A Family Case Study Illustrating Issues in Pediatric MDR TB
MDR TB and drug-susceptible TB cases commonly live in the same household in South Africa. In one family, the maternal grandmother had her fourth episode of TB in 2007 and had previously been identified as an MDR TB case. The grandfather died of MDR TB before 2004. An uncle had drug-susceptible TB during that same period and has since been treated and cured.
When the uncle left the household, the mother and a child aged 10 months remained. At the time, the child was asymptomatic and had a negative Tine tuberculin skin test;b it was unknown whether a chest xray had been taken. He was started on a regimen of isoniazid prophylaxis. The child presented 4 months later when the grandmother was again admitted for confirmed MDR TB. The child had had a cough for a week; his weight was in the 75th percentile; he was clinically well, but his Mantoux testc converted to positive at 30 mm and was ulcerating; his chest x-ray showed some nodes and opacification; and he was HIV-negative.
The child was started on a treatment regimen of isoniazid, pyrazinamide, ethambutol, ethionamide, ofloxacin, and amikacin. Gastric aspirates were taken, two of which were culture positive, resistant to isoniazid and rifampicin, and susceptible to ethambutol. The grandmother’s second-line drug resistance returned a few months later—this time not only to isoniazid and rifampicin but also to amikacin. The child’s treatment was changed from amikacin to capreomycin, and terizidone was added.
During the child’s follow-up, hearing tests could not be administered because the child was too young, but renal function was normal. Each of the six monthly follow-up cultures was negative. The child was treated for 18 months after the first negative culture. The capreomycin was stopped after 4 months, for a total of 6 months of injectable drug treatment. The child was discharged in April 2008. The grandmother was diagnosed with pre-XDR TBd and died in March 2008.
The mother was pregnant and moved to live with the paternal grandmother in a nearby town. She was diagnosed with TB in August 2008, 4 months after the child was discharged, and did not disclose that the paternal grandmother had MDR TB. The child was still on MDR TB treatment. The mother started treatment but defaulted and, not surprisingly, did not respond to the treatment. She was smear positive at 2 months, when her baby was born, and MDR TB was confirmed in December 2008. She died of MDR TB 3 months later. It was confirmed 3 months after her death that her TB had been susceptible to second-line drugs.