Drug – Resistant TuberculosisA Worldwide Epidemic Poses a New Challenge

Robert Loddenkemper, Barbara HauerDeutsches Zentralkomitee zur Bekämpfung der

Tuberkulose, Stralauer Platz 34, Berlin, Germany

Dtsch Arztebl Int 2010; 107(1–2): 10–9

Objective

• to obtain insight into the problem of resistance development in tuberculosis;

• to master the fundamentals of the diagnosis and treatment of drug-resistant tuberculosis;

• to be able to assess epidemiological developments in this area.

Epidemiology

• 2007: 9.27M new cases of Tb and 1.78M deaths• WHO report of increase to 5% of ~9 million TB

patients are infected with drug – resistant TB in 2008

• MDR-TB or XDR-TB– resistant to at least one of the fluoroquinolones and to

one of the threee injectable second – line anti – TB drugs (amikacin, kanamycin and capreomycin)

– WHO reported 2.9% MDR-TB cases– 2006: 20% of 17,000 isolates is MDR; 2% extensive

resistance 2%; extremely extensive resistance is present

WHO estimated incidence of tuberculosis (all types) per 100 000 population per year in the world population for the year 2007

45 countries with confirmed cases of XDR tuberculosis by February 2008;the number rose to 55 countries by the end of 2008.

Estimated percentage of multidrug-resistant (MDR) tuberculosis in newly diagnosed andnot previously treated tuberculosis patients worldwide, from 1994 to 2007.

Risk factors for MDR-TB

• Prior anti-TB treatment• Immigration from a region with a high

prevalence of MDR-TB• Contact with MDR-TB patients• Imprisonment• Possibly, HIV infection

Development of resistance to the five first-line anti-tuberculosis drugs used in Germany from 2002 to 2007

Diagnosis of drug – resistant TB

• Confirmed only with the aid of standardized, quality – controlled bacteriological sensitivity testing

• Gold standard of resistance testing: culture• New technique: MODS or Microscopic

Observation of Drug Susceptibility

Treatment

• Non – resistant TB: standard chemotherapy• Antibiotic resitance: treatment may last up to

2 years and is often poorly tolerated– requires a high degree of patient cooperation– extensive patient education and counseling are

needed• Supportive measures• Surgery indicated only for selected patients

Strategy for Drug - resistance

• WHO Goal: lower new infections and death rate from TB to half by 2015– 2050: eradication of the disease

• Prerequisite for prevention: adherence to the stated principles of treatment; DOTS

• Strategy: DOTS– Extended: DOTS-plus

• WHO Green Light Committee• Global Stop TB Partnership