Prevalence of nits and lice in sampls of cut hair from floors of barbershop and beauty parlors in Belo Horizonte, Minas Gerais state, Brazil

A louse survey based on samples of cut hair collected from floors of barbershops and beauty parlors was conducted in Belo Horizonte, Minas Gerais State, Brazil, from October 1984 to April 1985, as an alternative way to determine the prevalence of pediculosis capitis in the population. Of 475 samples examined for nits, nymphs, or adults of Pediculus capitis, 140 were infested (29.5%). A total of 58 lice and 3.553 nits were found in 33.632.9 g of hair collected, giving a ratio of 0.10 nit/g. Almost 29% of the nits were viable and capable of being transmitted after hatching. There was significant difference among the infestation rates by socioeconomic levels, and samples from barbershops with male customers were the most infested. based upon the number of haircuts in each sample, we estimated that 5 or 6% of the population might be infested by this species.

The importance of the opossum (Didelphis albiventris) as a reservoir for Trypanosoma cruzi in Bambuí, Minas Gerais state

In a survey realized on the sylvatic and peridomestic environment at Bambuí county, Minas Gerais State, 44 (37.9%) out of 116 opossums (Didelphis albiventris) captured were found to be naturally infected with Trypanosoma cruzi. One handred and forty three parasite samples were obtanied from 43 infected opossums using simultaneously hemoculture, xenodiagnosis (Triatoma infestans, Panstrongylus megistus and Rhodnius neglectus) and examination of anal glands contents. The parasite samples were characterized according to six isoenzyme patterns. All samples, independently of the method of isolation, presented an isoenzyme pattern similar to the standard T. cruzi Z1, showing that either xenodiagnosis or hemoculture can used without selecting parasite subpopulation from naturally infected opossums. Preveous isoenzyme patterns reported for human T.cruzi isolates from same region were completely different. This isoenzyme dissimilarity between sylvatic and domiciliar environments suggests the existence of two independent T. cruzi transmission cycles in Bambuí. The epidemiological implicatinos of these results are discussed.

Intestinal parasites in Iaualapiti indians from Xingu Park, Mato Grosso, Brazil

Brine flotation and gravity sedimentation coproscopical examinations were performed in stool samples from 69 of the 147 Iaualapiti Indians of the Xingu Park, Mato Grosso State, Brazil. Intestinal [arasites were present in 89.9% of the population examined. High rates of prevalence were found for some parasite species. Ancylostomidae, 82.6%; Enterobius vermicularis, 26.1%; Ascaris lumbricoides, 20.3%; and Entamoeba coli, 68.1%. Infection by Trichuris trichuria, Schistosoma mansoni, Taenia spp. and Hymenolepis nana was not detected. Helminth's prevalence in children aged one year or less was comparatively low (33.3%). Quantitative coproscopy was done in positive samples for Ascaris and Ancylostomidae and the results expressed in eggs per gram of feces (EPG). Quantitative results revealed that worm burdens are very low and overdispersed in this Indian tribe, a previously unreported fact.

The threat of reintroduction of natural transmission of Chagas' disease in Bambuí, Minas Gerais state, Brazil, due to Panstrongylus megistus

In the Epidemiological Surveillance Program in the county of Bambuí, Minas Gerais, between August 1986 and December 1988, 154 Panstrongylus megistus were captured by the local population in both peridomicile and intradomicile environments. Fifteen (9.8%) of the P. megistus harboured Trypanosoma cruzi. Preciptin tests showed that the most frequent triatomine blood meal sources were birds, but other sources were dogs, men and cats. The isoenzyme characterization of 13 T. cruzi strains showed that six belonged to zymodeme Z1, corresponding to the wild parasites, and seven belonged to zymodeme Z2, corresponding to parasites isolated from chronic chagasic patients (domestic cycle). As P. megistus were found to be naturally infected by parasites from both cycles, they are cleary able to transmit T. cruzi from the wild cycle to the domestic cycle. Furthermore the capacity of P. megistus in colonizing houses was observed in one residence, vacant for several years, in wich 153 triatomines were captured. The data show the possibility of P. megistus reintroducing transmission of Chaga's disease in the county if Epidemiological Surveillance is interrupted.

Biomphalaria occidentalis paraense, 1981 in the state of Minas Gerais, Brazil

A population of Biomphalaria occidentalis was found for the first time in the State of Minas Gerais. It was probavly introduced into the Várzea das Flores dam, in the municipality of Contagem, the area o0f study, during fish stocking in 1985. There is possibility of "competitive exclusion"between that species and B. glabrata, previously the only Biomphalaria found in the region. The present geographical distribution of B. occidentalis in Brazil is listed.

Biological control program against simuliids in the State of São Paulo, Brazil

In Brazil, the use of biological vector-control methods has been largely confined to experimental research, with little or no application of such techniques by public institutions responsible for implementing control programs. The notable exceptions have been the black fly control program carried out by the Health Secretariat in the State of São Paulo. Since the 1980s, São Paulo's "Superintendência de Controle de Endemias" has been conducting studies on the viability of using Bacillus thuringiensis (H-14) for simuliid control, and the results have been so encouraging that the agency has now incorporated this method into its Simuliid Control Program.

Interrelationship between Ectoparasites and Wild Rodents from Tijucas do Sul, State of Paraná, Brazil

Sixteen species of ectoparasites were collected from 50 wild rodents, from August 1990 to August 1991, in an area of Araucaria augustifolia forest, in the municipality of Tijucas do Sul, State of Paraná, Brazil. Ectoparasites infested 98% of the rodents, with the highest indices of infestation found in the dry-cool season. Species that occurred in single or multiple infestations were recorded. Ectoparasite/host associations were significant (p<0.01) for Gigantolaelaps wolffsohni/Oryzomys nigripes, Polygenis pradoi/Oxymycterus sp. and Amblyopinus sp./Oxymycterus sp. The following represent new host records: Polygenis (Polygenis) tripus from Akodon serrensis and Hoplopleura sciuricola from Sciurus aestuans. New geographic records are given for two species of flea and one sucking lice.

Detection of poxvirus in cattle associated with human cases in the State of Rio de Janeiro: preliminary report

This preliminary report describes human and cow cases of poxvirus that recently ocurred in the State of Rio de Janeiro. The electron microscopic findings were consistent with parapoxviral and orthopoxviral infection. Orthopoxvirus strains were isolated from human and cow cases. Detailed viral characterization by means of genetical techniques is under investigation. Based on these informations, poxviral diseases should be also considered an emerging viral zoonosis that can affect human beings.

Monitoring the domiciliary and peridomiciliary invasion process of Triatoma rubrovaria in the State of Rio Grande do Sul, Brazil

The presence of Triatoma rubrovaria in Brazil has only been confirmed in the States of Paraná and Rio Grande do Sul (RS), where it is found naturally infected with Trypanosoma cruzi. In the wild environment it occurs in rocky habitats and has an eclectic diet, feeding from cockroaches, reptiles and mammals. Data from the Chagas Disease Control Program obtained by the Fundação Nacional de Saúde, between 1975 and 1997, indicate a growing domiciliary and peridomiciliary invasion of T. rubrovaria in RS, where it has become the most frequently Triatominae species captured in this state since the control of Triatoma infestans. In order to monitor this process, we analyzed collection data derived from 22 years of control campaigns against T. infestans. Collection data for triatomines from domestic habitats show an inverse relationship, with high numbers of T. infestans and low numbers of T. rubrovaria during 1976-1987, compared to the following ten years, 1986-1997, when the number of T. infestans dropped drastically and that of T. rubrovaria increased. There are no consistent indications of intradomiciliary colonization by T. rubrovaria, since only low numbers of nymphs have been captured in the intradomiciliary ecotopes. Nevertheless, this species appears to have preadaptive characteristics for anthropic ecotopes, and should be kept under constant epidemiological surveillance.

Cutaneous leishmaniasis caused by members of Leishmania braziliensis complex in Nayarit, State of Mexico

An epidemiological study was carried out in the northern Mexican state, Nayarit. Fourteen patients with possible cutaneous leishmaniasis skin lesions gave positive Montenegro skin tests. Biopsies were taken from the skin ulcer and analyzed by polymerase chain reaction (PCR) with specific primers for the Leishmania mexicana complex; however all biopsies were not amplified. PCR carried out with specific primers for the L. braziliensis complex resulted in the amplification of all patient DNA. DNA from 12 out of 14 biopsies gave positive amplification with primers species specific for L. (Viannia) braziliensis and hybridized with a species specific L. (V.) braziliensis probe. These results demonstrate the presence in Nayarit of at least two members of the L. braziliensis complex. Most of the cutaneous lesions were caused by L. (V.) braziliensis and two by another species belonging to the L. braziliensis complex. As far as we are aware, this is the first report of L. (V.) braziliensis in Nayarit. The main risk factor associated with the contraction of this disease in Nayarit is attributed to working on coffee plantations.

Geographical distribution of Biomphalaria snails in the State of Minas Gerais, Brazil

Published and unpublished observations on geographical distribution of Biomphalaria snails in the State of Minas Gerais, Brazil, were compiled. This work is aimed at knowing the present occurrence of Biomphalaria species in this region, and at contributing to the elaboration of the planorbid chart of Minas Gerais. In malacological surveys, performed by several researchers, the presence of seven species of this genus was recorded. Those planorbids were found in 12 mesoregions, in 283 (33.1%) municipalities out of 853 with the following distribution: B. glabrata (185 municipalities), B. straminea (125), B. tenagophila (58), B. peregrina (57), B. schrammi (26), B. intermedia (20) and B. occidentalis (2). B. glabrata and B. tenagophila are found naturally infected by Schistosoma mansoni in Minas Gerais. In 24 municipalities the three snail hosts of S. mansoni in Brazil, B. glabrata, B. tenagophila and B. straminea, are present.