As the incidence of infectious diseases has recently decreased, we are faced with new problems, such as emerging and re-emerging infectious diseases, food poisoning, zoonosis, and bio-terrorism. In light of these new conditions, the National Institute of lnfectious Diseases, the Local Institutes of Public Health, public health offices, and other medical organization must maintain close relationship in order to protect the health and safety of the citizens.

Diarrheagenic Escherichia coli (DEC) represents an elusive target, since they are not easily distinguished from fecal coliforms. To clarify if DEC are prevalent among sporadic cases of diarrheal illness in Osaka City, Japan, diarrheal specimens were examined for E. coli that were enterohemorrhagic (EHEC), enteropathogenic (EPEC), enterotoxigenic (ETEC), enteroinvasive (EIEC), or enteroaggregative (EAggEC). EAST1EC, a strain of E. coli that does not possess any diarrheagenic characteristics except the EAggEC heat-stable toxin 1 (EAST1) gene, was also included as a possible DEC. A total of 924 specimens were examined between July 1997 and March 2000. DEC and Salmonella were isolated from 7.3% (67/924) and 6.8% (63/924) of specimens, respectively. DEC was therefore as prevalent as Salmonella among sporadic cases. The 67 strains were composed of 17 EPEC (26%), 10 EHEC (15%), four ETEC (6%), 13 EAggEC (20%), and 23 EAST1EC (35%), including two strains of EAST1EC O166:H15. Although PCR and tissue culture adhesion tests were useful to detect DEC, the effectiveness of serotyping was limited: only 40 strains (17.5%) out of 229 isolates that had been assumed to be enterovirulent on the basis of their O antigen were recognized to be diarrheagenic. In conclusion, not only EHEC but also the other subgroups of DEC, including EAST1EC, seem to play an important role in causing sporadic diarrheal illnesses. Methods to detect and unified criteria to identify various kinds of DEC are strongly desired.

Myiasis is the infestation of live human and vertebrate animals with dipterous larvae, which, at least for a certain period, feed on the host's dead or living tissue, liquid body substances, or ingested food. Intestinal myiasis is usually an accidental phenomenon, which occurs due to the ingestion of eggs or larvae present in food. Usually the patient is asymptomatic and the larvae are excreted harmlessly in the feces. In some cases, however, the passage of larvae may be associated with symptoms. The present paper describes two such cases.

An outbreak of leptospirosis occurred during the rainy season in the city of Mumbai, India. Out of 169 suspected cases, 74 (43.7%) were determined serologically positive by microagglutination test (MAT) carried out with a battery of eight pathogenic serovars, while 78 (46.1%) were shown positive for lgM antibodies to leptospira by enzyme-linked immunosorbent assay. On the basis of MAT, serovar Copenhageni accounted for 66 (89.1%) out of the 74 cases admitted during the period of the outbreak. Myalgia, conjunctival suffusion, cough with hemoptysis, icterus, and oliguria were significantly more common in patients whose samples were determined positive by MAT. The presence of pulmonary signs and symptoms and renal failure were significantly associated with mortality in patients presumed to be suffering from leptospirosis.

In Japan, Tsutsugamushi disease, which is caused by Orientia tsutsugamushi, is re-emerging with newly recognized strains and is now endemic. in all prefectures except Hokkaido and Okinawa. We analyzed recent surveillance data to describe the epidemiology of Tsutsugamushi disease and to evaluate the newly implemented national surveillance system according to the CDC guidelines for evaluating surveillance systems. In 2000, 756 cases of Tsutsugamushi disease were reported from 37 of 47 prefectures; two of these cases were fatal. The median age of case-patients was 64 years (range: 2-94 years); 414 (54.8%) were male. In northern Japan, most cases were diagnosed in the months of May through July and in the months of October through December, and in southern Japan, cases were diagnosed almost year-round with a peak from October through December and in January. Reporting and transfer of surveillance information from the prefecture to the national level was effective and timely, but the completeness and quality of case reporting could still be improved. The current system for Tsutsugamushi disease surveillance is useful for describing epidemiologic patterns by time, prefecture, and demographic characteristics. However, collection of additional information on suspected place of transmission, activity performed at the place of transmission, or the case-patient's profession would likely make the system more valuable for outbreak detection and for better defining populations at risk.