Epidemics of drug-resistant bacterial infections observed in infectious disease surveillance in Japan, 2001-2005.
BACKGROUND
Drug-resistant bacteria have been increasing together with advancement of antimicrobial chemotherapy in recent years. In Japan, the target diseases in the National Epidemiological Surveillance of Infectious Diseases (NESID) include some drug-resistant bacterial infections.


METHODS
We used the data in the NESID in Japan, 2001-2005. Target diseases were methicillinresistant Staphylococcus aureus (MRSA), penicillin-resistant Streptococcus pneumoniae (PRSP) and multi-drug-resistant Pseudomonas aeruginosa (MDRPA) infections. The numbers of patients reported by sentinel hospitals (about 500) on a monthly basis were observed.


RESULTS
The numbers of patients per month per sentinel hospital of 2001-2005 were 3.37-3.98 in MRSA, 0.96-1.19 in PRSP, and 0.11-0.13 in MDRPA infections. The sex ratios (male / female) of patients were 1.69-1.82, 1.34-1.43, and 1.71-2.52, respectively. More than 50% of all patients were adults aged 70 years or older in MRSA and MDRPA infections, but more than 60% were children under 10 years in PRSP infections. The number of patients per sentinel hospital in MRSA infections showed little variation between months, but evidenced a large variation in PRSP and MDRPA infections. The annual trend in the number of patients per sentinel hospital was increasing significantly for the 5-year period in MRSA and PRSP infections, but not in MDRPA infections.


CONCLUSIONS
We revealed sex-age distributions of the patients reported to NESID in Japan, 2001- 2005. An increasing incidence of MRSA and PRSP infections and monthly variation in PRSP and MDRPA infections were observed for the 5-year period. Extended observation would be necessary to confirm these trends and variations.
Izumida
Michiko
M
Department of Public Health, Saitama Medical University Faculty of Medicine, 38 Morohongo, Moroyama-machi, Iruma-gun Saitama 350-0495, Japan. kidomi@saitama-med.ac.jp
Nagai
Masaki
M
Ohta
Akiko
A
Hashimoto
Shuji
S
Kawado
Miyuki
M
Murakami
Yoshitaka
Y
Tada
Yuki
Y
Shigematsu
Mika
M
Yasui
Yoshinori
Y
Taniguchi
Kiyosu
K
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001424:Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D003141:Communicable Diseases / Q000453:epidemiology* / Q000382:microbiology; D004196:Disease Outbreaks; D024881:Drug Resistance, Bacterial; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011550:Pseudomonas aeruginosa; D018571:Sentinel Surveillance; D017678:Sex Distribution; D013211:Staphylococcus aureus; D013296:Streptococcus pneumoniae