Holidays in the Sun and the Caribbean’s Forgotten Burden of Neglected Tropical Diseases

Almost 40 million people live on the islands, islets, and cays that comprise the Caribbean [1]. This is one of the most tourism-dependent regions in the world, with approximately one-quarter of the workforce involved in a business that in some way caters to tourists [2]. According to the Caribbean Tourism Organization (CTO), an association of government and private sector agencies that disseminates data on the region, almost 22 million visitors come to the Caribbean annually, where they spend an estimated US$21.6 billion [3]. More than 80% of these visitors are people of means from the United States (11.4 million), Canada (1.7 million), and Europe (5.3 million), almost all of whom come to the region for the purpose of a holiday vacation [3]. Away from the beaches, resorts, and cruise ships, however, there lies a hidden underbelly of poverty in the Caribbean, and with this poverty, endemic neglected tropical diseases (NTDs) [4]. Shown in Table 1 are four Caribbean countries— Dominican Republic (DR), Guadeloupe, Haiti, and Jamaica—that exhibit an unusually high burden of NTDs. In addition, the island nations of Antigua and Barbuda, Barbados, Saint Lucia, and Trinidad and Tobago also stand out for their high NTD disease burdens. For example, of the Western Hemisphere’s 720,000 cases of lymphatic filariasis, a mosquitotransmitted disfiguring parasitic helminth infection caused by Wuchereria bancrofti that can result in elephantiasis, almost 90% of the cases occur in the Caribbean, including 560,000 cases in Haiti and 50,000 in DR [5]. Outside of Brazil, the second largest number of cases of the blood fluke infection, schistosomiasis (caused by Schistosoma mansoni), occur in the DR (258,000 cases) [6], especially in the eastern part of the island where the Biomphalaria snail vector is still present [7,8]. Another 4,400 cases occur in Guadeloupe, and transmission still occurs in Saint Lucia and Antigua and Barbuda [6]. High prevalence of the three major intestinal helminth infections—ascariasis, trichuriasis, and hookworm infection—are also found throughout the poorest areas of the Caribbean, particularly in the DR, Haiti, and Jamaica, but also in Barbados and Trinidad and Tobago [9]. The existence of high rates of lymphatic filariasis, schistosomiasis, and hookworm infection in the region is made all the more poignant by an observation made recently in PLoS Neglected Tropical Diseases that these NTDs were most likely introduced into the Caribbean through the Atlantic slave trade [10], and even today such infections still occur almost exclusively among people living in poverty or people of African descent (P. Hotez, M. Bottazzi, C. Franco-Paredes, S. Ault, M. Roses Periago, unpublished data). In addition to the slavery-associated parasitic infections, there are other NTDs of great importance. Leprosy is still reported from Cuba, DR, Haiti, Jamaica, Saint Lucia, and Trinidad and Tobago [11], but because of the availability of multi-drug treatments, it is no longer considered a major public health threat to the region. However, dengue fever is now a serious problem, which is now common not only in the poorest Caribbean countries listed in Table 1, but also in Puerto Rico and other more developed areas [12]. The emergence of this mosquito-borne infection has been linked to an increase in flooding from hurricanes and other natural phenomena that may result from global warming [13]. The ratborne zoonotic NTD leptospirosis has also emerged in Jamaica and elsewhere following flooding and hurricanes [14]. With the possible exceptions of dengue [15] and cutaneous larva migrans resulting from canine hookworm infection [16], most of the Caribbean’s NTDs are not considered significant threats to the health of American, Canadian, and European tourists. The real tragedy of these conditions is that despite the enormous amount of wealth infused into the Caribbean economy every year through tourism, very little if any trickles down to the poorest people in the region who suffer daily from chronic, debilitating, disfiguring, and stigmatizing NTDs. Equally tragic is the evidence base to support the feasibility of NTD elimination and at low cost. For instance, through a demonstration project conducted in Leogane, Haiti, annual mass drug administration (MDA) with diethylcarbamazine (DEC) and albendazole has resulted in the near elimination of lymphatic filariasis after five rounds [17]. DEC can be purchased for pennies per person, while albendazole is donated freeof-charge by GlaxoSmithKline [18]. Similarly, it is possible to eliminate schistosomiasis by MDA with the low-cost generic drug praziquantel and achieve dramatic reductions in the prevalence and intensity of the intestinal helminth infections ascariasis and trichuriasis through MDA with donated albendazole or mebendazole [19]. Given that industry is either donating the NTD drugs, or they are available as low-cost generic drugs, these last vestiges of American slavery could be controlled or eliminated for a ridiculously small amount.