Mycobacterium tuberculosis strains that are resistant to an increasing number of second-line drugs used to treat multidrug-resistant tuberculosis (MDR TB) are becoming a threat to public health worldwide. We surveyed the Network of Supranational Reference Laboratories for M. tuberculosis isolates that were resistant to second-line anti-TB drugs during 2000-2004. We defined extensively drug-resi...

The emergence of drug-resistant tuberculosis (TB) compromises global tuberculosis control. The incidence of multidrug-resistant strains (MDR) defined as resistant to the two main antituberculosis drugs, rifampicin and isoniazid, was raised in the 1990s. Ten percent of these strains have developed additional resistance to the main second-line antituberculosis drugs: fluoroquinolones and aminogly...

Extensively drug-resistant tuberculosis (XDR TB) has been detected in most provinces of South Africa, particularly in the KwaZulu-Natal province where several hundred cases have been reported since 2004. We analyzed the transmission dynamics of XDR TB in the region using mathematical models, and observed that nosocomial transmission clusters of XDR TB may emerge into community-based epidemics u...

We expanded second-line tuberculosis (TB) drug susceptibility testing for extensively drug-resistant Mycobacterium tuberculosis isolates from South Africa. Of 19 patients with extensively drug-resistant TB identified during February 2008-April 2009, 13 (68%) had isolates resistant to all 8 drugs tested. This resistance leaves no effective treatment with available drugs in South Africa.

Keertan Dheda and colleagues (May 22, p 1798) report extremely poor treatment outcomes for patients with extensively drug-resistant (XDR) tuberculosis in South Africa and conclude that prevention of XDR tuberculosis through strengthening of tuberculosis pro grammes overall should be prioritised. Most patients diagnosed with XDR tuberculosis in this cohort (72%) had previously been diagnosed wit...

We evaluated risk factors and treatment outcomes associated with multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis (TB) in Germany in 2004-2006. In 177 (4%) of 4,557 culture-positive TB cases, Mycobacterium tuberculosis isolates were identified as MDR TB; an additional 7 (0.15%) met criteria for XDR TB. Of these 184 patients, 148 (80%) were born in countries of the for...

Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 13, No. 9, September 2007 1429 niazid chemoprophylaxis due to resistance of the infecting organism. Decreased susceptibility to isoniazid among M. kansasii isolates is common (7,8), and this microorganism is naturally resistant to pyrazinamide (9). This pattern of resistance is a serious obstacle for the use of these drugs in monotherapy or ...

780 Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 13, No. 5, May 2007 part of this study, all samples from malaria case-patients identifi ed through clinical diagnosis were subject to a Paracheck-Pf immunoassay test (Orchid Biomedical Systems, Verna, Goa, India). Results indicated that, at the peak of the apparent malaria outbreak, the percentage of samples from clinically diagnosed cas...