LONDON — The number of people who caught tuberculosis last year inched downward, according to an estimate by the World Health Organization, but the agency warned that drug-resistant strains are still spreading.
In a report issued Wednesday, the UN agency estimated there were about 8.7 million new cases of TB last year, down from about 8.8 million in 2010. The number of deaths was unchanged at about 1.4 million — making it the second-leading killer among infectious diseases after AIDS.
But no one knows for sure what the actual figures are. The WHO report said it was too expensive and complicated to measure the exact number of new TB cases every year.
Drug-resistant TB is often the result of patients not being treated properly for regular TB; it is more expensive to treat and the drugs have worse side effects. WHO estimates that only 1 in 5 cases of drug-resistant TB are identified globally, meaning the others are spreading the disease without being treated.