Jellyfish Envenomation Events in Selected Coastal Provinces of Thailand 1998-2008

Background: Lethal jellyfish envenomation has occurred sporadically in Thailand for years, but limited data exists describing the public health burden of envenomation, or the presence of the most dangerous types of jellyfish (Cubazoan,or box jellyfish) in Thailand.  We conducted an investigation to study morbidity and mortality of jellyfish envenomation, identify species and implement prevention measures. Methods: A descriptive study was conducted by medical records review in 2 coastal provinces. A case was defined as a jellyfish envenomation injury documented by a medical professional from 2003-2008. Events were analyzed by place, time, age, gender and severity. Jellyfish specimens were collected by local fishermen and speciated by marine biologists. Results: From 2003-2008, 54 cases occurred, including 1 death. Of cases, 49% were 21-40 years old; median age was 26 years. Thai to foreigner ratio was 2.6:1; male to female ratio was 1:1.2.  The most frequent sites of attack were leg (28.7%), forearm (15.1%), foot (12.3%) and hand (12.3%). Symptoms included burning pain (36.7%), pain (26.5%) and respiratory discomfort (18.4%). Signs included erythema (51.2%), burning (19.5%) and swelling (12.2%). Twenty-three percent required hospitalization. Number of events peaked in April for Trat and May for Krabi province. Of 12 jellyfish specimens collected from Trat, marine biologists identified all as Cubazoan (box jellyfish).  Conclusion: Jellyfish envenomation is a significant public health problem in the coastal provinces. Global warming could increase the scope of this problem.  Based upon this investigation, the Bureau of Epidemiology is developing public health jellyfish warnings for four coastal provinces. Vinegar, which denatures the cysts which contain venom, should be available in all beach areas.  Fishermen should wear long sleeves and gloves. 

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).