No abstract

Bill & Melinda Gates Foundation.

BackgroundThe proportion of extrapulmonary tuberculosis (EPTB) among all the reported tuberculosis (TB) cases has increased in different populations. Despite the large burden of TB in China, the epidemiology of EPTB in China remains largely understudied and the risk factors for having EPTB diagnosis in China have not been identified.MethodsTo gain insight to EPTB epidemiology in China, we analyzed TB surveillance data collected in Tianjin, China, during 2006 to 2011. The frequency of EPTB among all TB cases and within different socio-demographic groups of the study patients aged 15 years and older was determined for EPTB in general and by specific types. The distribution of socio-demographic characteristics was compared between pulmonary TB (PTB) group and EPTB group by chi-square test. Crude and multiple logistic regression-derived adjusted odds ratios (aOR) and 95% confidence intervals (CI) were determined to assess the associations between having EPTB diagnosis and each individual explanatory variable in question.ResultsAbout one-tenth (1,512/14,561) of the patients investigated in this study had EPTB. Of these 1,512 EPTB cases, about two thirds were pleural TB. Significant difference in age, occupation, and urbanity of residence were found between PTB and EPTB groups (p<0.05). Patients with EPTB diagnosis were more likely to be 65 years or older (aOR = 1.22, 95% CI: 1.02, 1.46), to be retired (aOR = 1.37, 95% CI: 1.08, 1.75), and to live in urban areas (aOR = 1 38, 95% CI: 1.22, 1.55).ConclusionsThe findings of this study extends the knowledgebase of EPTB epidemiology in developing countries and highlight the need for improved EPTB detection in China, especially in subpopulations with high risk for EPTB or having limited access to medical facilities with adequate capacity for EPTB diagnosis.

Limited vaccination programs in the 1980s have resulted in many Chinese women with inadequate protection against measles and an accordingly low efficiency of transplacental transmission to a fetus. Current vaccination programs, which target children aged 8 months through adolescence may be ineffective in controlling transmission of measles to infants.

DBS are an alternative for adults and children but pose challenges in infants, and improve with experience. In a resource-limited environment or in a scenario where more invasive techniques like venipuncture may be less accepted by the study population, DBS can be the preferred technique to efficiently obtain serum specimens for analyte testing.