TRAVELLERS are facing a "significant and growing" public health threat from a type of parasitic worm found in Africa, South America and the Middle East.

Research has shown that a fifth of Scots returning from regions where the parasitic disease, shistosomiasis, is endemic had picked up the infection.

The study, published in the Journal of Public Health, revealed that 1623 travellers returning to Scotland between 2001 and 2015 tested positive for antibodies to Schistosoma - a type of flatworm which burrows through the skin and lay eggs around the bowel and bladder. A total of 8163 people had been tested after travelling to areas where the disease is widespread.

The majority of Scottish travellers affected had travelled to Malawi or Uganda, but cases were also detected among people returning from the Middle East, Asia, Central and South America, Australia and New Zealand, as well as Lithuania, a region deemed to be free from the disease. Around half of the travellers were aged 30 years or below.

The results were based on blood samples taken by researchers from Glasgow Royal Infirmary and Health Protection Scotland, led by Dr Claire Alexander of the Scottish Parasite Diagnostic and Reference Laboratory. The authors said that since those infected often showed no symptoms, the actual prevalence among returning travellers is likely to be higher.

They write: "This report provides supporting evidence to highlight imported schistosomiasis as being a significant public health concern in Scotland particularly as the burden of disease is

likely to be underestimated.

"Requests for laboratory testing are greater than that for any other parasitic disease in Scotland. Although travel clinics offering pre-travel advice have contributed to the increase in numbers of travellers being tested, the true number of imported cases is likely to be greatly underestimated given that diagnosis often relies on patient self-referral."

"Around half of travellers tested were aged thirty or below and it is likely that the numbers of travellers, particularly schools and university groups volunteering for work schemes, will

continue to increase.

"This is due to strong connections between Scotland and Africa which exist due to the Scotland–Malawi partnership and the Malawi Development Programme. Uganda partnerships have also been established since the year 2000."

Travellers can become infected with the microscopic worms while swimming in freshwater lakes and rivers and by showering in untreated water in many countries with poor sanitation.

However, the condition has been treated effectively with the drug Praziquantel. More serious complications, which include bladder cancer, are more common in people who live in affected countries.

The researchers call for greater awareness of testing.

They write: As the majority of imported cases are asymptomatic initially, serological testing is key to diagnosing this disease to ensure treatment is administered that will prevent potential long-term

issues.

"It is essential to raise awareness to promote testing through educating the public and healthcare professionals."