Abstract and Introduction
Abstract
Tungiasis is caused by infestation with the sand flea (Tunga penetrans). This ectoparasitosis is endemic in economically depressed communities in South American and African countries. Tungiasis is usually considered an entomologic nuisance and does not receive much attention from healthcare professionals. During a study on tungiasis-related disease in an economically depressed area in Fortaleza, northeast Brazil, we identified 16 persons infested with an extremely high number of parasites. These patients had >50 lesions each and showed signs of intense acute and chronic inflammation. Superinfection of the lesions had led to pustule formation, suppuration, and ulceration. Debilitating sequelae, such as loss of nails and difficulty in walking, were constant. In economically depressed urban neighborhoods characterized by a high transmission potential, poor housing conditions, social neglect, and inadequate healthcare behavior, tungiasis may develop into severe disease.
Introduction
Tungiasis is a common, but neglected, health problem in economically depressed communities in South American and sub-Saharan African countries. This ectoparasitosis is caused by the sand flea (Tunga penetrans, Siphonaptera: Tungidae, Tunginae), also called the jigger flea. The female jigger flea penetrates into the skin of its host, undergoes a peculiar hypertrophy, expels several hundred eggs for a period of ≤3 weeks, and eventually dies. The shriveled carcass is then sloughed from the epidermis by host repair mechanisms. Within 10 days, the flea increases its volume by a factor of approximately 2,000, finally reaching the size of a pea. Through its hindquarters, which serve for breathing, defecating, and expulsing eggs, the flea remains in contact with the air, leaving a sore (240-500 mm) in the skin; the sore is an entry point for pathogenic microorganisms. The preferred localization for jiggers is the periungual region of the toes, but lesions may occur on any part of the body.
Tungiasis, a zoonosis, affects a broad range of domestic and peridomestic animals, such as dogs, cats, pigs, and rats. Where humans live in close contact with these animals and where environmental factors and human behavior favor exposure, the risk for infection is high
Numerous case reports detail the clinical aspects of tungiasis. However, they almost all exclusively describe travelers who have returned from the tropics with a mild disease. Having reviewed 14 cases of tungiasis imported to the United States, Sanushi reported that the patients showed only one or two lesions and, that except for itching and local pain, no clinical pathology was observed. In contrast, older observations show that indigenous populations and recent immigrants, as well as deployed military personnel, frequently suffered from severe disease, characterized by deep ulcerations, tissue necrosis leading to denudation of bones, and auto-amputation of digits, resulting in physical disability, such as being unable to work and walk. Tungiasis has also been associated with lethal tetanus in nonvaccinated persons. In a study in São Paulo State, Brazil, tungiasis was identified as the place of entry in 10% of tetanus cases.
We present the clinical findings as well as the demographic and environmental characteristics of 16 persons with severe tungiasis who were identified during a prospective study on Tunga penetrans-associated disease at a Primary Health Care Center (PHCC) in a economically depressed neighborhood (favela) in Fortaleza, northeast Brazil. The results indicate that in resource-poor populations important disease may frequently occur and seems to be related to a combination of intense transmission, economic deprivation, social neglect, and inadequate healthcare behavior.