Dengue epidemic in the state of Rio de Janeiro, Brazil: virological and epidemiological aspects

Laboratorial studies were carried out on 3178 patients with signs and symptoms suggestive of dengue infection from April 1986 to December 1987 in the State of Rio de Janeiro, Brazil. The epidemic had two peaks following the first virus isolation and affected the inhabitants of 17 counties. Both sex and all age groups were affected. Dengue virus type 1 was isolated from 1039 sera and the number of confirmed cases was increased to 1874 (59%) by MAC-ELISA. Isolation rate confirmed cases reached 80% in the specimens obtained until the 4th day after the onset of disease and viraemia ranged from 10 3.0 to 10(8.5) TCID50/ml.

Epidemiological and ecological aspects related to malaria in the area of influence of the lake at Porto Primavera dam, in western São Paulo State, Brazil

A study was carried out in the area of influence of the Porto Primavera Hydroelectric Power Station, in western São Paulo State, to investigate ecological and epidemiological aspects of malaria in the area and monitor the profile of the anopheline populations following the environmental changes brought about by the construction of the lake. Mosquitoes captured were analyzed by standardized indicator species analysis (ISA) before and during different flooding phases (253 m and 257 m elevations). The local human population was studied by means of parasitological (thin/thick blood smears), molecular (PCR) and serological tests. Serological tests consisted of Enzyme Linked Immunosorbent Assay (ELISA) with synthetic peptides of the circumsporozoite protein (CSP) from classic Plasmodium vivax, P. vivax variants (VK247 and "vivax-like"), P. malariae and P. falciparum and Indirect Immunofluorescence Assay (IFA) with asexual forms of P. vivax, P. malariae and P. falciparum. The results of the entomological survey indicated that, although the Anopheles darlingi population increased after the flooding, the population density remained very low. No malaria, parasite infection or DNA was detected in the inhabitants of the study area. However, there was a low frequency of antibodies against asexual forms and a significant prevalence of antibodies against P. vivax, P. vivax variants, P. falciparum and P. malariae; the presence of these antibodies may result from recent or less recent contact with human or simian Plasmodium (a parallel study in the same area revealed the existence of a sylvatic cycle). Nevertheless, these results suggest that, as in other places where malaria is present and potential vectors circulate, the local epidemiological conditions observed could potentially support the transmission of malaria in Porto Primavera Lake if infected individuals are introduced in sufficient numbers. Further studies are required to elucidate the phenomena described in this paper.

Epidemiological investigation of an acute case of Chagas disease in an area of active transmission in Peruvian Amazon region

The study objective was to investigate an acute case of Chagas disease in the San Pedro de Shishita community, Pebas District, in the Peruvian Amazon basin, a non-endemic area. Both parents of the index case (acute case) were thoroughly interviewed, a seroepidemiological survey was carried out in the community, parasitological exams were carried out only in relatives of the index case, and triatomine bugs were searched for inside houses, peridomiciliary, and in wild environments. Seroprevalence for IgG anti-T. cruzi antibodies was 1/104 (0.96%), using an ELISA test and an indirect immunofluorescence assay. Panstrongylus geniculatus and Rhodnius pictipes adults were found. The index case is autochthonous from San Pedro de Shishita, but the source of transmission is unknown.

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.

Cutaneous leishmaniasis in northeastern Brazil: a critical appraisal of studies conducted in State of Pernambuco

American cutaneous leishmaniasis (ACL) is a complex disease with clinical and epidemiological features that may vary from region to region. In fact, at least seven different Leishmania species, including Leishmania (Viannia) braziliensis, Leishmania (Viannia) guyanensis, Leishmania (Viannia) lainsoni, Leishmania (Viannia) naiffi, Leishmania (Viannia) shawi, Leishmania (Viannia) lindenbergi, and Leishmania (Leishmania) amazonensis, have been implicated in the etiology of ACL in Brazil, and numerous phlebotomine sandfly species of the genus Lutzomyia have been regarded as putative or proven vectors. Because ACL is a focal disease, understanding the disease dynamics at the local level is essential for the implementation of more effective control measures. The present paper is a narrative review about the ACL epidemiology in Pernambuco, northeastern Brazil. Furthermore, the need for more effective diagnosis, treatment, control and prevention strategies for the affected populations is highlighted. This paper will provide researchers with a critical appraisal of ACL in Pernambuco. Hopefully, it will also be helpful for public health authorities to improve current control strategies against ACL at the state and country levels.

Current epidemiological profile of Chagasic megaesophagus in Central Brazil

Introduction Chagasic megaesophagus (CM) is the most common digestive manifestation of Chagas disease in Brazil, and the State of Goiás is one of the most affected regions. In recent decades, the Hospital das Clínicas (HC)/Universidade Federal de Goiás (UFG) has been a reference center for the study and treatment of CM. The objective of this study was to characterize the current epidemiological profile of patients with CM observed at the HC of the UFG from 1998 to 2010. Methods In total, 939 patient records were analyzed, and age, gender, place of birth, serology, symptoms and radiological classification according to Rezende et al. were analyzed. Results The median patient age was 55 years. Male patients were more (54%) prevalent than female patients. The prevalence of younger patients (less than 31 years of age) was 4.2%, but 82.1% of the younger patients were from State of Bahia. Patients older than 40 years were the majority (85.5%). The radiological groups were distributed as follows: Group I (35.9%), Group II (32.9%), Group III (17%) and Group IV (14.2%). Conclusions Compared with previous studies by the same group in 1975, 1994 and 1995, the number of younger patients decreased, and the frequency curve has shifted to older patients.

Studies on Phlebotominae (Diptera: Psychodidae) in the Campus FIOCRUZ Mata Atlântica, Jacarepaguá, in the City of Rio de Janeiro, Brazil

INTRODUCTION: The presence of American cutaneous leishmaniasis (ACL) in the communities of the Campus FIOCRUZ Mata Atlântica (CFMA) in the City of Rio de Janeiro initiated the investigation of the Phlebotominae fauna in the Atlantic Forest to determine the occurrence of putative ACL vectors associated with the enzootic cycle. METHODS: For 24 consecutive months, sand flies were captured inside the forest and in the border area near the communities. RESULTS: The following sand fly species were identified: Brumptomyia brumpti, Brumptomyia cunhai, Brumptomyia nitzulescui, Lutzomyia edwardsi, Lutzomyia pelloni, and Lutzomyia quinquefer. Other identified sand fly vectors, such as Lutzomyia intermedia (the predominant species), Lutzomyia migonei, Lutzomyia whitmani, Lutzomyia fischeri, and Lutzomyia hirsuta hirsuta, are associated with ACL transmission, and the vector for American visceral leishmaniases (AVL), Lutzomyia longipalpis, was also found. CONCLUSIONS: All sand fly vectors were found in both studied environments except for Lutzomyia whitmani, which was only identified in the forest. This study represents the first identification of Lutzomyia longipalpis in the CFMA, and the epidemiological implications are discussed.

Clinical and epidemiological profile of female blood donors with positive serology for viral hepatitis B

ABSTRACTINTRODUCTION:Since women are frequently the minority among blood donors worldwide, studies evaluating this population usually reflect male features. We assessed the features of female blood donors with positive serology for HBV and compared them with those of men.METHODS The study comprised consecutive blood donors referred to a specialized liver disease center to be evaluated due to HBsAg- and/or anti-HBc-positive tests.RESULTS: The study encompassed 1,273 individuals, 219 (17.2%) of whom were referred due to positive HBsAg test and 1,054 (82.8%) due to reactive anti-HBc test. Subjects' mean age was 36.8±10.9 years, and 28.7% were women. Female blood donors referred for positive HBsAg screening tests demonstrated higher prevalence of healthcare workers (9.3% vs 2.5%) and lower prevalence of sexual risk behaviors (15.1% vs 41.1%) and alcohol abuse (1.9% vs 19.8%) compared to men. Women had lower ALT (0.6 vs 0.8×ULN), AST (0.6 vs 0.8×ULN), direct bilirubin (0.2 vs 0.3mg/dL), and alkaline phosphatase (0.5 vs 0.6×ULN) levels and higher platelet count (223,380±50,293 vs 195,020±53,060/mm3). Women also had a higher prevalence of false-positive results (29.6% vs 17.0%). No differences were observed with respect to liver biopsies. Female blood donors referenced for reactive anti-HBc screening tests presented similar clinical, epidemiological, and biochemical characteristics to those reported for positive HBsAg screening tests and similarly had a higher prevalence of false-reactive results.CONCLUSIONS: Compared to men, female blood donors with positive HBsAg and/or anti-HBc screening tests demonstrated higher prevalence of professional risk and false-positive results and reduced alteration of liver chemistry.

Epidemiological study of hepatitis B and C in a municipality with rural characteristics: Cássia dos Coqueiros, State of São Paulo, Brazil

Abstract: INTRODUCTION: Hepatitis B and C viral infections remain an important cause of global morbidity and mortality. Studies have been conducted in population groups of large cities, leaving gaps in the knowledge regarding the situation in small municipalities. We aimed to measure the prevalence of hepatitis B and C markers and presence of infection-associated factors. METHODS: All inhabitants of Cássia dos Coqueiros aged ≥18 years who agreed to participate in the research were included. We collected blood as well as information via a questionnaire between March 2011 and December 2013. Univariate and multivariate analyses were conducted. RESULTS: Among the 1,001 participants, 41 (4.1%) participants had a serological profile of hepatitis B viral exposure, and only one (0.1%) participant was considered a virus carrier. The frequency of isolated antibody to hepatitis B virus surface antigen (anti-HBs) markers was 17.8% for the overall population. In the multivariate analysis, hepatitis B virus (HBV) infection was associated with age, birth outside the State of São Paulo, history of hepatitis, ≥2 sexual partners in the last 6 months, and tattoos. Four (0.4%) participants had a serological profile of hepatitis C viral exposure. However, after confirmation using viral ribonucleic acid (RNA) evaluation, only one (0.1%) individual remained positive. CONCLUSIONS: The positivity rates for hepatitis B and C were low, despite greater sexual freedom and the recent emergence of illicit drugs, as observed by the health personnel working in Cássia dos Coqueiros.

Distribution of hepatitis B infection in Brazil: the epidemiological situation at the beginning of the 21 st century

Abstract Brazil was formerly considered a country with intermediate hepatitis B endemicity, with large heterogeneity between Brazilian regions and areas of high prevalence, especially in the Amazon basin. Systematic vaccination of children was initiated in 1998. Between 2004 and 2009, a large population-based study reported decreased prevalence in all regions of Brazil. This review analyzed the current hepatitis B epidemiological situation in Brazil through a systematic search of the scientific literature in MEDLINE, LILACS, and CAPES thesis database, as well as disease notifications to the Information System for Notifiable Diseases. The search strategy identified 87 articles and 13 theses, resulting in 100 total publications. The most recent results indicate reduced hepatitis B prevalence nationwide, classifying Brazil as having low endemicity. Most studies showed HBV carrier prevalence less than 1%. However, there are still isolated regions with increased prevalence, particularly the Amazon, as well as specific groups, such as homeless people in large cities and isolated Afro-descendant communities in the center of the country. This review alsao detected successful vaccination coverage reported in a few studies around the country. The prevalence of anti-HBs alone ranged from 50% to 90%. However, isolated and distant localities still have low coverage rates. This review reinforces the downward trend of hepatitis B prevalence in Brazil and the need to intensify vaccination strategies for young people and adults in specific regions with persisting higher HBV infection prevalence.

Measuring male infertility: epidemiological aspects

Evidence suggests that human semen quality may have been deteriorating in recent years. Most of the evidence is retrospective, based on analysis of data sets collected for other purposes. Measures of male infertility are needed if we want to monitor the biological capacity for males to reproduce over time or between different populations. We also need these measures in analytical epidemiology if we want to identify risk indicators, risk factors, or even causes of an impaired male fecundity-that is, the male component in the biological ability to reproduce. The most direct evaluation of fecundity is to measure the time it takes to conceive. Since the time of conception may be missed in the case of an early abortion, time to get pregnant is often measured as the time it takes to obtain a conception that survives until a clinically recognized pregnancy or even a pregnancy that ends with a live born child occurs. A prolonged time required to produce pregnancy may therefore be due to a failure to conceive or a failure to maintain a pregnancy until clinical recognition. Studies that focus on quantitative changes in fecundity (that does not cause sterility) should in principle be possible in a pregnancy sample. The most important limitation in fertility studies is that the design requires equal persistency in trying to become pregnant and rather similar fertility desires and family planning methods in the groups to be compared. This design is probably achievable in exposure studies that make comparisons with reasonable comparable groups concerning social conditions and use of contraceptive methods.

Electrophysiological Studies and Radiofrequency Ablations in Children and Adolescents with Arrhythmia

Background:Radiofrequency ablation is the standard non-pharmacological treatment for arrhythmias in pediatric patients. However, arrhythmias and their associated causes have particular features in this population.Objective:To analyze the epidemiological characteristics and findings of electrophysiological diagnostic studies and radiofrequency ablations in pediatric patients referred to the Electrophysiology Unit at Instituto de Cardiologia do Rio Grande do Sul, in order to characterize the particularities of this population.Methods:Cross-sectional study with 330 electrophysiological procedures performed in patients aged less than 20 years between June 1997 and August 2013.Results:In total, 330 procedures (9.6% of the overall procedures) were performed in patients aged less than 20 years (14.33 ± 3.25 years, age range 3 months to 19 years), 201 of which were males (60.9%). A total of 108 (32.7%) electrophysiological diagnostic studies were performed and of these, 48.1% showed abnormal findings. Overall, 219 radiofrequency ablations were performed (66.3%) with a success rate of 84.8%. The presence of an accessory pathway was the most prevalent finding, occurring in 158 cases (72.1%), followed by atrioventricular nodal reentrant tachycardia (16.8%), typical atrial flutter (3.1%) and extrasystoles originating from the right ventricular outflow tract (2.7%). Three patients developed complications during ablation (1.4%). Among congenital heart diseases, which occurred in 51 (15.4%) patients, atrial sept defect was the most frequent (27.4%), followed by ventricular sept defect (25.4%) and Ebstein's anomaly (17.6%).Conclusion:Electrophysiological study and radiofrequency ablation are effective tools for diagnosis and treatment of arrhythmias in the pediatric population.

Poliomyelitis: epidemiological aspects in Rio de Janeiro (Guanabara State) and adjacent areas in the period from 1961 to 1970

Based on the available data from the Hospital responsible for the care of paralitic poliomyelitis cases in Rio de Janeiro City (Guanabara State) and adjacent areas, and the laboratory studies carried out on these patients, the authors analize epidemiological aspects of poliomyelitis in a period of ten years (1961 to 1970). Paralitic poliomyelitis remains a public health problem, with a typical incidence in the less than 4 year age group. All three poliovirus types have been prevalent for at least one period of time during the last ten years. Trivalent oral vaccine has been used since 1961 but the vaccination levels achieved were not enough to a permanent control of the disease. A definite seasonal distribution of cases could not be observed with the available data. Active mass campaign vaccinations with previous motivation of all segments of the population, specially the low-income groups instead of passive waiting of children in Vaccination Centers seems to be the best aproach to control poliomyelitis in this area.

Studies on Trypanosoma rangeli Tejera, 1920: V - Developmental pattern in the alimentary canal of Rhodnius prolixus

The morphological sequence of Trypanosoma rangeli development in the alimentary canal of Rhodnius prolixus, is described, with observation made in dissected guts from 6 hours to 45 days post-infection. No metacyclic-forms are produced in the digestive tract at any time, and transmission by the contaminative route must be considered atypical. Amastigotes appear to be an essential stage in the development of T. rangeli in the gut of R. prolixus. The epidemiological importance of the developmental pattern of T. rangeli in the vector´s gut is discussed, and its usefulness for aging infection is considered.

Studies on Trypanosoma rangeli Tejera 1920: VI. Developmental pattern in the haemolymph of Rhodnius prolixus

The morphological sequence of Trypanosoma rangeli development in the body cavity of Rhodnius prolixus is described. The metacyclic trypanosome is the product of successive division and transformation during the intra and extracellular development in the haemocoele. The significance of the early invasion of T. rangeli into the haemolymph is discussed. The epidemiological importance of the developmental pattern of T. rangeli in the vectors haemolymph and the host-response to the parasite are considered.