Source: WHO Disease Outbreak News – 29 May 2025

In a rare and concerning development, Thailand has confirmed five human cases of cutaneous anthrax, including one fatality, marking the country's first anthrax-related death since 1994. The cases, reported in Mukdahan Province near the border with the Lao People's Democratic Republic, were linked to the slaughtering and handling of infected cattle, according to the World Health Organization (WHO).

The outbreak began in early May 2025 when Thai health authorities notified WHO of four confirmed cases, all with direct exposure to cattle carcasses. One individual succumbed to the infection, while the remaining three recovered following intensive treatment with levofloxacin and doxycycline. A fifth case was reported shortly after, also linked to cattle slaughter.

Anthrax, caused by Bacillus anthracis, is a zoonotic bacterial disease that primarily affects grazing animals. It can spread to humans through skin contact, ingestion, inhalation, or injection of spores. In this outbreak, all cases were of the cutaneous form, the most common type, characterized by ulcerating skin lesions and significant local swelling.

Public health authorities in Thailand launched a rapid response, implementing animal quarantines, livestock vaccination campaigns, and extensive community outreach. A total of 636 people were identified as at risk, with 28 individuals directly involved in slaughtering activities. All high-risk individuals were given post-exposure antibiotic prophylaxis.

According to WHO, the diagnosis of anthrax in this outbreak was confirmed through Real-Time PCR (RT-PCR) testing of blood and wound samples at Thailand’s Department of Medical Sciences and Bamrasnaradura Institute. This highlights the critical role of molecular diagnostics in confirming cases quickly and accurately—especially during zoonotic outbreaks where clinical symptoms can overlap with other skin infections or febrile illnesses.

PCR testing detects the genetic material (DNA) of B. anthracis directly from patient samples, even when bacterial culture might take longer or be inconclusive. In field outbreaks like this one—where speed, specificity, and biosafety matter—PCR has become the gold standard for anthrax confirmation.

While anthrax outbreaks are rare in humans, especially in Southeast Asia, the Thailand case is a reminder of how occupational exposure and food handling practices can lead to dangerous infections. Molecular detection systems like Real-Time PCR allow laboratories and public health institutions to:

• Detect Bacillus anthracis within hours, not days
• Avoid cross-reactivity with other skin-infecting bacteria
• Confirm cutaneous, inhalation, or gastrointestinal anthrax based on sample source
• Enable surveillance of environmental samples, such as meat, knives, soil, and water sources, as was done in this case

Sacace Biotechnologies: PCR Solutions for Zoonotic Disease Surveillance To meet such diagnostic needs, Sacace Biotechnologies provides validated Real-Time PCR kits and reagents designed for high-consequence bacterial pathogens, including:

• Bacillus anthracis (available as part of custom or research-use-only pathogen panels)
• Salmonella spp., Listeria monocytogenes, Brucella, and other zoonoses
• Compatible with a full reagent workflow: DNA extraction kits, master mixes, positive/negative controls
• CE-IVD certified platforms for clinical labs and RUO kits for veterinary and food safety applications

Sacace’s modular PCR approach allows for detection of environmental and clinical samples, as seen in the Thailand outbreak—where positive B. anthracis DNA was found not only in patient wounds but also on cutting tools and meat remnants.

As zoonotic diseases continue to resurface—often in unpredictable ways—PCR remains a critical line of defense in outbreak confirmation, containment, and risk mitigation. The Thailand anthrax case reminds us that even rare pathogens can pose major public health risks when early detection is delayed.

By combining WHO-recommended outbreak protocols with field-ready PCR systems, health authorities and diagnostic labs can respond rapidly and accurately—protecting lives and curbing further transmission.