Aetiology and incidence of diarrhoea requiring hospitalisation in children under 5 years of age in 28 low-income and middle-income countries: findings from the Global Pediatric Diarrhea Surveillance network.

INTRODUCTION: Diarrhoea remains a leading cause of child morbidity and mortality. Systematically collected and analysed data on the aetiology of hospitalised diarrhoea in low-income and middle-income countries are needed to prioritise interventions. METHODS: We established the Global Pediatric Diarrhea Surveillance network, in which children under 5 years hospitalised with diarrhoea were enrolled at 33 sentinel surveillance hospitals in 28 low-income and middle-income countries. Randomly selected stool specimens were tested by quantitative PCR for 16 causes of diarrhoea. We estimated pathogen-specific attributable burdens of diarrhoeal hospitalisations and deaths. We incorporated country-level incidence to estimate the number of pathogen-specific deaths on a global scale. RESULTS: During 2017-2018, 29 502 diarrhoea hospitalisations were enrolled, of which 5465 were randomly selected and tested. Rotavirus was the leading cause of diarrhoea requiring hospitalisation (attributable fraction (AF) 33.3%; 95% CI 27.7 to 40.3), followed by Shigella (9.7%; 95% CI 7.7 to 11.6), norovirus (6.5%; 95% CI 5.4 to 7.6) and adenovirus 40/41 (5.5%; 95% CI 4.4 to 6.7). Rotavirus was the leading cause of hospitalised diarrhoea in all regions except the Americas, where the leading aetiologies were Shigella (19.2%; 95% CI 11.4 to 28.1) and norovirus (22.2%; 95% CI 17.5 to 27.9) in Central and South America, respectively. The proportion of hospitalisations attributable to rotavirus was approximately 50% lower in sites that had introduced rotavirus vaccine (AF 20.8%; 95% CI 18.0 to 24.1) compared with sites that had not (42.1%; 95% CI 33.2 to 53.4). Globally, we estimated 208 009 annual rotavirus-attributable deaths (95% CI 169 561 to 259 216), 62 853 Shigella-attributable deaths (95% CI 48 656 to 78 805), 36 922 adenovirus 40/41-attributable deaths (95% CI 28 469 to 46 672) and 35 914 norovirus-attributable deaths (95% CI 27 258 to 46 516). CONCLUSIONS: Despite the substantial impact of rotavirus vaccine introduction, rotavirus remained the leading cause of paediatric diarrhoea hospitalisations. Improving the efficacy and coverage of rotavirus vaccination and prioritising interventions against Shigella, norovirus and adenovirus could further reduce diarrhoea morbidity and mortality.

Household transmission of rotavirus in a community with rotavirus vaccination in Quininde, Ecuador.

BACKGROUND: We studied the transmission of rotavirus infection in households in peri-urban Ecuador in the vaccination era. METHODS: Stool samples were collected from household contacts of child rotavirus cases, diarrhea controls and healthy controls following presentation of the index child to health facilities. Rotavirus infection status of contacts was determined by RT-qPCR. We examined factors associated with transmissibility (index-case characteristics) and susceptibility (household-contact characteristics). RESULTS: Amongst cases, diarrhea controls and healthy control household contacts, infection attack rates (iAR) were 55%, 8% and 2%, (n = 137, 130, 137) respectively. iARs were higher from index cases with vomiting, and amongst siblings. Disease ARs were higher when the index child was <18 months and had vomiting, with household contact <10 years and those sharing a room with the index case being more susceptible. We found no evidence of asymptomatic infections leading to disease transmission. CONCLUSION: Transmission rates of rotavirus are high in households with an infected child, while background infections are rare. We have identified factors associated with transmission (vomiting/young age of index case) and susceptibility (young age/sharing a room/being a sibling of the index case). Vaccination may lead to indirect benefits by averting episodes or reducing symptoms in vaccinees.

Rotavirus VP4 and VP7 genotypes circulating in Cameroon: Identification of unusual types.

Rotavirus remains a priority candidate for vaccine development, because it is the major cause of viral diarrhea in children worldwide. This study characterized rotavirus strains in 195 stool specimens collected from children <5 years of age with diarrhea, in the Southwest Province and Western Province of Cameroon during 1999-2000. The predominant G type was G1 (detected in 44.9% of specimens) and the most predominant P type was P[8] (in 82.7%). The most common G-P combination detected was G1P[8] (in 37.1% of specimens), followed by G9P[8] (in 14%). Rotavirus strains with unusual G-P combinations, such as G1P[4], G2P[8], G8P[8], G9P[4], G5P[8], and G10P[8], were also observed in significant numbers. Analysis of the age distribution showed that G1P[8] was found circulating in all age groups except in infants <6 months old. Strains G2P[4] and G3P[8] were identified in children >37 months and 19-24 months of age, respectively. Strain G9P[8] was found circulating among children >25 months of age. Unusual strains and mixed infections were found circulating in the different age groups, albeit at lower levels. The high prevalence of mixed infections and diversity of rotavirus strains detected in this first study based on genotyping of Cameroonian strains reinforce the need to continue with surveillance programs in Africa, where a high diversity of strains has been reported.