Pneumococcal Infections in Trinidad: Patterns of Antimicrobial Susceptibility: 1994-2002

ABSTRACT

SUMMARY: Antimicrobial susceptibilities of 156 Streptococcus strains isolated from 1994 through 2002 were studied. Of this total, 38.7, 26.3, 16.7, 8.9, and 9.6 percent were recovered from patients with bacteremia, pneumonia, otitis media, sinusitis, and meningitis, respectively. All S. pneumoniae strains were fully susceptible to amoxicillin-clavulanic acid and ampicillin, with 9.0 and 2.6 percent being resistant to penicillin and ceftriaxone, respectively. The ratios of resistant strains to tetracyclin, co-trimoxazole, and chloramphenicol were 73.7, 69.3, and 63.5 percent, respectively. Approximately 90 percent of strains remain sensative to erythromycin. A high prevalence of resistance to penicillins cephalosporin does not exist in Trinidad, althought a trend towards that pattern seems to be developing. The most frequent serotype was 14(37.8 percent), followed by 6B(20.0 percent) , 23F(10.3 percent), and 4(6.4 percent), and all were recovered from children. The other serotypes accounted for <6 percent of the total isolates. All penicillin and ceftriaxone- resistant strains belonged to serotype 14 (MIC greater than or equal to 2 microg/ml and greater than or equal to 4 microg/ml), respectively. Identifiable risk factors for resistant isolates included the prevelance of otitis media and sinusitis among children treated inadequately with oral cephalosporins; the ease of obtaining antibiotics without a perscription at many pharmacies; and the indiscriminate perscribing of antibiotics by general practitioners.