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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 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.