Impact of cotrimoxazole on non-susceptibility to antibiotics in Streptococcus pneumoniae carriage isolates among HIV-infected mineworkers in South Africa.
OBJECTIVE
To investigate risk factors for pneumococcal carriage and non-susceptibility among HIV-infected mineworkers in South Africa.


METHODS
In a cross-sectional study, HIV clinic attendees were questioned about risk factors for pneumococcal carriage and antimicrobial non-susceptibility. Oropharyngeal and nasopharyngeal swabs were taken for pneumococcal culture, serotyping and susceptibility testing.


RESULTS
Among 856 participants (854 male, median age 41.5years, median CD4 290cells/mm(3)), 294 (34.3%) were receiving cotrimoxazole prophylaxis. Overall, 75/856 (8.8%) carried S. pneumoniae; among those taking vs. not taking cotrimoxazole, 8.2% vs. 9.1% were carriers. Risk factors for pneumococcal carriage were living with a child (adjusted OR 2.12, 95% CI 1.06-4.62) and recent hospitalisation (adjusted OR 1.80; 95% CI 0.98-3.30). Among participants not taking cotrimoxazole, the prevalence of carriage was higher in individuals with lower CD4 counts. Comparing participants taking cotrimoxazole vs. not, 60.9% vs. 22.4% (p=0.001) isolates were non-susceptible to cotrimoxazole and 30.4% vs. 8.2% were non-susceptible to penicillin (p=0.014). Thirty three/72 (45.8%) isolates were paediatric serotypes/groups. Nasopharyngeal compared with oropharyngeal swabs had higher sensitivity in detecting carriage (53/75, 70.7% vs. 31/75, 41.3%), and adding oropharyngeal sampling increased detection from 6.2% to 8.8%.


CONCLUSIONS
Non-susceptibility to cotrimoxazole and penicillin was more common among isolates from participants taking cotrimoxazole prophylaxis. Surveillance for antimicrobial susceptibility is important where prophylaxis is used. Treatment for pneumococcal disease should take into account a higher risk of non-susceptibility to antibiotics amongst individuals taking cotrimoxazole prophylaxis.
Pemba
L
L
Aurum Institute for Health Research, P. O. Box 61587, Marshalltown 2107, South Africa. lifp@novonordisk.com
Charalambous
S
S
von Gottberg
A
A
Magadla
B
B
Moloi
V
V
Seabi
O
O
Wasas
A
A
Klugman
K P
KP
Chaisson
R E
RE
Fielding
K
K
Churchyard
G J
GJ
Grant
A D
AD
D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use*; D018791:CD4 Lymphocyte Count; D002353:Carrier State / Q000453:epidemiology / Q000382:microbiology*; D003430:Cross-Sectional Studies; D024881:Drug Resistance, Bacterial; D005260:Female; D015658:HIV Infections / Q000150:complications* / Q000276:immunology; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010614:Pharynx / Q000382:microbiology; D011008:Pneumococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D012307:Risk Factors; D012703:Serotyping; D013019:South Africa / Q000453:epidemiology; D013296:Streptococcus pneumoniae / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000494:pharmacology / Q000627:therapeutic use*
D000900:Anti-Bacterial Agents; D015662:Trimethoprim, Sulfamethoxazole Drug Combination