Non-endemic cases of lymphatic filariasis

Several cases of lymphatic filariasis (LF) have been reported in non-endemic countries due to travellers, military personnel and expatriates spending time in and returning from endemic areas, as well as immigrants coming from these regions. These cases are reviewed to assess the scale and context of non-endemic presentations and to consider the biological factors underlying their relative paucity.

Cases reported in the English, French, Spanish and Portuguese literature during the last 30 years were examined through a search of the PubMed, ProMED-mail and TropNet resources.

The literature research revealed 11 cases of lymphatic filariasis being reported in non-endemic areas. The extent of further infections in recent migrants to non-endemic countries was also revealed through the published literature.

The life-cycle requirements of Wuchereria and Brugia species limit the extent of transmission of LF outside of tropical regions. However, until elimination, programmes are successful in managing the disease, there remains a possibility of low rates of infection being reported in non-endemic areas, and increased international travel can only contribute to this phenomenon. Physicians need to be aware of the signs and symptoms of lymphatic filariasis, and infection should be considered in the differential diagnosis of people with a relevant travel history.