Seroprevalence of measles, mumps, and rubella and genetic characterization of mumps virus in Khartoum, Sudan

Background: In Sudan, neither mumps nor rubella vaccines are currently used and comprehensive data on the seroepidemiology of measles, mumps, and rubella (M.M.R), as well as information about circulating mumps virus genotypes, are lacking. Methods: In 2015/2016, dried blood spot samples were collected from 294 children, 153 adults from the general population, and 241 healthcare workers (HCWs) from Khartoum. The samples were investigated for M.M.R IgG antibodies using ELISA. Oral fluid samples from 16 clinical mumps cases collected in 2017 were characterized by RT-PCR and sequencing. Results: The seroprevalence of M.M.R antibodies among children was 93.5%, 63.6%, and 55.8%, while it was 93.5%, 90.8%, and 94.1% among adult volunteers and 99.2%, 97.1%, and 97.9% among HCWs. A high measles seroprevalence was observed among all children age groups, suggesting an effective control programme, while the mumps and rubella seroprevalence increased significantly with age (p < 0.001), documenting active wild-type circulation. Our results demonstrated higher M.M.R seropositivity rates and IgG titres in HCWs compared to adult volunteers. Phylogenetic analysis showed the presence of genotype C mumps virus for the first time in Sudan. Conclusions: The study findings provided new information on M.M.R epidemiology in Sudan, which may guide future control programmes in the country. (c) 2019 The Authors. Published by Elsevier Ltd on behalf of International Society for Infectious Diseases. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).