Thailand informs World Health Organization about rare anthrax outbreak

Thailand has reported its first human anthrax-related death in 30 years.

In May, Thailand informed the World Health Organization (WHO) of four cases of cutaneous anthrax. One person died as a result of disease complications, while the other three were hospitalized. It is the first reported anthrax-related death in Thailand since 1994.

All of the patients had direct contact with cattle suspected to be infected with anthrax.

In late May, an additional patient was associated with the slaughtering of cattle. Disease control measures, including animal quarantine, a vaccination campaign targeting cattle within a 5 kilometer radius, public awareness, and enhanced surveillance, were implemented in the affected area.

Anthrax is a life-threatening disease caused by the spore-forming bacterium Bacillus anthracis. Humans can get it from infected animals or contaminated animal products.

Cutaneous anthrax is the most common form. Infection follows direct contact with infected animals, carcasses, animal tissues, parts or products. Symptoms include an itchy, painless papule, which evolves into a larger vesicle or blister and progresses into a necrotic ulcer with a black, depressed central crust. Gastrointestinal anthrax follows ingestion of contaminated, undercooked meat and causes nausea, vomiting, abdominal pain, and sometimes diarrhea.

Incident response
The age range of the confirmed patients is 36 to 58 years old. Three are men and one is a woman. Patients were identified in Mukdahan Province, near the border with Lao People’s Democratic Republic.

All of the patients are epidemiologically linked to the slaughtering of cows. The first cow was slaughtered in mid-April and its meat was distributed among villagers. A second cow was killed in late April. Exposure to meat or contact during the slaughtering process of these animals is believed to be the source of infection for all confirmed patients. 

Screening of at-risk individuals was conducted across three villages, identifying two suspected cases who had diarrhea and fever. However, samples were negative for Bacillus anthracis. A total of 636 people were identified as at risk and monitored up to May 10. Among them, 28 people were directly involved in the slaughter of cattle, while others consumed raw beef.

Anthrax is endemic in several countries across the South-East Asia region. In Thailand, however, human infections are very rare.

The Department of Disease Control, Ministry of Public Health and the Department of Livestock Development, Ministry of Agriculture and Cooperatives, implemented measures to control potential disease spread including environmental cleaning and disinfection in 23 high-risk households, identified based on consumption of potentially contaminated meat. 

Farmers were told to report any sick or dead animals to officials and not to consume raw meat. Samples were collected from knives and cutting boards used by the first patient, as well as from soil at the slaughter site and beef from the slaughtered cows. All of them tested positive for Bacillus anthracis.

Earlier this year, one confirmed and 16 suspected anthrax cases were reported in North Kivu Province in the Democratic Republic of Congo. Seven suspected cases were also recorded in the western Kabale district of Uganda.

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