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Biomedical subjects

A Herrer

Publications and source records attributed to A Herrer.

At least 19 recordsLinked to original sources

Leishmania braziliensis in the Panamanian two-toed sloth, Choloepus hoffmanni.

A total of 498 two-toed sloths, Choloepus hoffmanni, collected in central Panama was examined for Leishmania braziliensis over a 10-year period. Isolations of the parasite from 96 (19.3%) of the animals were confirmed by culture and inoculation of golden hamsters. Improved culture techniques developed toward the end of the study assisted in determining a greater prevalence of the disease. Infectins were completely cryptic in all animals, and the parasite was isolated from skin, blood, liver, spleen, bone marrow and lung tissues. Sloths maintained under seminatural conditions remained infected up to 23 months, the longest period of survival. This edentate, considered the principal reservoir host of L. braziliensis in Panama, showed infection rates from 0-59.4% in various communities, which appeared to correlate with the parasite prevalence in the indigenous human populations.

Age Factors↗

Epidemiological patterns of cutaneous leishmaniasis in Panama. I. Epidemics among small groups of settlers.

Epidemic of cutaneous leishmanniasis among a small group of people established in a Panamanian forested area was studied. The first settlers arrived in June 1971, and by June 1973 there were 37 persons, 33 of whom had no previous history of the disease. Epidemiological surveys were made in June 1973 and March 1974. The disease developed in 14 (42.4%) of the 33 susceptible persons by June 1973, with an exposure time ranging from one to 14 months. The last case occurred in April 1973, and no new cases were observed during the ensuing 11 months. Two (15.4%) of 13 dogs examined were found with cutaneous leishmaniasis, but none of 41 feral mammals studied, mainly terrestrial rodents, was infected. Four leishmanial strains characterized, three from patients and one from a dog, were identified as Leishmania braziliensis. Phlebotomine sandfly population composition was studied and the probable vectors involved in the transmission to man were determined.

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Epidemiological patterns of cutaneous leishmaniasis in Panama. II. Incidental occurrence of cases in non-endemic settlements.

Epidemiological studies on cutaneous leishmaniasis were carried out in a settlement in the Bayano region, Republic of Panama, during 1971-72. This settlement was established about 12 years earlier for the purpose of cattle raising by small groups of settlers. The primary forest was cut and cleared and the area planted with grass. The presence of active cases of cutaneous leishmaniasis among humans and animals, both domestic and ferals, was investigated. In addition, phlebotomine sandflies were collected to determine their species composition. In 1971, nine of the 161 persons interviewed had active lesions; all but one of the patients were males and of these seven were adults. Five (9%) of 55 dogs and one (3%) of 33 feral mammals examined also were found infected. Strains of the parasite infecting both humans and animals were characterized as Leishmania braziliensis. About 60% of the sandflies collected belong to four man-biting species previously incriminated as vectors of human cutaneous leishmaniasis in Panama. The extensive pasture, together with periodic applications of insecticides in the houses by the antimalarial agency in this country, provided an effective barrier against transmission within the settlement itself. However, both humans and dogs acquired the disease during excursions into the surrounding forest. No new cases were found in 1972.

Animals↗

Panamanian forest mammals as carriers of Salmonella.

Enteric bacteria pathogenic to man were sought in a total of 974 forest mammals collected from a variety of sites in rural and jungle areas of Panamá. The highest incidence of infection among the mammals was observed during the Panamanian dry season, which normally extends from January through April. A minimum of 10 Salmonella serotypes including, three of the Arizona group and Ewardsiella tarda, was isolated. Opossums of the genera Philander, 11 of 54 (20.1%), and Didelphis, 12 of 102 (11.8%) demonstrated high infection rates. One sloth of the genus Choloepus and specimens of two genera of rodents also were infected to varying degrees: 1(11.1%) of 9 Choloepus, 8 (1.1%) of 704 Proechimys and 1 (16.7%) of 6 Diplomys.

Animals↗

Epidemiological patterns of cutaneous leishmaniasis in Panama. III. Endemic persistence of the disease.

Endemic persistence of cutaneous leishmaniasis is described in El Aguacate, a community established in the forest of central Panama about 75 years ago. Physiographic pecularities partially isolate El Aguacate from other villages in the region. Some of the original forest environment has been preserved and man-biting species of phlebotomine sandflies were abundant as was the two-toed sloth, Choloepus hoffmanni, the principal reservoir host of Leishmania braziliensis in Panama. The inhabitants, as well as their dogs, were examined for natural leishmaniasis in 1969 and 1973. Mammals and phlebotomine sandflies were collected from 1968 to 1973 in a search for reservoir hosts and potential vectors of the disease. Similar studies were undertaken in two nearby villages during 1968 and 1969. L. braziliensis has persisted for many years in El Aguacate, and infection is acquired during childhood. Dogs also were found naturally infected, and the two-toed sloth showed yearly infection rates up to 47.8%. Parasites were demonstrated from a night monkey, Aotus trivirgatus.

Adolescent↗

Natural cutaneous leishmaniasis among dogs in Panama.

A search for cutaneous leishmaniasis among dogs was conducted in several forest settlements of central Panama from 1968 to 1973. A total of 11 (3.3%) of 333 animals examined was found infected and, in 9 of these, parasites were isolated in culture and characterized as Leishmania braziliensis. Infected dogs occurred in three settlements, one of which was free of human leishmaniasis. In the latter case, infections were acquired in the nearby forest during hunting excursions. Ulcerated skin lesions primarily on the lower aspect of ears, or depigmentation and inflammation of the nostrils were manifested, with persistence as long as 45 months. The parasites did not disseminate from the lesion to viscera or other areas of the skin. The dog may serve as an incidental reservoir host of human leishmaniasis and/or a liaison of the infection between the jungle and forest settlements in the Republic of Panama.

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Infrequency of gross skin lesions among Panamanian forest mammals with cutaneous leishmaniasis.

Natural leishmanial infections among feral mammals in the Republic of Panama were studied in relation to gross skin alterations. Three dermatotropic species of Leishmania, L. braziliensis, L. mexicana and L. hertigi, isolated from 230 sylvatic animals of 5 mammalian orders were involved. In 205 (89%) of the cases there were no gross skin alterations. Cryptic infections of all three leishmanial species among wild animals were confirmed by culture and hamster inoculation. This type of infection was always present in the sloths, Choloepus hoffmanni and Bradypus infusatcus, infected with L. braziliensis and in the porcupine, Coendou rothschildi, infected with L. hertigi. Suggestive skin alterations were encountered in 10 (4%) of infected animals. Only 15 (7%) of infected animals exhibited typical leishmanial lesions. It was possible to correlate skin depigmentation with the course of leishmanial infection in one animal, a young kinkajou, Potos flavus.

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