Neglected Tropical Diseases outside the Tropics

Francesca F Norman,Ana Pérez De Ayala,Begoña Monge-Maillo,Rogelio López-Vélez,Pilar Zamarrón,José-Antonio Pérez-Molina,Kirsten E Lyke

doi:10.1371/journal.pntd.0000762

Francesca F Norman, Ana Pérez De Ayala + Show 5 more

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https://doi.org/10.1371/journal.pntd.0000762

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Abstract

BackgroundThe neglected tropical diseases (NTDs) cause significant morbidity and mortality worldwide. Due to the growth in international travel and immigration, NTDs may be diagnosed in countries of the western world, but there has been no specific focus in the literature on imported NTDs.MethodsRetrospective study of a cohort of immigrants and travelers diagnosed with one of the 13 core NTDs at a Tropical Medicine Referral Unit in Spain during the period April 1989-December 2007. Area of origin or travel was recorded and analyzed.ResultsThere were 6168 patients (2634 immigrants, 3277 travelers and 257 VFR travelers) in the cohort. NTDs occurred more frequently in immigrants, followed by VFR travelers and then by other travelers (p<0.001 for trend). The main NTDs diagnosed in immigrants were onchocerciasis (n = 240, 9.1%) acquired mainly in sub-Saharan Africa, Chagas disease (n = 95, 3.6%) in immigrants from South America, and ascariasis (n = 86, 3.3%) found mainly in immigrants from sub-Saharan Africa. Most frequent NTDs in travelers were: schistosomiasis (n = 43, 1.3%), onchocerciasis (n = 17, 0.5%) and ascariasis (n = 16, 0.5%), and all were mainly acquired in sub-Saharan Africa. The main NTDs diagnosed in VFR travelers were onchocerciasis (n = 14, 5.4%), and schistosomiasis (n = 2, 0.8%).ConclusionsThe concept of imported NTDs is emerging as these infections acquire a more public profile. Specific issues such as the possibility of non-vectorial transmission outside endemic areas and how some eradication programmes in endemic countries may have an impact even in non-tropical western countries are addressed. Recognising NTDs even outside tropical settings would allow specific prevention and control measures to be implemented and may create unique opportunities for research in future.

Highlights

The neglected tropical diseases (NTDs) are a group of mainly chronic illnesses identified as causing considerable morbidity and mortality typically amongst the world’s poorest populations and which have been shown to promote poverty [1]
We present the experience of a Tropical Medicine Unit in a major European city, over a 19-year period, describing and comparing NTDs diagnosed amongst immigrants, travelers and travelers visiting friends and relatives (VFRs)
The main NTDs diagnosed in immigrants were onchocerciasis, Chagas disease and ascariasis; most frequent NTDs in travelers were schistosomiasis, onchocerciasis and ascariasis, and onchocerciasis and schistosomiasis in VFRs

Summary

Introduction

The neglected tropical diseases (NTDs) are a group of mainly chronic illnesses identified as causing considerable morbidity and mortality typically amongst the world’s poorest populations and which have been shown to promote poverty [1]. NTDs cause over 500, 000 deaths annually and have been estimated to result in a greater number of disabilityadjusted life years lost than malaria and tuberculosis [2,3]. In this sense many infections could be included, 13 core NTDs have been targeted due to their prevalence and the burden of disease they cause globally and they include helminths, protozoa and tropical bacteria [1,2]. Due to the growth in international travel and immigration, NTDs may be diagnosed in countries of the western world, but there has been no specific focus in the literature on imported NTDs

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