RESUMO
Two surveys to determine the patterns of bacterial infections and trends in resistance to antibiotics of bacteria causing infections in patients admitted to hospitals in Thailand were conducted in 36 and 37 hospitals throughout Thailand in June 1997 and February 2000. Approximately 50 per cent of infections in hospitalized patients in Thailand were hospital-acquired infections. Urinary tract and lower respiratory tract were the most common sites of infections. Eighty per cent of infections were caused by gram negative bacteria. Gram negative bacteria causing infections in 2000 were more resistant to most commonly used antibiotics when compared with those in 1997. The prevalence of gram positive bacteria causing hospital-acquired infections significantly increased during this period. The trend of increase in resistance in most gram positive bacteria in 2000 was not clearly observed.