Background: Nigeria ranks fourth among the 22 high tuberculosis (TB) burden countries. The estimated incidence of all TB cases in 2009 was 311/100,000 population. Since the implementation of DOTS in Ebonyi state, southeast Nigeria, the epidemiology of TB in the region has not been documented. Therefore, the objective of this study was to assess the type and case notification dynamics of TB following DOTS expansion and to examine age- and sex-specific trends in TB notification rate.
Methods: A retrospective trend analysis of case notification data from the Ebonyi State Ministry of Health records from 1998 to 2009 was conducted. Patients were diagnosed according to the National TB and Leprosy Control Programme guidelines. Denominators for TB notifications were derived from population census data.
Results: Of the 24, 475 cases notified between 1998 and 2009, 66% were smear-positive, 31% smear-negative and 3% had extra-pulmonary tuberculosis. Overall, the proportion of new smear-positive cases notified decreased continuously from 67% to 48% in 2009 while that of smear-negative cases increased from 29% to 40% in 2009. In 2005, 13 (100%) of the local government areas were covered by DOTS. Despite initial increase in case notification with DOTS expansion, the case notification rate had a mean annual decline of 3.1% for all TB cases (falling from 123/100,000 to 77/100,000), and of 5% for smear-positive patients (falling from 80/100,000 to 32/100,000). Smear-positive notification rate in children <14 years was consistently low while 25-34-year-old persons were affected most. However, smear-positive rates among persons aged =65 years did not change. Overall, annual new smear-positive notification rates were persistently lower in females than males.
Conclusion: TB notification rate shows a decreasing trend in our region with a pool of infectious cases in young-persons. Additional targeted, type and age-/sex- specific interventions for TB control are needed.
Keywords: DOTS; Epidemiology; Nigeria; Tuberculosis; case finding; control.