October 17, 2013
Tuberculosis symptoms – Common symptoms of active pulmonary TB cough with sputum sometimes tinged with blood, chest pain, weakness, weight loss, fever and night sweats.
Many countries still use a method used long consisting of a microscopic examination of sputum for the diagnosis of tuberculosis. Of qualified laboratory technicians examine sputum samples under a microscope to detect the presence of the tubercle bacillus. Through three of these tests, the diagnosis can be made in a day, but the test fails to detect many cases of forms of tuberculosis less infectious.
It can be more complex to diagnose MDR-TB (see section on MDR below) and HIV-associated TB. A new test with results available in less than two hours and proved highly effective in diagnosing tuberculosis and the presence of drug resistance, is now established in many countries.
TB is particularly difficult to diagnose in children.
Global impact of tuberculosis
Tuberculosis is present everywhere in the world. In 2011, the largest number of new TB cases was recorded in Asia, which accounts for 60% of new cases worldwide. However, sub-Saharan Africa has the largest proportion of new cases per capita, with more than 260 cases per 100,000 inhabitants in 2011.
In 2011, approximately 80% of reported cases of tuberculosis occurred in 22 countries. In some countries, the decline in the number of cases is important, while in others, the number of cases decreases only very slowly. Brazil and China are, for example, among the 22 countries recorded a significant decline in the number of tuberculosis cases in the past 20 years. During the last decade, the prevalence of tuberculosis in Cambodia dropped by nearly 45%.