iitsvopoe 107890000 frse tsn 60 o ed 50 ion tsu 40 tro 30 rpop 1200 % 0 58.5 84.5 93.8 <7 yrs 7-13 yrs Age category >13 yrs PFrigouporerti1on (%) of children with IgG antibody Proportion (%) of children with IgG antibody. is faming and success in the activity is not entirely based on level of education but many other factors. The overall rubella seropositivity rate was found to be 79.9% and it increased with age from 58.5% among those aged 4–6 years to 93.8% among those aged over 13 years. This is indicative of widespread viral transmission in the study population. Increasing seropositivity with age can be explained by the complex effect of natural disease exposure over time [10]. The rates found in this study are comparable to those found by other investigators in non- vaccinating countries and it compares well with a previous study carried out in India where the rate was 86.5% [11]. Nardone et al., 2008 in his review cited increased rubella seropositivity with increased age in Romania using pre- vaccination data [12]. Results from this study showed that despite high prevalence of rubella, there exist few children who attain adolescence age while seronegative for rubella. In future, it is important to conduct a study targeting preg- nant women and roll it to include active CRS case surveil- lance in the country. Rubella antibody titers should be determined among pregnant women to determine immu- nity rates as use of DBS was not appropriate as used in the current study [13]. Table 2: Results of multivariate logistic regression model Variable Age(yrs) Family with television set Child leisure Number of siblings Working adults residing with family Category As continuous Yes No Games Singing Less than 3 >Two Yes No BMC Public Health 2009, 9:269 http://www.biomedcentral.com/1471-2458/9/269 Ownership of a television set reduced the odds of rubella seropositivity and this factor showed significance at 95% level of confidence in the multivariate analyses. This could be regarded as a proxy measure for socio-economic status of a family. The finding implied that children from lower socio-economic backgrounds got infected much earlier in life compared to their counterparts who lived in better conditions in the same area and even attended the same schools. The likely reason for increased risk among low socioeconomic group can be attributed to crowding and this has been cited elsewhere [10,14]. It is therefore important that during development of rubella control policy in Kenya a good strategy geared towards lower socio-economic groups be given priority as these groups are more vulnerable. This finding represents what might be expected in any unvaccinated population living in crowded settings. Conclusion The study was an important step in generating baseline seroprevalence data on rubella infection among children in Uasin Gishu. Findings from this study are useful in the development of rubella control programme in Kenya. Two significant risk factors for rubella were identified. Low socio-economic status and age less than seven years were the major risk factors for rubella infection. The mean age of children in the preprimary school was 6 years and those in class one was 8 years. This meant that children got either infected in or before pre-primary school and any rubella control programme should focus on these children just before joining pre-primary school to protect them from rubella infection. In a community like this one where young girls start giving birth early in life it is impor- tant to establish a formal implementation of rubella and CRS surveillance system. If rubella vaccination is to be considered in future the strategy adopted has to protect the children as well as the small proportion of women who attain childbearing age while seronegative. There are risks of CRS occurring even with low proportion of sus- ceptibility individuals [15] Unweighted ORs(95%CI) Weighted ORs(95%CI) 4.00(2.26–7.08) 0.00 3.26(1.28–8.33) 1.00 0.92(0.61–1.40) 1.00 0.42(0.11–1.59) 1.00 2.31(1.06–5.04) 4.01(2.46–6.53) 1.00 3.30(1.45–7.48) 1.00 0.95(0.53–1.68) 1.00 0.41(0.10–1.63) 1.00 2.41(0.88–6.59) p-value 0.000 0.012 0.82 0.165 0.08 Page 4 of 5 (page number not for citation purposes)