Changes in Escherichia coli resistance to co-trimoxazole in tuberculosis patients and in relation to co-trimoxazole prophylaxis in Thyolo, Malawi.
In Thyolo district, Malawi, an operational research study is being conducted on the efficacy and feasibility of co-trimoxazole prophylaxis in preventing deaths in HIV-positive patients with tuberculosis (TB). A series of cross-sectional studies were carried out in 1999 and 2001 to determine (i) whether faecal Escherichia coli resistance to co-trimoxazole in TB patients changed with time, and (ii) whether the resistance pattern was different in HIV-positive TB patients who were taking co-trimoxazole prophylaxis. Co-trimoxazole resistance among E. coli isolates in TB patients at the time of registration was 60% in 1999 and 77% in 2001 (P < 0.01). Resistance was 89% among HIV-infected TB patients (receiving cotrimoxazole), while in HIV-negative patients (receiving anti-TB therapy alone) it was 62% (P < 0.001). The study shows a significant increase of E. coli resistance to co-trimoxazole in TB patients which is particularly prominent in HIV-infected patients on co-trimoxazole prophylaxis. Since a high degree of plasmid-mediated transfer of resistance exists between E. coli and the Salmonella species, these findings could herald limitations on the short- and long-term benefits to be expected from the use of co-trimoxazole prophylaxis in preventing non-typhoid Salmonella bacteraemia and enteritis in HIV-infected TB patients in Malawi.
Zachariah
R
R
Médecins sans Frontières-Luxembourg, Thyolo District, Malawi. zachariah@internet.lu
Harries
A D
AD
Spielmann
M P
MP
Arendt
V
V
Nchingula
D
D
Mwenda
R
R
Courtielle
O
O
Kirpach
P
P
Mwale
B
B
Salaniponi
F M L
FM
D017088:AIDS-Related Opportunistic Infections / Q000150:complications / Q000517:prevention & control*; D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D003430:Cross-Sectional Studies; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000187:drug effects; D004927:Escherichia coli Infections / Q000150:complications / Q000188:drug therapy*; D005243:Feces / Q000382:microbiology; D005260:Female; D006801:Humans; D008297:Male; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000627:therapeutic use*; D014376:Tuberculosis / Q000150:complications / Q000517:prevention & control*
D000900:Anti-Bacterial Agents; D015662:Trimethoprim, Sulfamethoxazole Drug Combination