Active circulation of varicella zoster virus among different age groups in Sudan.

In Sudan, data on varicella infections are lacking and the vaccine is currently not in use. The aim of this study was to investigate previous exposure to varicella zoster virus (VZV) among children and adults from the general population and among health-care workers (HCWs) in Khartoum. Dried blood spot samples collected between 2015 and 2016 from 294 children aged 1‒15 years, 153 adult volunteers and 241 HCWs were investigated for the presence of VZV IgG antibodies using ELISA. The overall seroprevalence of VZV IgG antibodies among the investigated cohorts was 50.4%, ranging between 14.3% in children and 79.3% in HCWs. Seropositivity increased with age among children and HCWs (P ⩽ 0.05). A relatively low seropositivity (64.7%) was observed among young adults and HCWs, suggesting that a high proportion of Sudanese adults remain susceptible. In hospital settings, this result implies a risk of nosocomial infection involving both HCWs and vulnerable patients. The results of this first VZV study in Sudan suggest active virus circulation in different age groups. Especially HCWs at the start of their career might benefit from vaccination, not only to save themselves from herpes zoster and its sequelae, but also to indirectly protect vulnerable patients.

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.