Household contacts have high risk of contracting multidrug-resistant TB

A Lima, Peru, study showed that the household contacts of patients who have multidrug-resistant tuberculosis have a high risk of contracting the disease and should be focused upon in screening and drug susceptibility testing.

The study was conducted among 693 households that had at least one MDR-TB infected patient in Lima between 1996 and 2003, Med Page Today reports. A total of 117 of the 4,503 contacts within the household were found to have the active disease when the patient began treatment.

During four years of follow-up studies, 242 additional households contacts developed active TB, according to Med Page Today. Very few studies have examined the burden endured by patients’ household contacts. The fact that new cases continued to occur throughout the four years of follow-up may suggest that current guidelines that call for two years of monitoring MDR contacts might not be enough.

“Our findings suggest a worrisome hypothesis: household members face a common and persistent exposure to MDR tuberculosis in the community,” the researchers wrote, according to Med Page Today. “These findings lend support to international guidelines that recommend prompt assessment of close contact of all patients with MDR tuberculosis, and to suspect a close contact presenting with active tuberculosis as having MDR tuberculosis until proven otherwise.”