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Biomedical subjects

M A Moraes

Publications and source records attributed to M A Moraes.

At least 19 recordsLinked to original sources
PubMed2005

[Onchocerciasis among Yanomámi Indians].

The main features of the Brazilian focus of onchocerciasis are reported. This focus encompasses large areas of the states of Amazonas and Roraima, in the densely forested highlands of Northern Brazil. It is not clear how the local inhabitants, Indians of the group Yanomámi, an isolated group that has lived in the region for centuries, acquired the infection. However, in some of their villages the prevalence rate among adults is as high as 80%. Aspects of the focus, as its origins, manifestations of the illness among the Indians, and the distribution and importance of the recognized vectors of O. volvulus in the region, are reviewed. The author also makes some considerations on the behavior and probable future of the focus, including the possible dissemination of onchocerciasis to some other sites of Brazil. Gold miners that in recent years have invaded the Yanomámi territory and became infected in contact with the Indians will be the cause of this dissemination. Methods for controlling onchocerciasis are discussed and, besides the treatment of the infected Indians with Ivermectin, it is proposed the use of larvicides to eliminate the vectors. This method would be employed in some limited areas where the population is already stable and shows a very high prevalence rate.

English Abstract↗
PubMed2001

Trypanosoma evansi experimental infection in the South American coati (Nasua nasua): clinical, parasitological and humoral immune response.

The course of Trypanosoma evansi infection in coatis (Carnivora, Procionidae) was followed for 262 days. Parasites were detected in all infected animals from day 2 post infection until the end of the study. No correlation between temperature and parasitemia was observed. Animals of the infected group demonstrated depression, weakness, lethargy and pale mucous membranes. Indirect fluorescent antibody tests detected anti-T. evansi antibodies within 7 to 14 days post infection and showed high levels until the end of the experimental period. The persistent parasitemia in coati and their relative tolerance to clinical signs suggested that this species develops a chronic disease and plays an important role in the epidemiology of trypanosomosis due to T. evansi in enzootic regions.

Animals↗
PubMed1998

A comparison of efficacy of sargramostim (yeast-derived RhuGM-CSF) and filgrastim (bacteria-derived RhuG-CSF) in the therapeutic setting of chemotherapy-induced myelosuppression.

A randomized, double-blind, multicenter study in 181 afebrile cancer patients with ANC levels < 500/microL receiving myelosuppressive chemotherapy was undertaken to compare sargramostim (yeast-derived recombinant human granulocyte-macrophage colony-stimulating factor, RhuGM-CSF) and filgrastim (bacteria-derived recombinant human granulocyte colony-stimulating factor, RhuG-CSF) in the treatment of chemotherapy-induced myelosuppression. Patients received daily subcutaneous (SC) injections of either agent until ANC levels reached at least 1500/microL. There was no statistical difference between treatment groups in the mean number of days to reach an ANC of 500/microL, but the mean number of days to reach ANC levels of 1000/microL and 1500/microL was approximately one day less in patients receiving filgrastim. Fewer patients in the sargramostim arm were hospitalized, and they had a shorter mean length of hospitalization, mean duration of fever, and mean duration of i.v. antibiotic therapy compared with patients who received filgrastim. Both growth factors were well tolerated. No patient was readmitted to the hospital after growth factor was discontinued. Sargramostim and filgrastim have comparable efficacy and tolerability in the treatment of standard-dose chemotherapy-induced myelosuppression in community practice.

Adult↗
PubMed1997

An epidemic of sylvatic yellow fever in the southeast region of Maranhao State, Brazil, 1993-1994: epidemiologic and entomologic findings.

Yellow fever virus transmission was very active in Maranhao State in Brazil in 1993 and 1994. An investigation was carried out to evaluate the magnitude of the epidemic. In 1993, a total of 932 people was examined for yellow fever from Maranhao: 70 were positive serologically, histopathologically, and/or by virus isolation, and another four cases were diagnosed clinically and epidemiologically. In Mirador (17,565 inhabitants), the incidence was 3.5 per 1,000 people (case fatality rate [number of deaths/number of cases diagnosed] = 16.4%), while in a rural yellow fever risk area (14,659 inhabitants), the incidence was 4.2 and the case-fatality rate was 16.1% (10 of 62). A total of 45.2% (28 of 62) asymptomatic infections were registered. In 1994, 49 serum samples were obtained and 16 cases were confirmed (two by virus isolation, two by seroconversion, and 12 by serology). No fatal cases were reported. In 1993, 936 potential yellow fever vectors were captured in Mirador and a single strain was isolated from a pool of Haemagogus janthinomys (infection rate = 0.16%). In 1994, 16 strains were isolated from 1,318 Hg. janthinomys (infection rate = 1.34%) and one Sabethes chloropterus (infection rate = 1.67%). Our results suggest that this was the most extensive outbreak of yellow fever in the last 20 years in Brazil. It is also clear that the lack of vaccination was the principal reason for the epidemic, which occurred between April and June, during the rainy season, a period in which the mosquito population in the forest increases.

Adolescent↗
PubMed1996

Dissemination of Leishmania (Viannia) braziliensis.

Destructive human mucocutaneous leishmaniasis may appear many years after the primary cutaneous infection with Leishmania (Viannia) braziliensis. Hamsters (Mesocricetus auratus) were infected with metacyclic L. braziliensis promastigotes. It was found that secondary metastatic visceral lesions could arise from a primary cutaneous lesion, or secondary cutaneous lesions from a primary visceral lesion. Parasites in the viscera were shown to be viable, multiplying and capable of metastasis to either secondary visceral or cutaneous sites. The finding of an early metastasis in the wall of a small cutaneous vessel indicates that dissemination can occur by the haematogenous route. Slow growing organisms in viscera may thus be a source for late metastasis to mucocutaneous sites or for systemic relapse after immunosuppression.

Animals↗
PubMed1987

The status of Simulium oyapockense and S. limbatum as vectors of human onchocerciasis in Brazilian Amazonia.

In an attempt to explain the current distribution of onchocerciasis in the forests of northern Brazil (Moraes et al., 1979, 1986), and its potential for dispersal to other areas, this study compares the vector status of Simulium oyapockense Floch and Abonnenc, 1946 in both a hypoendemic and an onchocerciasis free area with that of S. limbatum Knab, 1915 in the latter area. Both species allowed the full development of Onchocerca volvulus (Leuckart) to the infective L3 stage after experimental infection with microfilariae. Their vector competence was significantly lower than for other efficient vector species in South America and Africa because of the lethal effect of the cibarial armature on ingested microfilariae. The low vector capacity of S. oyapockense, together with the low prevalence and intensity of infection of O. volvulus, probably explains why onchocerciasis has not significantly increased in intensity over the last 10 years in the hypoendemic part of the Amazonian focus. Omnipresence of both vector species in the adjacent savanna region, however, could facilitate the spread of onchocerciasis if human population movements continue from the hyperendemic part of the onchocerciasis focus.

Animals↗
PubMed1983

The concentration of Mansonella ozzardi microfilariae in skin capillaries.

The densities of microfilariae of Mansonella ozzardi in different regions of the body of infected individuals were studied. The density in venous blood closely approximated to that found in finger capillaries, but was significantly lower than the densities in capillaries of the scapular region and buttocks. A possible explanation for this concentration of microfilariae is the lack of glomi in these two sites, which consequently have a lower flow of blood than areas where glomi occur and where microfilarial densities are lower. No relationship was found between blood and skin densities in the buttocks and scapular region, probably due to the inadequacy of the skin snip method used for the detection of this species of filaria. It was concluded that the most acceptable detection method for M. ozzardi remains the sampling of finger capillary blood. It could not be decided, due to the paucity of data, whether any relationship exists between skin microfilarial densities and the biting sites of the vectors.

Adolescent↗
PubMed1981

An epidemic of yellow fever in Central Brazil, 1972-1973. II. Ecological studies.

Results of ecological studies undertaken during the 1972-1973 epidemic of yellow fever (YF) in Goiás State, Brazil, suggest that mosquitoes of the genus Haemagogus were the only vectors infected with YF virus. Nine isolations of the agent were made from 1,688 Haemagogus spp. caught within or near forests from 27 January to 3 March 1973. Seven of these isolations cane from mosquitoes collected on the forest floor. No YF virus isolation was made from 791 Haemagogus leucocelaenus or 1,096 Sabethes chloropterus. Haemagogus were caught both in and outside houses located 500 m from the forest, although at a lower rate than in the forest. Haemagogus collection rates in a secondary growth forest were similar to or even higher than those in primary forests. YF virus was recovered from a Cebus monkey and hemagglutination-inhibition and/or neutralizing antibody to YF virus was found in seven (30.4%) of 23 primates examined. There was, however, little evidence of sick or dying monkeys. Among other wild-caught animals only a single marsupial (Caluromys) had antibodies to the virus. These data show that sylvan YF is not confined to the forest, nor always associated with conspicuous epizootics.

Animals↗
PubMed1980

Simulium species of the amazonicum group as vectors of Mansonella ozzardi in the Brazilian Amazon.

Experimental infection with Mansonella ozzardi of common haematophagous Diptera collected at a Ticuna Indian village on the upper reaches of the Solimões river in the Brazilian Amazon, showed that Simulium amazonicum and Simulium n.sp. are capable of supporting full development of the parasite. Natural infections with this filaria were found in both species including infective larvae in Simulium n.sp. No development of M. ozzardi occurred in Mansonia amazonensis, Culicoides insinuatus or Lepiselaga crassipes (Tabanidae). The dimensions of developing larvae of M. ozzardi in both species of black-fly were recorded. Infective larvae of this species may easily be distinguished from those of Onchocerca volvulus, also transmitted in the Amazon by a species closely resembling S. amazonicum, by the presence of a bifid tail and higher anal ratio in M. ozzardi.

Animals↗
PubMed1978

An epidemic of yellow fever in central Brazil. 1972-1973. I. Epidemiological studies.

An epidemic of jungle yellow fever occurred in Goiás State, Brazil, between December 1972 and March 1973. Laboratory confirmed cases were observed in 36 counties located in the central and southern parts of the State. Seventy-one cases were proved, of which 44 were fatal. The diagnosis was made on the basis of pathology, serology, and virus isolation. Besides yellow fever, malaria and viral hepatitis were present, and in two fatal cases there was malarial pigment in the liver in addition to the specific lesions associated with yellow fever virus infection. The fact that male patients strikingly outnumbered females (9:1) and that young adults were predominantly affected indicates that transmission occurred mainly inside or adjacent to the forests. The lack of cases in urban areas can be attributed to the absence of Aedes aegypti in these areas. Yellow fever complement-fixing antibody in high titers was found in 18 of 1,201 (1.4%) persons living in eight counties of the affected area. This finding suggests that at least 21,000 persons out of the 1.5 million rural inhabitants of the three districts where the epidemic occurred had been infected by the virus. The epidemic subsided following an intensive vaccination campaign, and the last four cases were observed in March 1973.

Adolescent↗
PubMed1978

Toxoplasmosis among the Ticuna Indians in the state of Amazonas, Brazil.

Results of a serologic survey for Toxoplasma gondii among 408 Ticuna Indians from five villages in western Brazil are presented and compared with the results of 61 non-Indian inhabitants of the town of Codajas, Amazonas. Indirect hemagglutination antibody titers greater than or equal to 64 were found in 39% of the Ticuna population as compared to 77% of the Codajas population. Prevalence rates of titers greater than or equal to 256 were 20.3% for Ticunas and 39.3% for Codajas. Prevalence rates of titers greater than or equal to 256 in Ticuna villages where dietary habits were most variable were higher and more similar to those of non-Indian populations than were the prevalence rates of this titer range in villages where the animal food source was predominantly fish.

Adolescent↗