A study of multidrug resistant tuberculosis among symptomatic household contacts of MDR-TB patients

Diagnosis and management of multidrug-resistant tuberculosis (MDR-TB) remains a global challenge and is associated with high morbidity and mortality. Burden of TB among symptomatic household contacts of MDR-TB is not extensively studied and screening of symptomatic contacts may provide a better opportunity for optimum management and effective TB control.

This prospective observational study was conducted in the department of Tuberculosis & Chest diseases, S.N. Medical College, Agra from February 2016 to January 2018. The study recruited 271 symptomatic household contacts of 87 index MDR-TB cases. Symptomatic contacts were screened for active disease and latent TB infection. Risk factors for the spread of disease were also looked for.

Out of 271 symptomatic household contacts, 97 (35.79%) had active TB. Among 97 diseased, 62 (22.87%) had MDR-TB and 35 (12.91%) had drug-susceptible TB. 124 contacts (45%) had latent TB infection. Risk factors associated with occurrence of TB included age less than 18 years (OR = 7160, p = 0.1908, RR = 0.8082, p = 0.1887), male sex (OR = 2.3108, p = 0.0021, RR = 1.7444, p = 0.0034), Sibling as index case (OR = 0.6404, p = 0.0804, RR = 0.7520, p = 0.0806), lack of BCG vaccination (OR = 1.7763, p = 0.0271, RR = 1.4338, p = 0.0247) malnutrition (OR = 1.8980, p = 0.0138, RR = 1.5166, p = 0.0159) and lower socioeconomic status (OR = 3.2399, p < 0.0001, RR = 2.1524, p < 0.0001).

The high case detection rate by screening symptomatic household contacts shows MDR-TB is highly transmissible and household contacts are at a higher risk of developing active disease. It provides an opportunity for early diagnosis, adequate treatment, and interrupt the chain of transmission. Identifying risk factors help prevent the progression of latent TB infection to active disease.