title: Serological evidence of acute rubella infection among under-fives in Mwanza: a threat to increasing rates of congenital rubella syndrome in Tanzania.
abstract: BACKGROUND
  Control of rubella infection is essential for preventing congenital rubella syndrome (CRS) and one of the important steps is to define a target population for vaccination. Therefore this study was done to determine serological evidence of acute rubella infection among under-fives in order to anticipate the magnitude of rubella virus transmission in Tanzania.
  
  
  METHODS
  A cross-sectional study involving children aged between 1 and 59 months was conducted between September and October 2014 before national rubella vaccination campaigns commenced. Rubella IgM antibodies were detected using commercial indirect enzyme-linked immunosorbent assay (ELISA). Data were analyzed using STATA version 11.
  
  
  RESULTS
  A total of230 under-fives were enrolled, their median age was 14 (Interquartile range (IQR) 7-26) months. The overall seroprevalence of rubella IgM antibodies was 10.9 % (25/230) with two confirmed cases of CRS. Two-sample Wilcoxon rank-sum test showed that the median age of rubella IgM seropositive children was significantly higher than that of IgM seronegative children (39 IQR: 18-51months vs. 14 IQR: 7-24 months, P < 0.001). On multivariate logistic regression analysis increase in age (OR: 1.07, 95 % CI; 1.03-1.1, P < 0.001) and residing in rural areas (OR: 8.07, 95 % CI; 1.43-45.6, P = 0.018) were independently found to predict acute rubella infection among under-fives.
  
  
  CONCLUSIONS
  Our findings indicate that rubella virus is prevalent in our setting posing a risk of transmitting to childbearing aged women hence increasing the risk of CRS. Increasing prevalence of acute infection with age in under-fives indicates the protective role of maternal antibodies among infants. The sustained vaccination programme of under-fives as effective measure to control CRS should be emphasized in developing countries.
authors.affiliation: Department of Microbiology and Immunology, Weill Bugando School of Medicine, P.O. Box 1464, Mwanza, Tanzania. mmmirambo@gmail.com.
authors.forename: Mariam M
authors.initials: MM
authors.lastname: Mirambo
authors.affiliation: Department of Microbiology and Immunology, Muhimbili university of Health and allied sciences, P.O. Box 65001, Dar es Salaam, Tanzania.
authors.forename: Said
authors.initials: S
authors.lastname: Aboud
authors.affiliation: Department of Microbiology and Immunology, Weill Bugando School of Medicine, P.O. Box 1464, Mwanza, Tanzania.
authors.forename: Martha F
authors.initials: MF
authors.lastname: Mushi
authors.affiliation: Department of Pediatrics and Child Health, Weill Bugando School of Medicine, P.O. Box 1464, Mwanza, Tanzania.
authors.forename: Mwanaisha
authors.initials: M
authors.lastname: Seugendo
authors.affiliation: Department of Microbiology and Immunology, Muhimbili university of Health and allied sciences, P.O. Box 65001, Dar es Salaam, Tanzania.
authors.forename: Mtebe
authors.initials: M
authors.lastname: Majigo
authors.affiliation: Institute of Medical Microbiology, Gottingen University Medical Centre, Gottingen, Germany.
authors.forename: Uwe
authors.initials: U
authors.lastname: Groß
authors.affiliation: Department of Microbiology and Immunology, Weill Bugando School of Medicine, P.O. Box 1464, Mwanza, Tanzania.
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Mshana
mesh_terms: D017677:Age Distribution; D000914:Antibodies, Viral / Q000276:immunology; D002675:Child, Preschool; D003140:Communicable Disease Control / Q000379:methods*; D003430:Cross-Sectional Studies; D003906:Developing Countries; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D018570:Risk Assessment; D012409:Rubella / Q000097:blood / Q000453:epidemiology* / Q000517:prevention & control*; D012410:Rubella Syndrome, Congenital / Q000453:epidemiology / Q000517:prevention & control*; D012411:Rubella Vaccine / Q000008:administration & dosage*; D012698:Serologic Tests; D013636:Tanzania / Q000453:epidemiology; D014611:Vaccination / Q000379:methods* / Q000706:statistics & numerical data
chemical_list: D000914:Antibodies, Viral; D012411:Rubella Vaccine; C040901:rubella antibodies
keywords: Congenital rubella syndrome; IgM; Mwanza; Rubella; Tanzania; Under-fives