Send letter to journal:
Re: Directly observed therapy might improve compliance

Dear Editor,

Bearing in mind the risk of transmission of disease posed by infected adults, irrespective of whether or not they are smear positive for mycobacterium tuberculosis(1)(2), the poor compliance rate documented for children receiving preventive chemotherapy(3)is in urgent need of review and improvement. In this respect there might be a role for directly observed therapy(DOT)although this has been evaluated more extensively in adults(4) than in children(5). A wide ranging review covering the human immunodeficiency virus(HIV) era evaluated 24 studies in which the defining feature was culture positivity of the sputum, and 10 in which the defining feature was smear positivity only. On average, the crude relapse rate following DOT was 3.6% in the 21 culture based studies that provided post treatment follow up, and 3.2% and 3.3%, respectively, in the two smear- based studies with post treatment follow up. On the basis of their evaluation of the literature on treatment of tuberculosis(TB)in the HIV era the authors conclude that HIV co-infection should not significantly affect failure rates since "the now extensive experience in treating TB patients with AIDS and other immunodeficiencies suggests that the drugs themselves, not the host's defences, carry most of the burden of cure"(4). Accordingly, they conclude, where there is a low prevalence of significant drug resistance, long term cure rates should exceed 95% in routine practice, even where HIV coinfection is common(4). In the absence of HIV co-infection, this degree of optimism appears to be applicable to the peadiatric population as well, as shown by an observational study conducted to determine the effectiveness of the DOT regime in 185 cases of paediatric tuberculosis in the age range 5 months to 17 years. The median age was 3 years for pulmonary tuberculosis, 4 years for hilar/mediastinal adenopathy, 5.5 years for cervical node disease, 14.5 years for pleural disease. Of the 175 evaluable children 142 completed the treatment in 6 months. In only 16 of the remaining 33 children was the need for more prolonged treatment attributable to poor adherence to the DOT. Only one patient relapsed 4 years after completion of therapy, and this was because she held the medications in her cheek and spat them down the sink after the DOT worker left her house(5).

References:

(1) Singh M., Mynak ML., Kumar L., Mathew JL., Jindal SK Prevalence and risk factors for transmission of infection among children in household contact with adults having pulmonary tuberculosis Archives of Disease in Childhood 2005:90:624-8

(2)Behr MA., Warren SA., Salamon H., et al Transmission of mycobacterium tuberculosis from patients smear-negative for acid fast bacilli Lancet 1999:353:444-9

(3)Marais BJ., van Zyl S., Schaaf HS., et al Adherence to isoniazid preventive chemotherapy: a prospective community- based study Archives of Disease in Childhood 2006:91:762-5

(4) Hill AR., Manikal VM., Riska PF Effectiveness of directly observed therapy(DOT) for tuberculosis Medicine 2002:81:179-93

Send letter to journal:
Re: Non-Adherence to TB treatment

Dear Editor,

Marais et al (1) reported on a prospective community based study into adherence of mono-chemotherapy with isoniazid in preventing tuberculosis in suburbs of Cape Town, South Africa. They studied children who were less than five years age and who had household contact with an adult pulmonary tuberculosis index case. The main evaluation was the children’s prescription collection at various intervals from the start of chemotherapy to the end at six months. They found that only 20 % of children completed > or equal to 5 months of unsupervised chemotherapy. The ethical underpinning and structure of this study is questioned. It was clear that during the early stages, i.e at one and two months into the study, a number of children were not compliant with therapy. At this stage the guardians were not questioned into the reasons for non-attendance or educated into importance of compliance. Furthermore, no arrangements were made for ensuring subsequent compliance. Instead the children were simply monitored for further non-compliance and ‘allowed’ to develop tuberculous disease; which is what six of them did! One would assume that ‘normal’ professional practice would be that whenever any non- compliers are located, a strict form of supervision or directly observed therapy (DOT) is instigated, i.e before any disease progression occurred. Also, the authors do not investigate the reasons for non-compliance. It is not possible that the guardians were too sick with their pulmonary tuberculosis or HIV ( not mentioned in the study, but assumed to be endemic in the suburbs of South Africa) to bring their children regularly to the clinics. Based on anecdotal experience of non-compliance we use dual therapy with rifampicin and isoniazid. As soon as any non- compliers are located, intensive supervised treatment or DOT is instigated.

M Khan
Consultant Paediatrician
Northwest London Hospital NHS Trust
Acton Lane
Park Royal
NW10 7NS

murtuza.khan@nwlh.nhs.uk

Reference: