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Characteristics of Trypanosoma cruzi infection were studied in a rural area of the eastern plains of Colombia. Using enzyme-linked immunosorbent assay and indirect fluorescent-antibody tests, the infection was determined in 11.6% of the inhabitants of 142 dwellings. During 6 months of community surveillance, in 42.3% dwellings, 609 triatomines were collected (597 Rhodnius prolixus and seven, three, one, and one of Panstrongylus geniculatus, Psammolestes arturi, Eratyrus mucronatus, and Triatoma maculata, respectively). Rhodnius prolixus was found in 80% peridomiciliary Attalea butyracea palms examined with baited traps, and its infection with T. cruzi was 30% and 38.5% in dwellings and palms, respectively. Trypanosoma cruzi was isolated in five of 35 triatomines and in one of 24 dogs. The blood of domestic and wild animals was identified in triatomines collected in the intradomicile and in palms. These results support the extension of the wild cycle of T. cruzi to human dwellings and the characterization of a new scenario for transmission in Colombia.

Pretende-se aqui expor uma breve reflexão sobre o exercício da medicina tropical no Brasil e em Portugal privilegiando as chamadas tripanossomíases humanas, patologias causadas pela ação de tripanosomas no organismo humano como a doença de chagas – tida simultaneamente como um emblema da ciência brasileira, mas símbolo de um país doente e negligenciado – e a doença do sono – que assumiu grande importância para Portugal em decorrência de suas possessões africanas e da necessidade de afirmação do pais como potência colonial diante da concorrência europeia por territórios na África .

The sleeping sickness trypanosomes Trypanosoma brucei rhodesiense and T. brucei gambiense are morphologically indistinguishable from each other and from T. brucei brucei, which does not infect humans. The relationships between these three subspecies have been controversial. Several years ago, the characterization of T. brucei gambiense was reviewed in an attempt to clarify and draw together the results, and to put them in the context of the biology of the organism. The discovery of a gene associated with human-serum resistance in T. brucei rhodesiense and the consequent reappraisal of the identity of this trypanosome prompt this companion article.

Background Uganda has active foci of both chronic and acute HAT with the acute zoonotic form of disease classically considered to be restricted to southeast Uganda, while the focus of the chronic form of HAT was confined to the northwest of the country. Acute HAT has however been migrating from its traditional disease focus, spreading rapidly to new districts, a spread linked to movement of infected cattle following restocking. Cattle act as long-term reservoirs of human infective T. b. rhodesiense showing few signs of morbidity, yet posing a significant risk to human health. It is important to understand the relationship between infected cattle and infected individuals so that an appropriate response can be made to the risk posed to the community from animals infected with human pathogens in a village setting. Methodology/Principal Findings This paper examines the relationship between human T. b. rhodesiense infection and human infective and non-human T. brucei s.l. circulating in cattle at village level in Kaberamaido and Dokolo Districts, Uganda. The study was undertaken in villages that had reported a case of sleeping sickness in the six months prior to sample collection and those villages that had never reported a case of sleeping sickness. Conclusions and Significance The sleeping sickness status of the villages had a significant effect with higher odds of infection in cattle from case than from non-case villages for T. brucei s.l. (OR: 2.94, 95%CI: 1.38–6.24). Cattle age had a significant effect (p16.3%) in a village herd over was associated with significantly higher likelihood of T. b. rhodesiense being detected in a herd (OR: 25, 95%CI: 1.2–520.71)., Author Summary Human African trypanosomiasis (HAT) is a fatal parasitic disease of humans. Domestic cattle act as reservoirs for T.b. rhodesiense HAT. In a survey of cattle in Ugandan villages; six that had a reported HAT case in the previous six months, and six which did not, an association was detected between presence of HAT in a village and infection of village cattle with human infective parasites. Village HAT status was significant (p

A new sensitive technique using the electrophoresis of superoxide dismutase to distinguish between tsetse blood meals of human and non-human origin is described. In Côte d'Ivoire, 602 blood meals were collected; 170 were from man (28.3%), 377 from animals (62.6%) and 55 were unidentified (9.1%) because no pattern was observed. When calculating the index of epidemiological risk, it is strongly correlated with the incidence of sleeping sickness cases.

Following the discovery of four cases of African human trypanosomiasis, an entomological survey was conducted along the Mouhoun river in southwest Burkina Faso to collect Glossina palpalis gambiensis and G.tachinoides. Among 226 flies dissected, 4.87% (eleven individuals) were infected in midgut or proboscis, but never in the salivary glands. Polymerase chain reaction analysis was undertaken, and was able to characterize all the proboscis infections, and half of the midgut infections. Only Trypanosoma simiae and T. vivax were found in the organs of infected flies, in single or mixed-species infections. Ten more flies, negative with parasitological examination, were tested with Trypanozoon primers and remained negative. The epidemiological significance of the absence of T.brucei group infections in wild tsetse populations and the presence of T.simiae in G.p.gambiensis are discussed.

Chagas heart disease is endemic in 21 countries with approximately 100 million people at risk. It is the most common cause of myocarditis in the Americas and is recognized to have existed for more than 4000 years (isolated from mummies). Chagas disease was discovered during the search to find a cause for the overwhelming deaths occurring in Brazil in the late 18th century. Physician Carlos Chagas discovered Trypanosome minasense in 1908 while researching on malaria. Subsequently, the existence of the barbeiro triatomine (insects bites on the face), the isolation of the Trypanosome cruzi in the triatomine and the first human description of a disease in a 9-month-old child depicted the existence of a new human trypanosomiasis. Chagas named the trypanosome species after his colleague and mentor Oswaldo Cruz. In subsequent papers, Chagas described the morphology and evolutionary cycle of the trypanosome and the clinical features of the disease, including involvement of the heart. Never before or since one physician has fully characterized a disease from its grass roots to the clinical forms more or less all by himself.

Des études sur les lieux de repos diurnes de Glossina palpalis palpalis ont été menées d'octobre 1981 à décembre 1982 dans le foyer de trypanosomia.se humaine de Bouaflé (Côte d'Ivoire). 1382 glossines (970 mâles et 412 femelles), ont été observées au repos dans leurs habitats naturels après 757 heures de recherche. Quelle que soit la saison, plus de 80% des mouches étaient trouvées au repos sur des lianes (Acacia pennata en particulier), sur des caféiers (Coffea indica), sur des composées représentées par l'espèce Eupatorium odoratum. La quasi totalité des mouches observées se reposaient de préférence sur la face inférieure des parties ligneuses des plantes choisies, à des hauteurs comprises entre 10 cm et 2,5 m du sol. Les diamètres des supports ligneuses allaient de 0,1 cm à 8 cm. II convient de noter que quelle que soit la saison, plus de 50% des mouches se reposaient à une hauteur inférieure à 50 cm et que plus de 90% d'entre elles étaient observées sur des supports de diamètres inférieures ou égaux à 3 cm. Sur la végétation bordant les villages ou les différentes voies d'accès, les glossines ont toujours été trouvées au repos en profonfeur dans cette végétation à des distances comprises entre 1 et 5 m des lisières. Environ 27 % des mouches capturées au repos ont été trouvées gorgées ou en phase intermédiare. La capture des glossines au repos dans leurs habitats constitue donc dans la zone d'étude, un moyen privilégié pour la collecte de repas de sang frais en vue de l'identification des hôtes naturels de G. palpalis palpalis. Les implications practiques d'une telle étude sont discutées et des recommandations sont formulées pour l'application sélective d'insecticides rémanents contre les vecteurs de la trypanosomiase humaine dans le foyer de Bouaflé

The present account of the distribution and ecology of tsetse-flies (Glossina) in Liberia is based primarily on observations made from December, 1943, to August, 1944, for the American Foundation for Tropical Medicine, Inc. I have included some information obtained on an earlier brief stay in the same territory, from July to November, 1926, as a member of the Harvard African Expedition under the leadership of Dr. (now Colonel) Richard P. Strong. It seems essential to introduce the discussion of the Liberian tsetses with a concise description of environmental conditions. Of the twenty-one species of Glossina generally recognized at present, only four are efficient vectors of human trypanosomiasis, while the others are negligible, not being positively known to transmit the disease. The occurrence, abundance and habits of each species are closely correlated with the outside factors, or the environment, particularly as they concern the spread of the disease.

Summary: The accurate identification of the causative organisms of disease is fundamental to the study of epidemiology. Hence molecular tools are now widely used to detect and distinguish pathogens, and have greatly improved our understanding of epidemiology. David Godfrey pioneered the use of molecular markers in the epidemiology of African trypanosomiasis, thus enabling the light of reliable evidence to shine on this previously problematic and controversial subject area. From the early 1970’s David’s group employed first isoenzyme electrophoresis and subsequently DNAbased characterization methods to aid identification of trypanosomes collected from a range of endemic countries across Africa. These investigations had a major impact on our understanding of the zoonotic nature of human trypanosomiasis in Africa and of the genetic diversity of African trypanosomes.

Chemotherapy of trypanosomiasis and leishmaniasis is far from satisfactory and the discovery of new drugs has been slow. Emphasis on the empirical approach to drug development is now shifting towards a more rational, directed approach, which employs the modern tools of science. This is illustrated with respect to the newly discovered drug target, trypanothione, a unique metabolite which is critical for survival of Trypanosoma and Leishmania and absent from the host.

Pièges pyramidaux (8000) ont été mis en place contre #Glossina fuscipes fuscipes$ afin de lutter contre la maladie du sommeil à #Trypanosoma rhodésiense$ dans le Busoga. Dans le but de comprendre les modalités du contact homme/mouche, la récolte des données sur la densité, la distribution spatiale et la mobilité des mouches, ont été mis en relation avec la dynamique de la transmission de la trypanosomiase humaine dans le Bugosa. Comme pour #T. gambiense$, peu de corrélations entre la densité globale de mouche et l'incidence de la maladie ont été trouvées. Cependant, des observations de terrain avec un enregistrement daté des mouvements saisonniers des hommes et des animaux dans des habitats favorables aux mouches demeure la clé de la compréhension de la transmission de la maladie. (Résumé d'auteur)

Epidemics of human trypanosomiasis (sleeping sickness) have been occurring in Uganda since the beginning of the present century. The first such epidemic occurred along the shores of Lake Victoria and claimed millions of human lives. Another outbreak involving about 2500 persons occurred in the same area from Jinja eastwards to the border with Kenya between 1939 and 194S. Since this outbreak, cases continued to be reported within the infected area, though not in epidemic proportions. Between 1960 and 1971, the two main foci of human trypanosomiasis in Uganda were in south-eastern Uganda (Busoga and Bukedi Districts) and West Nile. In 1971, the infection in south-eastern Uganda spilled north of the usual focus and involved up to 169 persons. Following the control of this small epidemic, surveillance programmes were not instituted because of the prevailing political and economic atmosphere in the country at the time. Hence, by 1976, the stage was set for another epidemic outbreak of the disease in the country. This paper presents a detailed review of the present disease situation in the country and a brief review of the past.

The first human case of trypanosomiasis caused by Trypanosoma evansi was recently discovered in India. We have focused on the parasite to investigate whether this atypical infection was due to a particular genotype of T evansi. The SRA gene was not detected by PCR in the Indian human T evansi (TEVH) DNA sample. TEVH appears to be closely related to Vietnam WH, with identical alleles for TRBPA and MT30-33 AC/TC microsatellites. Furthermore, T evansi has homogeneous kDNA minicircles and the minicircles of isolate TEVH were shown to be of Type A. Thus, the T evansi isolated from an Indian patient appears to be a typical T evansi as far as we can judge, suggesting that the explanation for this unusual infection may lie with the patient. circle dot 2006 Elsevier B.V. All rights reserved.

The first reported human case of trypanosomiasis caused by Trypanosoma evansi was treated using suramin. Patient follow-up indicates that the drug and specific regimen used were well tolerated. Clinical, serological and parasitological investigations at 6 months indicate complete cure of the patient. Suramin should be considered in the treatment of other cases of human T evansi infection, if they occur. (c) 2005 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.

(2000). Clinical and biological evolution of human trypanosomiasis in Cote d'Ivoire. Annals of Tropical Medicine & Parasitology: Vol. 94, No. 8, pp. 831-835.

After discovery of the first recorded case of human infection with Trypanosoma evansi, serologic screening of 1,806 persons from the village of origin of the patient in India was performed using the card agglutination test for trypanosomiasis and T. evansi. A total of 410 (22.7%) people were positive by whole blood, but only 81 were confirmed positive by serum. However, no trypanosomes were detected in the blood of 60 people who were positive at a high serum dilution. The results probably indicate frequent exposure of the human population to T. evansi in the study area, which suggests frequent vector transmission of parasites to humans. Although T. evansi is not infective for humans, a follow-up of seropositive persons is required to observe the evolution of human infection with this parasite.

Human trypanosomiasis in the Eastern Hemisphere may be regarded as synonymous with African human trypanosomiasis, commonly but rather misleadingly known as sleeping sickness. Although trypanosomes of lower mammals have been found in man in India and Malaysia on rare isolated occasions, these are parasitological curiosities which need not be considered here. Because this article is concerned with drug treatment of African human trypanosomiasis, detailed accounts of the epidemiology and clinical features of the infection would be inappropriate. Instead, brief outlines of these topics are included as an introduction to the main subject. Those who desire further information about these aspects of the disease or who are interested in its history, its causative organisms and their insect vectors should consult the major work on the African trypanosomiases edited by Mulligan (1970). This book covers both the human and animal infections, the latter so important to the economy of the countries affected. More attention will be given here to the diagnosis of African human trypanosomiasis, since chemotherapy must be based on a firm foundation, and to the techniques that are used to assess the results of treatment.

Un des moyens de lutte contre les glossines est de les attirer sur des supports artificiels impregnes d'insecticide. Jusqu'a present, les supports utilises etaient de simples ecrans bidimentionnels de tissu bleu. Nous decrivons un nouveau modele a ecrans croises bleu-noir dont la tridimentionnalite augmente l'attractivite. Un toit de plastique protege les ecrans de la pluie et augmente la remanence de l'insecticide. Des rabats de tulle moustiquaire et de plastique creent un corps de piege interne dans lequel les glossines peuvent penetrer et avoir un contact prolonge avec l'insecticide. Modifie pour la capture, ce modele est au moins aussi efficace que le piege biconique. Sa grande simplicite de fabrication le rend trois fois moins couteux que ce dernier. Il a permis de reduire les populations de glossines de 98% en une semaine dans le foyer de trypanosomiase humaine de Kayes, au Congo. Avec une reimpregnation mensuelle, ces resultats sont maintenus depuis plus de 8 mois. Summary A new screen-trap for tsetse control: Description and trials in a focus of human trypanosomiasis in the Congo One method for control of tsetse flies is to attract them to artificial structures impregnated with insecticide. Up to now the structures used have been simple two dimensional screens of blue fabric. This paper reports a new model with two intersecting blue and black screens in which the three dimensional nature of the trap increases its attractiveness. A plastic roof protects the screens from rain and increases the residual life of the insecticide. Mosquito net and plastic flaps create partially enclosed spaces which the tsetse can enter and in which they have prolonged insecticidal contact. A design modified to capture the flies was at least as efficient as a bi-conical trap. The extreme simplicity of construction makes the cost of the new trap only a third of the bi-conical. In one week the new trap achieved a 98% reduction in the tsetse population in the Kayes focus of human trypanosomiasis in the People's Republic of the Congo. With monthly re-impregnation this level of control was maintained for more than 8 months.

During the 1977/78 dry season an experiment was conducted in the Volta Noire source tributaries area of Upper Volta, to assess the feasibility of controlling human trypanosomiasis by reducing the vector, Glossina palpalis gambiensis, by a combination of techniques. The objective was to suppress the target tsetse population by chemical means and then to achieve a further reduction or eradication by the release of sterile males. Sixteen kilometres of the fringing forest of the upper River Guenako were treated with the synthetic pyrethroid decamethrin (OMS-1998) applied from a helicopter as an aerosol at a dosage of 0.2 g/ha. Two applications at 14 days interval reduced the target G.p. gambiensis population by over 95% and caused important changes in the qualitative composition of both G.p. gambiensis and G. tachinoides populations. Subsequent over-flooding of the residual G.p. gambiensis population by sterile males was easily achieved.

The 1976–1982 epidemic of human trypanosomiasis in south-east Uganda affected new foci to the north of the old endemic area bordering Lake Victoria, and was associated with a different vector, Glossina fuscipes fuscipes; isoenzyme studies revealed that the epidemic involved different strains of pathogenic trypanosomes also. 58 Trypanozoon isolates from the epidemic area and from the adjoining endemic area of West Central Kenya were compared by thin-layer starch gel electrophoresis for 11 enzymes. Six different trypanosome zymodemes were circulating in man in the Ugandan epidemic, including the zymodeme found before 1976 in the old endemic area; all stocks examined from West Central Kenya belonged to this latter zymodeme. Trypanosomes identical to those found in man were found in cattle and a dog in Uganda, and in cattle in Kenya; these animals were presumably reservoir hosts of the human disease. Four isolates from triturated G. f. fuscipes collected in 1971 were identical but differed from all mammalian isolates examined.

Resume Les auteurs presentent une technique de diagnostic immunoenzymatique (« Micro E.L.I.S.A. ) de la trypanosomiase africaine, utilisant un conjugue marque a la peroxydase et un ultrasonnat de T. brucei gambiense comme antigene. L'application aux enquetes epidemiologiques est envisagee (prelevement sanguin sur papier filtre). La specificite est definie par comparaison de serums de sujets normaux et de malades porteurs de differentes parasitoses. Seule la leishmaniose semble susceptible de donner des reactions croisees avec la trypanosomiase. Des variations dans la positivite des resultats ont ete observees en fonction de l'origine des preparations antigeniques (souche malienne ou congolaise).

The spread of human trypanosomiasis towards Central Africa from sources in the Congo at the beginning of the present century, has been linked to population changes and movements between the affected states.The re-appearance of the disease in this part of Africa during the last 10 to 15 years raises again the question of how this disease is propagated. Although present day population movements are not so pronounced as those at the beginning of the century, these are significant population movements along major lines of communication (large rivers particularly). Of equal importance are disease foci which straddle national boundaries. Migrant populations (fishermen from Nigeria and displaced persons or refugees) also play important roles in the dispersal of the disease.Even within certain foci, the mobility of rural populations helps to sustain the endemicity of the disease over large areas.The risks of introducing or increasing trypanosomiasis must not be neglected when populating new areas and when developing agro-industrial complexes which require large labour forces.

Summary 1. Origin of the Outbreak.—No fresh light has been thrown on the origin of the outbreak. The alternatives remain as they were in 1922, and it is at present not more probable that infection was derived from game than that it was introduced with a human infect. The evidence available is to the effect that the outbreak, as an appreciable outbreak, is of recent occurrence. 2. Method of Spread.—Cyclical infection appears likely to have been at play; but even here man is indicated as a probable infector of the fly. 3. Game Distribution.—The position in 1922 was exactly as it was described by me at the time (1923, p. 324), execpting that the arrow in my map, between Kilalo and Ngasamo, indicating a game movement and a good deal of game abundance, should, I find, have been extended unbrokenly to Mtukuza. Observations made outside the area, or at a date when it has been to all intents and purposes a game reserve for eighteen months, are irrelevant. The position described in 1922 and the fact that it was preceded by very heavy slaughter of game were matters of observation and investigation, and the facts have been confirmed by others. The belief that the oft-urged experiment in game destruction has been practically carried out in the area was a statement of opinion. It may be correct or it may be mistaken. 4. Source of Infections.—The importance of infected man as a source of infection of the fly has probably been very greatly under-estimated. Actual evidence against the game as a reservoir of Rhodesian sleeping sickness is still confined to the resemblance between the trypanosomes, and, as regards this theory, the laboratory analogy relied on by Dr. Duke . The game may be a reservoir, but, especially in view of Taute's experiments, that needs to be proved. 5. Inference from Discoveries of T. rhodesiense Infection.—The mere fact of the occurrence of an autbreak is not “A link in a chain of evidence that wherever game infected with the brucei-type of trypanosome, fly of the morsitans group and man are brought into sufficiently close contact” cases of human sleeping sickness will arise. Many outbreaks, perhaps most, possibly all, may be originated by infected human beings. The evidence must be closely sifted and the probabilities separately arrived at for every outbreak and case. There has been such continuous movement of people between infected and uninfected areas during and since the war, that it will be surprising if cases and outbreaks of man-introduced infection are not found to be ubiquitous. 6. Effect of the Measures Adopted.—Most of the figures of sick for 1923 came from country which had been unsearched or in which control was otherwise incomplete in 1922. The Sultanates most fully searched and brought under control in 1922 showed the figures 2, 0 and 0 in 1923. This, it is believed by those best in a position to judge, was a true indicant of the success of the measures taken. 7. The Effect of the Prevalence of the “One-family” Bush Village.—Owing to the small size of such villages the feral conditions essential to the presence of tsetse in numbers exist right up to them and to their very small fields, and the inhabitants, sick and well, are attended by the flies in all their occupations. A maximum number of flies are thus laid open to infection, and a maximum number of healthy people. Thus, with village to village intercourse also considerable, epidemic is likely to be facilitated by a prevalence of the small village.

The two subjects considered in this paper are of practical importance to those interested in research of the kind carried out at the Human Trypanosomiasis Research Institute, Uganda. Their discussion would seriously encumber a report on experimental work and would distract the reader's attention from the main theme. The subjects are therefore dealt with separately, since they bear on all work, past and present, carried out at the Institute.

The actual commencement of the great wave of human trypanosomiasis, which claimed so many thousands of lives along the shores of Lake Victoria, is difficult to determine. The attention of Europeans was first attracted to the disease early in 1901, when eight cases of sleeping sickness were admitted to Mengo hospital by the Drs Cook, who had been established in Uganda some five years, to whom the clinical picture was quite new. Enquiry among the chiefs of Buganda revealed the fact that sleeping sickness was known to the natives as mongota, and was more prevalent in the eastern portion of the Protectorate than in Buganda itself. A large number of deaths had already occurred in Busoga Province and in Buvuma Island.