Nasal carriage in Vietnamese children of Streptococcus pneumoniae resistant to multiple antimicrobial agents

Resistance to antimicrobial agents in Streptococcus pneumoniae is increasin g rapidly in many Asian countries. There is little recent information conce rning resistance levels in Vietnam. A prospective study of pneumococcal car riage in 911 urban and rural Vietnamese children, of whom 44% were nasal ca rriers, was performed. Carriage was more common in children <5 years old th an in those greater than or equal to 5 years old (192 of 389 [49.4%] versus 212 of 522 [40.6%]; P, 0.01), A total of 136 of 399 isolates (34%) had int ermediate susceptibility to penicillin (MIC, 0.1 to 1 mg/liter), and 76 of 399 isolates (19%) showed resistance (MIC, >1.0 mg/liter), A total of 54 of 399 isolates (13%) had intermediate susceptibility to ceftriaxone, and 3 o f 399 isolates (1%) were resistant. Penicillin resistance was 21.7 (95% con fidence interval, 7.0 to 67.6) times more common in urban than in rural chi ldren (35 versus 2%; P, <0.001), More than 40% of isolates from urban child ren were also resistant to erythromycin, trimethoprim-sulfamethoxazole, chl oramphenicol, and tetracycline. Penicillin resistance was independently ass ociated with an urban location when the age of the child was controlled for . Multidrug resistance (resistance to three or more antimicrobial agent gro ups) was present in 32% of isolates overall but in 39% of isolates with int ermediate susceptibility to penicillin and 86% of isolates with penicillin resistance. The predominant serotypes of the S, pneumoniae isolates were 19 , 23, 14, 6, and 18, Almost half of the penicillin resistant isolates serot yped were serotype 23, and these isolates were often multidrug resistant. T his study suggests that resistance to penicillin and other antimicrobial ag ents is common in carriage isolates of S, pneumoniae from children in Vietn am.