Comparison between Human Immunodeficiency Virus Positive and Negative Patients with Tuberculosis in Southern Brazil

The objective of this study is to determine the different characteristics of human immunodeficiency virus (HIV) positive and negative patients treated for tuberculosis (TBC) in a tertiary hospital in Southern Brazil. We conducted a retrospective cohort study over a 5-year period, from January 1992 through December 1996. We reviewed medical charts of patients from our institution who received TBC treatment. We reviewed 167 medical charts of patients with confirmed TBC. HIV positivity was detected in 74 patients. There were statistically significant difference between HIV positive and negative patients in sex and age. HIV-infected patients showed significantly more signs of bacteremia than HIV-negative patients. Extra-pulmonary TBC was present respectively in 13 (17.6%) and 21 (22.6%) HIV positive and negative patients. There was a significant difference between chest radiograph presentation in HIV positive and negative patients. There were significantly lower hematocrit, hemoglobin, leukocyte and lymphocyte levels in HIV-positive compared to HIV-negative patients. Outcome was significantly different in the two groups with a death rate of 36.5% and 10.8% in HIV-positive and in HIV-negative patients. The difference between HIV positive and negative patients may have importance in the diagnosis, management and prognosis of patients with TBC.

Parasitism of Ixodes (Multidentatus) auritulus Neumann (Acari: Ixodidae) on birds from the city of Curitiba, state of Paraná, southern Brazil

The tick-bird relationship of 56 specimens of birds (Passeriformes and Columbiformes) collected in the city of Curitiba, State of Paraná, between 1990 and 1995, among which 102 specimens of Ixodes (Multidentatus) auritulus were found and analyzed. New host records were also produced including the first report of I. auritulus on a Columbiformes bird in Brazil.

Infections by Helminth Parasites in "Puyenes", Galaxias maculatus (Galaxiidae, Salmoniformes), from Southern Argentina with special reference to Tylodelphys barilochensis (Digenea, Platyhelminthes)

The occurrence of Tylodelphys barilochensis, Acanthostomoides apophalliformis, Contracaecum sp. and Camallanus corderoi infecting Galaxias maculatus ("puyenes") was quantified for the first time in Lake Nahuel Huapi, southern Argentina. T. barilochensis was recorded in this lake for the first time. The role of G. maculatus population in transmission of parasites to the salmonids is more important for Contracaecum sp. (prevalence 14-34%) and A. apophalliformis (prevalence 30-54%) than for C. corderoi (prevalence 6-8%). The absence of Diphyllobothrium spp. in samples shows that the G. maculatus population does not play any role in the life cycles of these important zoonotic parasites. The sex of the host had no effect on T. barilochensis abundance. Statistical differences in T. barilochensis abundance between "puyenes" of the same size class between sampling stations and positive correlation between prevalence of infected snails and T. barilochensis abundance in fish suggest that different stocks have been sampled. Factors influencing T. barilochensis abundance are discussed.

Hepatitis C virus prevalence among an immigrant community to the Southern Amazon, Brazil

A community-based random survey was conducted in a southern Brazilian Amazonian county aiming to investigate hepatitis C virus (HCV) infection prevalence and the association of demographic variables and lifestyle behaviours. Seven hundred eighty individuals were serologically screened with a third generation enzyme-linked immunosorbent assay to detect anti-HCV antibodies between 1994/1995. Positive samples were retested for confirmation with a line immunoassay (LIA, Inno-LIA HCV Ab III). Most of these subjects were low income and came from southern Brazilian states (65.8). Two point four percent (IC 95% 1.2%- 4.6%) of the subjects had LIA-confirmed anti-HCV antibodies reactivity. The age-specific prevalence of HCV antibodies slightly increased with age, with the highest prevalence after the age of 40 years. The results of multivariate analysis indicate a strong association between HCV antibodies and previous surgery and history of intravenous drug use. There were no apparent association with gender, hepatitis B virus markers, blood transfusion, and sexual activity. Mean time living in Amazon did not differ between confirmed and negative anti-HCV individuals. The present data point out an intermediate endemicity of HCV infection among this immigrant community to the Amazon region and that few HCV infected participants presented known risk factors.

Antimicrobial susceptibility of Campylobacter jejuni subsp. jejuni assessed by E-test and double dilution agar method in Southern Chile

The susceptibility patterns of 108 Campylobacter jejuni subsp. jejuni clinical strains, to six antimicrobial agents was determined by using the E-test and the double dilution agar methods. Using both metods, no strain was found to be resistant to ciprofloxacin, erythromycin and gentamicin, but two (1.8%) were resistant to tetracycline and all to aztreonam. Seven (6.5%) strains were resistant to ampicillin by the E-test and five (4.6%) by the double dilution agar method and by both meyhods. No great discrepancies were observed between both methods.

A review of the ticks (Acari, Ixodida) of Brazil, their hosts and geographic distribution - 1. The State of Rio Grande do Sul, Southern Brazil

A review of the ticks (Acari, Ixodida) of the State of Rio Grande do Sul, southern Brazil, was completed as a step towards a definitive list (currently indicated as 12) of such species, their hosts and distribution. The ticks: Argas miniatus (poultry), Ixodes loricatus (opossums), Amblyomma aureolatum (dogs), A. calcaratum (anteaters), A. cooperi (capybaras), A. nodosum (anteaters), A. tigrinum (dogs) (Neotropical) and Rhipicephalus sanguineus (dogs) (introduced, cosmopolitan, Afrotropical) were confirmed as present, in addition to the predominant, Boophilus microplus (cattle) (introduced, pan-tropical, Oriental). Of the further 18 species thus far reported in the literature as present in the state, but unavailable for examination: only Ornithodoros brasiliensis (humans and their habitations) (Neotropical), Ixodes affinis (deer) (Nearctic/Neotropical) and I. auritulus (birds) (Nearctic/Neotropical/Afrotropical/ Australasian) are considered likely; 13 species would benefit from corroborative local data but the majority appear unlikely; reports of A. maculatum (Nearctic/Neotropical, but circum-Caribbean) are considered erroneous; the validity of A. fuscum is in doubt. The very recent, first known report of the tropical Anocentor nitens (horses)(Nearctic/Neotropical), but still apparent absence of the tropical A. cajennense (catholic) (Nearctic/Neotropical) and the sub-tropical/temperate Ixodes pararicinus (cattle) (Neotropical) in Rio Grande do Sul are important for considerations on their current biogeographical distribution and its dynamics in South America. The state has relatively long established, introduced ("exotic"), Old World tick species (B. microplus, R. sanguineus) that continue to represent significant pests and disease vectors to their traditional, introduced domestic animal hosts, cattle and urban dogs. There are also indigenous, New World ticks (A. miniatus, O. brasiliensis, A. aureolatum, A. nitens), as both long established and possibly newly locally introduced species in the state, that should be considered as potential and emergent pests and pathogen vectors to humans and their more recently acquired, introduced domestic animal hosts; rural poultry, dogs and horses.

Trypanosoma cruzi infection in Didelphis marsupialis in Santa Catarina and Arvoredo Islands, southern Brazil

Between 1984 and 1993 the prevalence of the Trypanosoma cruzi infection in opossums (Didelphis marsupialis) was studied in Santa Catarina and Arvoredo Islands, State of Santa Catarina, Brazil. The association of the triatomine bug Panstrongylus megistus with opossums nests and the infection rate of these triatomines by T. cruzi was also studied. Thirteen different locations were studied in Santa Catarina Island (SCI), in which 137 D. marsupialis were collected. Sixty two opossums were collected at the Arvoredo Island (AI), located 12 miles north from SCI. All captured animals were submitted to parasitological examinations that revealed the presence of T. cruzi in 21.9% of the opossums captured in SCI and 45.2% among opossums captured in the AI. The presence of P. megistus was detected in most of the D. marsupialis nests collected in the SCI, however, in the non-inhabited AI only eight triatomines were collected during the whole study. The presence of T. cruzi-infected D. marsupialis associated with P. megistus in human dwellings in the SCI, and the high infection rate of D. marsupilais by T. cruzi in the absence of a high vector density are discussed.

Simulium (Psaroniocompsa) tergospinosum new species (Diptera: Simuliidae) in siolii group from the southern part of the State of Amazonas, Brazil

The larva, pupa, male and female of Simulium tergospinosum n. sp. are described and illustrated. The adults of this new species share many characters with species in the subgenus Psaroniocompsa, where it is placed. The larva of this species bears dorsal and lateral triangular tubercles on the abdomen and multiply branched scale-like setae on the body, suggesting that it belongs to the S. siolii species group. S. tergospinosum n.sp. was collected along the Juma River, Apuí county, in the southern part of the State of Amazonas, Brazil. The Juma, a black-water river, is a tributary of the Aripuanã River in the Madeira River hydrographic basin, on the southern part of Amazonas. Females were collected biting humans along the water courses during the sampling period (in the dry season).

Nematodes of elasmobranch fishes from the southern coast of Brazil

New records for nematode species recovered from elasmobranch fishes in Brazil are established and new systematical arrangements proposed. Parascarophis sphyrnae Campana-Rouget, 1955 from the spiral valve of Sphyrna zygaena is referred for the first time in South America as a new host record. Procamallanus (S.) pereirai Annereaux, 1946, from the spiral valve of Raja castelnaui is reported parasitizing an elasmobranch host. Nematode larvae of the genera Anisakis, Contracaecum, Pseudoterranova and Raphidascaris are listed from the stomach and spiral valves of several hosts. Anisakidae larvae previously referred in Brazil in the genus Phocanema should be reallocated in Pseudoterranova. Nematodes of the genera Anisakis, Contracaecum, Pseudoterranova and Raphidascaris are reported for the first time parasitizing elasmobranchs in Brazil.

Leucocytozoon toddi and Haemoproteus tinnunculi (Protozoa: Haemosporina) in the Chimango caracara (Milvago chimango) in southern Chile

Two species of blood protozoans were identified from blood smears collected from 15 specimens of the Chimango caracara (Milvago chimango) on Isla Grande de Chiloé in southern Chile. These included Leucocytozoon toddi in 13 birds, including all 5 of the 4-6 week old nestlings examined, and 8 of the subadults or adults. One of the nestlings also had a dual infection of L. toddi and Haemoproteus tinnunculi. These are the first reports of blood parasites from M. chimango.

Digenea and acanthocephala of elasmobranch fishes from the southern coast of Brazil

New records for helminth species recovered from elasmobranch fishes in Brazil are established. Digenean and acanthocephalan parasites of elasmobranch fishes are reported from the southern coast of Brazil: Otodistomum veliporum (Creplin, 1837) Stafford, 1904 (Digenea: Azygiidae) in the stomach and spiral valve of Dipturus trachydermus and in the spiral valve of Squatina sp. Cystacanths and juveniles of the acanthocephalans Corynosoma australe Johnston, 1937 and Corynosoma sp., in the spiral valve of Squatina sp., Galeorhinus galeus and Hexanchus griseus and in the stomach of Squalus megalops; a juvenile of Gorgorhynchus sp., in the spiral valve of Sphyrna zygaena. Dipturus trachydermus and Squatina sp. are new host records for O. veliporum. Digeneans and acanthocephalans are reported for the first time parasitizing elasmobranch fishes in Brazil.

Morphometric discrimination of females of five species of Anopheles of the subgenus Nyssorhynchus from Southern and Northwest Colombia

The most important vectors of human Plasmodium in the neotropics belong to the subgenus Nyssorhynchus. These species are generally sympatric in terms of their geographical distributions. Some are difficult to identify based solely on examination of adult females using the available morphological keys, in these cases examination of immature stages and male genitalia is required to make correct determinations. However, in epidemiological studies it is necessary to identify the species of adult females which are found near humans, i.e. in studies of malaria transmission or evaluation of control measures. The purpose of the present study was to evaluate the discrimination of adult females of different species of Nyssorhynchus isolated mainly from Southern Colombia (department of Putumayo), using morphometric analysis. Adult females were obtained after rearing larvae collected in natural breeding places and from the progeny of females collected on humans. The morphological characteristics of the immature stages allowed the identification of four species of the subgroup Oswaldoi from Southern Colombia: Anopheles rangeli Gabaldon, Cova Garcia & Lopez, An. oswaldoi (Peryassu), An. benarrochi Gabaldon, Cova Garcia & Lopez and An. triannulatus (Neiva & Pinto). The species An. nuneztovari (Gabaldon) from the Northwest of Colombia was included for comparison. Morphometric analysis allowed differentiation of the females of all species to a confidence level approaching 90% using principal components analysis of 10 wing and leg variables, followed by canonical variate analysis of the first four principal components. We conclude that morphometrics may represent a useful taxonomic tool for this group and that its use should be further studied.

Chagas disease: current epidemiological trends after the interruption of vectorial and transfusional transmission in the Southern Cone countries

Chagas disease, named after Carlos Chagas who first described it in 1909, exists only on the American Continent. It is caused by a parasite, Trypanosoma cruzi, transmitted to humans by blood-sucking triatomine bugs and by blood transfusion. Chagas disease has two successive phases, acute and chronic. The acute phase lasts 6 to 8 weeks. After several years of starting the chronic phase, 20% to 35% of the infected individuals, depending on the geographical area will develop irreversible lesions of the autonomous nervous system in the heart, esophagus, colon and the peripheral nervous system. Data on the prevalence and distribution of Chagas disease improved in quality during the 1980's as a result of the demographically representative cross-sectional studies carried out in countries where accurate information was not available. A group of experts met in Brasília in 1979 and devised standard protocols to carry out countrywide prevalence studies on human T. cruzi infection and triatomine house infestation. Thanks to a coordinated multi-country program in the Southern Cone countries the transmission of Chagas disease by vectors and by blood transfusion has been interrupted in Uruguay in1997, in Chile in 1999, and in 8 of the 12 endemic states of Brazil in 2000 and so the incidence of new infections by T. cruzi in the whole continent has decreased by 70%. Similar control multi-country initiatives have been launched in the Andean countries and in Central America and rapid progress has been recorded to ensure the interruption of the transmission of Chagas disease by 2005 as requested by a Resolution of the World Health Assembly approved in 1998. The cost-benefit analysis of the investments of the vector control program in Brazil indicate that there are savings of US$17 in medical care and disabilities for each dollar spent on prevention, showing that the program is a health investment with good return. Since the inception in 1979 of the Steering Committee on Chagas Disease of the Special Program for Research and Training in Tropical Diseases of the World Health Organization (TDR), the objective was set to promote and finance research aimed at the development of new methods and tools to control this disease. The well known research institutions in Latin America were the key elements of a world wide network of laboratories that received - on a competitive basis - financial support for projects in line with the priorities established. It is presented the time line of the different milestones that were answering successively and logically the outstanding scientific questions identified by the Scientific Working Group in 1978 and that influenced the development and industrial production of practical solutions for diagnosis of the infection and disease control.