Contacts of multidrug-resistant TB (MDR-TB) patients in whom latent infection is diagnosed are often infected with the same strain as the index case. Studies from high-burden TB areas have shown that approximately two-thirds or more of household members will have the same strain of TB7,8,9,10.
There have been very few studies of the use of second-line anti-TB drugs to prevent disease in MDR-TB contacts. Due to the lack of evidence, lack of consensus about whether close contacts of MDR-TB patients should be given chemoprophylaxis and which drugs should be given, routine chemoprophylaxis for close contacts of MDR-TB patients cannot be recommended at this time.
Close contacts of drug-resistant TB patients should be followed for at least two years. If active disease develops, prompt initiation of treatment with a regimen designed to treat the index case is recommended.