Are global tuberculosis control targets overlooking an essential indicator? Prolonged delays to diagnosis despite high case detection rates in Yunnan, China.

Delay in treating active tuberculosis (TB) impedes disease control by allowing ongoing transmission, and may explain the unexpectedly modest declines in global TB incidence. Even though China has achieved TB control targets under the global Directly Observed Treatment, Short course (DOTS) strategy, TB prevalence in western provinces, including Yunnan, is not decreasing. This cross-sectional study investigates whether prolonged delay in identifying and correctly treating TB patients, which is not routinely monitored, persists even when there is a well-functioning TB control programme and global targets are being met. Records of adult smear-positive pulmonary TB patients diagnosed with between 2006 and 2013 were extracted from the Yunnan Centre for Disease Control electronic database, which contains information on the entire population of TB patients managed across 129 diagnostic centres. Delay was investigated at three stages: delay to DOTS facility (period between symptom onset and first visit to at a CDC unit providing standardized treatment); delay to TB confirmation (period between reaching a CDC unit and confirmation of smear-positive TB) and delay to treatment (period between confirmation of TB and initiation of treatment). Data from 76 486 patients was analysed. Delay to reaching a DOTS facility was by far the largest contributor to total delay to treatment initiation. The median delay to reaching a DOTS facility, to TB confirmation and to treatment was 57 days (IQR 25-112), 2 days (IQR 1-6) and 1 day (IQR 0-1) respectively. Prolonged delays to reaching a facility providing standardized TB care occurred in a substantial subset of the population despite all TB control targets being met; overall, 32% (24 676) of patients experienced a delay of more than 90 days to reaching a DOTS facility. Policies that focus on reducing delays in accessing appropriate health services, rather than only on increasing overall case-detection rates, may result in greater progress towards reducing TB incidence.