LABORATORY EVALUATION OF THE DEVELOPMENT OF Aedes aegypti IN TWO SEASONS: INFLUENCE OF DIFFERENT PLACES AND DIFFERENT DENSITIES

Aedes aegypti is an important vector in Brazil being the main vector of the dengue-fever. This paper employs survival curves to describe the time in days from larvae to adult forms of Aedes aegypti raised, individually and collectively, and compares it during winter and spring when positioned inside and outside a laboratory. The study was conducted in São Vicente, a coastal city in Southeastern Brazil. The lowest water temperature in winter and in spring was 20 °C and the highest was 26 °C in spring. Higher and more stable temperatures were measured in the intra compared to the peri in both seasons. Consequently, larvae positioned in the intra resulted in the lowest median time to develop in the individual and collective experiment (nine and ten days, respectively). At least 25% of the larvae positioned in the intra in the individual experiment in the spring took only seven days to reach adulthood. Sex ratios and the median time development by sex did not show significant differences. These results indicate that efforts to control Aedes aegypti must be continuous and directed mainly to prevent the intra-domiciliary sites that can be infested in a week in order to reduce the human-vector contact.

PREVALENCE OF Calodium hepaticum (SYN. Capillaria hepatica) IN Rattus norvegicus IN THE URBAN AREA OF RIO DE JANEIRO, BRAZIL

The nematode Calodium hepaticum (syn. Capillaria hepatica) is a zoonotic helminth found mainly infecting rats. It was studied the prevalence of C. hepaticum infection in Rattus norvegicus in an urban area of Rio de Janeiro (Brazil), with low urban planning and sanitation. The presence of C. hepaticum was identified through visible yellowish-white lesions in liver tissue and histological analyses. The total prevalence of infection was 45%, with no significant differences between sex and age. The presence of infected rodents near the peridomestic area poses substantial risk to human health.

Trypanosoma cruzi in marsupial didelphids (Philander frenata and Didelhis marsupialis): differences in the humoral immune response in natural and experimental infections

Philander frenata and Didelphis marsupialis harbor parasitism by Trypanosoma cruzi without developing any apparent disease and on the contrary to D. marsupialis, P. frenata maintains parasitism by T. cruzi II subpopulations. Here we compared the humoral immune response of the two didelphids naturally and experimentally infected with T. cruzi II group, employing SDS-PAGE/Western blot techniques and by an Indirect immunofluorescence assay. We also studied the histopathological pattern of naturally and experimentally infected P. frenata with T. cruzi. P. frenata sera recognized more antigens than D. marsupialis, and the recognition pattern did not show any change over the course of the follow up of both didelphid species. Polypeptides of 66 and 90kDa were the most prominent antigens recognized by both species in the soluble and enriched membrane fractions. P. frenata recognized intensely also a 45kDa antigen. Our findings indicate that: 1) there were no quantitative or qualitative differences in the patent or subpatent phases in the recognition pattern of P. frenata; 2) the significant differences in the recognition pattern of parasitic antigens by P. frenata and D. marsupialis sera suggest that they probably "learned" to live in harmony with T. cruzi by different strategies; 3) although P. frenata do not display apparent disease, tissular lesions tended to be more severe than has been described in D. marsupialis; and 4) Both didelphids probably acquired infection by T. cruzi after their evolutionary divergence.

Bancroftian filariasis in an endemic area of Brazil: differences between genders during puberty

Gender differences in susceptibility to infectious diseases have been observed in various studies. A survey was performed in a bancroftian filariasis endemic area in the city of Olinda, Brazil. All residents aged 5 years or older were examined by thick blood film. People aged 9 to 16 years were interviewed and also tested for filarial antigenaemia. Data were analyzed by contingency table methods and regression models. The risk of microfilaraemia for males was significantly higher. Among those aged 9 to 16 years, the analysis of gender and filariasis by age showed that boys from 15 to 16 years had a higher risk of infection than girls. No association was found between menarche and filariasis in girls. The data suggest that variations between gender in filariasis could result, at least in part, from an increase in susceptibility of men. This epidemiologic feature needs to be considered while formulating elimination plans.

HIV genotyping among female sex workers in the State of Santa Catarina

The objective of this study was to investigate the frequency of HIV infection among female sex workers in the port area of Imbituba (State of Santa Catarina), and to identify the viral subtype and its susceptibility to antiretroviral medications. Ninety women were interviewed between December 2003 and February 2004. Six (6.7%) were HIV-positive. Genotyping for HIV, performed on four samples, detected subtype C in three of them, which is predominant in Africa and Asia, and subtype B in one of them, which is prevalent in Brazil, USA and Europe. The results suggest that the Port of Imbituba may be one of the gateways for HIV-1 subtype C to enter Brazil, and for its dissemination to the rest of the country and the Mercosul area, along the highway BR-101. This points towards the need for preventive work to reduce the introduction and dissemination of HIV subtype C in Brazil.

Epidemiological and molecular characteristics of HIV-1 infection among female commercial sex workers, men who have sex with men and people living with AIDS in Paraguay

An HIV seroprevalence and molecular study was conducted among 935 subjects: 723 female commercial sex workers, 92 men who have sex with men and 120 HIV-positive volunteers. The reported injection drug use rates were 0.7% in female commercial sex workers and 3% in men who have sex with men. Sexually transmitted infections were reported in 265 (37%) of the female commercial sex workers and 38 (41%) of the men who have sex with men. A total of 20 (2.8%) female commercial sex workers and 12 (13%) men who have sex with men became HIV infected during the study period. A history of sexually transmitted infection increased the risk of subsequent HIV infection twofold (adjusted odds ratio of 2.5) among the female commercial sex workers, while cocaine use had an adjusted odds ratios of 6.61 among men who have sex with men. From 130 samples, and based on heteroduplex mobility assaying for the env gene, with sequencing of part of pol and/or full genomes, subtype B was the predominant subtype identified (66%); followed by subtype F (22%) and subtype C (4%). Recombinant CRF12-BF strains were identified in 6% and CRF17_BF was identified in 2%.

Vertical transmission of HIV-1 in the western region of the State of São Paulo

INTRODUCTION: This study aimed to determine the prevalence of vertical HIV-1 transmission in the western region of the State of São Paulo, Brazil. METHODS: The study analyzed the medical records of HIV-1-infected mothers and infant pairs living in the municipalities of São Paulo Regional Health Departments DRS II (Araçatuba) and DRS XI (Presidente Prudente). From March 2001 to March 2006, blood samples were collected and referred to the Molecular Biology Unit of the Adolfo Lutz Institute (ALI), Presidente Prudente. HIV-1-RNA viral load was determined by bDNA assay. RESULTS: The number of births (109/217, 50.2%) and vertical HIV-1 transmissions (6/109, 5.5%) that occurred in DRS II was similar to births (108/217, 49.8%) and vertical transmissions (7/108, 6.5%) in DRS XI (p > 0.05). Although 80% (4/5) of the infected children were male in DRS II, while in DRS XI, 75% (6/8) were female, no differences between sex regarding infected and noninfected children in the regions of Araçatuba and Presidente Prudente were verified. The overall vertical HIV-1 transmission rate was 6%. No consistent reduction in the prevalence of vertical HIV-1 transmission occurred over the years. About 20% of mothers did not know the HIV-1 status of their newborns eight months after delivery. CONCLUSIONS: In the present study, MTCT prevalence rates were about 70% higher than those previously determined in the State of São Paulo, with noreduction throughout the period.Furthermore, a significant number of mothers did not know the HIV-status of their newborns eight months after delivery.

Detection of Dientamoeba fragilis in patients with HIV/AIDS by using a simplified iron hematoxylin technique

INTRODUCTION: Studies strongly indicate Dientamoeba fragilis as one of the causes of diarrhea in human immunodeficiency virus (HIV) patients. METHODS: The objective of the present study was to evaluate the prevalence of D. fragilis associated with the causes of diarrhea in 82 HIV/ AIDS patients hospitalized at the Instituto de Infectologia Emílio Ribas from September 2006 to November 2008. RESULTS: In total, 105 samples were collected from 82 patients. Unprotected sex was the most frequent cause of HIV infection (46.3%), followed by the use of injectable or non-injectable drugs (14.6%). Patients presented with viral loads of 49-750,000 copies/ mL (average: 73,849 ± 124,850 copies/mL) and CD4 counts ranging of 2-1,306 cells/mm³ (average: 159 ± 250 cells/mm³). On an average, the odds of obtaining a positive result by using the other techniques (Hoffman, Pons and Janer or Lutz; Ritchie) were 2.7 times higher than the chance of obtaining a positive result by using the simplified iron hematoxylin method. Significant differences were found between the methods (p = 0.003). CONCLUSIONS: The other techniques can detect a significantly greater amount of parasites than the simplified iron hematoxylin method, especially with respect to Isospora belli, Cryptosporidium sp., Schistosoma mansoni, and Strongyloides stercoralis, which were not detected using hematoxylin. Endolimax nana and D. fragilis were detected more frequently on using hematoxylin, and the only parasite not found by the other methods was D. fragilis.

Adverse reactions following mass drug administration with diethylcarbamazine in lymphatic filariasis endemic areas in the Northeast of Brazil

INTRODUCTION: The Global Programme to Eliminate Lymphatic Filariasis was launched with the goal of eliminating this disease via the annual mass drug administration (MDA) of a single dose of antifilarial drugs. Adverse drug reactions following MDA are a major factor of poor treatment adherence in several countries. This study assessed the occurrence of adverse drug reactions (ADRs) following the first round of mass treatment in two communities treated with different dosages of diethylcarbamazine (DEC) in the City of Recife, Brazil. METHODS: Population-based cross-sectional surveys were conducted in a random sample of the population living in both communities (Areas I and II). The dose of DEC recommended by the WHO (6mg/kg) was calculated based on the individual's weight-for-age. In Area II, weight differences between the genders were also considered when determining dosage. Data were obtained through interviews conducted in the first 12 to 48h and on the 5th day after MDA during household visits. RESULTS: A total of 487 and 365 individuals were interviewed in Areas I and II, respectively. The prevalence of ADRs in Area I (23.6; 95%CI: 19.1-29.5) was higher than in Area II (16.2; 95%CI:11.9-21.5)(p=0.0078). The prevalence of ADRs among females was higher than in males in Area I (p=0.0021). In Area II, no significant difference between the genders was observed (p=0.1840). Age was not associated with ADRs in either area. CONCLUSIONS: Adjusting MDA dosage schedules according to weight-for-age and sex may be may contribute to reduce the occurrence of adverse drug reactions in the population.

Epidemiological profile of Trypanosoma cruzi-infected mothers and live birth conditions in the state of Minas Gerais, Brazil

INTRODUCTION: The aim of this study was to assess the epidemiological characteristics of Trypanosoma cruzi-infected mothers and the live birth conditions of neonates.METHODS:A serological survey with IgG-specific tests was conducted using dried blood samples from newborn infants in the State of Minas Gerais. T. cruzi infection was confirmed in mothers through positive serology in two different tests, and infected mothers were required to have their infants serologically tested after the age of 6 months. The birth conditions of the neonates were obtained from the System of Information on Live Births database.RESULTS:The study included 407 children born to T. cruzi-infected mothers and 407 children born to uninfected mothers. The average age of seropositive mothers was 32 years (CI95% 31.3-32.6), which was greater than the average age of seronegative mothers - 25 years (CI95% 24.8-25.2). The mothers' level of education was higher among uninfected mothers (41% had 8 or more years of education, versus 22% between the infected mothers). Vaginal delivery was more frequent among infected mothers. There was no evidence of inter-group differences with respect to the child's sex, gestational age, birth weight or Appearance, pulse, grimace, activity and respiration (APGAR) scores at 1 and 5 minutes.Conclusions:The level of education and the greater number of previous pregnancies and cases of vaginal delivery reflect the lower socioeconomical conditions of the infected mothers. In the absence of vertical transmission, neonates had similar health status irrespective of the infection status of their mothers.

Differences in virulence markers between Helicobacter pylori strains from the Brazilian Amazon region

Introduction This study compares virulence markers of Helicobacter pylori isolated from patients in 2 cities in the Brazilian Amazon. Methods The study analyzed 168 patients with chronic gastritis from Belém and 151 from Bragança, State of Pará, Brazil. Levels of bacterial DNA associated with cagA and vacA alleles were checked by PCR, and hematoxylin-eosin staining was used for histologic diagnosis. Results In Bragança 87% of patients were genotype s1m1 cagA-positive (s1m1 cagA+), compared with 76% in Belém. In samples from patients in both cities, there was an association between s1m1 cagA+ strains and gastric mucosal damage. Conclusions Both cities have a high frequency of s1m1 cagA+ strains of H. pylori.

HIV, hepatitis B and C, and syphilis prevalence and coinfection among sex workers in Southern Brazil

Introduction Sex workers (SWs) are vulnerable to HIV, hepatitis, and syphilis coinfection. Methods A cross-sectional study was conducted in Tubarão, Laguna, and Imbituba, Southern Brazil. We surveyed 147 SWs using face-to-face interviews and blood sampling for serological evaluation. Results Prevalence of hepatitis B (HBV) was 23.1%, syphilis 19.7%, hepatitis C (HCV) 8.8%, and HIV 8.8%. Of 13 HIV-infected patients, 3 were co-infected with HCV, 4 with syphilis, and 5 with HBV. Conclusions SWs had high HIV infection rates, and coinfection with viral hepatitis and syphilis.

Do differences exist between chronic hepatitis C genotypes 2 and 3?

Introduction Six genotypes of the hepatitis C virus (HCV) have been identified thus far, and their distribution is well defined. Genotype 1, which is the most prevalent worldwide, is always compared to genotypes 2 and 3, particularly in terms of treatment response. However, little is known about the differences between genotypes 2 and 3 because these genotypes are analyzed together in most studies. Therefore, the aim of this study was to evaluate differences in the clinical, epidemiological, laboratory, and histological parameters between HCV-2 and HCV-3. Methods Patients with chronic hepatitis C infected with genotypes 2 and 3 were studied retrospectively and compared according to clinical, laboratory, and histological aspects. Hepatitis C virus-ribonucleic acid (HCV-RNA) was analyzed quantitatively by TaqMan® real-time PCR, and the HCV genotype was determined by sequencing the 5′-untranslated region. Results A total of 306 patients with chronic HCV-2 (n=50) and HCV-3 (n = 256) were studied. Subtype 2b (n=17/50) and subtype 3a (n=244/256) were the most prevalent among patients infected with HCV-2 and HCV-3, respectively. The mean age was 47 ± 10 years, and there was a predominance of men in the group studied (61%). Comparative analysis between HCV-2 and HCV-3 showed a younger age (p=0.002), less prevalence of arterial hypertension (p=0.03), higher serum albumin levels (p=0.01), more advanced stage of liver fibrosis (p=0.03), and higher frequency of steatosis in patients with HCV-3 (p=0.001). After multivariate regression analysis, all the variables, except serum albumin, remained as variables associated with HCV-3 in the final model. Conclusions Clinical and histological differences exist between HCV-2 and HVC-3, which suggests the need for separate analyses of these genotypes.

Sexing the human skull through the mastoid process

OBJECTIVE: The purpose of this study was to evaluate the significance for sex determination of the measurement of the area formed by the xerographic projection of 3 craniometric points related to the mastoid process: the porion, asterion, and mastoidale points. METHOD: Sixty skulls, 30 male and 30 female, were analyzed. A xerographic copy of each side of the skull was obtained. On each xerographic copy, the craniometric points were marked to demarcate a triangle. The area (mm²) of the demarcated triangle for each side of the skull (right (D) and left (E) sides) was determined, and the total value of these measures (T) was calculated. RESULTS: Concerning the right area of the male and female skulls, 60% of the values overlapped; for the left area, 51.67% overlapped, and for the total area, 36.67% overlapped. The analysis of the differences between the sexes in the areas studied was significant for the 3 areas. Regarding the total area, which is the preferred measurement because of the asymmetry between the sides of the skull, the value of the mean was 1505.32 mm² for male skulls, which was greater than the maximum value obtained in the female skulls. The value of the mean for female skulls was 1221.24 mm², less than the minimum value obtained for the male skulls. CONCLUSIONS: This study demonstrates a significant result in the 3 studied areas, (D), (E), and (T). The total area values show less overlapping of values between the sexes, and therefore can be used for sexing human skulls. For the population studied, values of the total area that were greater than or equal to 1447.40 mm² belonged to male crania (95% confidence). Values for this area that were less than or equal to 1260.36 mm² belonged to female crania (95% confidence).

Sex determination in the Giant fish of Amazon Basin, Arapaima gigas (Osteoglossiformes, Arapaimatidae), using laparoscopy

The Giant of Amazon basin, pirarucu, Arapaima gigas, is the largest scaled freshwater fish in the world. pirarucu cultivation has recently started, driven by the decline in natural populations and high market value. Currently, there are no reliable methods for sexual differentiation in this species other than direct examination of gonads, which requires dissection of specimens. A non-lethal and less invasive method for sexual identification is highly desirable in order to properly group broodstock for mating and offspring production. We utilized laparoscopic examination in anesthetized pirarucu to differentiate between male and female individuals. This method allowed for the observation and differentiation of the reproductive organs within an individual. Our results suggest that laparoscopy is an efficient method for sex differentiation in pirarucu causing minimal stress to the fish.