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1.
BMC Infect Dis ; 18(1): 595, 2018 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-30477434

RESUMEN

BACKGROUND: American histoplasmosis is a mycosis caused by Histoplasma capsulatum. A variety of clinical features of histoplasmosis have been commonly described ranging from asymptomatic infections to severe pulmonary infections. In immunocompromised individuals, progressive disseminated forms are frequent, leading to fatal outcome if untreated. However, H. capsulatum sinusitis is unusual with a few cases documented over the last three decades and may be underdiagnosed or confused with other fungal aetiologies, especially outside endemic regions. CASE PRESENTATION: In this study, we report an atypical case of Histoplasma capsulatum sinus fungus ball-like in a patient with Acquired Immunodeficiency Syndrome due to Human Immunodeficiency Virus complicated by a disseminated histoplasmosis with a death ending. Diagnosis relied on CT-Scan imaging and on both direct examination of H. capsulatum yeast forms (Gomory methenamine Grocott) in the sinus specimen (aspirate, biopsy) and on positivity of the culture further confirmed by qPCR. CONCLUSIONS: Since last few decades, among the eight reviewed patients, H. capsulatum sinusitis occurred mostly in HIV-immunocompromised patients and for three cases as a sinusitis with disseminated histoplasmosis. Even if this is a rare clinical presentation, its diagnosis is crucial as it could represent an early expression of an Histoplasma capsulatum exposure that can evolve into a disseminated fatal infection when immunity decreases.


Asunto(s)
Infecciones Oportunistas Relacionadas con el SIDA , Histoplasma , Histoplasmosis , Sinusitis , Femenino , Guyana Francesa , Humanos , Persona de Mediana Edad
2.
Ann Dermatol Venereol ; 141(8-9): 514-7, 2014.
Artículo en Francés | MEDLINE | ID: mdl-25209814

RESUMEN

BACKGROUND: Paracoccidioidomycosis is a systemic fungal infection common in Latin America. Cutaneous involvement is frequent and usually affects multiple sites, being most frequently associated with lesions of the oropharyngeal mucosa. The cutaneous form on its own is rare. PATIENTS AND METHODS: We report a case of paracoccidioidomycosis isolated from the ear of a 43-year-old immunocompetent man. The lesion consisted of a partially ulcerated plaque on the auricle of the left ear. Direct examination, histopathological examination and PCR revealed the presence in the skin lesion of yeasts identified as Paracoccidioides brasiliensis. DISCUSSION: The sites of paracoccidioidomycosis on the ear can be confused with other tropical diseases frequently found in the Amazon region such as leishmaniasis, leprosy and lobomycosis. The absence of any other cutaneous sites in this case raised the question of whether the lesion was of primary or secondary origin.


Asunto(s)
Enfermedades del Oído/microbiología , Oído Externo , Adulto , Enfermedades del Oído/diagnóstico , Humanos , Masculino , Paracoccidioidomicosis/diagnóstico
3.
Ann Trop Med Parasitol ; 105(2): 107-22, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21396247

RESUMEN

Anopheles darlingi, one of the main malaria vectors in the Neotropics, is widely distributed in French Guiana, where malaria remains a major public-health problem. Elucidation of the relationships between the population dynamics of An. darlingi and local environmental factors would appear to be an essential factor in the epidemiology of human malaria in French Guiana and the design of effective vector-control strategies. In a recent investigation, longitudinal entomological surveys were carried out for 2-4 years in one village in each of three distinct endemic areas of French Guiana. Anopheles darlingi was always the anopheline mosquito that was most frequently caught on human bait, although its relative abundance (as a proportion of all the anophelines collected) and human biting rate (in bites/person-year) differed with the study site. Seasonality in the abundance of human-landing An. darlingi (with peaks at the end of the rainy season) was observed in only two of the three study sites. Just three An. darlingi were found positive for Plasmodium (either P. falciparum or P. vivax) circumsporozoite protein, giving entomological inoculation rates of 0·0-8·7 infectious bites/person-year. Curiously, no infected An. darlingi were collected in the village with the highest incidence of human malaria. Relationships between malaria incidence, An. darlingi densities, rainfall and water levels in the nearest rivers were found to be variable and apparently dependent on land-cover specificities that reflected the diversity and availability of habitats suitable for the development and reproduction of An. darlingi.


Asunto(s)
Anopheles/parasitología , Insectos Vectores/parasitología , Malaria/epidemiología , Animales , Anopheles/clasificación , Ecosistema , Femenino , Guyana Francesa/epidemiología , Humanos , Incidencia , Malaria/transmisión , Plasmodium/aislamiento & purificación , Lluvia , Ríos , Estaciones del Año
4.
Med Trop (Mars) ; 70(5-6): 425-7, 2010 Dec.
Artículo en Inglés, Francés | MEDLINE | ID: mdl-21520639

RESUMEN

Despite lack of supporting evidence from epidemiologic studies and/or confirmed case reports over the last 30 years, maps in non-specialist works on tropical medicine as well as in documents from specialized organizations (e.g. WHO) systematically include Congo and Gabon, two French-speaking countries, within the zone of endemic filariasis due to Wuchereria bancrofti. One certainty is that no cases were found in field studies carried out in these countries in the late 1970s and 1980s but unfortunately published only in French. Studies that we carried out in the Congo between 1982 and 1987 as part of the National Project on Onchocerciasis and Other Filarioses confirmed the presence of four types of human filariasis: onchocerciasis, loaiasis filarioses caused by Mansonella perstans and M. streptocerca. However, there were no confirmed cases of lymphatic filariosis (bancroftosis). Hopefully the WHO program aimed at the elimination of lymphatic filariasis as a public health problem will provide up-to-date data on the distribution and endemicity of filariasis in Central Africa. Achievement of this objective will depend not only on carrying out new field studies but also on taking into account past studies published in languages other than Shakespeare's.


Asunto(s)
Filariasis Linfática/epidemiología , África Central/epidemiología , Filariasis Linfática/diagnóstico , Filariasis Linfática/parasitología , Encuestas Epidemiológicas , Humanos , Organización Mundial de la Salud
5.
Med Trop (Mars) ; 69(1): 19-25, 2009 Feb.
Artículo en Francés | MEDLINE | ID: mdl-19499726

RESUMEN

The last study describing the epidemiology of malaria in French Guiana was published 20 years ago. Yet French Guiana in the Americas along with Mayotte in the Indian Ocean is the only French territory with persisting endemic malaria. The purpose of this study is to provide an update based on official malaria surveillance data as well as on information from hospital records and various field surveys that have been carried out in recent years. Due to recurrent problems in collecting thorough, continuous, and consistent data, exact determination of incidence by plasmodium species has always been difficult in French Guiana. These problems include not only the remote location of endemic areas and intense unpredictable migration patterns but also poor data collection methods that do not always ensure consistency and homogeneity. Another factor hindering thorough collection of conventional epidemiological data is the requirement for rapid effective treatment in remote regions. The overall incidence of malaria in French Guiana appears to have remained stable since the beginning of the decade with an average of 3,920 case reports per year for an incidence rate of 20 per thousand, noting that three fourths of the 206,000 inhabitants of French Guiana live outside of endemic areas. Overall involvement of P. falciparum and P. vivax appears to be equal with P. malariae accounting for only 2.6% of cases. Trends in recent years indicate an increase in the number of cases involving P. vivax especially in the eastern zones, i.e. in the Oyapock focus where annual incidences in children have reached up to 500 per thousand and in the whole region located between Saint Georges and Cayenne. Conversely a decrease in endemic levels has been observed in western areas, especially for P. falciparum in the upper and middle focuses of the Maroni. Most zones now causing problems are located near migration points, particularly in relation with clandestine gold panning activities. In the coastal strip where the three main cities with most of the population are located, most reported cases are imported but local cases may occur. In general local transmission in these areas has been promptly controlled but trends indicate that incidence of these events may be rising. Anopheles darlingi is still recognized as the main vector but its role in transmission is less obvious in eastern areas where increasing evidence suggests that other species may contribute to maintaining endemic levels. These findings indicate that the extensive resources deployed in this French territory (public financing, health care network, public awareness campaigns, and training of health care personnel in diagnosis and treatment of malaria) have helped reduce the number of severe cases in an unfavorable epidemiological setting.


Asunto(s)
Malaria/epidemiología , Animales , Control de Enfermedades Transmisibles , Enfermedades Endémicas , Guyana Francesa/epidemiología , Humanos , Incidencia , Insectos Vectores
6.
Am J Trop Med Hyg ; 78(2): 195-7, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18256411

RESUMEN

Like domestic cats, wild felids are involved in the complete infective cycle of Toxoplasma gondii because they can host in their gastrointestinal tract sexually mature parasites and shed infective oocysts in their feces. We report, to our knowledge, the first isolation and molecular characterization of a T. gondii strain from the heart tissue of a free-living jaguar (Panthera onca) in French Guiana. Sequencing at six polymorphic markers indicated that the jaguar isolate had an atypical genotype, including an allele at TgM-A previously found only in isolates from South America, and an allele at GRA6, which was previously reported only in Californian sea otter isolates. These findings are consistent with the recent description of atypical T. gondii strains involved in severe toxoplasmoses in immunocompetent patients in French Guiana that seemed to be linked to a neotropical forest-based cycle involving wild cats and their prey.


Asunto(s)
Antígenos de Protozoos/genética , Corazón/parasitología , Repeticiones de Microsatélite/genética , Panthera/parasitología , Proteínas Protozoarias/genética , Toxoplasma/genética , Animales , Anticuerpos Antiprotozoarios/análisis , Secuencia de Bases , ADN Protozoario/química , Guyana Francesa , Genotipo , Masculino , Ratones , Datos de Secuencia Molecular , Polimorfismo Genético/genética , Alineación de Secuencia , Toxoplasma/aislamiento & purificación , Toxoplasma/patogenicidad
7.
Med Trop (Mars) ; 68(5): 533-6, 2008 Oct.
Artículo en Francés | MEDLINE | ID: mdl-19068990

RESUMEN

In French Guiana cutaneous leishmaniasis occurs mainly in the localized form with L. guyanensis accounting for more than 90% of cases. Mucocutaneous leishmaniasis is uncommon (less than 2% of cases) with L. braziliensis accounting for all previously reported cases. The purpose of this report is to describe a case of mucocutaneous leishmaniasis due to L. guyanensis that led to diagnosis of HIV infection in a patient living in French Guiana.


Asunto(s)
Infecciones por VIH/complicaciones , Leishmania guyanensis , Leishmaniasis Mucocutánea/etiología , Adulto , Animales , Humanos , Masculino
8.
Bull Soc Pathol Exot ; 100(4): 251-60, 2007 Oct.
Artículo en Francés | MEDLINE | ID: mdl-17982853

RESUMEN

Cutaneous leishmaniases are endemic over the entire territory of French Guiana. At least 5 distinct Leishmania species coexist in the sylvatic ecotopes of this French territory. The present paper checks the advances in the ecological research field during the past 5 years. The current epidemiological situation and trends are detailed successively Links between the recrudescence of leishmaniases and gold-mining are highlighted. The potential adaptation of the pathogenic complexes to the newly anthropized habitats is also described.


Asunto(s)
Enfermedades Endémicas/estadística & datos numéricos , Leishmaniasis Cutánea/epidemiología , Animales , Reservorios de Enfermedades , Ecosistema , Guyana Francesa/epidemiología , Humanos , Incidencia , Insectos Vectores/parasitología , Leishmania/clasificación
9.
Bull Soc Pathol Exot ; 99(4): 254-7, 2006 Oct.
Artículo en Francés | MEDLINE | ID: mdl-17111973

RESUMEN

Guadeloupe is one of the French West Indies, where, until 1960, intestinal parasitic infections were endemic. In the microbiological laboratory of the university hospital of the island, we carried out a retrospective study of the 17,660 stool examinations received from 1991 to 2003. All the stool specimens were examined using at least a wet mount preparation and a concentration method (Bailenger). Specific techniques such as Ziehl-Neelsen modified acid fast stain, chromotrope staining procedure or Baermann's technique were used when indicated. A parasite considered as really pathogenic is detected in only 5.6% of the cases of the 17,660 stool examinations. The intestinal protozoa count for 10.8% of them, G. intestinalis (60%) is the most common, followed by Cryptosporidium sp (26%) and Isospora belli in AIDS patients while Entamoeba histolytica/dispar rarely appears (2.3%). Among the parasitic intestinal helminths, Strongyloïdes stercoralis is seen as the most prevalent (82%) whereas hookworms and Trichuris trichuria count respectively for 9.8% and 5.6%. Schistosoma mansoni appears as an exception. This epidemiological change for intestinal parasitic infections results from the improvement of socio-economic and sanitary way of living of the population. However the persistence of the strongyloidiasis constitutes the outstanding fact in a area of strong prevalence of the HTLV1 infection.


Asunto(s)
Enfermedades Endémicas , Parasitosis Intestinales/epidemiología , Guadalupe/epidemiología , Hospitales Universitarios , Humanos , Parasitosis Intestinales/parasitología , Estudios Retrospectivos
10.
Bull Soc Pathol Exot ; 99(4): 227-9, 2006 Oct.
Artículo en Francés | MEDLINE | ID: mdl-17111967

RESUMEN

The authors report a new case of African Histoplasmosis in a 60-year-old patient. It was an humeral localization revealing a pathological fracture which grew into an extension of osteolysis and a cutaneous fistulization likely to be a malignant bone tumor. The case has been diagnosed by surgical biopsy and histological analysis. Its antifungal treatment in progress resulted in the drainage of the out-flow that should permit the bone reconstruction by graft. The authors stress on the need to focus on this affection whenever, in a tropical area, one is faced with any chronic bone fistula that cannot positively be cured in spite of sound medical cares.


Asunto(s)
Enfermedades Óseas/complicaciones , Fracturas Espontáneas/etiología , Histoplasmosis/complicaciones , Fracturas del Húmero/etiología , Femenino , Humanos , Persona de Mediana Edad
12.
Med Trop (Mars) ; 66(5): 495-503, 2006 Oct.
Artículo en Francés | MEDLINE | ID: mdl-17201300

RESUMEN

Toxoplasmosis, a typical cosmopolitan parasitosis, is a major health problem in French Guiana. Three factors account for this situation, i.e., (1) severity of toxoplasmosis in patients with HIV infection that is particularly prevalent in the area, (2) high risk of congenital transmission as shown by the steadily increasing prevalence of seropositivity in function of age in most of the Guianese population and (3) recent identification of severe primary toxoplasmosis infection in immunocompetent patients. In AIDS patients, the epidemiologic aspects of toxoplasmosis are correlated to the special features of the HIV-positive population in French Guiana and its clinical expression, mainly in the form of cerebral toxoplasmosis, does not suggest involvement of a particularly virulent strain of Toxoplasma. Similarly congenital toxoplasmosis does not present special tropical features other than problems associated with prevention, diagnosis and follow-up in poor and/or remote settings. These features are fully compatible with the classic domestic cat cycle of Toxoplasma gondii. However severe forms of primary infection, particularly in immunocompetent adults, appear to be associated with atypical features. These forms appear to be correlated with a forest-based cycle involving wild cats, which are still numerous in French Guiana, and their prey. Ingestion of undercooked wildcat prey, which is also a delicacy for man, can also be a source of contamination as can be consumption of untreated river water infected with oocysts excreted by felines. Observation of higher toxoplasmosis seroprevalence in wild noncarnivorous mammals that live by foraging on the ground in uninhabited forest zones suggests that infection can also be due to ingestion of oocysts eliminated into the soil. Since there are no domestic cats in the area, it must be assumed that these oocysts are shed by wild felines. More convincing proof can be seen in the fact that T. gondi strains presenting polymorphism, similarities and atypical genetic features can be found both in this animal reservoir, particularly in jaguars, and in patients presenting the more severe form of toxoplasmosis. In addition to the purely scientific interest of confirming the existence of the forest-based cycle, knowledge of this atypical form of toxoplasmosis that is probably not confined to French Guiana or to the Amazon region has obvious practical medical implications not only for diagnosis but also for therapy and prevention.


Asunto(s)
Toxoplasmosis , Animales , Femenino , Guyana Francesa , Humanos , Masculino , Factores de Riesgo , Toxoplasma/fisiología , Toxoplasmosis/epidemiología , Toxoplasmosis/etiología , Toxoplasmosis/parasitología , Toxoplasmosis Congénita/epidemiología , Medicina Tropical
13.
Bull Soc Pathol Exot ; 98(5): 363-4, 2005 Dec.
Artículo en Francés | MEDLINE | ID: mdl-16425714

RESUMEN

Cases of scrotal elephantiasis operated in the Brazzaville' hospital are naturally imputed to Wuchereria bancrofti, in spite of the absence of parasitological proof. This is due to the fact that data's diffused by WHO which are widely included in the literature, unfortunately present this filariasis as being endemic in the Republic of Congo. But it is impossible to identify what works are at the origin of this assertion during the 30 last years. What is certain, it is that no case of lymphatic filariasis was found at the time of the field surveys carried out on filariasis both in the Congo and in Gabon, country also presented as an endemic territory, at the end of the Seventies and during the Eighties. These works were unfortunately published in French. Since this time no publication related a fieldwork or a conclusive clinical observation has confirmed the presence of Wuchereria bancrofti in these two countries of Central Africa.


Asunto(s)
Filariasis Linfática/diagnóstico , Enfermedades de los Genitales Masculinos/parasitología , Escroto/parasitología , Animales , Congo , Filariasis Linfática/parasitología , Enfermedades Endémicas , Filariasis/clasificación , Gabón , Humanos , Masculino , Mansoneliasis/diagnóstico , Oncocercosis/diagnóstico , Wuchereria bancrofti/aislamiento & purificación
15.
Bull Soc Pathol Exot ; 98(3): 187-92, 2005 Sep.
Artículo en Francés | MEDLINE | ID: mdl-16267958

RESUMEN

Immune reconstitution syndrome (IRIS) is an unusual inflammatory reaction to an opportunistic infection in an HIV-positive patient. This syndrome occurs when immunity is restored in the first months of an effective highly active antiretroviral treatment (HAART). First, we described all patients with a cutaneous form of IRIS. Then, between 1992 and 2004 we conducted a retrospective cohort study comparing Herpes Zoster and Herpes Simplex infections among untreated patients, patients treated by HAART for < or = six months, and patients treated for > six months. We observed three cases of atypical leprosy and three original observations: two of these were fistulisation of lymph node histoplasmosis and tuberculosis, the third one reports the recurrence of a treated cutaneous leishmaniasis. Multivariate analysis showed that, after controlling for age, sex and CD4 counts, patients receiving HAART for < or = six months were more likely to develop Herpes Zoster or herpes simplex infections (p < 0.005). Herpes Simplex and Herpes Zoster infections are the two most frequent dermatological manifestations in our tropical setting. Although mycobacterial infections are more rarely observed than in visceral IRIS, the increased incidence of leprosy may be quite significant when the availability of HAART spreads to developing countries.


Asunto(s)
Terapia Antirretroviral Altamente Activa , Dermatitis/etiología , Infecciones por VIH/tratamiento farmacológico , Lepra/complicaciones , Enfermedades Cutáneas Infecciosas/etiología , Absceso/etiología , Adulto , Estudios de Cohortes , Fístula Cutánea/etiología , Dermatitis/inmunología , Susceptibilidad a Enfermedades , Femenino , Fístula/etiología , Guyana Francesa/epidemiología , Infecciones por VIH/complicaciones , Herpes Simple/etiología , Herpes Simple/inmunología , Herpes Zóster/etiología , Herpes Zóster/inmunología , Histoplasmosis/complicaciones , Histoplasmosis/inmunología , Humanos , Huésped Inmunocomprometido , Memoria Inmunológica , Leishmaniasis Cutánea/complicaciones , Leishmaniasis Cutánea/inmunología , Lepra/inmunología , Enfermedades Linfáticas/etiología , Masculino , Persona de Mediana Edad , Recurrencia , Estudios Retrospectivos , Enfermedades Cutáneas Infecciosas/inmunología , Tuberculosis Ganglionar/complicaciones , Tuberculosis Ganglionar/inmunología
16.
Ann Dermatol Venereol ; 132(2): 133-5, 2005 Feb.
Artículo en Francés | MEDLINE | ID: mdl-15798563

RESUMEN

INTRODUCTION: Histoplasma capsulatum var capsulatum is a dimorphic fungi predominating on the American continent. It is responsible for disseminated histoplasmosis associated with AIDS. The presentation in the form of cutaneous ulceration is uncommon and misleading. OBSERVATION: A 25 year-old man presented with 3 ulcerations, of 2 to 4 cm in diameter, localized on the lower lip and knees. The patient exhibited fever, alteration in his general status of health and a pulmonary interstitial syndrome. He was seropositive for the human immunodeficiency syndrome (HIV). His lymphocyte CD4+ level was of 1/mm3. Diagnosis of histoplasmosis was established by direct examination and culture of the cutaneous ulcerations and bronchoalveolar washing fluid. DISCUSSION: The clinical aspect of cutaneous localizations of disseminated histoplasmosis is usually multiple, disseminated, papular or nodular-type lesions. Ulcerations represent less than 20% of the cases described. In our patient, the aspect of the lesions at first evoked cutaneous leishmaniosis. Direct mycological examination followed by culture confirmed the final diagnosis.


Asunto(s)
Infecciones por VIH/complicaciones , Histoplasmosis/patología , Histoplasmosis/virología , Úlcera Cutánea/microbiología , Adulto , Recuento de Linfocito CD4 , Histoplasma/patogenicidad , Histoplasmosis/etiología , Humanos , Rodilla/patología , Labio/patología , Masculino , Úlcera Cutánea/etiología
17.
Ann Dermatol Venereol ; 132(2): 136-9, 2005 Feb.
Artículo en Francés | MEDLINE | ID: mdl-15798564

RESUMEN

INTRODUCTION: Paracoccidio-domycosisis a deep mycosis due to a dimorphic fungus:Paracoccidioides brasiliensis. The principle endemic country is Brazil. We describe the first case of paracoccidio-domycosis, in its cutaneous-mucosal form, diagnosed in French Guiana. OBSERVATION: A 20 year-old Brazilian man, having mover to French Guiana a few months earlier, presented with multiple disseminated cutaneous lesions, predominating on the face, and composed of multiple nodules and two ulcerations. The clinical examination also revealed voluminous superficial lymph nodes and ulcerations of the pharynx and larynx. Direct examination, anatomopathology and culture of cutaneous biopsies revealed specific images of Paracoccidioides brasiliensis. HIV serology was negative. Treatment combining cotrimoxazole and itraconazole eliminated the lesions in one month. DISCUSSION: Because the patient had just moved to Guiana, this observation probably corresponded to an imported disease. The principle differential diagnosis was leishmaniosis.


Asunto(s)
Antiinfecciosos/uso terapéutico , Antifúngicos/uso terapéutico , Itraconazol/uso terapéutico , Paracoccidioidomicosis/tratamiento farmacológico , Paracoccidioidomicosis/patología , Combinación Trimetoprim y Sulfametoxazol/uso terapéutico , Adulto , Diagnóstico Diferencial , Cara/patología , Guinea , Humanos , Leishmaniasis/diagnóstico , Masculino , Paracoccidioidomicosis/diagnóstico
18.
Med Trop (Mars) ; 65(2): 149-54, 2005.
Artículo en Francés | MEDLINE | ID: mdl-16038355

RESUMEN

The Oyapock region is the second largest malaria outbreak area in French Guiana after Maroni. This area that has been less extensively studied that Maroni is characterized by the presence of an exclusively American Indian population on the French bank and by a high incidence of Plasmodium vivax associated with Plasmodium falciparum. The purpose of this study was to determine the incidence of malaria attacks in Camopi, a population center in which most inhabitants live in 15 small villages located along the middle part of the Oyapock River on the Brazilian border. Study involved diagnosis of malaria attacks (ongoing fever or reported fever within 48 hours and presence of asexual Plasmodium parasites with no other apparent etiology) and accurate estimation of its incidence as well as evaluation of the American Indian population. Study was carried out over the two-year period between April 2000 and March 2002. The mean annual incidence of malaria was 486 per 1000. Incidence was comparable for the two Plasmodium species: 248 p. 1000 for P. falciparum versus 259 p. 1000 for P. vivax but was much higher in children than adults (402 p. 1000 versus 92 p. 1000). The incidence of P. falciparum varied during the year and from one year to the next. Mixed infection documented by microscopic evidence was uncommon. With an annual incidence of around 500 p 1.000, the Oyapock area of French Guiana must be considered as a malaria hot spot.


Asunto(s)
Brotes de Enfermedades , Indígenas Norteamericanos , Malaria Falciparum/epidemiología , Malaria Vivax/epidemiología , Adolescente , Adulto , Factores de Edad , Animales , Niño , Preescolar , Guyana Francesa/epidemiología , Humanos , Incidencia , Lactante , Recién Nacido , Persona de Mediana Edad , Plasmodium falciparum/aislamiento & purificación , Plasmodium falciparum/patogenicidad , Plasmodium vivax/aislamiento & purificación , Plasmodium vivax/patogenicidad , Población Rural
19.
Int J Parasitol ; 34(10): 1185-96, 2004 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-15380690

RESUMEN

The majority of Toxoplasma gondii strains from a variety of human and animal sources have been grouped into three highly clonal but closely related lineages. The low occurrence of nucleotide differences among the three predominant lineages and their unusual dimorphic allelic composition suggest that they have arisen from a recent common ancestry. Less than 1% of the previously studied strains contain unique genotypes and high divergence of DNA sequence, and therefore are considered 'exotic' or 'atypical' strains. The seemingly low genetic diversity in T. gondii may have been underestimated because most parasite strains in previous studies were collected from human patients and domestic animals in North America and Europe. To investigate the genetic diversity of T. gondii, we analysed parasite strains isolated from remote geographical regions by multilocus microsatellite sequencing and phylogenetic analysis. The genetic diversity indices, the molecular analysis of microsatellite genotypes and the constructed phylogram considered together suggest that the global T. gondii population is highly diversified and not characteristic of a clonal organism. The most parsimonious hypothesis is that T. gondii presents a complex population structure with a mix of clonal and sexual propagation as a function of the environmental conditions. The comparison between domestic strains data on one hand and wild strains data on the other hand is in favour of more frequent sexual recombinations in wild environment even though Toxoplasma subpopulation in human and domestic animals is largely clonal.


Asunto(s)
Enfermedades de los Animales/parasitología , Genes Protozoarios , Toxoplasma/genética , Toxoplasmosis/parasitología , Animales , Animales Domésticos/parasitología , Secuencia de Bases , Clonación Molecular , Femenino , Variación Genética , Humanos , Masculino , Datos de Secuencia Molecular , Reproducción , Alineación de Secuencia
20.
Am J Trop Med Hyg ; 28(1): 53-5, 1979 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-373472

RESUMEN

Two cases are reported which illustrate important epidemiological aspects of lymphatic filariasis--prolonged longevity of the adult parasite and the possibility of transmission by individuals with ultra-low level microfilaremia. These cases demonstrate that people can remain carriers of microfilariae in the peripheral blood for many years without reinfection, and even those with a low level microfilaremia can constitute a significant reservoir of mosquito infection. Such cases represent one of the most serious obstacles to the eradication of lymphatic filariasis in regions where control is based on chemotherapy.


Asunto(s)
Aedes/parasitología , Filariasis/parasitología , Adulto , Anciano , Femenino , Filariasis/transmisión , Humanos , Masculino , Microfilarias/aislamiento & purificación , Polinesia , Factores de Tiempo , Virulencia , Wuchereria bancrofti/aislamiento & purificación
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