WHO South-East Asia Epi Bulletin On Thailand's Anthrax Outbreak

 

#18,471

Two days ago, in Cambodian MOH Guidance On Thailand's Anthrax Outbreak, we looked at reports of an anthrax outbreak in Cambodia where the `official' toll was reportedly 3 infected, with 1 death - but with nearly 100 others were `still at risk.

Overnight the WHO published their weekly South-East Asia Region Epidemiological Bulletin, which raises the number of confirmed cases to 4 (1 fatal), and provided additional information on the outbreak and ongoing response.

This week's Epi report also includes updates on the Myanmar Earthquake, Mpox, Influenza, Dengue, and COVID. 

Situation overview as of 06 May 2025  

• On 01 May 2025, the Thailand Ministry of Public Health issued a press release regarding a fatal anthrax case in  Don Tan district, Mukdahan Province, near the border with Laos. The case was a 53-year-old diabetic male construction worker and developed sores on his right hand in late April. He did not consult healthcare services until the wound deteriorated and passed away.

• As of 06 May 2025, Mukdahan Provincial Authorities have reported a total of four confirmed human cases of anthrax including the fatal case. All four cases were involved in slaughtering. Additionally, there are two suspected cases awaiting laboratory results.

• Initial investigations suggested that people were likely exposed to the bacteria through slaughtering of cattle at a merit-making event and the distribution of the slaughtered cattle meat to the villagers. Of note, on 28 April, a cow died in the barn from unknown causes. Investigations are ongoing.

• According to the Division of Epidemiology, the last reported anthrax cases in Thailand occurred in 2000 (15 cases in Phichit and Phitsanulok, with no deaths) and in 2017 (2 cases in Mae Sot from handling a goat carcass from Myanmar).

Thailand Ministry of Public Health Response

• According to the Thailand Ministry of Public Health, a total of 638 individuals are considered having had potential exposure and at risk of developing the disease, including 36 butchers, 472 individuals who ate undercooked beef, and 130 individuals who had contact with the butchers. Of these, 98 remain under monitoring until 10 May 2025. 

• Authorities have implemented preventive measures, including providing antibiotic treatment for exposed individuals. Authorities are also actively sharing information with villagers, including through public awareness campaigns across various media platforms.

 Thailand Department of Livestock Development Response

• Authorities have implemented preventive measures, including providing antibiotic treatment for exposed individuals. Authorities are also actively sharing information with villagers, including through public awareness campaigns across various media platforms.

Thailand Department of Livestock Development Response

• A total of 1 222 cattle within a 5-km radius have been vaccinated against anthrax as part of livestock control measures to prevent disease spread and ensure herd health.

• A total of 123 cattle herds, suspected of being the source of human infections, were quarantined. The animals received penicillin for seven days and will be monitored for at least 20 days.

• Disinfection has been carried out in all at-risk areas. Animal, soil and water samples have been collected for testing, with results pending.

• Officials have also banned cattle slaughter during ceremonies and are closely monitoring practices in nearby areas. Cattle movement is being strictly controlled through four designated checkpoints to prevent the spread of infection and ensure effective containment measures.

1 Thailand Ministry of Public Health, Press release – 1 May 2025
2 Thailand Ministry of Public Health, Press release – 2 May 2025
3 Mukdahan Provincial Public Relations Office – Press release - 5 May 2025
4 Thailand Ministry of Public Health, Press release – 7 May 2025

These days anthrax is most commonly reported in Asia and Africa, but anthrax spores are naturally occurring, and the United States and Europe occaisionally report sporadic cases. 

While infected animals are the most common vector (see 2019's Texas DSHS Cautions Residents On Avoiding Sick or Dead Wildlife), we've seen other modes of transmission:

• In 2018, we saw a report from San Diego: 6 Cases Of Wound Botulism Among Injection Drug Users, which sadly happens more often than you'd think.

• In 2014 Eurosurveillance released a report ( Injectional anthrax - new presentation of an old disease) describing more than 70 cases (37% fatal) of anthrax infection via contaminated drugs.

• In 2014 the EID Journal reported on an inhalational anthrax infection in a Florida resident who was on a motor trip across the western states (see Investigation of Inhalation Anthrax Case, United States). The patient had no known contact with dead or infected animals.

• Between 2007 and 2009 the U.S. saw several reports of anthrax exposure either through drum making (see MMWR Cutaneous Anthrax Associated with Drum Making Using Goat Hides from West Africa --- Connecticut, 2007) or drumming with an animal skin (see MMWR  Gastrointestinal Anthrax after an Animal-Hide Drumming Event --- New Hampshire and Massachusetts, 2009).

• In Europe, in 2006 and 2008, two fatal cases were linked to drums as well (see Drumming-associated anthrax incidents: exposures to low levels of indoor environmental contamination).

While exceedingly rare in the United States, the CDC maintains an Anthrax webpage:

Clinical Overview of Anthrax

Key points

• Anthrax can cause severe illness and death if not treated quickly after symptoms develop.
• Prophylactic antibiotics should be administered immediately to patients who might have been exposed to anthrax.
• Anthrax exposure is rare in the U.S., but some activities can put people at greater exposure risk.
• Anthrax is not contagious.

Overview

Anthrax is a serious infectious disease caused by Bacillus anthracis bacteria or other Bacillus-expressing anthrax toxin. It occurs naturally in soil and commonly affects domestic and wild animals around the world. People can also contract anthrax if they are exposed during a bioterrorism event.

Anthrax is not contagious, and it can cause severe illness in both people and animals. It is very uncommon for people in the United States to be exposed to and become ill with anthrax.

People can contract anthrax if they:

• Come in contact or work with infected animals or contaminated animal products (including hides)
• Consume food or water contaminated by B. anthracis
• Are exposed to anthrax in a laboratory that handles anthrax
• Are exposed during a bioterrorism attack

Certain activities or occupations can also increase a person's chances of exposure and infection to B. anthracis.

         (Continue . . . )