Initial drug resistance patterns to the essential anti-tuberculous drugs in previously untreated newly diagnosed pulmonary tuberculous patients attending Mulago hospital.

Abstract

World Health organization (WHO) recommends a continuous assessment of tuberculosis (TB) drug resistant patterns as a means of assessing drug regimens and National Tuberculosis Programme (NTP) performance. In addition, an accurate estimation of drug resistance would serve as an indicator of transmission of drug resistant organism in the community. In Mulago, Uganda, last anti-TB drug resistances were performed over a decade ago. In addition, there are reports from other areas that there is poor response to our current treatment regimens leading to frequent relapses. Thus, it is timely to assess the level of primary/initial drug resistance patterns to essential anti-TB drugs in our community. Results obtained from this study will form a baseline on which a national survey can be done. Objectives: To determine the prevalence of TB drug resistance among newly diagnosed PTB patients attending Mulago hospital. Methodology: This was a cross-sectional descriptive study carried out between September 2004 and February 2005. Smear positive PTB patients were screened consecutively after informed consent/assent from suspected PTB patients admitted on medical wards in New Mulago hospital and outpatients in the TB clinic, until sample size was achieved. One sample of their sputum was taken to the national reference laboratory in Wandegeya for culture and sensitivity using Lowenstein-Jensen media. Data was entered in pre-tested questionnaire then into EPI data and analyzed using SPSS version 11.0. Results: A total of 186 sputum smear positive PTB patients were recruited into the study, whom 168 (90.4%) were culture positive and subjected to sensitivity studies of four essential antituberculous drugs (isoniazid, rifarnpicin, ethambutol, and streptomycin). One hundred and thirty-eight (82.1%) had complete reports on sensitivity patterns to all the four drugs tested. Seventy-nine (57.2 %) of the 138 samples were sensitive to all the four drugs and 59 (42.8%) were resistant to at least one of the four drugs. Highest resistance was to streptomycin 39 (28.3%) followed by ethambutol 29 (21.0%). Resistance to isoniazid 6 (4.3%) and rifampicin 7 (5.1%) relatively low. Initial 'primary' MDR (resistance to at least isoniazid and rifampicin) was found in 6 (4.3%) of the patients. Conclusion: Initial 'primary' drug resistance to streptomycin 39(28.3%) and ethambutol 29 (21%) is high in Mulago hospital. The prevalence of primary MDR however, still remains low. We recommend a national survey to see if a similar trend will occur nation-wide.