Malaysia Joins Thailand, Cambodia, and Vietnam in Disease That is Leading to Tourist Crisis: New Shocking Outbreaks You Need to Know Before Travelling in 2026!

As 2025 unfolds, several Southeast Asian countries face significant disease outbreaks, many of which could disrupt travel plans well into 2026. Countries like Cambodia, Malaysia, Thailand, and Vietnam have seen escalating cases of infectious diseases such as Avian Influenza, Dengue fever, Chikungunya, Zika virus, and Measles. For those planning to visit these nations, it is crucial to understand the risks associated with these outbreaks, how they spread, and the precautions necessary to stay safe during travel. Disease outbreaks in Southeast Asia often affect both locals and tourists, but understanding the nature of these diseases and following expert advice can help mitigate health risks. This article dives deep into the diseases affecting Southeast Asia in 2025, offering important insights for travellers to avoid the dangers they may pose in 2026.

Cambodia: Avian Influenza and the Threat to Travellers

Cambodia has become a focal point in the fight against Avian Influenza (also known as bird flu) as H5N1 continues to affect both poultry and humans. As of 2025, Cambodia has reported multiple human infections, with an alarming fatality rate of approximately 44%. This has caused significant concern, particularly in areas where humans come into close contact with poultry or contaminated environments. For instance, the latest WHO reports highlight over 11 human cases in 2025 alone, adding to the overall 27 cases since 2023. Human-to-human transmission of H5N1 is rare, but the disease poses a severe risk to anyone involved in poultry handling or farming. The disease is highly contagious among birds, and when humans are infected, it can result in severe respiratory issues and even death.

Travellers heading to Cambodia in 2026 should take special care when visiting areas where poultry farming is common. Avoiding live bird markets and direct contact with birds or poultry is crucial to reduce the risk of exposure to the virus. Despite the high mortality rate, the general population risk remains low, as the virus primarily spreads through direct contact with infected animals. Therefore, precautionary measures like wearing masks, practicing good hygiene, and avoiding poultry-related activities can significantly reduce the chances of contracting the virus.

Malaysia: The Ongoing Battle Against Dengue Fever

Malaysia is no stranger to disease outbreaks, and in 2025, it is grappling with an especially severe wave of Dengue fever. The country recorded approximately 122,423 cases in 2024, marking a 17% increase from the previous year. Dengue is a mosquito-borne viral infection spread by Aedes mosquitoes, and it continues to affect both locals and visitors in popular tourist destinations like Kuala Lumpur and Penang. The disease causes a variety of symptoms ranging from mild fever to severe hemorrhagic fever, and while it is rarely fatal, the healthcare burden from the growing number of cases is significant. According to local reports, the rainy season (from June to October) sees a rise in cases, making travel during these months riskier.

For travellers in 2026, the risks posed by Dengue will still be high, especially since the disease is endemic in the region. Visitors must take extra precautions to avoid mosquito bites, such as wearing long sleeves and long pants, using mosquito repellent containing DEET, and staying in air-conditioned accommodations or places with adequate mosquito netting. Additionally, it’s important to stay up-to-date with the latest travel health advisories and take note of areas with ongoing outbreaks.

Thailand: A Multiplicity of Mosquito-Borne Risks

Thailand continues to be affected by several mosquito-borne diseases in 2025, with outbreaks of Dengue, Chikungunya, and Zika virus presenting serious health threats. These diseases are spread by Aedes mosquitoes, which thrive in tropical climates and urban environments. Dengue fever remains the most concerning of these, with over 100,000 cases reported annually across Thailand. Chikungunya, while less common, causes severe joint pain and can result in long-term disabilities for those infected. Meanwhile, Zika virus poses a particular threat to pregnant women, as it can cause birth defects in babies.

In 2025, the Thai government has taken significant steps to curb the spread of these diseases, including increased mosquito control efforts and public awareness campaigns. However, travellers must remain vigilant. In 2026, the ongoing risks from mosquito-borne diseases in Thailand will be high, especially during the rainy season when mosquito populations spike. Preventive measures such as using mosquito repellent, sleeping under nets, and avoiding outdoor activities at dawn and dusk are highly recommended. Pregnant women or those planning to conceive should consider postponing travel to Thailand or seek medical advice before embarking on their journey.

Vietnam: Emerging Diseases and Health Risks

Vietnam, like other Southeast Asian nations, has had its fair share of outbreaks. While Dengue fever remains a significant threat, with tens of thousands of cases recorded annually, there are also growing concerns about other diseases in 2025. Measles outbreaks have been reported across Southeast Asia, with Vietnam being no exception. The resurgence of measles is largely attributed to insufficient vaccination coverage and the spread of the virus across urban and rural populations. In addition to Dengue, the Zika virus and Yellow Fever are risks for travellers, especially in regions with poor sanitation and inadequate mosquito control.

In 2025, Vietnam is also dealing with the African Swine Fever epidemic, which has significantly impacted the country’s pig farming industry and led to disruptions in food supply chains. This has raised concerns about food safety for both locals and visitors. However, it is important to note that African Swine Fever does not pose a direct risk to humans, although it could impact the availability of pork products.

As Vietnam moves into 2026, travellers must ensure they are up-to-date on their routine vaccinations, including measles and Dengue. Avoiding contact with mosquitoes and staying informed about local outbreaks is essential. Pregnant women, in particular, should avoid travelling to areas with active Zika virus outbreaks, as the disease can cause serious birth defects.

Preventive Measures and Travel Advice for Southeast Asia in 2026

As disease outbreaks continue to challenge the region, travellers to Southeast Asia in 2026 must stay vigilant and well-prepared. Here are several critical preventive measures that should be followed to ensure a safe journey:

1. Vaccinations: Ensure you are up-to-date with routine vaccinations, including measles, influenza, and Hepatitis A and B. Depending on the countries you plan to visit, additional vaccines for Dengue, Typhoid, and Japanese Encephalitis may be recommended.
2. Mosquito Prevention: Since most of the diseases affecting Southeast Asia are mosquito-borne, it is crucial to take preventive measures. This includes using mosquito repellents, wearing long-sleeved clothing, and staying in air-conditioned hotels or rooms with mosquito nets.
3. Avoid High-Risk Areas: If you are visiting countries with known outbreaks of diseases like Avian Influenza or Zika, avoid live bird markets, poultry farms, and areas with active mosquito-borne outbreaks.
4. Stay Informed: Regularly check travel advisories from the World Health Organization (WHO) and local health authorities for updates on disease outbreaks in the region.
5. Food and Water Safety: In countries with disease outbreaks and uncertain food safety, avoid consuming unboiled water, raw food, and undercooked meats to reduce the risk of foodborne illnesses.

Conclusion

The year 2025 has seen a range of disease outbreaks across Southeast Asia, and many of these outbreaks are likely to continue influencing travel plans in 2026. Whether it’s Avian Influenza in Cambodia, Dengue fever in Malaysia, or the ongoing Zika and Chikungunya outbreaks in Thailand, travellers need to be prepared and aware of the risks they face when visiting these countries. By following health guidelines, taking appropriate precautions, and staying updated on local health advisories, travellers can minimize their risk and enjoy their trips to this vibrant region. Safety comes first, and with the right knowledge, any traveller can navigate these challenging times and ensure a safe, enjoyable experience in Southeast Asia.