Reports of dengue fever, a mosquito-borne infection, have more than doubled in UK travellers from 166 reported cases in 2009 to 406 in 2010, according to new figures from the Health Protection Agency (HPA).

Dengue fever does not occur in the UK and the highest proportion of cases were associated with travel to India - 84 cases (21 per cent) and Thailand - 61 cases (15 per cent).

This increase in dengue reports is coupled with a 34 percent rise in the number of reported cases of chikungunya, another mosquito borne infection, which rose from 59 cases in 2009 to 79 in 2010. Nearly 50 per cent of these cases were associated with travel to India.

Both diseases are endemic in Asia and Africa and dengue is also common in many other parts of the world including South America, Central America and the Caribbean and the Western Pacific.

Neither disease is spread from person to person but only through the bite of an infected mosquito. Symptoms for both dengue and chikungunya include sudden onset of a flu-like illness with fever, muscle pain, headache and a rash. Chikungunya can cause joint pains that can persist for several months but serious complications from dengue and chikungunya are not common in UK travellers. There is no vaccine or drug to prevent or treat either disease and supportive care is based on management of symptoms.

Dr Jane Jones, head of the HPA's travel and migrant health section, said: "These figures demonstrate that the importance of taking precautions to avoid mosquito bites extends to protecting against other infections, not just malaria. Unlike for malaria where drugs can be taken to prevent infection, there is no such option available to prevent either dengue or chikungunya.

"The mosquitoes that spread dengue and chikungunya bite in the day, compared with those that spread malaria which are mainly active from dusk to dawn. To minimise the risk of being bitten it is advisable to wear appropriate clothing to cover up - such as long sleeve tops and trousers - and use insect repellents. In areas where both malaria and these other mosquito borne illnesses co-exist, protection against mosquito bites should be used around the clock, including the use of mosquito nets at night.

"Anyone travelling to a tropical destination should take appropriate advice from a health professional or a travel health clinic at least 6-8 weeks before they travel to ensure they are aware of the risks and how they can best protect themselves from illness."

Notes

1. There is no active surveillance of either dengue fever or chikungunya in the UK so there may be more cases than reported by the HPA. The data presented in this report is derived from laboratory tests either requested by referring clinicians or undertaken at the laboratory's suggestion on the basis of symptoms and travel history in cases of imported fever. The information presented in the report, particularly around travel destinations, will help public health professionals offer preventative advice to prospective travellers.

Source:
Health Protection Agency