Epidémiologie moléculaire du rotavirus du groupe A associé aux gastroentérites chez les enfants de moins de 5 ans dans la ville de Yaoundé (Cameroun)

Le rotavirus est la première cause de gastroentérites grave chez les enfants de moins de 5 ans. La gravité et la mortalité de la maladie sont majorées dans les pays à revenus faibles d’Asie du sud et d’Afrique subsaharienne. Au Cameroun, la forte prévalence des rotaviroses, associées aux spécificités génotypiques locales du virus, soulignent l’importance de disposer de données épidémiologiques sur le virus. Cette étude visait à contribuer à une meilleure connaissance des principales souches de rotavirus responsables des gastroentérites chez les enfants de moins de 5 ans dans la ville de Yaoundé. Il s’agit d’une étude descriptive transversale d’une durée de 4 mois, dans 8 formations sanitaires de la ville de Yaoundé. Les échantillons de selles d’enfants de moins de 5 ans, hospitalisés pour gastroentérite ont été prélevés. La recherche du rotavirus s’est faite avec le kit ELISA Oxoid ProSpec TTM, et la détermination des génotypes du virus s’est faite par RT - PCR. Cent trente échantillons de selles d’enfants souffrant de gastroentérite ont été collectés. 66,1% de ces échantillons provenaient des hôpitaux FCB/CME, du CHE et de HDE. Le rotavirus a été isolé chez 30% des enfants, dont 40% avait entre 6 et 11 mois. Le CHE (6,9%) et l’HGY (0%) avaient respectivement la prévalence la plus élevée et la plus basse de la ville. Un nombre élevé de combinaisons génotypiques a été isolé, parmi lesquels prédominaient G1P[8] (31%) suivit de G3P[6] (28%) et de G4P[6] (13 %). Les génotypes mixtes G1P[6][8], G2P[6][8], et G1G3P[8] représentaient 22% des isolats. Un type G (3%) est resté indéterminé durant cette étude.© 2015 International Formulae Group. All rights reserved.Mots clés: Epidémiologie moléculaire, rotavirus, génotypes, gastroentérite, enfants, YaoundéEnglish Title:  Molecular epidemiology of group A rotavirus associated to gastroenteritis in children less than 5 years in Yaoundé (Cameroon)English AbstractRotavirus is the leading cause of severe gastroenteritis in children less than 5 years. Severity and mortality of this disease are majored in low-income countries of South - Asia and sub - Saharan Africa. In Cameroon, the high prevalence of rotaviruses associated to local genotypic specificities of virus enhances the importance of epidemiological database on the virus. This study aimed at contributing to a better knowledge of the main rotavirus strains responsible for gastroenteritis in children less than 5 years in Yaoundé. We carried out a descriptive and cross sectional study during 4 months, in 8 health centers in Yaoundé. Stool specimens were collected from children less than 5 years old, hospitalized for gastroenteritis. Rotavirus was detected with ELISA kit Oxoid ProSpecTTM, and genotypes determined by RT - PCR. One hundred and twenty seven stool specimens were collected during the study. FCB/CME, CHE, HDE provided 66.1% of specimens collected. Rotavirus was isolated in 30% of children, and 40% of these children were between 6 to 11 months old. The CHE (6. 9%) and the HGY (0%) had respectively the highest and the lowest prevalence of the town. A large number of genotype has been isolated and G1P[8] (31%) were predominant, followed by G3P[6] (28%) and G4P[6] (13%). Mixt genotypes G1P[6][8], G2P[6][8], and G1G3P[8] represented 22% of isolates. One G - type remained untypable.© 2015 International Formulae Group. All rights reserved.Keywords: Molecular epidemiology, rotavirus, genotypes, gastroenteritis, children, Yaound

Hepatitis B infection awareness, vaccine perceptions and uptake, and serological profile of a group of health care workers in Yaoundé, Cameroon

Abstract Background Cameroon is one of the countries in Africa with the highest burden of Hepatitis B infection. Health care workers are known to be at risk of occupational exposure to blood and other infectious bodily fluids. The aim of this study was to assess the profile of serological markers of hepatitis B virus (HBV) infection, knowledge and perceptions regarding HBV infection among health care workers in a health area in Yaoundé. Methods A cross-sectional study was conducted in the Mvog-Ada Health Area of the Djoungolo Health District from March 1 to November 31, 2014. All consenting health care workers were included in the study. Serological markers of HBV (HBs Ag, Hbe Ag, anti-HBs Ab, anti-HBe Ab, anti-HBc Ab) were qualitatively tested using Biotech®(OneHBV-5 parameter rapid test website) in each participant and the anti-HBs antibodies were quantified by ELISA (Biorex) among those who were positive with the qualitative test. Chi square test or its equivalents were used to compare qualitative variables and a p-value less than or equal to 0.05 was considered significant. Result A total of 100 participants were retained for the study out of 163 in the health area giving a response rate of 61.34 %; the mean age was 30.5 (SD 6.8) years and 71 % of participants were women. Forty seven percent (47 %) of workers had good level of knowledge of HBV infection. The men were 3.20 times (95 % CI: 1.02–9.19, p = 0.04) more likely to have a good level of knowledge than women. Participants with a university study level were more (95 % CI: 3.17–25, p < 0.0001) likely to have a good level of knowledge than those with a high school study level. Ninety-six percent of participants thought that they were at a greater risk of becoming infected with HBV than the general population, 93 % felt that the vaccine should be compulsory and all (100 %) were willing to recommend it to others. However, only 19 % had received at least one dose of the vaccine. The proportion of HBs Ag was 11 %. The different serological profiles with regard to HBV infection were naive subjects (62 %), chronic carriers (11 %), vaccinated (19 %) and subjects naturally immunized (8 %). Three out of the 19 participants who received at least one dose of the vaccine, only 9 (47.4 %) of whom had titers ≥100 IU/l indicating a good response to vaccination. Among those who received three doses of the vaccine (n = 12, 63 %), 2 (16, 66 %) had poor response to vaccination (HBs Ab titers < 100 IU/l). Conclusion The prevalence of HBs Ag among health care workers in the Mvog-Ada Health Area is high (11 %). These workers are at high risk of HBV infection because of very low vaccine uptake and poor post-exposure practices. Their knowledge of HBV infection is non-optimal

Comparative whole genome analysis reveals re-emergence of human Wa-like and DS-1-like G3 rotaviruses after Rotarix vaccine introduction in Malawi

G3 rotaviruses rank among the most common rotavirus strains worldwide in humans and animals. However, despite a robust long-term rotavirus surveillance system from 1997 at Queen Elizabeth Central Hospital in Blantyre, Malawi, these strains were only detected from 1997 to 1999 and then disappeared and re-emerged in 2017, five years after the introduction of the Rotarix rotavirus vaccine. Here we analysed representative 27 whole genome sequences (G3P[4], n=20; G3P[6], n=1; and G3P[8], n=6) randomly selected each month between November 2017 and August 2019 to understand how G3 strains re-emerged in Malawi. We found four genotype constellations that were associated with the emergent G3 strains and co-circulated in Malawi post-Rotarix vaccine introduction: G3P[4] and G3P[6] strains with the DS-1-like genetic backbone genes (G3-P[4]-I2-R2-C2-M2-A2-N2-T2-E2-H2) and G3-P[6]-I2-R2-C2-M2-A2-N2-T2-E2-H2), G3P[8] strains with the Wa-like genetic backbone genes (G3-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1), and reassortant G3P[4] strains consisting of the DS-1-like genetic backbone genes and a Wa-like NSP2 (N1) gene (G3-P[4]-I2-R2-C2-M2-A2-N1-T2-E2-H2). Time-resolved phylogenetic trees demonstrated that the most recent common ancestor for each RNA segment of the emergent G3 strains was between 1996 and 2012, possibly through introductions from outside the country due to the limited genetic similarity with G3 strains which circulated before their disappearance in the late 1990s. Further genomic analysis revealed that the reassortant DS-1-like G3P[4] strains acquired a Wa-like NSP2 genome segment (N1 genotype) through intergenogroup reassortment; an artiodactyl-like VP3 through intergenogroup interspecies reassortment; and VP6, NSP1 and NSP4 segments through intragenogroup reassortment likely before importation into Malawi. Additionally, the emergent G3 strains contain amino acid substitutions within the antigenic regions of the VP4 proteins which could potentially impact the binding of rotavirus vaccine-induced antibodies. Altogether, our findings show that multiple strains with either Wa-like or DS-1-like genotype constellations have driven the re-emergence of G3 strains. The findings also highlight the role of human mobility and genome reassortment events in the cross-border dissemination and evolution of rotavirus strains in Malawi necessitating the need for long-term genomic surveillance of rotavirus in high disease burden settings to inform disease prevention and control

SHARED G12 VP7 GENE AMONG HUMAN AND BOVINE ROTAVIRUSES DETECTED IN CAMEROONIAN VILLAGES

Group A rotaviruses (RVA) are an important enteric pathogen in humans and livestock animals. Transmission of animal RVA strains to humans has been documented on several occasions. A reverse route of transmission of RVA under natural circumstances is anticipated, although evidence is scarce. However, experimental studies indicated that animals can be infected with human RVAs. By screening the stool samples collected from 157 cattle during 2011 in two Cameroonian villages, four samples (2.5%) were found positive for RVA. Upon sequence analysis of a 410 bp fragment of the VP7 gene, the RVA strains shared up to 100% nt identity to each other and to G12 RVAs identified in human patients living in the same geographic regions. This finding provides evidence for a human-to-animal transmission of an epidemic human rotavirus strain

One Year Survey of Human Rotavirus Strains Suggests the Emergence of Genotype G12 in Cameroon

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