A description of influenza-like illness (ILI) sentinel surveillance in Cambodia, 2006-2008.

Influenza-Like Illness (ILI) sentinel surveillance was initiated by the Communicable Disease Control Department (CDC), Ministry of Health, Cambodia and its partners to evaluate the epidemiology of influenza and identify the circulating strains. The surveillance started in late 2006 in four sentinel sites. The objectives of this study were 1) to document the incidence of LI and confirmed influenza cases reported in the national surveillance system from 2006 to 2008, just after the system and the definition were revised, 2) to identify the strains of influenza virus, 3) to compare the major demographic and clinical characteristics between ILI patients having positive and negative tests for influenza virus. An ILI case was defined as having a fever of at least 38 degrees C (axillary), cough or sore throat. A total of 155,866 ILI cases were reported to the CDC from 4 sentinel sites in Cambodia from August 2006 to December 2008. Specimens were collected in 1.8%. Of these, 9.6% tested positive for influenza. Influenza was observed to occur mainly from August to December, with a clear seasonal peak in October, as shown in the data from 2008. A new case definition beginning in August 2008 resulted in a decrease in weekly RI reported cases (from an average of 1,474 cases to 54 cases) and the proportion of positive tests for influenza increased (5.3% vs 29.3%). Influenza and ILI are seasonal in Cambodia. A higher body temperature was used to define ILI, which improved the influenza positivity rates.

Human plague outbreak in two villages, Yunnan Province, China, 2005.

Plague is still a serious public health problem in Asia. On July 5, 2005, a suspected outbreak of human plague in two Chinese villages was reported to Yunnan Institute of Endemic Disease Control and Prevention (YIEDC). Active case finding, laboratory investigation, environmental inspection, and control measures were conducted by provincial and local health authorities. A suspected case was an individual who resided in one of the two villages and developed fever and painful swollen lymph nodes in the groin, axilla, and neck between June 26 and July 11, 2005. Confirmation was by indirect hemagglutination test (IHA) for plague F1 antibody. A confirmed animal plague case was an animal that tested positive for one of the following tests: IIA, reverse indirect hemagglutination, or bacterial culture. There were three confirmed and one suspected case of human plague. Of nine retrieved rats, three were confirmed cases. Most surveyed houses had poor sanitation, and there was a history of dead rats observed in the villages. After control measures were implemented, the rat density and flea index decreased to acceptable levels and no new cases occurred. The cause of this outbreak was likely due to rat die off in the villages, such that rat flea populations migrated to humans under environmentally favorable conditions. The outbreak was controlled after implementing environmental and educational control measures.

Autochthonous visceral leishmaniasis: a report of a second case in Thailand.

Visceral leishmaniasis (VL) is a rare disease in Thailand. Only one previous case has been reported in which transmission was likely autochthonous. We conducted an investigation of a case of VL, which included serological and symptom surveys of people who lived near the case in Nan Province and Bangkok, serological surveys of domestic animals in his home village and sand fly surveys in his home village and in Bangkok. No humans interviewed met our case definition for possible VL. One hundred thirty-one villagers were seronegative for Leishmania antibodies. We found three cows and one cat that had positive direct agglutination tests for Leishmania spp, but we were unable to confirm current infection by PCR. Sand fly surveys showed that most of the flies were of the Sergentomyia genus, which has not previously been reported as a competent vector in Thailand. Nonetheless, we conclude, based on the patient's lack of travel outside Thailand and the presence of seropositive domestic animals in his home village, that he was most likely infected by the bite of a sand fly in Thailand. We believe this is the second case of autochthonously transmitted VL in Thailand.

Environmental and travel factors related to leptospirosis in Thailand.

To identify potential environmental and travel factors related to leptospirosis, we conducted an unmatched case controlled study and household assessment of cases and controls in Nakhon Ratchasima province (north-eastern, Thailand) from August to December, 1998. Fifty-six cases and 145 controls were included in the study. Cases were hospitalized patients who had been diagnosed with leptospirosis and tested positive for anti-leptospiral IgM antibody using the Panbio ELISA (Panbio Inc, Brisbane, Australia). Controls were the neighbors of cases who had tested negative. Standardized questionnaires and household assessments were used to collect information on demographics, number of animals kept, evidence of rats in the home, presence of rat food inside the home, road characteristics, awareness of leptospirosis disease, environment, and travel history. Multivariant, unconditional logistic regression demonstrated that travel on potholed roads was independently associated with leptospirosis infection (OR 5.0; 95%CI 1.2-20.2) and traveling by car was a protective factor (OR 0.2; 95%CI 0.06-0.9).

Outbreaks of Shigella sonnei infections in Denmark and Australia linked to consumption of imported raw baby corn.

We investigated an outbreak of Shigella sonnei infections in Denmark and Australia associated with imported baby corn from one packing shed in Thailand. We reviewed nationwide surveillance and undertook case finding, food trace-back and microbiological investigation of human, food and environmental samples. A recall of baby corn and sugar snaps was based on descriptive epidemiological evidence. In Denmark, we undertook a retrospective cohort study in one workplace. In total, 215 cases were laboratory-confirmed in Denmark, and 12 in Australia. In a multivariable analysis, baby corn was the only independent risk factor. Antibiotic resistance and PFGE outbreak profiles in Denmark and Australia were indistinguishable, linking the outbreaks. Although we did not detect S. sonnei in baby corn, we isolated high levels of other enteric pathogens. We identified a packing shed in Thailand that supplied baby corn to Denmark and Australia, and uncovered unhygienic practices in the supply chain. This outbreak highlights the importance of international communication in linking outbreaks and pinpointing the source.