods: A cross-sectional study was conducted using 1,190 stool samples collected in Duc Hoa district, Long An province, Vietnam, from July, 2017 to November 2018. The stool specimens were transported to the Laboratory of Medical Parasitology, Pham Ngoc Thach University of Medicine within two hours of collection at an appropriate temperature of 25 oC. All samples were stored at 2 - 8°C and processed within 48 hours for microscopic examination. Molecular detection was carried out at Laboratory of Molecular Biology, Pham Ngoc Thach University of Medicine, Hochiminh city, VietNam. Results: Of the 1,190 samples tested, Strongyloides spp. larvae were detected in 79 specimens (6.6%) by two classical parasitological methods, namely direct microscopy and the modified Harada-Mori filter paper culture. DNA was extracted from 70 of the 79 samples of Strongyloides spp. larvae, which was subsequently characterized by real-time PCR amplification of the 18S and 28S regions of the rDNA gene. The results showed that 97.1% of the DNA samples were S. stercoralis, 2.9% were co-infections with S. ratti and S. stercoralis, and 2.9% belonged to S. ratti. For all 14 isolates, nucleotide sequencing was compared with other human pathogenic species of Strongyloides whose sequences are available in GenBank. The identity of 12/14 sequences were confirmed as S. stercoralis with a high level of similarity (91.3% - 100%) and over 98% for S. ratti. Between the two co-infection samples, the higher similarity belonged to S. stercoralis. Conclusion: A molecular amplification of small subunit ribosome RNA followed by sequence analysis has been proved to be a suitable method for discrimination of Strongyloides spp. retrieved from stool samples.
REVIEW | doi:10.20944/preprints202212.0077.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: Complexity; policy-recommendation; mathematical models
Online: 5 December 2022 (11:33:35 CET)
In sub-Saharan Africa, malaria is a leading cause of mortality and morbidity. As a result of the interplay between many factors, the control of this disease can be challenging. However, few studies have demonstrated malaria's complexity, control, and modeling although this perspective could lead to effective policy recommendations. This paper aims to be a didactic material providing the reader with an overview of malaria. More importantly, using a system approach lens, we intend to highlight the debated topics and the multifaceted thematic aspects of malaria transmission mechanisms, while showing the control approaches used as well as the model supporting the dynamics of malaria. As there is a large amount of information on each subject, we have attempted to provide a basic understanding of malaria that needs to be further developed. Nevertheless, this study illustrates the importance of using a multidisciplinary approach to designing next-generation malaria control policies.
ARTICLE | doi:10.20944/preprints202211.0386.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: autodissemination; dengue; ovitraps; Philippines; pyriproxyfen; spatial analysis
Online: 21 November 2022 (09:44:35 CET)
Dengue infection is one of the most important vector-borne diseases worldwide and is a significant public health problem in the tropics. Mosquito control continues to be the primary approach to reducing the disease burden and the dengue virus (DENV) spread. Aside from the traditional larviciding and adulticiding interventions, autodissemination using pyriproxyfen-treated (AD-PPF) ovitraps is one of the promising methods to complement existing vector control strategies. Our paper assessed the efficacy of AD-PPF in reducing DENV infection in two barangays in Parañaque City. Using saliva samples from the participants from both the control and intervention sites, we collected the seroprevalence data for three months in each of the two years. Spatial analysis was conducted to determine hotspot areas and identify DENV infection distributions across the trial periods. Results showed that the intervention site was identified as having clustering of DENV infection in Month 0 of Year 1 and shifted to random dispersion of dengue cases at the end of Month 3 in Year 2. The disappearance of the clustering of the intervention site translates to a decrease in the cases of DENV infection relative to the control site. Furthermore, we also identified that DENV infection transmission occurs at a small-scale level that did not go beyond 86 meters. In conclusion, AD-PPF is suggested to be an effective strategy and may be used as an additional vector control approach, albeit in its short-term implementation.
ARTICLE | doi:10.20944/preprints202209.0343.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: Lymphatic Filariasis; Indonesia; National Surveillance; Registry; BELKAGA
Online: 22 September 2022 (10:41:18 CEST)
Lymphatic filariasis (LF) is a vector-borne disease caused by parasitic helminths and constitutes a serious public health issue in tropical regions. According to the World Health Organization (WHO), infected cases in Southeast Asia constitute 50% of the estimated 120 million infections globally. In Indonesia, LF is caused by all filarial species, and in 2018, 236 districts from a total of 514 districts in the entire country were declared as endemic areas. The global program to eliminate filariasis has been running for the last 19 years and has been conducted as a full national initiative for the last 8 years in Indonesia. The study describes the surveillance of LF cases and prevalence in Indonesia for the past 17 years (2001-2017) – during the global and national LF elimination programs-, using national registry-based data. The data demonstrates that the national program has been largely effective in the areas it has been active the longest, while there are provinces lagging behind in the successful suppression of LF. The high geographical fragmentation of the country with the associated ecological parameters relating to LF incidence, likely play an important role in maintaining the highly varied incidence rate across Indonesia.
ARTICLE | doi:10.20944/preprints202207.0366.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: onchocerciasis; community directed treatment with ivermectin; elimination; epilepsy; focus group discussions; misconceptions
Online: 25 July 2022 (09:27:22 CEST)
Despite of over 20 years of community directed treatment with ivermectin (CDTI), a high prevalence of onchocerciasis and onchocerciasis-associated epilepsy were observed in rural villages in Mahenge, Tanzania. Therefore, we assessed the knowledge, attitude and practice about onchocerciasis in four rural villages in the Mahenge area. This was a qualitative study conducted between June and July 2019. Eleven focus group discussions were organized with persons with epilepsy and their caretakers, community resource persons, and community drug distributors (CDDs), and two in-depth interviews with district programme coordinators of neglected tropical diseases (NTD). Most participants were aware about symptoms of onchocerciasis using local terminologies such as “ukurutu/rough dry skin” and “kuwashwa/itching”. A small proportion of people did not take ivermectin during CDTI for fear of adverse reactions such as itching and swelling. Some men believed that ivermectin may decrease libido. Challenges for high CDTI coverage included, long walking distance by CDDs to deliver drugs to households, persons being away for farming, low awareness of the disease and limited supervision by the NTD coordinators. In conclusion, ivermectin uptake in Mahenge should be optimised by continuous advocacy about the importance of taking ivermectin to prevent onchocerciasis-associated morbidity and by improving supervision during CDTI.
ARTICLE | doi:10.20944/preprints202201.0414.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: Giardia duodenalis; Assemblages; Epidemiology; Genetic diversity
Online: 27 January 2022 (11:18:33 CET)
Gut protozoan parasites are neglected and not targeted by specific control initiatives and this have led to a knowledge gap concerning their regional diversity and epidemiology. The present study aims to explore Giardia duodenalis genetic diversity and assess the epidemiologic scenario of subclinical infections in different Brazilian biogeographic regions. Cross-sectional surveys (n=1,334 subjects) were conducted in the Amazon, Cerrado, Semiarid and Atlantic Forest. Microscopy of non-diarrheal feces and nucleotide sequencing of a β-giardin gene fragment were performed. Twenty-seven (52.9%) β-giardin sequences were characterized as assemblage A and 24 (47.1%) as assemblage B. In Amazon, assemblage B was the most frequently detected with 2 novel sub-assemblages. Assemblage A predominated in the extra-Amazon region, with 5 novel sub-assemblages. Prevalence rates reached 17.8% in Amazon, 8.8% in Atlantic Forest, 7.4% in Cerrado and 2.3% in the Semiarid. People living in poverty and extreme poverty presented significantly higher positivity rates, reaching 11.9% and 14.5%, respectively. Giardiasis tended to be more frequent in stunted (21.6%) than in eutrophic children (12.9%). In conclusion, subclinical giardiasis in endemic in Brazilian communities in different biogeographic regions, presenting high genetic diversity and a heterogeneous genotypic distribution.
REVIEW | doi:10.20944/preprints202108.0364.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: dengue virus; antiviral targets; NS5; flavivirus; polymerase; nucleoside inhibitors; non-nucleoside inhibitors
Online: 17 August 2021 (14:07:29 CEST)
Dengue is the most prevalent arthropod-borne disease globally and affects approximately 2.5 billion people living in over 100 countries. The increasing geographic expansion of Aedes aegypti mosquitoes which transmit the virus has made dengue fever a global health concern. There are currently no approved antivirals available to treat dengue, and the only approved vaccine used in some countries is limited to seropositive patients. Treatment of dengue therefore remains largely supportive to date; hence research efforts are being intensified for the development of antivirals against dengue. The NS3 and NS5 nonstructural proteins have been the major targets for dengue antiviral development due to their indispensable enzymatic and biological functions in the viral replication process. NS5 is the largest and most conserved nonstructural protein encoded by flaviviruses including dengue. Its multifunctionality makes it an attractive target for antiviral development against dengue, but research efforts are hindered due to its limited structural characterization compared to the NS5 of other flaviviruses like the Zika virus. Increase in structural insights into the dengue NS5 protein will accelerate drug discovery efforts focused on NS5 as an antiviral target. In this review, we will give an overview of the current state of therapeutic development against dengue.
REVIEW | doi:10.20944/preprints202101.0447.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: Malaria, Fever, Plasmodium falciparum, falciparum vivax, under-five, determinants, risk factors, review
Online: 22 January 2021 (13:08:29 CET)
Background/Purpose: In recent times, Sub-Sahara Africa (SSA) had been rated by the World Health Organization, (WHO), as the most malaria endemic region in the world. Evidence synthesis of the risk factors associated with malaria among children aged under-five in SSA is urgently needed. This would help to inform decisions that policy makers and executors in the region need to make for the effective distribution of scare palliative resources to curb the spread of the illness. This scoping review is aimed to identify studies that have used multivariate classical regression analysis to determine risk factors associated with malaria among children under-five years old in SSA. Methods/Design: The search terms followed PICOTS, (Population, Intervention, Comparator, Outcome, Timing, Setting), and were used in searching through the following databases: PubMed, MEDLINE, Web of Science, Cumulative Index of Nursing and Allied Health Literature (CINAHL), Scopus, and MeasureDHS. The databases were searched for published articles from January 1990 to December 2020. Results: Among the 1154 studies identified, only thirteen (13) studies met the study’s inclusion/exclusion criteria. Narrative syntheses were performed on the selected papers to synchronise the various risk factors identified. Factors ranging from child-related, (age, birth order and use of bed net), parental/household-related, (maternal age and education status, household wealth index) and community-related variables, (community wealth status, free bed net distribution), were some of the identified significant risk factors. Conclusion: It is timely to have a synthesis of risk factors that influence the malaria status of children under-five in SSA. The outcome of the review will increase the knowledge of the epidemiology of morbidity that will form the basis for designing efficient and cost-effective distribution of palliatives and controls of malaria in SSA.
REVIEW | doi:10.20944/preprints202011.0689.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: Plasmodium vivax; Erythrocyte Invasion Mechanisms; Duffy Negative; Africa; Immunology; Epidemiology
Online: 27 November 2020 (13:08:59 CET)
Plasmodium vivax malaria is a neglected tropical disease, despite being more geographically widespread than any other form of malaria. The documentation of P. vivax infections in different parts of Africa where Duffy-negative individuals are predominant suggested that there are alternative pathways for P. vivax to invade human erythrocytes. Duffy-negative individuals may be just as fit as Duffy-positive individuals and are no longer resistant to P. vivax malaria. In this review, we describe the complexity of P. vivax malaria, characterize pathogenesis and candidate invasion genes of P. vivax, and host immune responses to P. vivax infections. We provide a comprehensive review on parasite ligands in several Plasmodium species that further justify candidate genes in P. vivax. We also summarize previous genomic and transcriptomic studies related to the identification of ligand and receptor proteins in P. vivax erythrocyte invasion. Finally, we identify topics that remain unclear and propose future studies that will greatly contribute to our knowledge of P. vivax.
ARTICLE | doi:10.20944/preprints202008.0636.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: COVID-19; stress; mental anxiety; depression; children and attributes
Online: 28 August 2020 (11:27:39 CEST)
Coronavirus is believed to have originated from a wet market in Wuhan, China, and has spread all over the world, resulting in a large number of hospitalizations and deaths. Social scientists are just beginning to understand its consequences on human behavior. One policy that public health officials put in place to help stop the spread of the virus were stay-at-home/shelter-in-place lockdown-style orders. Schools, Colleges and Universities across the country have now been shut down till now due to Covid-19. Some Governments in India impose lockdown to reduce the crises created by this unknown virus. It is now difficult to make final assessments by school, school leaving examinations and entrance tests for undergraduate and post-graduate courses. This disruption implies for students across the socio-economic spectrum, both in terms of learning outcomes , food and economic security. Here the aim is to discuss the implications of lockdown-induced in schools in both urban and rural areas in India.The whole world implemented a nationwide lockdown to curb the transmission of the virus. A survey was over Five hundred families to complete a questionnaire with questions around symptoms of depression, anxiety, stress, and family affluence. The humans who do not have enough supplies to sustain the lockdown were most affected Families with affluence were found to be negatively correlated with stress, anxiety, and depression. Stress, anxiety, and depression more than others are seen in students and healthcare professionals. The main aim of the paper is to find out how symptoms of depression, anxiety and stress on parents due to COVID-19.
REVIEW | doi:10.3390/sci2030068
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: COVID-19; pooling clinical trials; hyperinfection; steroids; treatment; targeted healthcare; population health management; cancer treatment; clinical research; clinical trials; developing vaccines; ranking and rating hospital quality; school closures; interventions for delirium; assessments of COVID-19 death inequities; regulatory safeguards; preventing child abuse and maltreatment; prevalence of health care worker burnout; nursing home ratings; challenging oncology practice; addressing racial; ethnic; social and economic divides; violence against sexual minority adolescents; primary tumors; metastasis; stages of cancer; reforming cancer clinical trials; supporting carers; protection and prevention; benign and malignant tumors; reforming cancer clinical trials; protection of healthcare personnel; comparing excess deaths in NYC; 1918 influenza pandemic; the possibility of full recovery from COVID-19; mental health impact of COVID-19 on young adults; ranking and rating nursing home quali
Online: 21 August 2020 (00:00:00 CEST)
The SARS-CoV-2 virus that causes the COVID-19 disease has wreaked havoc on the world community in terms of every imaginable parameter. The research output on COVID-19 has been nothing short of phenomenal, especially in the medical and biomedical sciences, where the search for a potential vaccine is being conducted in earnest. Much of the advanced research has been distributed in the leading medical journals, including the Journal of the American Medical Association (JAMA), where the latest research is distributed on a daily basis. The purpose of this paper is to provide some perspectives on 44 interesting and highly topical research papers that have been published in JAMA, at the time of writing, within the past two weeks. The diverse topics include public health, general medicine, internal medicine, oncology, paediatrics, geriatrics, and biostatistics.
ARTICLE | doi:10.3390/sci2020045
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: adverse drug reactions; antimalarial; Ghana; herbal remedies; malaria; questionnaire; street sale; orthodox; unnatural medicines; patient preference
Online: 12 June 2020 (00:00:00 CEST)
Malaria is a serious infection affecting millions of people in Africa. Our study investigated the personal preferences and applications of antimalarial medicines in Ghana. Based on over 1000 questionnaires distributed in Ghana from January to May 2019, we noticed that although Western medications to fight this disease are widely available, most patients in Ghana prefer treatment with locally produced herbal remedies. This preference appears to be due to a combination of traditional venues for obtaining medicines “on the street” rather than in licensed pharmacies, trust in local and “green” products, extensive advertisement of such local products, and an inherent distrust of imported and synthetic or unnatural medicines. Going local and natural is a trend also observed in other countries across the globe, and adds to the acceptance or rejection of drugs regardless of their activity or toxicity. In fact, adverse side effects associated with herbal remedies, such as general weakness and swollen, sore mouth, do not seem to deter the respondents of this study in Ghana. We propose a combination of (a) increasing public awareness of the benefits of modern medicine and (b) an improvement and control of the quality of herbal remedies to raise the standard of malaria treatment in countries such as Ghana.
ARTICLE | doi:10.20944/preprints202005.0269.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: case fatality; Lassa virus; pattern; positivity rate; outcome; ribavirin
Online: 16 May 2020 (16:41:27 CEST)
The prevalence and case fatality rates of Pediatric Lassa fever disease (LFD) are not well documented. This study was aimed at determining the prevalence, pattern and outcome of Pediatric LFD. It was a prospective observational study. A total of 183 subjects that met the criteria for LFD suspects were recruited consecutively and subjected to Lassa virus PCR test. Structured questionnaire was used to collect information. Of the 183 children recruited, 24 tested positive to Lassa virus PCR, giving a positivity rate of 13.1%. Mean duration of illness at presentation was 8.54 ± 3.83 days. Fever, abdominal pain and vomiting were the three highest presenting complaints. Seven out of 24 children died giving a case fatality rate (CFR) of 29.2%. Subjects with bleeding, poor urine output, convulsions and unconsciousness were more likely to die of LFD. Positivity and CFR of LFD are high. Improved case finding and prompt treatment is advocated.
REVIEW | doi:10.20944/preprints202003.0205.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: Aedes spp.; dengue; vector control; autodissemination; pyriproxyfen
Online: 12 March 2020 (09:06:48 CET)
The new emergence and re-emergence of arbovirus infections vectored by Aedes mosquitoes have been spread across Southeast Asia, Central Africa, United States, tropical Oceania and become a major of public health concerns. These arbovirus diseases found to have a similar vector, symptoms of the diseases and environments. The situation has become complicated without any specific vaccine or treatment for the diseases. As far as we concern, vector control is the best defense with many challenges, a scattered breeding site and biological behavioral sometimes, more difficult to control. Herein, we present a review of studies on current techniques proposed to combat arbovirus infections vectored by Aedes mosquitoes. A crucial gap in a vector control program is the inability to eliminate and destroy the cryptic breeding site by using conventional control methods. The idea and proper concept of using mosquitoes to bring insecticide to their oviposition site had been getting more interest in people to explore. Autodissemination is a self-delivery technique by manipulating the behavior of mosquitoes, carrying the insecticide and disseminate to cryptic breeding sites. This technique has shown a promising result in some countries and can be considered as additional tools in a vector control program
ARTICLE | doi:10.20944/preprints201911.0323.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: Zika virus; flavivirus; cross-reactivity; neutralization; diagnostics; serology; plaque reduction neutralization test; flavivirus exposure
Online: 27 November 2019 (03:45:37 CET)
Zika virus (ZIKV) co-circulates with several closely related flaviviruses which exhibit similar clinical manifestations thus, clinicians rely on molecular and serological techniques for diagnosis. Cross-reactivity of patient specimens to flaviviruses is a significant impediment to serological diagnosis in areas where multiple flaviviruses co-circulate. Furthermore, patient exposure history to any of these viruses could complicate serological response patterns which could result in over and/or underdiagnosis of ZIKV infection. Three strains of ZIKV, dengue serotypes 1-4, West Nile virus, Japanese Encephalitis virus, and Yellow Fever virus were evaluated for neutralizing properties against 3 monoclonal antibodies, 4 ZIKV-naïve patients with flavivirus exposure history, 5 patients with verified ZIKV exposure and unknown flavivirus exposure history, and 5 flavivirus-naive patients with ZIKV-only exposure. Patients naïve for ZIKV exposure effectively neutralized multiple strains of ZIKV. Overall, the prototype ZIKV isolate MR-766 did not behave like the other ZIKV isolated used in this study. MR-766 was neutralized more completely by polyclonal patient serum than recent ZIKV isolates. MR-766 was neutralized better than dengue virus in ZIKV-naïve patients with prior dengue exposure. MR-766 was neutralized significantly less than recent ZIKV isolates when treated with monoclonal antibodies. The data herein show that without RT-PCR, serological diagnosis may not be possible in areas where multiple flaviviruses are endemic.
ARTICLE | doi:10.20944/preprints201909.0123.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: Active case findings; Tuberculosis; TOUCH Agent; High TB burden area; TB Surveillance; 4S Screening; THALI Project; SORT IT; Operational Research
Online: 11 September 2019 (13:30:30 CEST)
Background: Active case finding for TB was implemented in selected sixty high TB burden wards of Kolkata, India. Community volunteers called TOUCH agents (TAs) identified and referred presumptive TB patients (PTBPs) to health facilities for TB diagnosis and treatment. We aimed to describe the ‘care cascade’ of PTBPs identified during July to December, 2018 and to explore the reasons for attrition as perceived by TAs and PTBPs. Methods: An explanatory mixed methods study with quantitative phase of cohort study using routinely collected data followed by descriptive qualitative study with in-depth interviews was conducted. Results: Of the 3, 86,242 individuals enumerated, 1132 (0.3%) PTBPs were identified. Only 713 (63.0%) PTBPs visited referred facility for TB diagnosis. TB was diagnosed in 177 (24.8%) and the number needed to screen for one TB was 2,183 individuals. The potential reasons for low yield were stigma and apprehension about TB, distrust about TA, wage loss for attending health facilities and substance abuse among PTBPs. Conclusion: The yield of ACF was suboptimal with low PTBP identification rate and high attrition rate. Interviewing each individual for symptoms of TB and supporting PTBPs for diagnosis through sputum collection and transport can be adopted to improve the yield.
ARTICLE | doi:10.20944/preprints201904.0086.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: Cryptococcal meningitis; Cryptococcus; HIV; CD4 T cells; CD8 T cells; adaptive immune response; IRIS
Online: 8 April 2019 (11:02:55 CEST)
Cryptococcal meningitis remains a significant opportunistic infection among HIV-infected patients, contributing 15%-20% of HIV-related mortality. A complication of initiating Antiretroviral therapy (ART) following opportunistic infection is Immune Reconstitution Inflammatory Syndrome (IRIS). IRIS afflicts 10-30% of HIV-infected patients with cryptococcal meningitis (CM), but its immunopathogenesis is poorly understood. We compared circulating T cell memory subsets and cytokine responses among 17 HIV-infected Ugandans with CM: 11 with and 6 without CM-IRIS. At meningitis diagnosis, stimulation with cryptococcal capsule component, glucuronoxylomannan (GXM) elicited consistently lower frequencies of CD4+ and CD8+ T cell memory subsets expressing intracellular cytokines (IL-2, IFN-γ and IL-17) among subjects who subsequently developed CM-IRIS. After ART initiation, T cells evolved to show a decreased CD8+ central memory phenotype. At the onset of CM-IRIS, stimulation more frequently generated polyfunctional IL-2+/IL-17+ CD4+ T cells in patients with CM-IRIS. Moreover, CD8+ central and effector memory T cells from CM-IRIS subjects also demonstrated more robust IL-2 responses to antigenic stimulation vs. controls. Thus, ART during CM elicits distinct differences in T cell cytokine production in response to cryptococcal antigens both prior to and during the development of IRIS, suggesting an immunologic foundation for the development of this morbid complication of CM infection.
ARTICLE | doi:10.20944/preprints201901.0231.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: Kala-azar, Dynamical System, Inverse Problem, Spatial Analysis, Asymptomatics
Online: 23 January 2019 (08:52:50 CET)
Background: Underreporting of Visceral Leishmaniasis (VL) in India remains a problem to public health controls. Effective and reliable surveillance systems are critical for monitoring disease outbreaks and public health control programs. However, in India, government surveillance systems are affected by levels of scarcity in resources and therefore, uncertainty surrounds the true incidence of asymptomatic and clinical cases, affecting morbidity and mortality rates. The State of Bihar alone contributes up to the 40\% of the worldwide VL cases. The inefficiency of surveillance systems occurs because of multiple reasons including delay in seeking health care, accessing non-authentic health care clinics, and existence of significant asymptomatic self healing infectious cases. This results in a failure of the system to adequately report true transmission rates and number of symptomatic cases that have sought medical advice (thus, high underreporting of cases). Objectives and Methods: There are several methods to estimate the extent of underreporting in the surveillance system. In this research, we use a mathematical dynamic model and two different types of data sets, namely, monthly incidence for 2003-2005 and yearly incidence from 2006-2012 from the Bihar's 21 most VL affected districts out of its 38 districts. The goals of the study are to estimate critical metrics to measure level of transmission and to evaluate the estimation process between the two data sets and 21 districts. In particularly, our focus is on (i) estimating infection transmission potential, underreporting level in incidence and proportion of self-healing cases, (ii) quantifying reproduction number of the$R_0$, and (iii) comparing underreporting incidence levels and proportion of self-healing cases between the two periods 2003-2005 and 2006-2012 and between 21 districts. Results: Our research suggests that the number of asymptomatic individuals in the population who eventually self-heal may have a significant effect on the dynamics of VL spread. The estimated mean self-healing proportion (out of all infected) is found to be $\sim 0.6$ with only 7 out of 21 affected districts having self-healing proportion less than $0.5$ for both data sets. The estimated mean underreporting level is at least $64$\% for the state of Bihar. The estimates of the basic reproduction numbers obtained are similar in magnitude for most of the districts, being in the range of (0.88, 2.79) and (0.98, 1.01) for 2003-2005 and 2006-2012, respectively. Conclusions: The estimates for the two types (monthly and yearly) of temporal data suggest that monthly data are better for estimation if less number of data points are available, however, in general, using such data set results in larger variances in parameters as compared to estimates obtained through aggregated yearly data. Estimated values of transmission related metrics are lower than those obtained from earlier analyses in the literature, and the implications of this for VL control are discussed. The spatial heterogeneity in these control metrics increases the risk of epidemics and makes the control strategies more complex.
ARTICLE | doi:10.20944/preprints201812.0206.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: Climate variability; dengue hemorrhagic fever incidence; average temperature; humidity; rainfall; Surabaya
Online: 17 December 2018 (16:15:14 CET)
Dengue hemorrhagic fever is an arboviral infectious disease that has occurred frequently as an extraordinary event due to its fast spread and lethal potential in Indonesia. The vector Aedes aegypti is sensitive to climate variability. This study determines the relationship between climate variability and dengue hemorrhagic fever in Surabaya, East Java, Indonesia from 2009 to 2017. This study used the monthly dengue hemorrhagic fever incidence obtained from the Surabaya Health Office and the monthly climate variability parameters (average temperature, rainfall, humidity) obtained from the Indonesian Agency for Meteorology, Climatology and Geophysics and website www.worldweatheronline.com. Data analysis was done using One-Sample Kolmogorov Smirnov Test and Spearman non-parametric correlation test. The results showed a correlation between all three climate variability parameters with dengue hemorrhagic fever incidence (average temperature p<0.05, r=-0.603; rainfall p<0.05, r=0.407; humidity p<0.05, r=0.7). Average temperature is negatively correlated to dengue hemorrhagic fever incidence, while rainfall and humidity are positively correlated to dengue hemorrhagic fever incidence. This study shows preliminary evidence on the correlation of climate variability and dengue hemorrhagic fever in Surabaya, East Java, Indonesia.
CASE REPORT | doi:10.20944/preprints201811.0254.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: dengue; chikungunya; Leptospira; co-infection; Colombia; Latin America
Online: 12 November 2018 (03:21:38 CET)
Background: The febrile patient from tropical areas, in which emerging arboviruses are endemic, represent a diagnostic challenge and potential co-infections with other pathogens (i.e bacteria or parasites) are usually overlooked. Objectives: We present a case of an elderly woman diagnosed with dengue, chikungunya and Leptospira interrogans co-infection. Study Design: Case report. Results: An 87-year old woman from Colombia complained of upper abdominal pain, arthralgia, myalgia, hyporexia, malaise and intermittent fever accompanied with progressive jaundice. She had a medical history of chronic heart failure (Stage C, NYHA III), without documented cardiac murmurs, right bundle branch block, non-valvular atrial fibrillation, hypertension, and chronic venous disease. Her cardiac and pulmonary status quickly deteriorated after 24 hours of her admission without electrocardiographic changes and she required ventilatory and vasopressor support. In the next hours the patient evolved to pulseless electrical activity and then she died. Dengue IgM, NS1 ELISA, MAT for Leptospira interrogans and RT-PCR for chikungunya, were positive. Discussion: This case illustrates a multiple co-infection in a febrile patient from a tropical area of Latin America that evolved to death.
ARTICLE | doi:10.20944/preprints201809.0513.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: Malawi, HIV, tuberculosis, anti-retroviral therapy, surveillance, patient monitoring, epidemic trends, drug supply, unique patient identifiers, data analysis
Online: 27 September 2018 (15:29:43 CEST)
Malawi has developed an excellent, nation-wide system for monitoring people infected with HIV and keeping track of key epidemic markers. Their success lies in two things: the focus on simplicity and the use of data collection not only to track the epidemic and identify problems but also to give regular feedback and support to every clinic in the country. This achievement is the more remarkable given that Malawi is one of the poorest countries in the world, ranking 190 out of 194 countries by GDP, but has one of the most severe epidemics of HIV in the world, ranking 9th out of 168 countries by HIV prevalence. We first discuss the current state and likely future epidemic trends in Malawi: unless we know where we are and where we are going we cannot decide what to do or how to do it to in order to achieve a better outcome. We then discuss the history and development of Malawi’s patient monitoring system, as reported in their Integrated HIV Program Reports,ix which have been published quarterly since the beginning of 2004. We consider the current state of patient monitoring and support as reflected in the most recent report for the third quarter (Q3) of 2016 and comment on some of the questions that this raises. Finally, we consider ways in which the current system could be improved by strengthening Malawi’s analytical capacity and making better use of this unique data set. The focus here is on HIV in adultsv because if ART is initiated early in all adults living with HIV this should include testing all pregnant women for HIV and starting them on treatment immediately. However, PMTCT is especially important and care must be given to reducing MTCT and identifying the long-term child survivors of mother-to-child transmission and this demands a complementary assessment. There is an ongoing debate about the relative merits of treatment and prevention in reducing transmission and it should be made clear that the primary reason for starting people on treatment early is that it is in the best interest of the individual patient to start treatment as soon as possible after becoming infected. Allowing a person’s immune system to deteriorate to any degree is not consistent with the clinician’s commitment to ‘first do no harm’ and even those with the highest CD4+ cell count are at a substantially increased risk of death. What matters, therefore, is to get as many people as possible onto ART, ensure that they remain virally suppressed, and consider prevention in this context.
REVIEW | doi:10.20944/preprints201805.0103.v1
Online: 7 May 2018 (07:39:03 CEST)
Rabies is one of the neglected tropical diseases, almost 100% fatal, but preventable. Rabies virus causes the disease and causes about 59000 human deaths annually. The author searched the Pubmed Database at NCBI for articles on rabies disease published between 2007 and 2018. All articles are open access, free for redistribution and in English. To examine rabies virus, Seller’s test was used. In this article, references written by the author were included and relevant publications were also included. The author reviewed a rabies dog case kept at Nelwan Institution for Human Resource Development. The dog showed clinical signs such as aggressive behavior, in-appetence, and soaking in water. Currently, there are no drugs to treat rabies. Vaccination is the best way to prevent the disease. To eradicate rabies, mass vaccination in dogs, post-exposure prophylaxis, and gene therapy can be used. To prevent rabies disease, minimum 70% of the dog population should receive vaccination. Humans with category II exposure should receive rabies vaccine and rabies immunoglobulin. For treatment, in vivo experiment showed that gene therapy can eliminate rabies from the infected neurons by using rAAV-N796. To fight rabies virus, induced pluripotent cells in combination with CRISPR/Cas9 system can also be beneficial. Furthermore, it needs US$ 8.6 billion to fight rabies annually.
ARTICLE | doi:10.20944/preprints201706.0052.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: Somali; conflict; health system; resilience; fragile; access; government; NGO
Online: 12 June 2017 (06:26:20 CEST)
Background: Human Immnodeficiency virus (HIV) continues to take a heavy toll on the lives of many people with worst impact on health and wellbeing for the affected individuals in fragile states. The HIV situation in Somalia is not clearly known and experiences of the people living with HIV in this war-torn region unexpressed. This pilot qualitative study sought to explore the experiences of people living with diagnosed HIV in Mogadishu and their resilience in access to care and social support. Method: Face-to-face in-depth interviews were conducted in Somali in May 2013 among patients who were receiving Antiretroviral therapy (ART) from the HIV clinic in Mogadishu. Participants were recruited through drug dispensers at the HIV clinic in Benader Hospital. These were tape recorded, transcribed and translated for content analysis. Results: Three women and four men who were living with HIV shared the following narratives. Their perception was that they had either got HIV from their spouces or through health care contamination. They were very knowledgable about the realities of HIV, how the medication works, nutritional requirements and drug adherence. They were always willing to go an extra mile to secure a good life for themselves. However the external HIV stigma impacted their access to care. They faced challenges in their homes and at work which compelled them to seek support from non-governmental organisations (NGOs) or close family members. This stigma often affected their disclosure to the wider community due to the uncertainity of the repercussions, leading to a life of extreme loneliness and financial difficulties. The participants’ coping mechansms included living together and starting their own NGO for support with very strong optimism about their prognosis. Conclusions: The people living with diagnosed HIV in Mogadishu are highly knowledgeable about HIV transmission, the realities of living with diagnosed HIV infection and efficacy of HIV treatment. Our small sample suggests adequate access to ART through NGOs. However, widespread HIV stigma limits HIV status disclosure to the families and communities which creates a risk of self isolation and ill health. But affected individuals have developed resilient mechanisms of managing the risks. They strive to remain employed for economic security, adhere to HIV treatment, engage in support groups and maintain utmost optimism about their prognosis.
ARTICLE | doi:10.20944/preprints201612.0006.v1
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: Dengue virus; E; NS1-2a; electroporation; DNA vaccine
Online: 1 December 2016 (10:37:10 CET)
Dengue virus (DENV), the causative agent of dengue fever (DF), is one of the most important mosquito-borne viruses that can infect humans. Although much effort has been made on prevention and control of dengue, there are currently no anti-viral drugs or worldwide approved vaccines yet. In this study, we immunized six-week-old Balb/c mice with DNA vaccine candidates E and NS1-2a of DENV serotype 2 or the combination of them (E+NS1-2a) via an electroporation (EP)-assisted intramuscular gene delivery system and evaluated the immune response and protection. The highest specific antibody titres and cytokine levels secreted by splenocytes as well as the highest survival rate were observed in the E+NS1-2a group, followed by E group and NS1-2a group. Our data suggested that the combination of E and NS1-2a delivered by EP may be a superior preventive strategy against DENV.