Malaria caused by bites from infected mosquitoes carried on airplanes, luggage or even in the mail is increasing in Europe.
These cases of “suitcase” malaria, also known as Odyssey malaria, have been reported sporadically for about five decades.
But a new study has found an increase over the past five years.
Malaria was eradicated in Western Europe in the 1970s and since then almost all cases have occurred in travelers returning from countries where the virus is still widespread.
However, some cases of malaria infections that are not contracted during travel are sporadically reported each year.
Cases of ‘suitcase’ malaria, also known as odyssey malaria, have been reported among travelers returning from countries where malaria is established
Malaria was eradicated in Western Europe in the 1970s and since then most cases have been reported among travelers returning from countries where malaria is established.
These include introduced infections, which are transmitted by a local mosquito after it bites a returning infected traveler who carries the disease in his or her blood.
They also include induced cases, which are related to other means of transmission, such as mother-to-child transmission and Odyssey malaria.
A systematic review analyzed Odyssey malaria data collected in Europe from 1969 to January 2024.
Of the 145 cases described in nine Western European countries, including the United Kingdom, 105 were classified as airport malaria, 32 as luggage malaria and eight as any type of malaria.
Most cases were reported in France, Belgium and Germany, and half among patients who lived near or worked at an international airport.
Reports of malaria cases in airports and luggage were found to be increasing, with a third of cases reported in the last five years, even as air traffic decreased during the Covid pandemic.
The researchers also found that people infected with malaria had an average age of 37.9 years and were more likely to be men than women.
In cases with known outcome, 124 patients recovered and nine died. The patients who died were on average older, with a mean age of 57.2 years.
Similar trends were also observed in another study that analyzed surveillance and case investigation data in France of locally acquired malaria between 1995 and 2022.
The researchers found a total of 117 locally acquired malaria cases, but and more cases of Odyssey have been reported since 2011.
Of the 117 cases, 51 were categorized as Odyssey.
Most cases occurred among men with a mean age of 34.5 years.
Half of the malaria patients were born in an African country where the disease is common and the other half were born in France.
More than half of the cases were reported in the Île-de-France region.
More than 100 people were hospitalized and seven patients died. Among patients with locally acquired malaria, severe cases and death were more common than in imported cases.
Malaria is one of the leading causes of death in the world, claiming the life of a child every two minutes, according to the World Health Organization (WHO).
To address Odyssey’s increasing risk of malaria, analysis researchers in France advised strictly applying “disinfestation,” the destruction of insects, on airplanes.
They also recommended that doctors consider the possibility of locally acquired malaria early in patients with unexplained fever, even if there is no travel history.
The authors of the larger systematic review highlighted the need for more structured surveillance of malaria cases in Europe, including a standardized case definition and preventive measures.
Of the 6,131 malaria cases reported in the EU/EEA in 2022, 99 percent were travel-related. This figure included malaria cases from Odyssey.
Malaria is generally found in tropical regions including large areas of Africa and Asia, Central and South America, and parts of the Middle East.
It is one of the leading causes of death in the world, claiming the life of a child every two minutes, according to the World Health Organization.
Most of these deaths occur in Africa, where 250,000 young people die each year from the disease.
In 2023, 2,004 cases of malaria will be confirmed in England, Wales and Northern Ireland after travel abroad, compared to 1,369 in 2022, according to government data.
The increase is believed to have been caused by travel and the resurgence of malaria in many countries.
High fever, sweating, chills and headaches, as well as stomach pain, loss of appetite and muscle pain are telltale signs of the disease.
It can also make children very tired and sleepy and cause those infected to have yellow skin, a sore throat and difficulty breathing, according to the NHS.
The NHS suggests that everyone traveling to an area where malaria is found get advice from a GP, nurse, pharmacist or travel clinic before travelling.