Tropical illnesses, including malaria, leprosy, Mpox, giardiasis, West Nile fever, typhoid, and dengue fever, are on the rise in Ireland, according to a report from the Health Protection Surveillance Centre. This increase follows a drop during the COVID-19 pandemic, with the years since lockdowns lifted seeing a resurgence in cases.
Dr. Graham Fry of the Tropical Medical Bureau attributes the surge primarily to increased international travel by Irish citizens for holidays, business, and humanitarian work. "The Irish are travelling for the usual reasons – one is the holiday trip, another is the business trip. The other is the non-government organisation type trip – in other words, they’re going off to work in Congo or wherever it is that there’s a disaster," Fry explained.
Shifting Travel Patterns and Disease Vectors
As air travel has become more accessible, holiday destinations have become more adventurous, increasing the risk of exposure to tropical diseases. Malaria cases, for instance, are reportedly rising in Europe, with 71 cases recorded in Ireland in 2025. While global warming plays a role, Dr. Fry emphasizes that travel is the dominant factor. Mosquitoes, known vectors for diseases like malaria, dengue fever, Zika, and West Nile virus, are migrating further north into Europe. Although Ireland has mosquitoes, their short lifespan and the climate prevent them from sustaining transmission cycles for diseases like malaria.
However, infected mosquitoes can travel via aircraft. Dr. Fry cited an instance where four baggage handlers in Frankfurt Airport contracted malaria without having traveled, suggesting an infected mosquito likely arrived in cargo and subsequently bit them.
Specific Illnesses and Travel Concerns
Diseases like Zika virus, while not typically causing problems for adults, can lead to microcephaly in unborn children if a pregnant individual is infected. Chikungunya, another mosquito-borne illness, causes high fever, severe joint pain, and muscle pain. Dengue fever, usually mild, can be life-threatening in rare cases. Both chikungunya and dengue fever are now prevalent in parts of southern Europe due to the spread of the Aedes aegypti mosquito, also known as the tiger mosquito.
Malaria notifications in Ireland have predominantly originated from sub-Saharan Africa. Leprosy, though rare, is also a concern for travelers presenting with undiagnosed nerve problems. Mpox, which spreads through skin-to-skin contact, remains present in Ireland.
Giardiasis, a parasitic infection often mistaken for Irritable Bowel Syndrome (IBS), can cause digestive issues and is contracted by swallowing untreated water or consuming contaminated food. Outbreaks have been reported in England, and Dr. Fry stresses the importance of testing for travelers with IBS-like symptoms. Other parasites, such as cryptosporidium and cyclospora, are also a concern in various regions, including the United States.
Prevention and Awareness
Dr. Fry advises travelers to exercise common sense and good hygiene to avoid illness. While vaccinations are beneficial, they are not a complete solution. Avoiding certain foods, such as undercooked shellfish, and being cautious in environments like petting zoos are also recommended. He notes that many countries lack the waste treatment infrastructure present in Ireland, increasing risks associated with food and water consumption. "I just think for the Irish people to travel, they really need to bring common sense with them," Fry stated. "Vaccines are great but they’re not perfect. You still have to have your personal hygiene considerations."