Tuberculosis case notification in the world
WHO has been collecting information on tuberculosis notification from the countries in the world. Here you can see tuberculosis case notification rates (rate: annual number of newly notified cases per 100 ,000 population) in several countries by region, which are derived from Tuberculosis - A Global Emergency: Case Notification Update, February 1996, Global Tuberculosis Programme, WHO, Geneva.
We need to understand the following issues when we see data:
- Definition of notified tuberculosis cases may be different from country to country. For instance, notified tuberculosis cases include pulmonary cases but not extrapulmonary cases in some country.
- Number of notified cases might be influenced by quality of diagnosis and reporting activities. For instance, cases diagnosed and treated in private sector are not included in official statistics in most developing countries.
Because of nature of these conditions, it should be considered that tuberculosis statistics bases on notification may not precisely reflect actual epidemiological situation of tuberculosis in some occasion. For instance, even if number of tuberculosis shows increase trend, it should be taken into consideration that the increase trend does not necessarily indicate worsening epidemiological situation and that it may just attribute to improvement of diagnosis and reporting activities in some countries. Therefore we call data shown here as case notification rate, not as incidence rate, which usually refers to rate of new cases occurring actually and which is the term used for theoretical discussion.
Graphs showing time trend of case notification rate in several countries by region: