Serological survey for Chagas' disease in school children in the Rio de Janeiro State, Brazil

A serological survey for Chagas' disease was carried out in school children in the Rio de Janeiro State, a zone considered as non-endemic for the infection. A total of 168 schools in 20 municipalities have been visited and 13,254 blood samples were obtained. The blood eluates were screened by the indirect fluorescence test (IFT), and all positive samples were checked and confirmed in sera by the complement fixation test (CFT). AH serologically positive children were subject to a clinical scrutiny, and the houses where the children lived have been searched for triatomine bugs. Only in two municipalities, Magé and Araruama, there was a significant number of children found positive. The total number of reactive samples by IFT and CFT from 13,004 blood samples screened was 143 (1.00 per cent). No serious clinicai symptoms suggestive of Chagas' disease have been found in any of the positive children, and no triatomine bugs were discovered in the dwellings where the children lived. The overall small percentage of children with positive serology postulates that the infection is not a serious health problem in the area investigated. It is recommended, however, to carry out a more detailed study in Magé and Araruama to find the reason for the relatively high percentage of serologically positive children encountered in these two municipalities.

Economic analysis in health care regulation : three essays

ABSTRACT - It is the purpose of the present thesis to emphasize, through a series of examples, the need and value of appropriate pre-analysis of the impact of health care regulation. Specifically, the thesis presents three papers on the theme of regulation in different aspects of health care provision and financing. The first two consist of economic analyses of the impact of health care regulation and the third comprises the creation of an instrument for supporting economic analysis of health care regulation, namely in the field of evaluation of health care programs. The first paper develops a model of health plan competition and pricing in order to understand the dynamics of health plan entry and exit in the presence of switching costs and alternative health premium payment systems. We build an explicit model of death spirals, in which profitmaximizing competing health plans find it optimal to adopt a pattern of increasing relative prices culminating in health plan exit. We find the steady-state numerical solution for the price sequence and the plan’s optimal length of life through simulation and do some comparative statics. This allows us to show that using risk adjusted premiums and imposing price floors are effective at reducing death spirals and switching costs, while having employees pay a fixed share of the premium enhances death spirals and increases switching costs. Price regulation of pharmaceuticals is one of the cost control measures adopted by the Portuguese government, as in many European countries. When such regulation decreases the products’ real price over time, it may create an incentive for product turnover. Using panel data for the period of 1997 through 2003 on drug packages sold in Portuguese pharmacies, the second paper addresses the question of whether price control policies create an incentive for product withdrawal. Our work builds the product survival literature by accounting for unobservable product characteristics and heterogeneity among consumers when constructing quality, price control and competition indexes. These indexes are then used as covariates in a Cox proportional hazard model. We find that, indeed, price control measures increase the probability of exit, and that such effect is not verified in OTC market where no such price regulation measures exist. We also find quality to have a significant positive impact on product survival. In the third paper, we develop a microsimulation discrete events model (MSDEM) for costeffectiveness analysis of Human Immunodeficiency Virus treatment, simulating individual paths from antiretroviral therapy (ART) initiation to death. Four driving forces determine the course of events: CD4+ cell count, viral load resistance and adherence. A novel feature of the model with respect to the previous MSDEMs is that distributions of time to event depend on individuals’ characteristics and past history. Time to event was modeled using parametric survival analysis. Events modeled include: viral suppression, regimen switch due virological failure, regimen switch due to other reasons, resistance development, hospitalization, AIDS events, and death. Disease progression is structured according to therapy lines and the model is parameterized with cohort Portuguese observational data. An application of the model is presented comparing the cost-effectiveness ART initiation with two nucleoside analogue reverse transcriptase inhibitors (NRTI) plus one non-nucleoside reverse transcriptase inhibitor(NNRTI) to two NRTI plus boosted protease inhibitor (PI/r) in HIV- 1 infected individuals. We find 2NRTI+NNRTI to be a dominant strategy. Results predicted by the model reproduce those of the data used for parameterization and are in line with those published in the literature.

Epidemiologic studies of chagas' disease in the urban zone of Teresina. State of Piauí, northeastern Brazil

The triatomine species Rhodnius nasutus and Triatoma pseudomaculata were captured on palm trees Orbignya martiana "babaçu ", in the urban zone of Teresina. This kind of palm tree is largely distributed in Piauí State. The predominant species was R. nasutus; the young in stars predominated. The infestation index of palm trees and the infection index of triatomines by flagellates were 96.0 ana 29.1%, respectively. Marsupiais, bats and a rodent were captured in palm trees. The flagellates found in both triatomines ana marsupiais were morphologically and biologically indistinguishable from Trypanosoma cruzi. Forty seven percent (481/1,025) of triatomines were found concentrated in six palm trees where marsupiais circulated. Of the total of 1,025 triatomines 230 (22%) were infected by flagellates and 53.0% (123/230) of these infected triatomines were present in the same six palm trees. No evidence of triatomine domiciliation or human transmission was observed in the houses in the vicinity of palm trees. The results suggest that marsupiais play an important role in the life-cycle of T. cruzi in this region. The natural focus of Chagas' disease, demonstrated in the present study could represent a potential epidemiological threat.

Trypanosoma cruzi-like bloodstream trypomastigotes in bats from the State of Piauí, Northeastern Brazil

One-hundred and thirty-five bats from 12 species were examined for thepresence of trypomastigotes by means of direct blood examination, xenodiagnosis, and hemoculture. Of those, 44 specimens (32.6%) from 8 species were infected with trypanosomes. Phyllostomus discolor discolor presented the highest rate of infection, being captured only in one locality, while Phyllostomus hastatus hastatus captured in four localities showed high rates. Two species, Anoura geoffroyii and Pteronotus (Phillodia) pamelli rubiginosa, were found infected by T. cruzi-like trypanosomes, apparently described for thefirst time. Flagellates from Artibeus jamaisensis jamaisensisa and A. geoffroyii were able toproduce detectable parasitaemia in young mice. One triatomine bug was found infected in natural conditions, Triatoma brasiliensis was associated with a P.h. hastatus colony, in which six captured bats were also found infected.

THE U.S. and European M&A cycles: A Markov switching and state space approach

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Finance from the NOVA – School of Business and Economics

The palm tree Copernicia cerifera (carnaúba) as an ecotope of Rhodnius nasutus in rural areas of the State of Piauí Northeastern Brazil

The C. cerifera palm tree (carnaúba) is widely distributed in the Northeastem Brazil, including the State of Piauí. This investigation revealed that R. nasutus is the ortly triatomine species captured on that palm tree, in five different localities. 78% of palm trees were infested with triatomines, and 4.0% were infected with flagellates morphologically and biologically indistinguishable from Trypanosoma cruzi. Birds, rodents and marsupials were found as major blood meai sources for R. nasutus.

Frequency of human leukocyte antigen (hla) in patients with malaria and in the general population of Humaitá county, Amazonas state, Brazil

In August 1983,85 inhabitants of the municipality of Humaitá, Amazonas State, Brazil were studied to determine the prevalence of antigens to HLA-A, -B, -C and DR. Thirty-eight were sick with malaria due to Plasmodium falciparum. All subjects were examined for splenomegaly, blood parasitaemia and antibodies to malaria. They constituted three groups: 1) 25 subjects native to the Amazon region who had never had malaria; 2) 38 Amazonian subjects who had malaria in the past or currently had an infection; 3) 22 patients with malaria who had acquired the infection in the Amazon Region but came from other regions of Brazil. Blood was taken from each person, the lymphocytes were separated and typed by the test of microlymphocytotoxicity. There was a high frequency of antigens that could not be identified in the groups studied which suggests the existence of a homozygote or phenotype not identified in the population. There was a high frequency of the phenotype Ag(W24) (44.7%) in group 2 when compared with group 1 (32%) or group 3 (9%). Also the individuals in group 2 showed an elevated frequency of antigen DR(4)80%) when compared with group 1 (36.6%) or group 3 (16.6%). These observations suggest the possibility of a genetic susceptibility to malaria among Amazonian residents and indicate a necessity for more extensive studies of the frequency of HLA antigens among inhabitants of this endemic malarial zone.

Malaria in humait a county, state of Amazonas, Brazil. XIX - evaluation of clindamycin for the treatment of patients with Plasmodium falciparum infection

A total of 207 patients with malaria caused by Plasmodium falciparum were submitted to 5 different treatment schedules with clindamycin from 1981 to 1984: A - 89 patients were treated intravenously and orally, or intramuscularly and orally with 20 mg/kg/day divided into two daily applications for 5 to 7 days; B-40 patients were treated orally with 20 mg/kg/day divided into two daily doses for 5 to 7 days; C-27 patients were treated with 20 mg/kg/day intravenously or orally divided into two daily applications for 3 days; D-16 patients were treated orally and/or intravenously with a single daily dose of 20 to 40 mg/kg/day for 5 to 7 days; E-35 patients were treated orally with 5 mg/kg/day divided into two doses for 5 days. Patients were examined daily during treatment and reexamined on the 7th, 24th, 21st, 28th and 35th day both clinically and parasitologically (blood test). Eighty three (40.1%) had moderate or severe malaria, and 97 (46.8%) had shown resistance to chloroquine or to the combination ofsulfadoxin and pyrimethamine. The proportion of cured patients was higher than 95% among patients submitted to schedules A and B. Side effects were only occasional and of low intensity. Three deaths occurred (1.4%), two of them involving patients whose signs and symptoms were already very severe when treatment was started. Thus, clindamycin proved to be very useful in the treatment of patients with malaria caused by Plasmodium falciparum and we recommend schedule A for moderate and severe cases and Bfor initial cases.

Environmental contamination by Toxocara sp eggs in public areas of Salvador, Bahia state, Brazil

A survey ofparasite eggs and cysts in soil and dog feces collected in public places of 23 boroughs of Salvador, a city in the Northeast of Brazil, was performed. High degree of contamination by Toxocara sp eggs was observed in all boroughs studied; other parasites found included: Ascaris lumbricoides, hookworms, whipworms and protozoan cysts. Parks andpublic gardens were more contaminated than streets and beachesfor all parasites, including Toxocara sp.

Structural characterization of the urea-unfolded state of Colicin Immunity Protein Im7 and Im9

Dissertação para obtenção do Grau de Mestre em Bioquímica Estrutural e Funcional

Tetanus as a cause of acute renal failure: possible role of rhabdomyolysis

To study the frequency and examine the role of rhabdomyolysis in the acute renalfailure in tetanus 18 patients with the diagnosis of generalized tetanus consecutively admitted to the infectious disease hospital were evaluated. Ofthese 14 were male and 4female with mean age of 31.8± 2.0 years. Except for mild proteinuria recorded in 9 patients, the urinalysis were unremarkable. Serum creatinine higher than 1.4mg/dl was recorded in 39% of the patients, abnormal levels of CPK in 87,5% and serum myoglobin greater than 120µg/l in 39% of the patients. Oliguria was documented in one patient and none required diafysis therapy. No correlation wasfound between renal failure and myoglobin and/or CPK serum levels. Acute renalfailure in tetanus was not infrequent; usualfy it was non-oliguric, mild and transient and not related to the severity of the disease or to serum levels of myoglobin and/or CPK.

Re-evaluation of the basic procedures involved in the storage of measles vaccine in public health units of the municipality of Niterói, state of Rio de Janeiro, Brazil

Four years after the first visit seventeen public health units were visited again and evaluated as to standards of storage recommended by the Brazilian Immunization Programme. In 100% of the units, refrigerators and proper inside location of vaccines in the refrigerator were adequatety or regularfy maintained and checked, respectively. However, when control of temperature was checked, onfy 64.7% presented adequate storage conditions. In 94.1 % of the units, health workers complained of lack of immediate technical support in emergency situations. In 55.2 % the titers vaccine samples of were under the minimal recommended potency. It is necessary that the factors concerning the cold chain be continualfy evaluated so that the quality of the vaccines that will be used is not affected.

Labrea-like hepatitis in Vitoria, Espirito Santo state, Brazil: report of a case

A case of fulminat hepatitis with microvesicular steatosis resembling Labrea 's fever, diagnosed in Vitoria (ES) is reported. The 16 year old bcy presented with severe epistaxis, agitation, jaundice and hemorrhagic vomiting and died two days after admission to the emergency unit of the Vnivesity Hospital. The disease started five days before with fever, myalgias, dark urine and jaundice andprogressed withpsychic agitation, torpor and coma. The liver andspleen were notpalpable. HBsAg was negative in the serum. The autopsy showed acute hepatitis with tylic necrosis confluent in the midizonal and periportal areas with massive microvesicular steatosis in the remaining hepatocytes. Mononuclear cellspredominated in the exudate. The reticulum showed condensation in the necrotic areas without typical bands of collapse. The portal tracts were edematous with mononuclear infiltration and mild bile duct proliferation. Absence of cholestasis. Exceptfor the confluent midzonalandperiportal necrosis this case showed several clinical and morphological aspects of the Labreafever describedfrom the East Amazon, demonstrating that the anatomical picture of this disease probabty is not in related to afactor peculiar to the Amazon region.

Clinical and epidemiological findings during a measles outbreak occurring in a population with high vaccination coverage

From March 1991 to April 1992, 250 measles suspected cases were studied in the Municipality of Niterói, State of Rio de Janeiro. The median age found was 11 years and 76.0% of the cases were in school age children. Exposure histories were present in 149 patients and schools were the most frequent sites of transmission (45.0%). Vaccination status was known for 127 studied cases and 76.4% of them had received measles vaccine before their first birthday. One or more complications were reported for 68 cases aitd in 8.9% of the studied cases hospitalization was required. Frequency of complications varied according to each age group studied and were more commonly encountered among children < 1 year of age (55.6%). The history of previous vaccination did not diminish the number of complications of the cases studied. The results of this work show changes in age distribution of measles leading to sizeable outbreaks among teenagers and young adults.