ERICA: patterns of alcohol consumption in Brazilian adolescents

ABSTRACT OBJECTIVE To describe the patterns of alcohol consumption in Brazilian adolescents. METHODS We investigated adolescents who participated in the Study of Cardiovascular Risks in Adolescents (ERICA). This is a cross-sectional, national and school-based study, which surveyed adolescents of 1,247 schools from 124 Brazilian municipalities. Participants answered a self-administered questionnaire with a section on alcoholic beverages consumption. Measures of relative frequency (prevalence), and their 95% confidence intervals, were estimated for the following variables: use of alcohol beverages in the last 30 days, frequency of use, number of glasses or doses consumed in the period, age of the first use of alcohol, and most consumed type of drink. Data were estimated for country and macro-region, sex, and age group. The module survey of the Stata program was used for data analysis of complex sample. RESULTS We evaluated 74,589 adolescents, who accounted for 72.9% of eligible students. About 1/5 of adolescents consumed alcohol at least once in the last 30 days and about 2/3 in one or two occasions during this period. Among the adolescents who consumed alcoholic beverages, 24.1% drank it for the first time before being 12 years old, and the most common type of alcoholic beverages consumed by them were drinks based on vodka, rum or tequila, and beer. CONCLUSIONS There is a high prevalence of alcohol consumption among adolescents, as well as their early onset of alcohol use. We also identified a possible change in the preferred type of alcoholic beverages compared with previous research.

ERICA: prevalences of hypertension and obesity in Brazilian adolescents

ABSTRACT OBJECTIVE To estimate the prevalence of arterial hypertension and obesity and the population attributable fraction of hypertension that is due to obesity in Brazilian adolescents. METHODS Data from participants in the Brazilian Study of Cardiovascular Risks in Adolescents (ERICA), which was the first national school-based, cross-section study performed in Brazil were evaluated. The sample was divided into 32 geographical strata and clusters from 32 schools and classes, with regional and national representation. Obesity was classified using the body mass index according to age and sex. Arterial hypertension was defined when the average systolic or diastolic blood pressure was greater than or equal to the 95th percentile of the reference curve. Prevalences and 95% confidence intervals (95%CI) of arterial hypertension and obesity, both on a national basis and in the macro-regions of Brazil, were estimated by sex and age group, as were the fractions of hypertension attributable to obesity in the population. RESULTS We evaluated 73,399 students, 55.4% female, with an average age of 14.7 years (SD = 1.6). The prevalence of hypertension was 9.6% (95%CI 9.0-10.3); with the lowest being in the North, 8.4% (95%CI 7.7-9.2) and Northeast regions, 8.4% (95%CI 7.6-9.2), and the highest being in the South, 12.5% (95%CI 11.0-14.2). The prevalence of obesity was 8.4% (95%CI 7.9-8.9), which was lower in the North region and higher in the South region. The prevalences of arterial hypertension and obesity were higher in males. Obese adolescents presented a higher prevalence of hypertension, 28.4% (95%CI 25.5-31.2), than overweight adolescents, 15.4% (95%CI 17.0-13.8), or eutrophic adolescents, 6.3% (95%CI 5.6-7.0). The fraction of hypertension attributable to obesity was 17.8%. CONCLUSIONS ERICA was the first nationally representative Brazilian study providing prevalence estimates of hypertension in adolescents. Regional and sex differences were observed. The study indicates that the control of obesity would lower the prevalence of hypertension among Brazilian adolescents by 1/5.

ERICA: sexual initiation and contraception in Brazilian adolescents

ABSTRACT OBJECTIVE To estimate the prevalence of sexual initiation and contraceptive use at the last sexual intercourse of Brazilian adolescents, according to sociodemographic features. METHODS The data were obtained from the Study of Cardiovascular Risks in Adolescents (ERICA), a national school-based cross-sectional study. We included 74,589 adolescents from 32 geographic strata (27 capitals and five sets of municipalities with more than 100,000 inhabitants of each of the five macro-regions of the Country). Information on sexual initiation and contraceptive use at the last sexual intercourse (male condom and oral contraceptive pill) has been used. We have estimated prevalence and confidence intervals (95%CI) considering sample weights according to sex, age, type of school, residence status, macro-region and capitals. RESULTS We observed that 28.1% (95%CI 27.0-29.2) of the adolescents had already initiated sexual life, with higher prevalence among those aged 17 years (56.4%, 95%CI 53.9-58.9), males (33.5%, 95%CI 31.8-35.2), studying at public schools (29.9%, 95%CI 28.5-31.4), and from the Northern region (33.9%, 95%CI 32.3-35.4), mainly from Macapa, Manaus, and Rio Branco. Among those who had started their sexual life, 82.3% (95%CI 81.1-83.4) reported the use of contraceptive methods at the last intercourse, and the prevalence of use was higher among adolescents aged 17 years (85.3%, 95%CI 82.7-87.6), females (85.2%, 95%CI 83.8-86.5) and those living in the Southern region (85.9%, 95%CI 82.9-88.5). Male condom was used by 68.8% (95%CI 66.9-70.7), with no difference by type of school or macro-regions; the contraceptive pill was used by 13.4% (CI95% 12.2-14.6), and more frequently used among women (24.7%, 95%CI 22.5-27,0) and 17-year-old adolescents (20.8%, 95%CI 18.2-23.6) from urban settings(13.7%, 95%CI 12.5-14.9) and from the Southern region (22.6%, 95%CI 19.0-26.8), and less often in the Northern region. CONCLUSIONS ERICA’s data analysis on sexuality and contraception shows heterogeneities in the prevalence of sexual initiation and use of contraceptive methods among Brazilian adolescents, depending on their age, where they live, and the type of school they study at. Younger adolescents and those living in the Northern region seem to be more vulnerable to the consequences of unprotected sexual intercourses.

ERICA: prevalence of common mental disorders in Brazilian adolescents

ABSTRACT OBJECTIVE To describe the prevalence of common mental disorders in Brazilian adolescent students, according to geographical macro-regions, school type, sex, and age. METHODS We evaluated 74,589 adolescents who participated in the Cardiovascular Risk Study in Adolescents (ERICA), a cross-sectional, national, school-based study conducted in 2013-2014 in cities with more than 100,000 inhabitants. A self-administered questionnaire and an electronic data collector were employed. The presence of common mental disorders was assessed using the General Health Questionnaire (GHQ-12). We estimated prevalence and 95% confidence intervals of common mental disorders by sex, age, and school type, in Brazil and in the macro-regions, considering the sample design. RESULTS The prevalence of common mental disorders was of 30.0% (95%CI 29.2-30.8), being higher among girls (38.4%; 95%CI 37.1-39.7) when compared to boys (21.6%; 95%CI 20.5-22.8), and among adolescents who were from 15 to 17 years old (33.6%; 95%CI 32.2-35.0) compared to those aged between 12 and 14 years (26.7%; 95%CI 25.8-27.6). The prevalence of common mental disorders increased with age for both sexes, always higher in girls (ranging from 28.1% at 12 years to 44.1% at 17 years) than in boys (ranging from 18.5% at 12 years to 27.7% at 17 years). We did not observe any significant difference by macro-region or school type. Stratified analyses showed higher prevalence of common mental disorders among girls aged from 15 to 17 years of private schools in the North region (53.1; 95%CI 46.8-59.4). CONCLUSIONS The high prevalence of common mental disorders among adolescents and the fact that the symptoms are often vague mean these disorders are not so easily identified by school administrators or even by health services. The results of this study can help the proposition of more specific prevention and control measures, focused on highest risk subgroups.

ERICA: smoking prevalence in Brazilian adolescents

ABSTRACT OBJECTIVE To estimate the prevalences of tobacco use, tobacco experimentation, and frequent smoking among Brazilian adolescents. METHODS We evaluated participants of the cross-sectional, nation-wide, school-based Study of Cardiovascular Risks in Adolescents (ERICA), which included 12- to 17-year-old adolescents from municipalities of over 100 thousand inhabitants. The study sample had a clustered, stratified design and was representative of the whole country, its geographical regions, and all 27 state capitals. The information was obtained with self-administered questionnaires. Tobacco experimentation was defined as having tried cigarettes at least once in life. Adolescents who had smoked on at least one day over the previous 30 days were considered current cigarette smokers. Having smoked cigarettes for at least seven consecutive days was an indicator for regular consumption of tobacco. Considering the complex sampling design, prevalences and 95% confidence intervals were estimated according to sociodemographic and socio-environmental characteristics. RESULTS We evaluated 74,589 adolescents. Among these, 18.5% (95%CI 17.7-19.4) had smoked at least once in life, 5.7% (95%CI 5.3-6.2) smoked at the time of the research, and 2.5% (95%CI 2.2-2.8) smoked often. Adolescents aged 15 to 17 years had higher prevalences for all indicators than those aged 12 to 14 years. The prevalences did not differ significantly between sexes. The highest prevalences were found in the South region and the lowest ones, in the Northeast region. Regardless of sex, the prevalences were found to be higher for adolescents who had had paid jobs, who lived with only one parent, and who reported having been in contact with smokers either inside or outside their homes. Female public school adolescents were found to smoke more than the ones from private schools. CONCLUSIONS Tobacco use among adolescents is still a challenge. Intending to reduce the prevalence of tobacco use among young people, especially the ones under socioeconomic vulnerability conditions, Brazil must consolidate and increase effective public health care measures.

Activity of praziquantel against Hymenolepis nana, at different development stages, in experimentally infected mice

Single doses of praziquantel were administered by oral route, at various time intervals, following the experimental infection of mice with Hymenolepis nana eggs (2000 per animal), to investigate the drug action against different development stages of the parasite. It was shown that either 25 or 50 mg/kg given on the 4th day after inoculation had just a partial effect against the cysticercoids. Moreover, 25 mg/kg given on the 7th day was not able to kill all juvenile forms as well. However, this dose administered on the 10th day, when the parasites had reached maturity taut oviposition was not yet initiated was 100% efficacious. The same degree of efficacy was achieved with the administration of 25 mg/kg on the 14th day when the fully mature worms already lay eggs. These animal findings indicate that in the treatment of human hymenolepiasis praziquantel, 25 mg/kg, should be taken twice, 10 days apart, so that the second dose kills the larval and juvenile forms which have survived the first one. This should be particularly recommended for treating H. nana infection in close communities.

Trypanosoma (Herpetosoma) rangeli Tejera, 1920: nota prévia sobre a histopatologia em camundongos infectados experimentalmente

Male mice (NMRI strain) of 3 and 5 g were inoculated i. p. with 8 x 10(6) and 9 x 10(4) metatrypomastigotes/g harvested from a 12-day-old LIT culture of Trypanosoma rangeli of the "Dog-82" strain. At regular intervals after inoculation, the animals were sacrificed and portions of heart, liver, spleen, lung, thigh, kidney, stomach, intestine, brain, sternum, and vertebral column were embedded in paraffin, sectioned, and stained with haematoxylin-eosin and Giemsa colophonium. Pathology was encountered in the first five tissues cited above. The subcutaneous, periosteal, interstitial, and peribronchial connective tissues, and later the muscle cells of the heart, were heavily parasitized by amastigotes and trypomastigotes. The possible reasons for the decrease in tissue parasitosis at the same time that the parasitemia is reaching its peak, and for the low level of inflammation in the parasitized tissues, are discussed. The observations of other workers, as well as the results described here, indicate that certain strains of T. rangeli under certain conditions may well cause pathological alterations in mammals.

Paracoccidioidomycosis: a sequential histopathologic study of lesions in experimentally-infected rats

Female albino rats were used for the sequential histopathological study of experimental paracoccidioidomycosis. The animals were inoculated intraperitoneally with a strain of Paracoccidioides brasiliensis in the yeast-like phase, and sacrificed at given intervals from 1 to 168 days after inoculation; each animal received an inoculum of 4 x 10(6) cells in 0.8 ml of saline. The control group received saline containing scrapings of the culture medium. Tissue from the inoculation site was examined. The cellular population, the extracellular matrix, and the presence and characteristics of fungi were analysed in the inflammatory granulomatous process by light microscopy. The results allowed to separate the kinetic of the inflammatory response into three stages: 1) neutrophilic or macrophagic-neutrophilic; 2) pre-granulomatous; 3) granulomatous. Synthesis of the extracellular matrix began with the depositing of fibrin-like material, and increased gradually with deposits of collagen, proteoglycans, and glycoproteins. Parasites were present in all of the examined periods. Recurrences of the disease were clearly shown through the concurrence of recently-formed granulomas with older granulomas, implying that this type of granulomatous process does not eliminate the disease, nor is it able to limit fungal dissemination over a prolonged period of time.

Reinfection after treatment of schistosomiasis: environment or "predisposition"?

Although very efficient for the control of morbidity due to S. mansoni in individual patients, chemotherapy has not proven successful in the management of transmission within hyperendemic areas when used alone, even if repeated at short intervals. Consequently, a great deal of effort has been expended toward immunologic investigation and development of a specific vaccine. Based upon a study of a group of children (5-14 years) from the state of Alagoas, the author demonstrates that the outcome one year after chemotherapy depends essentially on the "risk rating" of the area of domicile. A regression analysis did not reveal significant correlation to neither age, sex or initial egg counts. Although the study was not designed to reveal individual variations in the immune status, it is postulated that putative differences in genetic make-up are irrelevant in terms of large-scale intervention. Since morbidity due to S. mansoni has substantially declined during the last two or three decades, a control policy based on vaccination can only be justified if high levels of protective immunity can be attained. At any rate, such a vaccine will have to be administered in early childhood (preferably below the age of three). It can also be demonstrated that immunization in adolescence or adulthood serves no purpose whatsoever. The author is convinced that environmental intervention, usually dismissed as unrealistic in terms of the developing countries, is not only feasible, if done on a selective basis, but prioritary.

Sedimentation in parasitological coproscopy

A sedimentation technique is described, in which a fecal suspension is placed on top of an aqueous sucrose solution of specific gravity 1.015 g/cm³. Using 100 by 15 mm test tubes, duplicate gravity sedimentation experiments were made using homogenized fecal suspensions (single-columns) and fecal suspensions placed on top of clear columns (double-columns). Egg- and cyst-counts, and turbidity determinations were made in the sediments obtained after definite time intervals. Most Ascaris lumbricoides, Trichuris trichiura and Ancylostomidae eggs sedimented within 20 minutes in single - and between 30 and 60 minutes in double-columns. Giardia duodenalis cysts required longer periods to sediment in double - than in single-columns; after 180 minutes (the maximum period of observation), double-column sediments produced 60.0% of the counts of single-columns. Double-column sediments were consistently less turbid than single-column ones

Lethal effect of a bait for Rhodnius prolixus (Hemiptera: Reduviidae), the vector of Chagas' disease, containing hexachlorocyclohexane (HCH), under laboratory conditions

The lethal effect of a bait containing an aqueous hexachlorocyclohexane (HCH) suspension at the concentration of 1g/l and maintained at room temperature was studied in the laboratory over a period of 12 weeks. The suspension was placed in a latex bag hanging inside a 1000-ml beaker tightly covered with nylon netting, and left there with no changes for 85 days. Sixteen groups of R. prolixas bugs, consisting on average of 30 specimens each, were successively exposed to the bait and observed at different intervals for one week each. The mortality rate was 100% for all groups, except for the 16th, whose mortality rate was 96.7%. As the groups succeeded one another, mortality started to occur more rapidly and was more marked at the 6- and 24-h intervals. Later tests respectively started at 6:00 a.m. and 6:00 p.m. showed that diurnal and nocturnal periodicity in the offer of food had no effect on mortality. First- and 2nd- instar nymphs and adults male were more sensitive and 5th- instar nymphs were more resistant to the active principle of the bait.

The prolonged use of niclosamide as a molluscicide for the control of Schistosoma mansoni

Applications of niclosamide at three-monthly intervals were undertaken for 14 years in foci of Biomphalaria glabrata in the water sources of Peri-Peri (Capim Branco, MG). All the residents of the area were submitted to an annual fecal examination (Kato/Katz) and those individuals eliminating Schistosoma mansoni eggs were treated with oxamniquine. A malacological survey was undertaken at three-monthly intervals by means of ten scoops with a perforated ladle each ten metres along the two banks of the ditches and streams of the region. Where snails were found, molluscicide was applied by means of dripping or aspersion using a 3 ppm aqueous suspension of niclosamide. Initially, a mean of 14.3% of snails in the region were found to be eliminating cercariae. Following the first four applications of molluscicide, this was reduced to 0.0% and maintained at about 1.5% throughout the program. Thus, there was a continued possibility of schistosomiasis transmission in the area and it was observed that the population of snails reestablished itself within three months of molluscicide application. The results obtained in this study do not encourage the continual use of niclosamide as the only method of control of schistosomiasis.

A municipal level approach to the management of schistosomiasis control in Peri-Peri, MG, Brazil

A schistosomiasis control program was implemented between 1974/87 in Peri-Peri,. MG (622 inhabitants). Molluscicide (niclosamide) was applied at three monthly intervals in water sources with Biomphalaria glabrata, and individuals eliminating Schistosoma mansoni eggs in the feces were treated annually with oxamniquine. From 1974 to 1983 the control measures were undertaken by staff of the "René Rachou" Research Center FIOCRUZ (CPqRR), and from 1984 to 1987 these measures were included in the Capim Branco basic health network activities. During both periods, the prevalence, incidence, intensity of infection and hepatosplenic form as well as the number of infected snails decreased significantly. The prevalence decreased from 43.5 to 4.4%, the incidence from 19.0 to 2.9%, the overall intensity of S. mansoni from 281 to 87 and of the hepatosplenic form from 5.9 to 0.0%. The results obtained suggest that the municipal management of control measures was as effective as the vertical program conducted by CPqRR staff.

Schistosoma mansoni: protective immunity in mice cured by chemotherapy at the chronic phase of the disease

Aiming at demonstrating a decrease of acquired immunity after chemotherapeutic cure, a group of mice was infected with 25 Schistosoma mansoni cercariae (LE strain). A part of these animals was treated with 400 mg/kg oxamniquine, at 120 days after infection. Challenge infections were carried out at 45, 90 and 170-day-intervals after treatment (185, 210 and 290 days after primoinfection, respectively). Recovery of worms at 20 days after reinfections showed that a residual immunity remains up to 90 days after treatment, and disappears at 170 days after cure. Using the ELISA method, it was possible to detect a decrease of antibody levels (total IgG) in the treated group, when antigens from different evolutive stages of S. mansoni were used. The epidemiological implications of the present results, and the possible mechanisms involved in the decrease of acquired immunity after treatment are discussed.

Identification of factors and groups at risk of infection with Schistosoma mansoni: a strategy for the implementation of control measures?

A fourteen year schistosomiasis control program in Peri-Peri (Capim Branco, MG) reduced prevalence from 43.5 to 4.4%; incidence from 19.0 to 2.9%, the geometric mean of the number of eggs from 281 to 87 and the level of the hepatoesplenic form cases from 5.9 to 0.0%. In 1991, three years after the interruption of the program, the prevalence had risen to 19.6%. The district consists of Barbosa (a rural area) and Peri-Peri itself (an urban area). In 1991, the prevalence in the two areas was 28.4% and 16.0% respectively. A multivariate analysis of risk factors for schistosomiasis indicated the domestic agricultural activity with population attributive risk (PAR) of 29.82%, the distance (< 10 m) from home to water source (PAR = 25.93%) and weekly fishing (PAR = 17.21%) as being responsible for infections in the rural area. The recommended control measures for this area are non-manual irrigation and removal of homes to more than ten meters from irrigation ditches. In the urban area, it was observed that swimming at weekly intervals (PAR = 20.71%), daily domestic agricultural activity (PAR = 4.07%) and the absence of drinking water in the home (PAR=4.29%) were responsible for infections. Thus, in the urban area the recommended control measures are the substitution of manual irrigation with an irrigation method that avoids contact with water, the creation of leisure options of the population and the provision of a domestic water supply. The authors call attention to the need for the efficacy of multivariate analysis of risk factors to be evaluated for schistosomiasis prior to its large scale use as a indicator of the control measures to be implemented.