No Thais on hantavirus cruise ship, Thailand studies listing it as a “dangerous communicable disease”

Thailand’s National Communicable Disease Committee met on Friday to consider how the country should respond to the hantavirus situation linked to an overseas cruise ship operating in the South Atlantic route.

After the meeting, Public Health Minister Pattana Promphat said the committee had instructed the Department of Disease Control (DDC) to coordinate with relevant experts to study whether hantavirus infection should be designated a “dangerous communicable disease” under the Communicable Diseases Act, B.E. 2558 (2015).

He said the DDC has also been tasked with preparing a risk assessment, technical recommendations, and readiness plans covering surveillance systems, laboratory capacity, emergency response guidelines, and risk communication for the public and relevant agencies. The aim is to ensure disease surveillance, prevention and control measures can be applied appropriately under the law, in line with the risk level and in step with developments.

The committee noted that hantavirus is considered a high-severity emerging/re-emerging zoonotic disease, associated with serious illness including pneumonia, respiratory failure and acute kidney failure, with an estimated case fatality rate of around 30-40%. It added that person-to-person transmission has been reported in some strains, the disease is linked to international travel, and there is no specific treatment and no widely used vaccine globally.

The meeting said Thailand is already implementing the following measures:

• International points of entry: International communicable disease control checkpoints have tightened surveillance of travellers from areas with reported cases, coordinating with airlines, ports and relevant agencies, while closely monitoring overseas developments.
• Domestic surveillance: Public health authorities have issued alerts to healthcare facilities nationwide to increase screening and investigations, focusing on people with a history of rodent exposure or travel from risk areas.
• Laboratory surveillance: Thailand has capacity to support hantavirus diagnostic testing.
• Risk communication: Authorities are continuing to provide factual information to the public on an ongoing basis.

Pattana said Thailand has not detected domestic outbreaks, although research has found rodent reservoirs carrying the virus. He stressed the disease does not spread easily in the way COVID-19 or influenza does, and advised people to protect themselves from contact with rodents and contaminated materials. He added that the risk to the general public is assessed as low, but the public health system must remain on alert.

No Thai nationals on the cruise ship

Dr Montien Kanasawadse, director-general of the DDC, said hantavirus is a zoonotic disease, with rodents—such as rats—acting as the main reservoirs.

He said transmission occurs through exposure to rodent urine, faeces and saliva, including particles that become airborne, or through contact with infected secretions that enter the body via skin wounds or mucous membranes such as the eyes, nose and mouth. In general, it does not spread from person to person, except in rare strains and typically only after prolonged close contact. The incubation period is 1-8 weeks after exposure.

He said symptoms fall into two main groups:

1. Haemorrhagic Fever with Renal Syndrome (HFRS)
   Found in Europe and Asia, and linked to kidney failure and haemorrhagic symptoms. Patients may have fever, severe headache, back pain, abdominal pain and nausea, and may develop low blood pressure, bleeding and acute kidney failure. The case fatality rate is 1-15%.
2. Hantavirus Pulmonary Syndrome (HPS)
   Found in the Americas and linked to severe lung disease. Initial symptoms include fever, fatigue and muscle pain. After about 4-10 days, patients may develop coughing, shortness of breath and chest tightness. The case fatality rate is 20-40%, and may reach 50%.

Dr Montien also confirmed that there were no Thai nationals on the cruise ship.

Global and Thailand situation

The DDC provided the following situation summary:

• United States (1993-2023): 890 cumulative cases; 35% case fatality rate
• Americas (2025): 229 cumulative cases; 59 deaths; 25.7% case fatality rate
• China: 5,000-10,000 cases per year; 1-2% case fatality rate
• South Korea: 300-600 cases per year; 1-2% case fatality rate
• Europe (2023): 1,855 cases reported
• Taiwan (2026): 2 cases; 1 death
• Thailand:
  • 1985: reports of patients with antibodies to a Hanta-like virus in Kanchanaburi and Bangkok
  • 1999-2000: a study of 115 patients with fever of unknown cause at Siriraj Hospital’s Faculty of Medicine found one case in Bangkok with confirmed diagnosis of Hanta-like virus infection