BCG coverage and the association between selected factors and the immunization coverage among children under the age of two years in rural and semi-rural Lhasa District, Tibet
Aim: Tuberculosis (TB) is a worldwide pandemic. The BCG vaccine still remains the standard for TB prevention in most countries because of its efficacy in preventing life-threatening forms of TB in infants and young children, and BCG is the only vaccine available. To achieve a high BCG coverage, it is important to investigate the BCG coverage in populations and the factors which affect the immunization status. Thus giving us clues for improving the coverage. Few such studies have been conducted in Tibet. The aim of the present study is to estimate the BCG immunization coverage and to investigate the association between the BCG coverage and the selected factors in children less than two years of age in semi-rural and rural areas of Lhasa District.
Methods: The present cross-sectional study was carried out among children less than two years of age in Quxu County (N=484) and in Damxung County (N=496) of Lhasa District, Tibet. In Quxu County we selected all the children less than two years of age and in Damxung County we used multi- stage sampling method to select the sample. The questionnaire consists of core question regarding socio-demographic characteristic of household, the knowledge and belief of mothers related to the immunization and TB, accessibility of health services and the BCG immunization history of children. BCG vaccination scar were checked on the children’s shoulder and recorded.
Results: The BCG coverage in the semi-rural area Quxu County was 77%, and that of rural-area Damxung County was 61%. In Quxu County the high BCG coverage was significantly associated with short walking time from home to nearest health facility (OR=3.1; CI, 2.0-4.8), ever vaccinated in health facility (OR=2.5 ; CI, 1.6-4.0), receiving outreaching services (OR=12.0; CI, 7.0-20.6), frequency of outreaching services once per month (OR=7.4; CI 3.7-14.9) or once per two to four months (OR=6.3; CI 2.8-14.5), knowing the time of next outreaching services (OR=2.0; CI, 1.1-3.6), hospital delivery (OR=1.8 ; CI, 1.1-2.7), type of delivery assistance (health worker) (OR=2.0; CI 1.3-3.1), and. In terms of cost of transportation, high BCG coverage were associated with inexpensive cost of transportation (OR=4.6; CI, 1.8-11.6). In Damxung County, the factors significantly associated with high BCG coverage of children were receiving outreaching services (OR=3.8; CI, 2.0-7.2), and knowing the time of next outreaching services (OR=2.7; CI, 1.6-4.5). There was a clear relation between high BCG coverage and frequency of outreaching services, compared to services once or twice per year the odds were as follows once per two to four months (OR=2.7; CI, 1.6-4.5), and monthly (OR=5.7; CI, 3.0 -11.0).
Conclusions: BCG coverage was significantly higher in semi-rural area Quxu County (77%) than in the rural-area of Damxung County (61%). In order to increase the immunization coverage in the rural and semi-rural area of Tibet, the frequency of the outreaching services should be increased, as well as more polite information about the time of such services should be given. To establish more health facilities to reduce the travel distance for the mothers or to set up transportation free of charge or to a low cost would be helpful. To encourage the mothers to give birth at hospitals would also increase immunization coverage. However, for many families in Tibet, this will be too expensive. At the same time, birth at hospitals would help in decreasing the mother and child mortality in Tibet
