Epidemiology of group A rotavirus in children under five years of age with gastroenteritis in N'Djamena, Chad.

BACKGROUND: Group A Rotaviruses (RVA) is one of the most common causes of severe diarrhoea in infants and children under 5 years of age. Unlike many countries in the world where RVA surveillance/control is active, in Chad , there is currently no applied RVA immunization program and surveillance strategy. The present study aims to determine the prevalence and associated risk factors of RVA gastroenteritis among children under five years of age in N'Djamena. METHOD: This study comprised two parts: (1) A cross-sectional study carried in four hospitals in N'Djamena between August and November 2019, to determine infection risk factors and evidence of RVA infection among children aged five and below, consulted or hospitalized for diarrhea. An ELISA based RVA VP6 protein detection was used to determine RVA infection prevalence. Infection results and sociodemographic data were statistically analysed to determine RVA infection risk factors. (2) A retrospective study that consisted of analysing the records of stool examinations of the period from January 2016 to December 2018, to determine the prevalence of infectious gastroenteritis among the target population. RESULTS: For the cross-sectional study, RVA infection prevalence was 12.76% (18/141) with males (61.11%) being more affected (sex ratio: 1.57). Children below 12 months were the most affected age group (44.44%) and 44.4% were malnourished. The mean Vesikari score shows that 38.8% of children have a high severity level and 41.1% have a moderate level. For the retrospective study, 2,592 cases of gastroenteritis hospitalization were analysed; 980 out of 2,592 cases (37.81%) of hospitalization due to diarrhoea were due to diarrhoeagenic pathogens including Emtamoeba hystolitica, Gardia lamblia, Trichomonas hominis, Hymenolepis nana, Escherichia coli, Shigella spp, Proteus mirabilis, and Klebsiella oxytoca. Cases of diarrhoea with negative pathogen search were 1,612 cases (62.19%). The diarrhoea peak was observed during the dry seasons, and the age group under 11 months was the most affected was (57.3%). CONCLUSION: This study describes the evidence of RVA infection among diarrhoeic children below five years of age in N'Djamena, thus indicates a serious health burden. Malnourishment younger age was the higher risk factor. Further studies are needed to determine the circulating strains prior to considering introduction of RVA vaccine and setup a routine rotavirus surveillance in Chad.

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

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.

Full genome characterization of human Rotavirus A strains isolated in Cameroon, 2010-2011: diverse combinations of the G and P genes and lack of reassortment of the backbone genes.

Over the past few years whole genome sequencing of rotaviruses has become a routine laboratory method in many strain surveillance studies. To study the molecular evolutionary pattern of representative Cameroonian Rotavirus A (RVA) strains, the semiconductor sequencing approach was used following random amplification of genomic RNA. In total, 31 RVA strains collected during 2010-2011 in three Cameroonian study sites located 120 to 1240 km from each other were sequenced and analyzed. Sequence analysis of the randomly selected representative strains showed that 18 RVAs were Wa-like, expressing G1P[6], G12P[6], or G12P[8] neutralization antigens on the genotype 1 genomic constellation (I1-R1-C1-M1-A1-N1-T1-E1-H1), whereas 13 other strains were DS-1-like, expressing G2P[4], G2P[6], G3P[6], and G6P[6] on the genotype 2 genomic constellation (I2-R2-C2-M2-A2-N2-T2-E2-H2). No inter-genogroup reassortment in the backbone genes was observed. Phylogenetic analysis of the Cameroonian G6P[6] strains indicated the separation of the strains identified in the Far North region (Maroua) and the Northwest region (Bamenda and Esu) into two branches that is consistent with multiple introductions of G6P[6] strains into this country. The present whole genome based molecular characterization study indicates that the emerging G6P[6] strain is fully heterotypic to Rotarix, the vaccine introduced during 2014 in childhood immunization program in Cameroon. Continuous strain monitoring is therefore needed in this area and elsewhere to see if G6s, besides genotype G1 to G4, G8, G9 and G12, may become a new, regionally important genotype in the post vaccine licensure era in Africa.

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.

Detection of novel porcine bocaviruses in fecal samples of asymptomatic pigs in Cameroon.

Improvements and widespread use of nucleic acid amplification and sequencing methods have led to the recognition of new virus diversity in various domestic animals, including pigs. In this study we utilized either virus species specific or broadly reactive PCR assays to describe the occurrence and genetic diversity of selected DNA viruses belonging to families Adenoviridae, Circoviridae, Anelloviridae and Parvoviridae in Cameroonian pigs. Fecal specimens were collected during spring of 2011. No adenoviruses, circoviruses and anelloviruses were detected, however, high prevalence and remarkable genetic diversity within the identified parvoviruses and, particularly, within bocaviruses was observed. PPV4 was the most prevalent virus (20%), followed by PBoV3 (18%), PBoV4 (18%), PBoV5 plus 6V/7V (16%), and PBoV1 plus PBoV2 (6%). The frequency of mixed infections with various combinations of these virus species reached 20%. Genetic analysis of the identified viruses showed that the capsid gene of PBoV1 and PBoV2 strains shared up to 91% and 94%nt sequence similarities to reference PBoV1 and PBoV2 strains, respectively. The identified PBoV3 and PBoV4 strains shared ≤ 95% and ≤ 98%nt identities with reference PBoV3 and PBoV4 strains, respectively, along the NS gene, whereas the PBoV5 strains shared 86%nt identities with Hungarian and 87%nt identities with Chinese PBoV5 strains along the capsid gene. In addition, a single PBoV5-like strain shared ≤ 71%nt sequence identity with other PBoV5 strains. This is the first study to report evidence of the circulation of bocaviruses in Africa and contributes to our understanding of the impact of globalization on the dispersal of new and emerging viruses.

Epidemiology of rotavirus diarrhea in children under 5 years in Northern Cameroon.

BACKGROUND: Rotavirus still remains the major cause of diarrhea in children below 5 years. No data on rotavirus epidemiology is available in the Northern regions of Cameroon. We aimed to determine the prevalence of group A rotavirus (RVA) in children below 5 years with diarrhea in two regions of Northern Cameroon (North West and Far North Regions) so as to improve our knowledge on the burden of rotavirus disease for imminent introduction of a rotavirus vaccine. METHODS: Stool samples were collected during 2010 and 2011 from 390 children below 5 years presenting with diarrhea in four hospitals in Northern Cameroon and were screened for rotavirus group A by reverse transcription-polymerase chain reaction. RESULTS: This study revealed that 42.8% of the children below 5 years had group A rotavirus infection, 46.5% in the Far North region while the North West had a prevalence of 33.9%. Of the 252 hospitalized and the 138 outpatient children, 124(49.2%) and 43(31.2%) (P=0.00085), respectively, were positive for group A rotavirus. Children below 24 months were most affected (44.7%), while the age group 49-60 months had the lowest prevalence (25%). The RVA prevalence was 44.6% in the urban and 28.9% in the rural settings of our study. It was observed that the proportion of children with diarrhea who had rotavirus accompanied with fever and vomiting in the outpatient group and inpatient group were 13.0% and 28.6% respectively, P=0.03. CONCLUSION: This study showed high incidence of rotavirus infection especially among hospitalized children in Northern Cameroon, suggesting that rotavirus is a major cause of childhood morbidity and mortality in this area.