REVIEW | doi:10.20944/preprints202305.0906.v2
Subject: Biology And Life Sciences, Virology Keywords: Respiratory viruses; Anosmia; Olfaction Disorders; loss of smell; Covid-19
Online: 16 October 2023 (08:54:50 CEST)
Acute respiratory viruses (ARVs) are leading cause of diseases in human worldwide. High risk individuals including children and elderly could potentially develop severe illness that could result in hospitalization or death in the worst case. Most common ARVs are Human respiratory syncytial virus, Human Metapneumovirus, Human Parainfluenza Virus, rhinovirus, coronaviruses (including SARS and MERS CoV), adenoviruses, Human Bocavirus, enterovirus (-D68 and 71), and influenza viruses. The olfactory deficits due to ARVs infection is a common symptom among patients. This mini review provides an overview of the role of SARS-CoV-2 and other common ARVs in the development of human olfactory pathophysiology. We highlight the critical need for understanding the signaling underlying the olfactory dysfunction and the development of therapeutics for this wide-ranging category of AVRs to restore the altered or loss of smell in affected patients.
ARTICLE | doi:10.20944/preprints202304.1240.v1
Subject: Medicine And Pharmacology, Epidemiology And Infectious Diseases Keywords: IL17A; malaria; Plasmodium falciparum; serum level; polymorphism.
Online: 30 April 2023 (02:35:08 CEST)
Malaria infection is a multifactorial disease partly modulated by host immuno-genetic factors. Recent evidence has demonstrated the importance of Interleukin-17 family proinflammatory cytokines and their genetic variants in host immunity. However, limited knowledge exists about their role in parasitic infections such as malaria. We aimed to investigate IL-17A serum levels in patients with severe and uncomplicated malaria, whether IL-17A gene polymorphisms are involved in severe malaria susceptibility and the polymorphism’s influence on the IL-17A serum levels. 125 malaria patients and 48 free malaria controls were enrolled in this research. Malaria patients were classified into severe malaria (SM) and uncomplicated malaria (UM). IL-17A serum levels were measured with ELISA. PCR and DNA sequencing were used to assess host genetic polymorphisms in IL-17A. We performed a multivariate regression to estimate the impact of human IL-17A variants on IL-17A serum level and malaria outcome. Elevated serum IL-17A levels accompanied by increased parasitemia were found in SM patients compared to UM and controls (P<0.0001). Also, the IL-17A levels were lower in SM patients who were deceased than in those who survived. In addition, the minor allele frequencies (MAF) of two IL-17A polymorphisms (rs3819024 and rs3748067) were more prevalent in SM patients than UM patients indicating an essential role in SM. Interestingly, the heterozygous rs8193038 AG genotype was significantly associated with higher levels of IL-17A than the homozygous wild type (GG). According to our results, it can be concluded that IL-17A may play a role in protection against fatal malaria outcomes.
ARTICLE | doi:10.20944/preprints202311.1372.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: COVID-19; SARS-CoV-2 antibodies; sero-epidemiological survey; Polytechnic High School; Senegal
Online: 24 November 2023 (04:12:01 CET)
Cross-sectional survey was conducted to capture the true extent of COVID-19 exposure among students and staff of Polytechnic High School (PHS). Random cluster sampling was carried out between May 19 and August 18, 2022, after the fourth wave of COVID-19 transmission. IgM and IgG SARS-CoV-2 antibodies were screened using WANTAI SARS-CoV-2 ELISA assays. Seroprevalence and descriptive statistics were calculated. Moreo-ver, the association between seropositivity and different factors (age, gender, preventive measures comorbidity, and symptoms, etc.) was determined using Logistic Regression. The overall IgG and IgM seroprevalence were 92% and 6.91% respectively. We found a higher IgM seroprevalence in men than women (9.4% vs. 5.6%) and a lower IgM seroprevalence in (18-25) age group compared to (55-65) years. Low compliance with preventive measures was found with a significant IgM seroprevalence depending on non-respect of social distancing (p = 0.008). A total of 70% of participants presented symptoms linked to COVID-19 at the moment of the survey. Results revealed a significant difference according to IgG seroprevalence among participants who declared fa-tigue symptoms 92.06% compared to those who did not 80.39% (p = 0.0027). IgM seropositivity was associated with Body Mass Indice (BMI) categorized (O.R. 0.238, p = 0.043), ethnic group (O.R. 0.723, p = 0.046) and marital status (O.R. 2.399, p = 0.021). Moreover, IgG seropositivity was associated with Chronic sinusitis comorbidity (O.R. 0.238, p = 0.043) and vaccination status (O.R. 4.741, p < 0.001). The majority of students and staff have al-ready been exposed to SARS-CoV-2 and confirm the circulation of SARS-CoV-2 in PHS at the time of the survey. Our results underline the importance of sero-epidemiological surveys to estimate the real impact of the COVID-19 pandemic in a community and to monitor disparities in antibody response in the population.
ARTICLE | doi:10.20944/preprints202310.1684.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: SARS-CoV-2; Seroprevalence; Pregnancy and COVID-19; Senegal
Online: 26 October 2023 (09:09:00 CEST)
This study aims to determine the seroprevalence of SARS-CoV-2 in pregnant women attending antenatal consultations (ANC) in Senegal. A non-redundant consecutive recruitment of participants was carried out between, March and July 2021 during the Delta wave of COVID-19. The plasma samples biobanked at -80°C were subjected to an enzyme-linked immunosorbent assay (ELISA) for the qualitative detection of IgG and IgM antibodies of SARS-CoV-2 using the WANTAI SARS-CoV-2 Ab ELISA (Wantai Biological Pharmacy Enterprise, Beijing). To assess factors associated with seropositivity, bivariate analysis was per-formed with JMP® Pro Version 15.0.0 software (SAS Institute Inc., Cary, NC, 1989–2021). For frequencies below 5%, chi2 or Fischer tests were performed. In all cases, significant statistical threshold was set at p-values considered to be less than 0.05. A total of 1,227 pregnant women were recruited in five health facil-ities, including two in Dakar (n=166) and one in each of the following regional capitals: Saint-Louis (n=400), Ziguinchor (n=264) and Kédougou (n=397). The median age among was 25 years [18 - 50]. The overall sero-prevalence observed was 64.9% (797/1227), with higher exposure rates in Dakar with 71.6% (119/166) and Ziguinchor with 68.1% (180/264). Kédougou and Saint-Louis reported 62.9% (250/397) and 62% (248/400), respectively. According to age group, the seroprevalence was 62.6% (331/528), 66.6% (238/357), 63.5% (148/223) and 67.2% (80/119) respectively for [18-23], [24-29], [30-35] and ≥36 years old. This variability in the seroprevalence of SARS-CoV-2 according to the localities was not statistically significant (p=0.7024). We found no association between factors such as recruitment period, age, level of education, marital and pro-fessional status.
ARTICLE | doi:10.20944/preprints202206.0096.v1
Subject: Biology And Life Sciences, Virology Keywords: Hepatitis E; Associated risk factors; Pregnant women; Environment; Prevention; Senegal
Online: 7 June 2022 (08:06:52 CEST)
In West Africa, research on the hepatitis E virus (HEV) is barely covered despite the recorded outbreaks. The still low level of access to safe water and adequate sanitation is one of the main factors of HEV spread in developing countries. HEV infection induces acute or sub-clinical liver diseases with a mortality rate ranging from 0.5 to 4%. The mortality rate is more alarming (15 to 25%) among pregnant women, especially in the last trimester of pregnancy. Here, we conducted a multicentric socio-demographic and seroepidemiological survey of HEV in Senegal among pregnant women. A total of 1,227 consenting participants attending antenatal clinics responded to our questionnaire. Plasma samples were collected and tested for anti-HEV IgM and IgG by using the WANTAI HEV-IgM and IgG ELISA assay. HEV global seroprevalence was 7.9% with 0.5% and 7.4% for HEV IgM and HEV IgG, respectively. One participant's sample was IgM/IgG positive, while four were declared indeterminate to anti-HEV IgM as per the manufacturer's instructions. From one locality to another, the seroprevalence of HEV antibodies varied from 0 to 1% for HEV IgM and from 1.5 to 10.5% for HEV IgG. The data also showed that seroprevalence varied significantly by marital status (p<0.0001), by the regularity of income (p=0.0043) and by access to sanitation services (p=0.0006). These data could serve as a basis to setup national prevention strategies focused on socio-cultural, environmental and behavioral aspects for a better management of HEV infection in Senegal.