Tungiasis in Haiti: a case series of 383 patients

Clinical and epidemiological survey of tungiasis in Madagascar

BACKGROUND

Tungiasis is a dermal parasitic infection, classified as a neglected tropical disease. Madagascar is one of endemic countries which have been committed for decades to control the tungiasis as a public health issue. Despite this medical importance, little is known about the prevalence and epidemiology of the disease in this country.

METHODS

A descriptive cross-sectional survey was performed in two endemic foci of Antananarivo and Toamasina.

RESULTS

In total, 2971 suspected individuals were surveyed. Of them, 643 individuals were excluded due to absence or refusing clinical examinations. Therefore, 2328 individuals with aforementioned criteria were clinically examined, 320 cases (13.7%) were found infected by Tunga penetrans. Of these 320 infected cases, 241 individuals came from rural regions against 79 from urban areas. The sex ratio of infected cases was 1.15 with an age average of 34.7 years old. Most of them were illiterate (185/320, 57.8%) with no habit of feet washing (210/320, 65.6%). The majority (198/320, 61.9%) inhabited in the houses constructed by falafa providing a suitable breeding location for Tunga ectoparasites. Based on clinical examination, most of the patients (298/320, 93.1%) had the lesions on their toes followed by those possessed the lesions on the plantar (140/320, 43.7%). The lesion stages of IV and V were observed in 49.1% (157/320) of visited patients which were more common in rural regions (86%) than in urban areas (14%). For treatment, removing the fleas using needle (122/320, 38.1%), followed by the application of petroleum (100/320, 31.2%) were among the most traditional remedies used by our patients.

CONCLUSION

This investigation highlights a high burden of tungiasis in studied endemic foci in particular in rural regions. These results can be helpful in control management strategies against this parasitosis in Madagascar.

Current status of the knowledge on the epidemiology of tungiasis in the Americas

Objectives.

To present the state-of-the-knowledge on the epidemiology of tungiasis in the Region of the Americas.

Methods.

A search of publications on the epidemiology of tungiasis in the Americas was performed in PubMed and LILACS databases from January 2007 to June 2021. In addition, a manual literature search on articles on the epidemiology of tungiasis was performed.

Results.

A total of 83 articles were analyzed which contained relevant information on tungiasis cases and their geographical distribution, prevalence and risk factors, life cycle, sites where transmission takes place, and zoonotic aspects. The on-host and off-host life cycles have been researched in detail. In certain contexts, the whole life cycle is completed indoors enabling transmission around the whole year. Cases were reported from 10 countries; 71% of them were from Brazil. In the general population, the prevalence varied between 1.0% and 82.6% according to the settings. Age-specific prevalence indicated that children and the elderly bear the highest disease burden. Risk factor studies indicate that tungiasis is associated with severe poverty.

Conclusions.

In the Americas, there are important gaps in information and knowledge of tungiasis. Understanding the burden, epidemiology, distribution, magnitude, related risk factors, and reservoirs, among others, is needed to develop and implement integrated control measures tailored to the context and patterns of transmission in the affected communities.

Distribution of tungiasis in latin America: Identification of areas for potential disease transmission using an ecological niche model

Background

Tungiasis is a neglected tropical disease (NTD) found in Sub-Saharan Africa and Latin America. Despite the high frequency in marginalized populations, little information is available on the geography and estimates of the population at risk in endemic regions. Here we used a geostatistical model to map the potential geographic distribution of areas suitable for tungiasis transmission in Latin America and estimated the at-risk population.

Methods

We developed an ecological niche model (ENM) using tungiasis occurrence records and remotely sensed environmental and socioeconomic data. The potential geographic distribution was then compared to the current population distribution of the region to derive the total population living in urban and rural areas.

Findings

We identified a total of 138 records of occurrences of tungiasis in Latin America, ranging from Mexico to Argentina; 27 reports were not included in the modeling, due to missing detailed geographic information. The occurrences with detailed geographic information (n = 112) included 17 countries in Latin America and the Caribbean. The locations were in environments that primarily consisted of forests (29%), croplands (16•5%), and shrublands (10•9%). We predicted environmentally suitable areas for tungiasis transmission in 45 countries. The estimated human population living in these areas is 450,546,547 with urban centers accounting for 347,007,103 and rural areas 103,539,444. Countries with significant ecological suitability and documented occurrences include Brazil, Colombia, Mexico, Argentina, Bolivia, Ecuador, French Guyana, Guatemala, Haiti, Paraguay, Peru, Trinidad and Tobago, and Venezuela.

Interpretation

This is the first study mapping the potential distribution of tungiasis in Latin America, evidencing the need for population-based studies and elaboration of integrated control measures.

Funding

This project was supported in part by an appointment to the Research Participation Program at the Centers for Disease Control and Prevention administered by the Oak Ridge Institute for Science and Education through an interagency agreement between the U.S. Department of Energy and the Centers for Disease Control and Prevention.

Parasitic Infections of the Skin and Subcutaneous Tissues

A variety of arthropods, protozoa, and helminths infect the skin and subcutaneous tissues and may be identified by anatomic pathologists in standard cytology and histology preparations. The specific organisms seen vary greatly with the patient's exposure history, including travel to or residence in endemic countries. Arthropods are the most commonly encountered parasites in the skin and subcutaneous tissues and include Sarcoptes scabei, Demodex species, Tunga penetrans, and myiasis-causing fly larvae. Protozoal parasites such as Leishmania may also be common in some settings. Helminths are less often seen, and include round worms (eg, Dirofilaria spp.), tapeworms (eg, Taenia solium, Spirometra spp.), and flukes (eg, Schistosoma spp.). This review covers the epidemiologic and histopathologic features of common parasitic infections of the skin and subcutaneous tissues.