REVIEW | doi:10.20944/preprints202305.0906.v1
Subject: Biology And Life Sciences, Virology Keywords: Respiratory viruses; Anosmia; Olfaction Disorders; loss of smell; COVID-19
Online: 12 May 2023 (08:49:10 CEST)
The novel coronavirus disease 2019 (COVID-19) known as severe acute respiratory syndrome - coronavirus 2 (SARS-CoV-2) has emerged in China in 2019, and caused an outbreak of unusual viral pneumonia. The olfactory dysfunction following the infection of different variants of SARS-CoV-2 is now accepted as a hallmark symptom in patients. Recent studies have pointed out the relationship between COVID-19 and altered or loss of smell in infected patients. This mini review provides an overview of the role of SARS-CoV-2 and the other acute respiratory viruses in the development the human olfactory pathophysiology. We highlight the importance of deciphering the molecular mechanisms underlying the olfactory dysfunction caused by SARS-CoV-2 to help design new drugs 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/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.