High prevalence of norovirus and rotavirus co-infection in children with acute gastroenteritis hospitalised in Brazzaville, Republic of Congo.

OBJECTIVE: To evaluate the clinical severity of diarrhoea associated to viral co-infection in children with acute gastroenteritis. METHODS: About 461 children under five years hospitalised with acute diarrhoea (266 males and 187 females) were enrolled in the study. Using stool samples, rotavirus and adenovirus infections were investigated by ELISA, and norovirus infections by nested duplex RT-PCR. We assessed social, demographic, clinical and behavioural conditions that might influence the occurrence of rotavirus, adenovirus and norovirus infections. RESULTS: Mono-viral infection was detected in 49% and mixed viral infection in 12% of patients. The prevalence of mixed infection was neither dependent on age nor sex. Three samples were infected with all three viruses. A significant association was found between fever (axillary temperature> 37.5 °C) and rotavirus-norovirus dual infection (aOR (CI 95%) = 2.1 (1.14-3.84), P = 0.016; aOR (CI 95%) = 0.37 (0.19-0.73), P = 0.004). Mixed infection was the most common during the dry season from June to October (71.4% versus 54.7%, P = 0.023). CONCLUSION: Co-infection with both rotavirus and norovirus is common in under-five hospitalised children but does not contribute to the severity of the disease.

OBJECTIF: Evaluer la sévérité clinique de la diarrhée associée à la coinfection virale chez les enfants atteints de gastroentérite aiguë. MÉTHODES: 461 enfants de moins de cinq ans hospitalisés pour une diarrhée aiguë (266 garçons et 187 filles) ont été inclus dans l'étude. Sur des échantillons de selles, les infections à rotavirus et à adénovirus ont été investiguées par ELISA et les infections à norovirus par RT-PCR duplex imbriqué. Nous avons évalué les conditions sociales, démographiques, cliniques et comportementales susceptibles d'influencer la survenue d'infections à rotavirus, adénovirus et norovirus. RÉSULTATS: Une infection mono virale a été détectée chez 49% des patients et une infection virale mixte chez 12% des patients. La prévalence des infections mixtes ne dépendait ni de l'âge ni du sexe. Trois échantillons étaient infectés par tous les trois virus. Une association significative a été observée entre la fièvre (température axillaire > 37,5 °C) et la double infection rotavirus-norovirus (aOR (IC95%) = 2,1 (1,14-3,84), P = 0,016; aOR (IC95%) = 0,37 (0,19-0,73), P = 0,004). Les infections mixtes étaient les plus courantes pendant la saison sèche de juin à octobre (71,4% contre 54,7%, P = 0,023). CONCLUSION: La coinfection à la fois par le rotavirus et par le norovirus est fréquente chez les enfants de moins de cinq ans hospitalisés, mais ne contribue pas à la sévérité de la maladie.

Occurrence of human astrovirus associated with gastroenteritis among Congolese children in Brazzaville, Republic of Congo.

INTRODUCTION: Acute viral gastroenteritis is a major public health concern, especially among children younger than 5 years of age. The aim of this study was to determine the occurrence of human astrovirus infection in children with acute gastroenteritis. METHODS: Stool specimens were collected from 506 children under 5 years of age hospitalized with acute diarrhoea (289 male and 208 female), and human astrovirus was investigated by RT-PCR. Associations of socio-demographic, clinical, and behavioural conditions with infection were analysed. RESULTS: The overall prevalence of human astrovirus was found to be 10.3%. The mean age of positive cases was 12.41 ± 6.21 months and this was associated with infection (p = 0.013). Children >18 months of age were at three times the risk of infection when compared to those aged 0-6 months (odds ratio (OR) 3.19, 95% confidence interval (CI) 1.15-8.88; p = 0.026). Children living in houses with more than one room (OR 0.60, 95% CI 0.28-0.96; p = 0.036) and mothers using treated water (OR 0.47, 95% CI 0.25-0.86; p = 0.015) were associated with reduced infection. CONCLUSIONS: In this study, infection with astrovirus was common in acute gastroenteritis cases among children younger than 5 years of age. Drinking treated water and living in non-crowded environments protected the children from infection.

Molecular characterization of norovirus infection responsible for acute diarrhea in Congolese hospitalized children under five years old in Brazzaville, Republic of Congo.

BACKGROUND: Acute diarrhea is a leading cause of morbidity and mortality among children under five worldwide. As no published data is available on the occurrence of this infection in the Republic of Congo, this study aimed at (1) determining the prevalence and (2) characterizing genotypes of norovirus strains in Brazzaville. METHODS: From June 2012 to June 2013, stool samples were collected from hospitalized young children with acute gastroenteritis. A total of 545 samples were tested for GI and GII norovirus infections using nested duplex reverse-transcription-polymerase chain reaction and sequencing. RESULTS: The GI and GII norovirus infection were detected in 148 samples. Males (28%) were not significantly more infected than females (25%). Norovirus infection was found exclusively in children aged under 24 months with a higher prevalence (P=0,048) in the age group of 7-12 months, and throughout the year with a peak in August and September. Genetic diversity of norovirus strains revealed that GII was the most prevalent (87%). No risk factor was significantly associated with norovirus infection. CONCLUSION: This study showed that noroviruses are important agents responsible for acute diarrhea in Congolese children and highlights the importance of continued surveillance.