PREVALENCE OF Entamoeba histolytica/Entamoeba dispar IN THE CITY OF CAMPINA GRANDE, IN NORTHEASTERN BRAZIL

There is a clear need to perform epidemiological studies to find the true prevalence of Entamoeba histolytica around the world. The evaluation of this prevalence has been hindered by the existence of two different species which are morphologically identical, but genetically different, namely E. histolytica, which causes amebiasis, and E. dispar, which is non-pathogenic. In Brazil, the E. dispar has been detected in communities in the Southeastern (SE) and Northeastern (NE) regions with poor sanitation. However, individuals infected with E. histolytica have been identified in other regions. There is an absence of reports on the prevalence of these parasites in the state of Paraíba, which also has areas with poor sanitary conditions where a high prevalence of the E. histolytica/E. dispar complex has been detected in children from urban slums. The present study evaluated the prevalence of E. histolytica and E. dispar in 1,195 asymptomatic children between two and 10 years of age, living in a sprawling urban slum in Campina Grande, in the state of Paraíba, in Northeastern Brazil. These children were examined and their feces samples were analyzed microscopically. A total of 553 children tested positive for the E. histolytica/E. dispar complex, and 456 of the positive samples were tested with the E. histolytica II® ELISA kit. All 456 samples were negative for the presence of the adhesin E. histolytica specific antigen. The evidence suggests that in this community E. histolytica is absent and E. dispar is the dominant species.

INSECTICIDE-TREATED BED NETS IN RONDÔNIA, BRAZIL: EVALUATION OF THEIR IMPACT ON MALARIA CONTROL

Mosquito nets treated with long-lasting insecticide (LLINs), when used in compliance with guidelines of the World Health Organization, may be effective for malaria vector control. In 2012, approximately 150,000 LLINs were installed in nine municipalities in the state of Rondônia. However, no studies have assessed their impact on the reduction of malaria incidence. This study analyzed secondary data of malaria incidence, in order to assess the impact of LLINs on the annual parasite incidence (API). The results showed no statistically significant differences in API one year after LLIN installation when compared to municipalities without LLINs. The adoption of measures for malaria vector control should be associated with epidemiological studies and evaluations of their use and efficiency, with the aim of offering convincing advantages that justify their implementation and limit malaria infection in the Amazon Region.

SIXTEEN YEARS OF PITYRIASIS VERSICOLOR IN METROPOLITAN AREA OF PORTO ALEGRE, SOUTHERN BRAZIL

SUMMARY Pityriasis versicolor is the most common of the diseases caused by Malasseziayeasts. The aim of this study is to determine the prevalence of pityriasis versicolor and its etiological aspects in the metropolitan area of Porto Alegre, Brazil. A retrospective crosssectional study with data from patients of a reference hospital from 1996 to 2011 was performed. Collected data included: date, age, gender, ethnicity, anatomical region of lesion and the direct mycological examination results. Among the positive results in the direct mycological examination, 5.8% (2,239) were positive for pityriasis versicolor. The angular coefficient (B) was -0.3%/year, showing a decrease over the years. The disease was more prevalent in men (7.1% of men versus 5.1% of women that underwent the direct mycological examination); younger age (median 31 years old); "pardo" and black people (3.7% more than expected in the sample); trunk (73.44% of the affected anatomic sites). Lesions in rare sites (groin, genitals, legs, feet and hands) were also observed in this study. In conclusion, due to the decrease in the prevalence of pityriasis versicolor, long-term epidemiological studies in the metropolitan area of Porto Alegre, Brazil, are needed to continue the monitoring of this disease.

EPIDEMIOLOGY OF HONEYBEE STING CASES IN THE STATE OF CEARÁ, NORTHEASTERN BRAZIL

In the American continent, honeybee envenomation is a public health problem due to the high incidence and severity of the cases. Despite its medical importance, there is a lack of epidemiological studies on this topic in Brazil, especially referring to the Northeastern states. The present study has aimed to describe the epidemiological features of honeybee envenomation cases in the state of the Ceará, Northeastern Brazil, from 2007 to 2013. Data were collected from the Injury Notification Information System database of the Health Department of Ceará. A total of 1,307 cases were analyzed. Cases were shown to be distributed in all the months of the studied years, reaching higher frequencies in August. The majority of cases occurred in urban areas and involved men aged between 20 and 29 years. Victims were mainly stung on the head and torso, and they received medical assistance predominantly within 3 hours after being stung. Local manifestations were more frequent than systemic ones. Most cases were classified as mild and progressed to cure. The high number of honeybee sting cases shows that Ceará may be an important risk area for such injuries. Moreover, the current study provides data for the development of strategies to promote control and prevention of bee stings in this area.

Human parvovirus B19 infection in HIV-positive patients

Parvovirus B19 infects predominantly erythroid cells, leading to transient inhibition of erythropoiesis. Immunocompromised patients may be unable to produce neutralizing antibodies and may develop severe chronic anemia. Epidemiological studies done on Niterói population showed that B19 infection occurs periodically in late spring and summer. We report a study from 55 HIV infected patients attending an infectious diseases outpatient clinic in this city during a 5-month period in which B19 circulation was well documented. All patients were under anti-retroviral therapy. No anti-B19 IgM was found, but a high prevalence of IgG anti-B19 (91%) was observed. In six patients, B19 DNA was found by dot-blot hybridization techniques, but this was not confirmed by PCR. None of these 6 patients manifested anemia and only one had CD4 cell count below 200 x 10(7)/L. We conclude that persistent infection causing anemia is an infrequent finding in our HIV positive patients under drug therapy.

Molecular evidence of mother-to-child transmission of HTLV-IIc in the Kararao Village (Kayapo) in the Amazon Region of Brazil

Blood samples from native Indians in the Kararao village (Kayapo), were analysed using serological and molecular methods to characterize infection and analyse transmission of HTLV-II. Specific reactivity was observed in 3/26 individuals, of which two samples were from a mother and child. RFLP analysis of the pX and env regions confirmed HTLV-II infection. Nucleotide sequence of the 5' LTR segment and phylogenetic analysis showed a high similarity (98%) between the three samples and prototype HTLV-IIa (Mot), and confirmed the occurrence of the HTLV-IIc subtype. There was a high genetic similarity (99.9%) between the mother and child samples and the only difference was a deletion of two nucleotides (TC) in the mother sequence. Previous epidemiological studies among native Indians from Brazil have provided evidence of intrafamilial and vertical transmission of HTLV-IIc. The present study now provides molecular evidence of mother-to-child transmission of HTLV-IIc, a mechanism that is in large part responsible for the endemicity of HTLV in these relatively closed populations. Although the actual route of transmission is unknown, breast feeding would appear to be most likely.

Diagnosing human asymptomatic visceral leishmaniasis in an urban area of the State of Minas Gerais, using serological and molecular biology techniques

A population-based cross-sectional study was set up in Sabará country, Southeastern Brazil, to identify asymptomatic human visceral leishmaniasis in an urban area of low disease prevalence. Blood was collected on filter paper (n=1,604 inhabitants) and examined by indirect immunofluorescent test, enzyme-linked immunosorbent assay and immunochromatographic strip test. The prevalence rates of infection ranged from 2.4 to 5.6% depending on the test used. One year later, venous blood was collected in a subset of 226 participants (102 seropositive and 124 seronegative). The tests performed were IFAT, ELISA, rk39-ELISA, polymerase chain reaction and hybridization with Leishmania donovani complex probe. No clinical signs or symptoms of leishmaniasis were observed. Using hybridization as a reference test, the sensitivity and specificity of serology were respectively: 24.8 and 71% (ELISA); 26.3 and 76.3% (rk-39); 30.1 and 63.4% (IFAT). Due to disagreements, different criteria were tested to define the infection and hybridization should be considered in epidemiological studies.

Hydatidosis cases in one of Mar del Plata City hospitals, Buenos Aires, Argentina

Hydatidosis is a zoonosis of worldwide distribution produced mainly by the metacestode Echinococcus granulosus. In Argentina, its distribution reaches endemic levels. The aims of this investigation were to contribute to the knowledge of hydatidosis in the southeast of Buenos Aires province, study its evolution at the Interzonal General Hospital for Acute Diseases between 1992 and 2002 and discuss its importance. Clinical records of operated and/or diagnosed patients were reviewed with regard to this disease. One hundred and twenty cases were analyzed. Among the patients, 56.7% were women. The average age was 42.2+16.8 years. 68.3% lived in urban areas. In 75% of the cases, ultrasonography was used. Hepatic location was most frequently seen. 89.2% received surgical treatment. Albendazole was used for 19 patients. The mean length of hospital stay was 16 days. We conclude that this zoonosis is a disease that generates high costs in medical care and for this reason more epidemiological studies should be carried out and public health authorities should implement control and prevention strategies in the region.

Distribution of hepatitis C virus genotypes among different exposure categories in the State of Pará, Brazilian Amazon

INTRODUCTION: Epidemiological studies concerning HCV genotypic distribution in the Brazilian Amazon are scarce. Thus, this study determined the patterns of distribution of HCV genotypes among different exposure categories in the State of Pará, Brazilian Amazon. METHODS: A cross-sectional study was conducted on 312 HCV-infected individuals belonging to different categories of exposure, who were attended at the HEMOPA, CENPREN and a private hemodialysis clinic in Belém. They were tested for HCV antibodies using an immunoenzymatic test, RNA-HCV, using real-time PCR and HCV genotyping through phylogenetic analysis of the 5' UTR. The population groups were epidemiologically characterized according to data collected in a brief interview or medical consultation. RESULTS: Genotype 1 predominated in all the different categories of HCV exposure. HCV genotypic distribution among blood donors comprised genotypes 1 (94%) and 3 (6%). All patients with chronic hematologic diseases had HCV genotype 1. The genotypic distribution in illicit-drug users comprised genotypes 1 (59.6%) and 3 (40.4%). In patients under hemodialysis, genotypes 1 (90.1%), 2 (3.3%), and 3 (6.6%) were detected. Finally, the frequency of genotypes 1 and 3 was significantly different between the groups: BD and DU, PUH and DU, PUH and PCHD and PCHD and DU. CONCLUSIONS: The genotypic frequency and distribution of HCV in different categories of exposure in the State of Pará showed a predominance of genotype 1, regardless of the possible risk of infection.

Interpretation of the presence of IgM and IgG antibodies in a rapid test for dengue: analysis of dengue antibody prevalence in Fortaleza City in the 20th year of the epidemic

INTRODUCTION: The diagnosis of dengue and the differentiation between primary and secondary infections are important for monitoring the spread of the epidemic and identifying the risk of severe forms of the disease. The detection of immunoglobulin (Ig)M and IgG antibodies is the main technique for the laboratory diagnosis of dengue. The present study assessed the application of a rapid test for dengue concerning detection of new cases, reinfection recognition, and estimation of the epidemic attack rate. METHODS: This was a retrospective, cross-sectional, descriptive study on dengue using the Fortaleza Health Municipal Department database. The results from 1,530 tested samples, from 2005-2006, were compared with data from epidemiological studies of dengue outbreaks in 1996, 2003, and 2010. RESULTS: The rapid test confirmed 52% recent infections in the tested patients with clinical suspicion of dengue: 40% detected using IgM and 12% of new cases using IgG in the non-reactive IgM results. The positive IgM plus negative IgG (IgM+ plus IgG-) results showed that 38% of those patients had a recent primary dengue infection, while the positive IgG plus either positive or negative IgM (IgG+ plus IgM+/-) results indicated that 62% had dengue for at least a second time (recent secondary infections). This proportion of reinfections permitted us to estimate the attack rate as >62% of the population sample. CONCLUSIONS: The rapid test for dengue has enhanced our ability to detect new infections and to characterize them into primary and secondary infections, permitting the estimation of the minimal attack rate for a population during an outbreak.

Hepatitis C and cutaneous alterations

While most of those infected with hepatitis C virus (HCV) are asymptomatic or only develop liver manifestations, a significant percentage evolves with autoimmune and lymphoproliferative disorders, resulting in a clinical condition called HCV syndrome. This work involving case studies of six patients with hepatitis C and varied skin manifestation aimed to report skin lesions occurring with HCV infection and its treatment. Skin manifestations in hepatitis C have been based on epidemiological studies. This justifies the need for studies that correlate HCV infection and its treatment with skin manifestations.

Demographic determinants of survival of people living with HIV attending an outpatient reference unit in the city of Três Lagoas, state of Mato Grosso do Sul, Brazil, in the period 1984-2009

INTRODUCTION: While the incidence of HIV infection and AIDS is increasing in small Brazilian cities, epidemiological studies are often conducted in large urban centers. METHODS: Our group conducted a retrospective analysis of survival determinants among 358 patients who attended a reference unit in a small city. RESULTS: Death risk was lower among men that had sex with men, patients with an HIV-seropositive partner, and those admitted after highly active antiretroviral therapy (HAART) was available. CONCLUSIONS: The study documents the striking beneficial effect of HAART. The finding of other groups with improved survival may aid in the development of programmatic strategies.

Molecular characterization of Candida spp. isolates from patients with bloodstream infections

Introduction The aim of this study was to conduct an epidemiological study comparing the genetic similarity of yeasts isolated from blood cultures. Methods Random amplification of polymorphic DNA (RAPD) techniques were used for the Candida samples obtained from patients at the Hospital Universitário da Universidade Federal do Mato Grosso do Sul (HU/UFMS) in Campo Grande, state of Mato Grosso do Sul, Brazil, from 1998-2000. Results The most frequently isolated species was Candida albicans (45.8%). DNA amplification from genomic yeast isolates indicated a genetic similarity of over 90%. Conclusions The RAPD profiles obtained were able to differentiate between the isolated Candida species, thereby suggesting that the method might be useful in epidemiological studies.

Laboratory diagnosis of amebiasis in a sample of students from southeastern Brazil and a comparison of microscopy with enzyme-linked immunosorbent assay for screening of infections with Entamoeba sp.

Introduction: Epidemiological studies on amebiasis have been reassessed since Entamoeba histolytica and E. dispar were first recognized as distinct species. Because the morphological similarity of these species renders microscopic diagnosis unreliable, additional tools are required to discriminate between Entamoeba species. The objectives of our study were to compare microscopy with ELISA kit (IVD®) results, to diagnose E. histolytica infection, and to determine the prevalence of amebiasis in a sample of students from southeastern Brazil. Methods: In this study, diagnosis was based on microscopy due to its capacity for revealing potential cysts/trophozoites and on two commercial kits for antigen detection in stool samples. Results: For 1,403 samples collected from students aged 6 to 14 years who were living in Divinópolis, Minas Gerais, Brazil, microscopy underestimated the number of individuals infected with E. histolytica/E. dispar (5.7% prevalence) compared with the ELISA kit (IVD®)-based diagnoses (15.7% for E. histolytica/E. dispar). A comparison of the ELISA (IVD®) and light microscopy results returned a 20% sensitivity, 97% specificity, low positive predictive value, and high negative predictive value for microscopy. An ELISA kit (TechLab®) that was specific for E. histolytica detected a 3.1% (43/1403) prevalence for E. histolytica infection. Conclusions: The ELISA kit (IVD®) can be used as an alternative screening tool. The high prevalence of E. histolytica infection detected in this study warrants the implementation of actions directed toward health promotion and preventive measures.

High similarity of Trypanosoma cruzikDNA genetic profiles detected by LSSP-PCR within family groups in an endemic area of Chagas disease in Brazil

IntroductionDetermining the genetic similarities among Trypanosoma cruzi populations isolated from different hosts and vectors is very important to clarify the epidemiology of Chagas disease.MethodsAn epidemiological study was conducted in a Brazilian endemic area for Chagas disease, including 76 chronic chagasic individuals (96.1% with an indeterminate form; 46.1% with positive hemoculture).ResultsT. cruzi I (TcI) was isolated from one child and TcII was found in the remaining (97.1%) subjects. Low-stringency single-specific-primer-polymerase chain reaction (LSSP-PCR) showed high heterogeneity among TcII populations (46% of shared bands); however, high similarities (80-100%) among pairs of mothers/children, siblings, or cousins were detected.ConclusionsLSSP-PCR showed potential for identifying similar parasite populations among individuals with close kinship in epidemiological studies of Chagas disease.