Studies on mosquitoes (Diptera: Culicidae) and anthropic environment: 10- survey of adult behaviour of Culex nigripalpus and other species of Culex (Culex) in South-Eastern Brazil

A survey of adult behaviour of Culex (Culex) species was carried out from August 1992 through December 1993 in a human modified (anthropic) environment in the Ribeira Valley, S.Paulo State, Brazil. Culex nigripalpus dominated the catches at several sites and it's tendency to increase in the anthropic environment became quite clear. Nevertheless no high level of synanthropy was demonstrated. So it seems that the mosquito may have a restricted role in natural arbovirus cycles. Nonetheless, Cx. nigripalpus must be considered a potential vector of arboviruses, especially St. Louis encephalitis virus outside dwellings.

Prevalence of alcohol and tobacco use among Brazilian adolescents: a systematic review

OBJECTIVE: To analyze alcohol and tobacco use among Brazilian adolescents and identify higher-risk subgroups. METHODS: A systematic review of the literature was conducted. Searches were performed using four databases (LILACS, MEDLINE /PubMed, Web of Science, and Google Scholar), specialized websites and the references cited in retrieved articles. The search was done in English and Portuguese and there was no limit on the year of publication (up to June 2011). From the search, 59 studies met all the inclusion criteria: to involve Brazilian adolescents aged 10-19 years; to assess the prevalence of alcohol and/or tobacco use; to use questionnaires or structured interviews to measure the variables of interest; and to be a school or population-based study that used methodological procedures to ensure representativeness of the target population (i.e. random sampling). RESULTS: The prevalence of current alcohol use (at the time of the investigation or in the previous month) ranged from 23.0% to 67.7%. The mean prevalence was 34.9% (reflecting the central trend of the estimates found in the studies). The prevalence of current tobacco use ranged from 2.4% to 22.0%, and the mean prevalence was 9.3%. A large proportion of the studies estimated prevalences of frequent alcohol use (66.7%) and heavy alcohol use (36.8%) of more than 10%. However, most studies found prevalences of frequent and heavy tobacco use of less than 10%. The Brazilian literature has highlighted that environmental factors (religiosity, working conditions, and substance use among family and friends) and psychosocial factors (such as conflicts with parents and feelings of negativeness and loneliness) are associated with the tobacco and alcohol use among adolescents. CONCLUSIONS: The results suggest that consumption of alcohol and tobacco among adolescents has reached alarming prevalences in various localities in Brazil. Since unhealthy behavior tends to continue from adolescence into adulthood, public policies aimed towards reducing alcohol and tobacco use among Brazilians over the medium and long terms may direct young people and the subgroups at higher risk towards such behavior.

Trends in alcohol and tobacco use among Brazilian students: 1989 to 2010

OBJECTIVE To analyze temporal trends of the prevalence of alcohol and tobacco use among Brazilian students. METHODS We analyzed data published between 1989 and 2010 from five epidemiological surveys on students from the 6th to the 12th grade of public schools from the ten largest state capitals of Brazil. The total sample consisted of 104,104 students and data were collected in classrooms. The same collection tool – a World Health Organization self-reporting questionnaire – and sampling and weighting procedures were used in the five surveys. The Chi-square test for trend was used to compare the prevalence from different years. RESULTS The prevalence of alcohol and tobacco use varied among the years and cities studied. Alcohol consumption decreased in the 10 state capitals (p < 0.001) throughout 21 years. Tobacco use also decreased significantly in eight cities (p < 0.001). The highest prevalence of alcohol use was found in the Southeast region in 1993 (72.8%, in Belo Horizonte) and the lowest one in Belem (30.6%) in 2010. The highest past-year prevalence of tobacco use was found in the South region in 1997 (28.0%, in Curitiba) and the lowest one in the Southeast in 2010 (7.8%, in Sao Paulo). CONCLUSIONS The decreasing trend in the prevalence of tobacco and alcohol use among students detected all over the Country can be related to the successful and comprehensive Brazilian antitobacco and antialcohol policies. Despite these results, the past-year prevalence of alcohol consumption in the past year remained high in all Brazilian regions.

Schistosoma mansoni: effects of anesthetics and antimonial drugs on worm shift in the mouse

Mice experimentally infected with Schistosoma mansoni were injected with sodium thiopental or sodium antimonyl gluconate (Triostib R), or submitted to halothane inhalation, with or without a previous injection of thiopental. Data obtained showed that halothane and thiopental induce worm shift to the liver (99 and 76%, respectively). Sodium gluconate and antimonium (Triostib R) shifted 52% of worms towards the liver. These results seem to indicate that the use of antimonium would be unnecessary, when surgical removal of schistosomules is carried out through the extracorporeal filtration technique, in patients with portal hypertension.

Parasitological and serological studies on Amoebiasis and other intestinal parasitic infections in Recife and its suburban area, northeast Brazil

Parasitological examinations were carried out during April to August, 1987, with 187 out-patients of the IMIP hospital, located in the center of Recife City, and 464 inhabitants of several villages around Cabo City, 50 Km southeast of Recife, Pernambuco, Brazil. Approximately 71% of the IMIP patients and 92% of the Cabo inhabitants were infected with at least one species of intestinal parasite. There was minimum difference in the prevalence rate of Trichuris trichiura between two areas, whereas the prevalence rates of Ascaris lumbricoides, hookworms, Strongyloides stercoralis, Schistosoma mansoni and Entamoeba histolytica were higher in the inhabitants of the Cabo City area. Only Giardia lamblia was more prevalent in the out-patients of IMIP hospital. Test tube cultivation revealed that the prevalence rate of Necator americanus in both areas was much higher than that of Ancylostoma duodenale , and also that the prevalence rate of S. stercoralis of the IMIP patients and Cabo inhabitants were 4.5% and 9.6%, respectively. Six hundred and fifteen sera were serologically examined for amoebiasis by the gel diffusion precipitation test (GDP) and enzyme linked immunosorbent assay (ELISA) using the antigen prepared from axenically cultured trophozoite of E. histolytica (strain HM-ITMSS). No positive reaction was observed in all of the sera as examined by GDP, while 32 out of 615 sera were positive on ELISA.

Cytomegalovirus and other herpesviruses infections in heart and bone marrow transplant recipients

From January 1988 to January 1989 all the heart transplant and bone marrow recipients at the Instituto do Coração of the Hospital das Clínicas of the University of São Paulo Medical School were studied for the incidence and morbidity associated with herpesviruses infections after transplantation. Five bone marrow and 5 heart transplant recipients were followed for a mean of 4.2 months post-transplantation. All the patients were seropositive for cytomegalovirus (CMV) before admission and 80% experienced one or more recurrences during the observation period. Of the 12 episodes of CMV infection, that were identified in this study, 83% were accompanied by clinical or laboratory abnormalities. However, there was only one case of severe disease. The overall incidence of infection for herpes simplex (HSV) was 50%. Although most of HSV reactivations were oral or genital, one case of HSV hepatitis occurred. One of the 6 episodes of HSV infections that were treated with acyclovir showed an unsatisfactory response and was successfully managed with ganciclovir. All the individuals had anti-varicella zoster virus antibodies, but none of them developed infection. The study emphasizes the importance of active diagnostic surveillance of herpesvirus infections in transplant patients. Both CMV and HSV reactivations showed high incidence and important morbidity and thus, deserve prophylactic therapy.

Parasitological and serological studies on amoebiasis and other intestinal parasitic infections in the rural sector around Recife, Northeast Brazil

Parasitological examinations were carried out during July to December, 1989, on 485 inhabitants of four villages in São Lourenço da Mata, 25 km northwest of Recife, Pernambuco, Brazil. Approximately 99.6% of the inhabitants were infected with at least one species of intestinal parasites. A high prevalence of Schistosoma mansoni (82.1%), hookworm (80.2%) Trichuris trichiura (69.9%), Ascaris lumbricoides (61.9%) and Entamoeba coli (36.7%) infections were demonstrated. Test tube cultivation revealed that the most common species of hookworm in this region was Necator americanus (88.4%), and also that the prevalence of Strongyloides stercoralis was 5.8%. Three hundred and thirty-four sera were serologically examined for amoebiasis by the gel diffusion precipitation test (GDP) and enzyme-linked immunosorbent assay (ELISA). No positive reaction was observed in all sera as examined by GDP, while 24 sera were positive by ELISA.

Seroprevalence of HIV, HTLV-I/II and other perinatally-transmitted pathogens in Salvador, Bahia

Generation of epidemiological data on perinatally-transmitted infections is a fundamental tool for the formulation of health policies. In Brazil, this information is scarce, particularly in Northeast, the poorest region of the country. In order to gain some insights of the problem we studied the seroprevalence of some perinatally-transmitted infections in 1,024 low income pregnant women in Salvador, Bahia. The prevalences were as follow: HIV-1 (0.10%), HTLV-I/II (0.88%), T.cruzi (2.34%). T.pallidum (3.91%), rubella virus (77.44%). T.gondii IgM (2.87%) and IgG (69.34%), HBs Ag (0.6%) and anti-HBs (7.62%). Rubella virus and T.gondii IgG antibodies were present in more than two thirds of pregnant women but antibodies against other pathogens were present at much lower rates. We found that the prevalence of HTLV-I/II was nine times higher than that found for HIV-1. In some cases such as T.cruzi and hepatitis B infection there was a decrease in the prevalence over the years. On the other hand, there was an increase in the seroprevalence of T.gondii infection. Our data strongly recommend mandatory screening tests for HTLV-I/II, T.gondii (IgM), T.pallidum and rubella virus in prenatal routine for pregnant women in Salvador. Screening test for T.cruzi, hepatitis and HIV-1 is recommended whenever risk factors associated with these infections are suspected. However in areas with high prevalence for these infections, the mandatory screening test in prenatal care should be considered.

The relevance of laboratory diagnosis of human cryptosporidiosis and other coccidia

Human infection by Cryptosporidium spp and other coccidia are due to opportunist non-host specific microorganisms. In HIV seropositive patients, the gastrointestinal symptoms accompanying such infections may be serious and prolonged and may include nausea, low-grade fever, abdominal cramps, anorexia and watery diarrhoea. We studied 188 stool samples from 111 patients (84 men and 27 women) with diarrhoea. A modified Ziehl-Nielsen technique for the detection of Cryptosporidium spp and Isospora belli was employed. The mean age of the patients was 31 years. Cryptosporidium spp was seen in 18% (n=20) of the patients, 90% (n=18) of whom were HIV seropositive. Isospora belli was recorded only from HIV seropositive patients (5.4% of all the patients studied and 6.5% of those who were HIV seropositive). These data confirm the good results obtained with this technique for the identification of Cryptosporidium spp and other coccidia and also reaffirm the clinical importance of correctly diagnosing the cause of diarrhoea, particularly in HIV seropositive patients.

GB virus C/Hepatitis G virus and other putative hepatitis non A-E viruses

The identification of the major agents causing human hepatitis (Hepatitis A, B, C, D and E Viruses) was achieved during the last 30 years. These viruses are responsible for the vast majority of human viral hepatitis cases, but there are still some cases epidemiologically related to infectious agents without any evidence of infection with known virus, designated as hepatitis non A - E. Those cases are considered to be associated with at least three different viruses: 1 - Hepatitis B Virus mutants expressing its surface antigen (HBsAg) with altered epitopes or in low quantities; 2 - Another virus probably associated with enteral transmitted non A-E hepatitis, called Hepatitis F Virus. Still more studies are necessary to better characterize this agent; 3 - Hepatitis G Virus or GB virus C, recently identified throughout the world (including Brazil) as a Flavivirus responsible for about 10% of parenteral transmitted hepatitis non A-E. Probably still other unknown viruses are responsible for human hepatitis cases without evidence of infection by any of these viruses, that could be called as non A-G hepatitis.

Blastocystis hominis and other intestinal parasites in a community of Pitanga City, Paraná State, Brazil

The objective was to estimate the prevalence of Blastocystis hominis, to evaluate the effectiveness of different techniques for its diagnosis as well as to estimate the prevalence of other intestinal parasites in the community of Campo Verde, a district of Pitanga. The work was carried out from August to October 2004. Samples of feces from children and adults were collected and submitted to the techniques of direct wet mount, flotation in zinc sulphate solution, tube sedimentation, sedimentation in formalin-ether and staining by Kinyoun and iron hematoxylin methods. From 181 studied individuals, 128 (70.7%) showed protozoa and/or helminths in stool samples. The most prevalent species were Endolimax nana (33.7%); B. hominis (26.5%); Giardia lamblia (18.2%); Entamoeba coli (17.1%); Ascaris lumbricoides (16.6%); Iodamoeba bütschlii (9.4%); and ancylostomatidae (7.7%). B. hominis was only identified by the techniques of direct wet mount, sedimentation in formalin-ether and staining by iron hematoxylin, though the latter was less sensitive than the other methods. The high frequency of B. hominis demonstrated by this study indicates the need to include laboratory techniques that enable identification of the parasite on a routine basis.

Giardia lamblia and other intestinal parasitic infections and their relationships with nutritional status in children in Brazilian Amazon

The objective of this survey was to assess the relationships between intestinal parasitism, nutritional status and hemoglobin level in children with Indian ascendancy living in an urban area in Brazilian Amazon. We carried out a cross-sectional survey obtaining anthropometric, parasitological and socioeconomic data, and hemoglobin measurements of children aged six to 84 months. Anthropometric data were expressed as z-scores for weight for age (WAZ), height for age (HAZ), weight for height (WHZ) and mid upper circumference for age (MUACZ) parameters. Parasitological examinations were performed through Ritchie (n = 307), Kato-Katz (n = 278), Baermann-Moraes (n = 238) and Safranin-methylene blue methods (n = 307). Hemoglobin measurements were obtained with a Hemocue® photometer (n = 282). Socioeconomic data were used in order to classify children in three family income strata (n = 242). Multiple linear regression analysis showed independent interactions between Giardia lamblia and WAZ (beta = -0.195, SE = 0.138, p = 0.003), WHZ (beta = -0.161, SE = 0.133, p = 0.018) and MUACZ (beta = -0.197, SE = 0.143, p = 0.011), controlling for age, sex, family income, Ascaris lumbricoides, and hookworm infection. Also, the multivariate model showed that the only variable associated with hemoglobin levels was age. Intestinal parasitism control should increase children's possibilities of full development in the studied area.