Mansonella ozzardi and its vectors in the New World: an update with emphasis on the current situation in Haiti.

Mansonella ozzardi (Nematoda: Onchocercidae) is a little studied filarial nematode. This human parasite, transmitted by two families of dipteran vectors, biting midges (most of them members of the genus Culicoides) and blackflies (genus Simulium), is endemic to the Neotropical regions of the New World. With a patchy geographical distribution from southern Mexico to north-western Argentina, human infection with M. ozzardi is highly prevalent in some of the Caribbean islands, along riverine communities in the Amazon Basin, and on both sides of the border between Bolivia and Argentina. Studies conducted in Haiti between 1974 and 1984 allowed the first complete description of the adult worm and permitted clarification of the taxonomic position of this filarial species. This paper reports the known geographical distribution of M. ozzardi in Neotropical regions of the Americas, and focuses on the current situation in Haiti where this filariasis remains a completely neglected public health problem.

Seroprevalence of human Taenia solium cysticercosis in Haiti.

Human Taenia solium cysticercosis is common in developing countries due to poor sanitary conditions and economics based on breeding livestock, especially pigs, with low hygiene standards. Neurocysticercosis, caused by migration of the larvae of the tapeworm in the nervous system, is the leading cause of acquired epilepsy in adults in Central and South America, sub-Saharan Africa, and East and South Asia. This makes neurocysticercosis a large public health problem in developing countries. Two clinical cases of neurocysticercosis have been observed recently in Haiti. In order to evaluate the prevalence of human T. solium cysticercosis in this country, in 2007 we conducted a cross-sectional serological retrospective survey using a Western blotting test (LDBIO Diagnostics) in Port-au-Prince, where sewage systems are rare and swine usually roam freely throughout the area. A total of 216 serum samples, obtained from healthy adults seen in the work setting of periodical medical visits, were tested after storage at - 20 degrees C. The frequency of antibodies in serum samples of the study population was 2.8% (6/216). The immunodominant bands recognized in Western blots were 23-26 kDa (100%), 39 kDa (67%), 45 kDa and 6-8 kDa (50%), 50-55 kDa (33%). These results confirm for the first time an endemic situation of cysticercosis in humans in Haiti, with similar prevalence as that reported in other Latin American and African countries. It reinforces the urgent need for control and prevention measures to be taken by local public health services.

[Update of knowledge on Neglected Diseases in Haiti: Mansonelliasis, Tungiasis, Leprosy, and Anthrax]. / Mise à jour des connaissances concernant quatre maladies délaissées en Haïti : mansonellose, tungose, lèpre, charbon.

Haiti, like most limited-resources countries in the world, faces numerous neglected infectious diseases. They represent a real public health issue with lethal consequences especially in children. We are reviewing here the available literature on four neglected infectious diseases, mansonelliasis, tungiasis, leprosy and anthrax. Filariasis, due to Mansonella ozzardi, has been totally neglected since its discovery in 1920 in Haiti; it persists in coastal homes with a high prevalence in adults when an effective treatment is available. The skin lesions caused by Tunga penetrans have existed since the pre-Columbian period in Haiti. They persist in the most retreated and hard-to-reach areas where the population lives in precarious conditions and in extreme poverty. New available research data show the importance of the problem with very high prevalence rates in some rural communities far away from any healthcare center. Cases of leprosy are recently reemerging as no monitoring program has been in place since 2004. Finally, anthrax is still endemic; small epidemics resurfacing periodically in families in rural areas. Screening of people for these diseases and managing the cases are necessary to improve health and reduce morbidity and mortality in Haiti.

Comme dans la plupart des pays pauvres de la planète, les maladies infectieuses négligées sont nombreuses en Haïti où elles représentent un réel problème de santé publique avec des conséquences létales, surtout pour les enfants. Nous faisons le point des données accessibles pour quatre d'entre elles. Totalement délaissée depuis la découverte de sa présence en Haïti en 1920, la filariose due à Mansonella ozzardi persiste en foyers côtiers avec une prévalence élevée chez les adultes alors qu'un traitement efficace est disponible. Connues depuis la période précolombienne dans l'île d'Hispaniola, les lésions cutanées dues à Tunga penetrans persistent dans les régions les plus reculées et difficiles d'accès où la population vit dans des conditions précaires et dans une très grande pauvreté. Nous rapportons les données d'enquêtes récentes qui montrent l'importance de cette ectoparasitose en Haïti où les taux de prévalence sont très élevés dans certaines communautés rurales isolées. Des cas de lèpre resurgissent en Haïti alors qu'aucun programme de surveillance n'est effectif depuis 2004. Enfin, la maladie du charbon est endémique dans les régions d'élevage où des épidémies familiales resurgissent périodiquement en milieu rural. Le dépistage des personnes atteintes de ces maladies et leur prise en charge sont nécessaires pour une amélioration de la santé et une baisse de la mortalité en Haïti.

[Hepatobiliary fascioliasis and echinococcosis/hydatidosis in domestic animals in Haiti]. / Distomatose hépatobiliaire et échinococcose- hydatidose des animaux domestiques en Haïti.

In Haiti, hepatobiliary fascioliasis and hepatic hydatid cysts cause major economic losses among livestock. Surveys show high prevalence rates for bovine distomatosis caused by Fasciola hepatica (10.7% to 22.78%). Among small ruminants, the prevalence of distomatosis is low (sheep: 3.2%, goats: 0.9%) although Dicrocoelium dendriticum is found in 1.1% of sheep. Hepatic hydatidosis is more common among pigs (5.2%) and sheep (2.1%) than among goats (0.9%) and cattle (0.3%). In the case of dogs, 21% excrete egg-bearing segments in their faeces and 25% harbour Echinococcus granulosus in the small intestine. As a result of local dietary habits (consumption of raw cress), environmental pollution by animal faeces, poverty and poor standards of hygiene in Haiti, these flatworms pose serious health risks to the population, even though this is largely unknown at present.

[Worldwide human zoonotic cryptosporidiosis caused by Cryptosporidium felis]. / La cryptosporidiose zoonosique humaine due à Cryptosporidium felis dans le monde.

Cryptosporidium is an important enteric pathogen worldwide distributed causing diarrhoeal illness in humans and animals. Identifying Cryptosporidium species using conventional criteria, such as oocyst morphology, is inadequate. The advent of molecular techniques has conducted to characterize different species and genotypes of Cryptosporidium infecting humans. The vast majority of human cases of cryptosporidiosis in the world are caused by both species, Cryptosporidium hominis and Cryptosporidium parvum. However other species including Cryptosporidium felis can infect humans too. In this review, we analyse 58 reported cases of human C. felis infection in different parts of the world. To date this emerging protozoan disease is present in humans around the world, except in Australia and Oceania. Adults and children are infected, more often when immunocompromised by HIV infection (83 % of reported cases). Apparently immunocompetent individuals are also infected by C. felis. In developing countries, inhabitants are more likely infected by C. felis probably through the oocyst contamination of drinking or recreational water. The public health importance of C. felis infection in tropical countries remains to be evaluated.

[Bilharziasis caused by Schistosoma mansoni in a traveler returning from Guinea: failure of serodiagnostic testing]. / Bilharziose à Schistosoma mansoniau retour de Guinée: défaillance du sérodiagnostic.

The purpose of this report is to describe a case of febrile hypereosinophilic syndrome in a traveler three weeks after returning from a sightseeing trip to Guinea. Laboratory testing demonstrated an inflammatory response syndrome and hepatic cytolysis. Parasite serology led to suspicion of toxocariasis that was treated using albendazole. Follow-up tests at two months showed the presence of Schistosoma mansoni eggs in stools despite negative standard serodiagnostic testing (hemagglutination). Secondarily Western blot testing of serum samples at one, two and 14 months after returning from Guinea continued to show only protein bands specific to toxocariasis with no bands specific to bilhariziasis. These findings provide further evidence of the limitations of serological testing for detection of bilharziasis in travelers and the difficulty of diagnosis. Guinea is a high-risk tourist destination. Intestinal and urinary bilharziasis are endemic over three-fourths of country. Travelers planning even short stays in areas where bilharziasis is endemic should be advised on preventive measures.

[Enteric parasites and AIDS in Haiti: utility of detection and treatment of intestinal parasites in family members]. / Parasites intestinaux et sida en Haïti: faut-il déparasiter l'entourage familial?

Intestinal parasites and human immunodeficiency virus (HIV) are major health problems in Haiti. Both entities are known to interact strongly with cell-mediated immunity. The purpose of this study undertaken in Port-au-Prince, Haiti was to evaluate the risk of enteric parasite transmission between HIV-infected patients and family members. Routine examination of stool specimens for parasites was conducted in 90 HIV-infected undergoing treatment for intestinal disorders due mainly to Cryptosporidium sp. (62%) and 123 healthy family member volunteers. A stool sample preserved in 10% formalin solution was examined to detect protozoa (MIF, modified Ziehl-Neelsen stain, Uvibio fluorescence technique, Weber stain) and helminth ova (Bailenger technique). In addition to Cryptosporidium sp., 14 parasitic species were identified: 6 Rhizopoda, 3 Flagellata (including Giardia duodenalis), 1 Coccidia (Cyclospora cayetanensis), 3 Nematoda (mainly Ascaris lumbricoides) and 1 Cestoda (Hymenolepis nana). This is the first time that 5 protozoa, i.e., Blastocystis hominis, Entamoeba hartmanni, E. polecki, Chilomastix mesnili, and Enteromonas hominis, have been reported in Haiti. As expected, enteric parasites were less common in HIV-infected subjects undergoing medical treatment (11.1%) than in uninfected family members (41.5%) (p = 0.0000). Multiple intestinal parasitism (infection by 2 to 4 parasites) was observed in 19.5% of family members. The findings of this study indicate that detecting and treating intestinal parasites in subjects living in close contact with HIV-infected patients as well as informing family members of the importance of personal hygiene in Haiti are highly recommended measures to preserve the health of AIDS patients.

[Intestinal helminthiasis in school children in Haiti in 2002]. / Helminthoses intestinales en milieu scolaire en Haïti en 2002.

A survey on intestinal helminths in school children was conducted in Haiti in 2002. This first nationwide study involving the entire country was stratified by department according to urban and rural zones using the cluster method. Focusing on elementary school children (n=5792; age range 3 to 20 years), it involved 26 urban and 49 rural schools randomly selected. Stools were preserved in formalin and examined by the Ritchie technique. Thirty-four per cent of stools (1981/5792) tested positive for intestinal helminths with the following parasites identified: Ascaris lumbricoides (27.3%), Trichuris trichiura (7.3%), Necator americanus (3.8%), Hymenolepsis nana (2%), Taenia sp. (0.3%) and Strongyloides stercoralis (0.2%). The helminth prevalence was higher in rural (38.4%) compared to urban areas (30%). There was no significant difference in prevalence by sex and age. The importance of geohelminths changed from one department to another with the highest prevalence found in the Southern department of Grande Anse (73.7%) and the lowest prevalence in the Center department (20.6%). Five out of the country's nine departments had a similar prevalence varying from 25.5% to 28.2%. Intestinal helminthic polyparasitism was observed in a percentage of infested school children comprise between 3.4% and 28.6% according in relation to the geographical area. A program to fight against geohelminths in school children should be initiated as a public health priority. Albendazole is the drug of choice. Frequency of drug distribution should be based on the prevalence of geohelminths in each department.

[Gametocyte carriage in asymptomatic Plasmodium falciparum infections in Haiti (2010-2013)]. / Portage de gamétocytes de Plasmodium falciparum en Haïti en 2010-2013.

A survey conducted from May 2010 to October 2013 in five from ten departments of Haiti among 5,342 persons aged from 1 to 107 years showed a gametocytic rate = 3.2%. However, it varies greatly from one Department to another, ranging from 0.5% in Grande Anse Department to 5.9% in Southeast Department. Malaria is present in Haiti in heterogeneous coastal foci. Gametocytes occur at all ages, but two times most often in male under 20 years. Entomological studies in Haiti are needed to better characterize the relationships between man and the vector Anopheles albimanus, adapting the fight more effectively.

Invasive infections due to Trichoderma species: report of 2 cases, findings of in vitro susceptibility testing, and review of the literature.

Trichoderma species are filamentous fungi that were previously considered to be culture contaminants. We report 2 well-documented cases of invasive Trichoderma infections, and we comprehensively review the literature on this topic. Trichoderma species are mainly responsible for continuous ambulatory peritoneal dialysis-associated peritonitis (7 cases) and invasive infections in immunocompromised patients (9 cases) with a hematologic malignancy or solid-organ transplant. Definitive diagnosis is difficult to achieve because of the lack of specific diagnosis tools. Species identification can benefit from a molecular approach. Trichoderma longibrachiatum is the most common species involved in these infections. Regardless of the type of infection, the prognosis was poor, with 8 deaths among 18 cases. This may be partially because of the resistance of these organisms to the majority of available antifungal agents, including amphotericin B. Trichoderma species now should be added to the growing list of emerging filamentous fungal pathogens.

Assessment of Culicoides barbosai as a vector of Mansonella ozzardi in Haiti.

Studies in the southern peninsula of Haiti showed that the biting midge, Culicoides barbosai, was capable of supporting the development of Mansonella ozzardi to the infective stage. The known vector, Culicoides furens, also was encountered. Both species showed distinct biting site preferences, i.e., 98% of the midges that engorged on the arms and head were C. barbosai whereas C. furens was collected mostly from the lower legs. Nine days after engorgement, 19 infective larvae were recovered from 13 C. barbosai versus six larvae from four C. furens. It was judged that C. barbosai may be as importantly involved in the natural transmission cycle as C. furens in this community.

Parasitological, serological, and clinical studies of Wuchereria bancrofti in Limbe, Haiti.

A survey for Wuchereria bancrofti in Limbe, Haiti (est. pop. = 10,500) revealed that 17% (231/1,450) had a patent infection. Nearly half of those surveyed harbored fewer than 10 microfilariae (mf) per 20 mm3 of finger-prick blood; the median mf density for females and males was 12.4 and 9.5, respectively. Parasitemias occurred as early as age 4. Antibody titers greater than or equal to 1:20 against adult D. viteae antigen were observed in 38% of microfilaremic individuals and in 29% of amicrofilaremic individuals. Peak antibody responsiveness (40%) was observed between 5 and 9 years of age. In all age groups there was no correlation between mf density and antibody titer. Among the mf carriers, 5.6% had no clinical symptoms. Lymphangitis was a common feature with 14.3% having lymphedema, 8.2% with edema of the lower extremities, and 1.3% reporting episodes of chyluria. Genital involvement among women was rare, but in males 5.4% had genital swelling and 4.5% had hydroceles. Culex pipiens quinquefasciatus (Say) was observed to support the complete development of W. bancrofti in Limbe.

Mansonella ozzardi in Haiti. IV. Evaluation of antibody reactivity to heterologous antigens.

Sera from individuals in an area of Haiti endemic for Mansonella ozzardi were analyzed for reactivity to antigens of Brugia pahangi, Dirofilaria immitis, Mansonella llewellyni or Ascaris lumbricoides using either an enzyme-linked immunosorbent assay or an indirect immunofluorescent antibody test. IgM and IgG reactivity to all antigens was observed with sera from both microfilaremic and amicrofilaremic individuals when compared to reactivity of sera from individuals from nonendemic areas. Antibody reactivity to B. pahangi was greater than that to other antigens. IgG reactivity of sera from endemic patients to filarial antigens was consistently greater than that of IgM. Antibody reactivity was not correlated with age or microfilarial density.

Failure of falciparum malaria prophylaxis by mefloquine in travelers from West Africa.

Due to the spread of chloroquine-resistant strains of Plasmodium falciparum in French speaking parts of Africa, we have found it necessary to prescribe mefloquine for antimalaria prophylaxis to travelers to this area. Weekly doses of 125 or 250 mg have been recommended for short journeys. In spite of this regimen, 16 documented cases of falciparum malaria in travelers have been recorded in the Bordeaux hospital center since October, 1988. Fifteen of these patients were tourists returning from West African countries, and one was an Ivorian student who had been on vacation to his home country. Nine of these patients were evaluated and found to have high plasma mefloquine levels. This report strongly supports the existence of mefloquine-resistant falciparum malaria in West Africa, especially in Sierra Leone, Burkina Faso, and Cote d'Ivoire.

Assessment of Leptoconops bequaerti as a potential vector of Mansonella ozzardi in Haiti.

Experimental studies in Bayeux, Haiti showed that the biting midge, Leptoconops bequaerti, is capable of supporting the complete development of Mansonella ozzardi but only on a very limited scale. This suggests that the species may not be involved in the natural transmission cycle despite its abundance and pestiferous nature in certain areas of Haiti. A midge-holding container is described which markedly enhanced the survival of engorged L. bequaerti in the laboratory.

Uptake and development of Wuchereria bancrofti in Culex quinquefasciatus that fed on Haitian carriers with different microfilaria densities.

In studies conducted between 1984 and 1986, the vector competency of Culex quinquefasciatus was assessed after bloodfeeding on 61 Haitian volunteers with different densities of Wuchereria bancrofti microfilariae (mf) and on 11 that were amicrofilaremic. Infected volunteers included persons previously given diethylcarbamazine citrate for 12 consecutive days and some that were untreated. Mosquitoes, derived from field-collected larvae, were released under bed nets and fed upon the volunteers while they slept. The mean mf uptake in mosquitoes that fed on 21 carriers with low to ultralow densities (1-28 mf/ml blood) was 0.2-4 mf/mosquito (mean = 1.7 mf). The observed infectivity rate of greater than 3,000 mosquitoes that fed on high (56-7,500 mf/ml blood; median = 525), low (11-49 mf/ml blood; median = 20), or ultralow (1-10 mf/ml blood; median = 3) density carriers was 4, 11, and 30 times higher, respectively, than the expected rate calculated from the estimated volume of the imbibed bloodmeal. These results indicate that "hidden" carriers (less than 50 mf/ml blood) may serve as a source of infection for mosquitoes, and support the increasing evidence that mosquitoes ingest more microfilariae than expected.

Epidemiology of Wuchereria bancrofti in Leogane, Haiti.

A survey for Wuchereria bancrofti in Leogane, Haiti, revealed that 140 of 421 individuals (33%) had a patent infection, of which 40% lived in the suburban outskirts of the city. The median microfilaria density was 19.1 per 20 mm3 of blood for suburban dwellers compared with only 8.8 for those living in the city. The vector, Culex quinquefasciatus (Say), breeds mostly in and around numerous rum distilleries, located exclusively around the periphery of the city, and this undoubtedly accounts for the higher prevalence and intensity of infection among suburban dwellers.

Biomphalaria glabrata in Haiti.

Biomphalaria glabrata, an intermediate host for Schistosoma mansoni, was first reported in Haiti in 1891 at one location in the Départment du Nord and in 1977 it was reported at several sites in one additional watershed. Our study identifies two additional locations each on a different watershed plus a third possible site. A wide but discontinuous distribution of the snail on the north coast of Haiti is confirmed (no autochthonous infections with S. mansoni have been reported). While there are many possible explanations for this discontinuous distribution, a role for the competitor Thiara granifera in shaping the current distribution of B. glabrata is suggested. The incursion of B. glabrata into Haiti is not recent but at the same time is not expanding.

[Filariasis in Haiti: a century of history]. / Filarioses en Haïti: un siècle d'histoire.

Wuchereria bancrofti and Mansonella ozzardi are both endemic in Haiti. Over the last hundred years, these human parasites have been by turn investigated and disregarded. Between 1894 and 1914, Haitian physicians encouraged by Dr. Léon AUDAIN studied the clinical and biological impact of W. bancrofti in the numerous infested patients in Port-au-Prince. During the American occupation (1915-1934), the presence of M. ozzardi was recognized by a Rockefeller mission and a first investigation of filariasis distribution in the country was carried out. Between 1935 and 1971, interest in the parasites ceased. However, many studies of W. bancrofti and M. ozzardi and their vectors have been conducted from 1972 until today. Lymphatic filariasis remains a great health hazard in localized leeward foci, where climatic conditions favourise the survival of the vector Culex quinque-fasciatus. Urban foci have been remarkably stable for the last 70 years in northern Haiti and along the Gulf of the Gonâve coast. Parasitological indices are high and the impact on public health is great. Ozzardiasis is prevalent in the rural coastal areas of northern and southern Haiti, where the principal vectors Culicoides furens and C. barbosai breed in abundance. The control of lymphatic filariasis is now possible and should be a public health priority in Haiti.

[Imported malaria in Bordeaux in 1989. Epidemiologic, clinical and therapeutic study of 71 cases]. / Le paludisme d'importation à Bordeaux en 1989. Etude épidémiologique, clinique et thérapeutique de 71 cas.

In 1989 there were 71 cases of imported malaria admitted to the hospital in Bordeaux. This is 16.5% and 29% lower than in 1988 and 1987 respectively, thanks to the widespread use in Africa of mefloquine chemoprophylaxis. Sub-Saharan Africa is involved in 95% of cases, mainly West Africa (70% of cases), unlike the situation in 1987, and the first cases of paludism despite mefloquine chemoprophylaxis appeared during the second semester from the seasonal mid-summer recrudescence onwards, in travellers returning from this region. The most frequent species is still Plasmodium falciparum (80% of declared cases). This imported disease especially affects young adults despite regular prophylaxis in 59% of cases. It is therefore important to recommend rigorous protection against anopheles. Male predominance (sex ratio: 5.5) was greater in 1989 than in the previous two years, and French nationals represented 85% of the population. Falciparum malaria presents symptoms in 95% of cases before the end of the month following the patient's return to France, while for P. ovale the time for symptoms to appear is between 39 days and two years after return. Management of patients on their return poses a problem of information, since in 40% of cases diagnosis is made more than a week after the first symptoms. Attacks are mild in most cases (93%); among the serious cases death occurred in a 3-year-old child. Thrombopenia is the most frequent biological sign (22.5% of cases), followed to a lesser degree by anaemia and leukopenia. Mild attacks respond well to classical treatment (halofantrine, mefloquine, quinine, chloroquine), while two cases of more complicated symptoms required exchange transfusion.