Hepatitis E virus (HEV) is a pathogen that has caused various epidemics and sporadic localized cases. It is considered to be a public health problem worldwide. HEV is a small RNA virus with a significant genetic diversity, a broad host range, and a heterogeneous geographical distribution. HEV is mainly transmitted via the faecal–oral route. However, some animals are considered to be natural or potential reservoirs of HEV, thus elucidating the zoonotic route of transmission via the environment through contact with these animals or consumption of their by-products. Other routes of human-to-human transmission are not negligible. The various human–animal–environment entities, taken under one health approach, show the circulation and involvement of the different species (mainly Paslahepevirus balayani and Rocahepevirus ratti) and genotypes in the spreading of HEV infection. Regarding P. balayani, eight genotypes have been described, of which five genotypes (HEV-1 to 4 and HEV-7) are known to infect humans, while six have been reported to infect animals (HEV-3 to HEV-8). Furthermore, the C1 genotype of the rat HEV strain (HEV-C1) is known to be more frequently involved in human infections than the HEV-C2 genotype, which is known to infect mainly ferrets and minks. Contamination can occur during run-off, flooding, and poor sanitation, resulting in all of these genotypes being disseminated in the environment, contaminating both humans and animals. This systematic review followed the PRISMA guidelines and was registered in PROSPERO 2025 CRD420251071192. This research highlights the importance of investigating the transmission routes and major circulating HEV genotypes in order to adopt a holistic approach for controlling its emergence and preventing future outbreaks. In addition, this article outlines the knowledge of HEV in Africa, underlining the absence of large-scale studies at the environmental, human, and animal levels, which could improve HEV surveillance on the continent.

The hepatitis E virus (HEV) is a zoonotic pathogen with various hosts, including pigs, which act as reservoirs. In industrialized countries, sporadic cases caused by genotype 3, contracted by ingesting contaminated uncooked or undercooked meat, have been reported. However, in developing countries, HEV infection is mainly dominated by genotype 2 and often associated with poor hygiene conditions and drinking water supplies. HEV infection and its circulation in domestic fauna in West Africa are poorly documented. This study aimed to assess the presence of HEV in pork sold in Saint-Louis, Senegal. Meat products (250 g samples, n = 74) were purchased in August 2022 from three locations. Then, 2 g/sample was minced to extract total nucleic acids using the Purelink™ Viral DNA/RNA kit. RT-PCR reactions were performed using the One-Taq™ One-Step RT-PCR kit targeting the HEV ORF2 genomic region. The products obtained were visualized on a 1% agarose gel. Of a total of 74 samples, divided into pork meat (n = 65) and pork liver (n = 9), 5.4% (n = 4) tested positive for HEV. In both cases, two samples were positive, representing a rate of 3.1% and 22.2% for meat and pork liver, respectively. All new viral sequences were obtained from a monophyletic group within HEV genotype 3. This study is the first to report the presence of HEV in pork sold in Senegal and the results reveal a potential circulation of HEV in the pig population. The high proportion of contamination in the pork liver samples highlights a major risk associated with their consumption.

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.

This study aimed to assess the microbiological quality of set of fruits and vegetables sold on stalls in the streets and open markets of Dakar, the capital city of Senegal. Samples purchased in seven sites were analyzed to isolate E. coli, Salmonella spp. and Vibrio spp. Some primary samples with a positive microbiological culture were subjected to DNA extraction and subsequent metagenomic analysis. A total of 240 fresh fruit and vegetable samples were collected including lettuce (n=40), tomatoes (n=40), mango slices (n=40), onion slices (n=40), mint leaves (n=40), strawberries and grapes (respectively n=20). Of these samples, 50.83% (122/240) and 60.41% (145/240) was contaminated with Escherichia coli and Vibrio spp. respectively, while Salmonella was not isolated in any product. Levels of contamination with both E. coli (1.3 103 to 6 106 CFU/g) and Vibrio spp. (4.55 102 to 8.73 106 CFU/g) were significantly above the thresholds acceptable for human consumption. The most contaminated samples were lettuce with a prevalence of 98% (39/40) for E. coli and for Vibrio spp. followed by mint leaves with 100% (40/40) and 93% (37/40) of the samples containing for E. coli and Vibrio spp. respectively. Out of 46 samples sequenced, metagenomic analysis revealed high contamination rates for E. coli, Vibrio spp. and Salmonella spp. with 100%, 67.39% and 93.47% of prevalence respectively. On the other hand, the alpha diversity analysis shows a high bacterial diversity in lettuce and mint leaf samples while beta diversity analysis highlighted the presence of two major clusters. Our results stress the need of a surveillance system that extends this investigation to a national scale while increasing the number of sampling sites and products analyzed.

Cross-sectional survey was conducted to assess 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. Moreover, the associations between seropositivity and different factors (age, gender, preventive, etc.) were determined using logistic regression. A total of 637 participants were recruited, including 563 students, followed by 52 TAS officers, and 22 professors. The median age among was 21 years [18–63]. 62.0% of the participants were female, and 36.89% were male, with a male-to-female ratio = 0.59. 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). 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 vaccination status (O.R. 4.741, p < 0.001). Our study revealed that the majority of students and staff have already been exposed to SARS-CoV-2, which confirms the circulation of SARS-CoV-2 in PHS at the time of the survey. Our results underline the importance of seroepidemiological surveys to estimate the real impact of the COVID-19 pandemic in a community and to monitor disparities in antibody response in the population.

Optimal storage conditions are crucial for preserving samples for microbiological analysis. This study aimed to determine the effect of storage temperature on the evolution of the bacterial flora of local spice samples. A panel of local spice samples were collected from two Dakar markets, transported at 4-8°C, and placed in sterile bags. They were stored at 4°C, -20°C, or -80°C for varying periods (from just after receipt to 3 months). Plate Count Agar (PCA) was used to measure aerobic mesophilic flora (FMAT). A panel of 140 samples was evaluated under the above temperature/storage time conditions. FMAT did not change between T0 and 4h later. However, there was a drop of over 400,000 CFU/g after 1 week of storage at +4°C, -20°C, and -80°C. After 2 weeks, 1 month, and 3 months of storage, the flora continued to decline, dropping from over 500,000 CFU/g to 256 CFU/g at 4°C, 228 CFU/g at -20°C and 444 CFU/g at -80°C, respectively. These results show that temperature and storage time influence the evolution of local spices FMAT. It is therefore essential that microbiological analyses be carried out within 4 hours of sampling to obtain the best results.