The epidemiologic profile and prevalence of cardiopathy in Trypanosoma cruzi infected blood donor candidates, Londrina, Paraná, Brazil

To describe the epidemiologic profile and prevalence of cardiopathy in 163 Trypanosoma cruzi serum positive blood donor candidates, a descriptive study was carried out between August, 1996 and November, 1997 at the Londrina State University Chagas Disease Outpatient Clinic. The profile found was: young, average age 42.95 ± 8.62 years; male (65%); Caucasian (84%); low level of schooling; low family income; agricultural worker (26%); born in the state of Paraná (67%); from rural areas (85%); migrated to the city (85%); and the vector as the main mechanism of transmission. During the clinical characterization a chronic cardiac form was found in 38% of the patients and classified as cardiac suggestive form in 21% and little suggestive of Chagas disease in 17%. No significant difference was found among age group distribution, sex and the presence of cardiac symptoms in patients with or without cardiopathy. This study emphasizes the importance of expanding medical services to areas with a greater prevalence of infected individuals, in a hierarchical manner and aiming at decentralization.

Update on the population structure of MRSA causing infection in a central hospital and in healthcare centers in Portugal

RESUMO:Staphylococcus aureus é um dos principais agentes patogénicos humanos, sendo frequentemente associado a infecções nosocomiais e infecções na comunidade. A prevalência de S. aureus resistentes à meticilina (MRSA) em hospitais portugueses é uma das mais elevadas da Europa e tem sido caracterizada extensivamente; contrariamente, a prevalência e epidemiologia de MRSA na comunidade em Portugal não tem sido devidamente seguida. Com o objectivo de compreender as causas possíveis do aumento na frequência de MRSA num dos maiores hospitais centrais portugueses (HSM) ao longo de 17 anos, isolados de MRSA recolhidos em 1993 (n=54) e 2010 (n=180) de pus, sangue e urina foram analisados por PFGE, MLST, tipagem do spa e tipagem de SCCmec. Os resultados mostraram que ocorreu uma mudança global nos tipos clonais predominantes, onde o clone ST22-IVh substituiu os clones, ST239-IIIvar e ST247-I, representando mais de 70% da população actual. Além disso, entre 1993 e 2010 verificou-se um aumento na diversidade genética dos tipos clonais de MRSA. Para determinar a frequência e a natureza clonal de MRSA e S. aureus sensíveis à meticilina (MSSA) isolados de infecções de pele e tecidos moles (SSTI) em pessoas que frequentam centros de saúde em Portugal, 73 amostras foram recolhidas em nove centros de saúde (Rede Médicos Sentinela). Isolou-se um total de 40 S. aureus (55%), dos quais 17,5% eram MRSA. Os isolados de MRSA pertenciam aos clones ST22-IVh (n=4), ST5-IVc (n=2) e ST105-II (n=1), que foram descritos neste estudo como sendo clones de origem hospitalar. Os nossos resultados sugerem que o aumento da frequência de MRSA no HSM pode estar associado à emergência de um clone de MRSA com maior capacidade epidémica. Além disso, verificámos que a principal causa de SSTI em pessoas que frequentam centros de saúde em Portugal são MRSA de origem hospitalar e não MRSA associados à comunidade.------ABSTRACT: Staphylococcus aureus is one of the most important human pathogens, being a major cause of infections worldwide both in the hospital and in the community. In Portugal, the prevalence of methicillin resistant S. aureus (MRSA) in hospitals is one of the highest in Europe and has been characterized extensively; contrarily the prevalence and epidemiology of MRSA in the community has not been followed in a meaningful way. To understand the epidemiological events that could explain a steep increase in MRSA frequency in a major Portuguese central hospital (HSM) within a 17 year period, two MRSA collections recovered in 1993 (n=54) and 2010 (n=180) from pus, blood and urine were analyzed by PFGE, MLST, spa and SCCmec typing. The results showed that a major clonal shift occurred, wherein ST22-IVh clone has replaced the previous ST239-IIIvar and ST247-I clones and accounts for more than 70% of the present population. Moreover, an increase in genetic diversity of MRSA clonal types was observed between the two study periods. With the aim of determining the frequency and clonal nature of MRSA and methicillin-susceptible S. aureus (MSSA) causing skin and soft tissue infections (SSTI) in patients attending healthcare centers in Portugal, 73 samples were collected from nine healthcare centers (Medicos Sentinela Network). A total of 40 S. aureus were isolated, accounting for 55% of the SSTI, of which 17.5% were MRSA. MRSA isolates belonged to ST22-IVh (n=4), ST5-IVc (n=2) and ST105-II (n=1) that have also been described in the hospital in an equivalent period. Our results suggest that the increase in MRSA frequency in HSM may be associated to the emergence of a MRSA clone with higher epidemic potential. Moreover, we propose that the spillover of MRSA from the hospital rather than community-associated-MRSA was the main cause of SSTI in persons attending healthcare centers in Portugal.

Seroprevalence for hepatitis E virus (HEV) infection among volunteer blood donors of the Regional Blood Bank of Londrina, State of Paraná , Brazil

A cross-sectional study was carried out among 996 volunteer blood donors enrolled from May 1999 to December 1999 to determine the seroprevalence of hepatitis E virus (HEV) infection among volunteer blood donors of the Regional Blood Bank of Londrina, State of Paraná, Brazil, and to evaluate whether the rate of seroprevalence of IgG anti-HEV antibodies is associated with sociodemographic variables and with seropositivity for hepatitis A virus (HAV) infection. All participants answered the questionnaire regarding the sociodemographic characterisitcs. Serum samples were tested for IgG antibodies to HEV (anti-HEV) by an enzyme linked immunoassay (ELISA). All serum samples positive for anti-HEV IgG and 237 serum samples negative for anti-HEV were also assayed for IgG anti-HAV antibodies by ELISA. Anti-HEV IgG was confirmed in 23/996 samples, resulting in a seroprevalence of 2.3% for HEV infection, similar to previous results obtained in developed countries. No significant association was found between the presence of anti-HEV IgG antibodies and the sociodemographic variables including gender, age, educational level, rural or urban areas, source of water, and sewer system (p > 0.05). Also, no association with seropositivity for anti-HAV IgG antibodies was observed (p > 0.05). Although this study revealed a low seroprevalence of HEV infection in the population evaluated, the results showed that this virus is circulating among the population from Londrina, South Brazil, and point out the need of further studies to define the clinical and epidemiological importance of HEV infection and to identify additional risk factors involved in the epidemiology and pathogenesis of this infection in this population.

Toxoplasma-IgM and IgG-avidity in single samples from areas with a high infection rate can determine the risk of mother-to-child transmission

Anti-Toxoplasma IgG-avidity was determined in 168 serum samples from IgG- and IgM-positive pregnant women at various times during pregnancy, in order to evaluate the predictive value for risk of mother-to-child transmission in a single sample, taking the limitations of conventional serology into account. The neonatal IgM was considered the serologic marker of transmission. Fluorometric tests for IgG, IgM (immunocapture) and IgG-avidity were performed. Fifty-one of the 128 pregnant women tested gave birth in the hospital and neonatal IgM was obtained. The results showed 32 (62.75%) pregnant women having high avidity, IgM indexes between 0.6 and 2.4, and no infected newborn. Nineteen (37.25%) had low or inconclusive avidity, IgM indexes between 0.6 and 11.9, and five infected newborns and one stillbirth. In two infected newborns and the stillbirth maternal IgM indexes were low and in one infected newborn the only maternal parameter that suggested fetal risk was IgG-avidity. In the present study, IgG-avidity performed in single samples from positive IgM pregnant women helped to determine the risk of transmission at any time during pregnancy, especially when the indexes of the two tests were analysed with respect to gestational age. This model may be less expensive in developing countries where there is a high prevalence of infection than the follow-up of susceptible mothers until childbirth with monthly serology, and it creates a new perspective for the diagnosis of congenital toxoplasmosis.

The role of detoxification in the mosquito Anopheles gambiae response to Plasmodium infection

Rute C. Félix PALAVRAS-CHAVE: Malária, mosquito vector, Anopheles gambiae, parasita, Plasmodium berghei, infecção, enzimas de detoxificação, citocromos P450, tubulinas A malária, uma das doenças mais devastadoras que ocorrem em África é causada por um parasita do género Plasmodium e é transmitida aos humanos por mosquitos vectores do género Anopheles durante a refeição de sangue. Apesar da resposta do mosquito à infecção por Plasmodium ter vindo a ser intensamente estudada nos últimos anos, as interacções entre o mosquito vector e o parasita são muito complexas e, est��o longe de serem completamente compreendidas. Este estudo tem como objectivo principal contribuir para o conhecimento da resposta do mosquito à infecção por Plasmodium, focando-se no papel das enzimas de detoxificação. Para atingir este objectivo realizouse uma análise transcript��mica com microarrays, com o intuito de identificar alterações de transcrição de enzimas de detoxificação no mosquito Anopheles gambiae em resposta à infecção por Plasmodium. Esta análise permitiu identificar alterações na expressão de 254 genes de destoxificação no est��mago e corpo gordo de A. gambiae durante a invasão do intestino médio pelos oocinetos e durante a libertação dos esporozoítos do oocisto. Os resultados mostraram que a invasão do intestino médio pelos oocinetos causou alterações num maior número de genes em ambos os tecidos estudados, sendo o intestino médio do mosquito o tecido mais afectado nas duas fases da infecção do parasita. De todos os genes de destoxificação com expressão alterada, as tubulinas e os citocromos P450 destacaram-se e foram escolhidos para continuar o estudo. As tubulinas foram seleccionadas porque est��o associadas à invasão do epit��lio do intestino médio e a sua função na resposta à invasão do Plasmodium ainda não est�� bem definida. Os citocromos P450 foram seleccionados porque já foram descritos como tendo a expressão alterada em resposta ao Plasmodium e a outras infecções. Para identificar e caracterizar o papel das tubulinas durante a infecção pelo parasita e a sua possível associação com os citocromos P450 foi utilizado o silenciamento génico por RNA de interferência e a injecção de inibidores químicos de tubulinas. O silenciamento e co-silenciamento das tubulinas causaram um aumento da taxa e intensidade da infecção. No entanto, apesar de o aumento ser consistente não foi significativo. Por outro lado, a injecção de paclitaxel, um inibidor de tubulinas, aumentou significativamente a taxa e intensidade da infecção, fortalecendo a hipótese do envolvimento das tubulinas na resposta à infecção por Plasmodium. Este trabalho também mostrou que o co-silenciamento da tubulina A e tubulina B e a injecção do inibidor de tubulinas colchicine causam alterações significativas na expressão da CYP6Z2, sendo este proposto como um possível elo de ligação entre as tubulinas e os citocromos P450. Finalmente, uma análise comparativa foi realizada para estudar as regiões promotoras dos citocromos P450: CYP6M2 e o CYP6Z1. Este estudo obteve novos dados sobre compostos que activam estes citocromos e quais os possíveis factores de transcrição envolvidos. Dos diferentes est��mulos utilizados, a exposição a insecticidas e a bact��rias foram os que mais afectaram estes citocromos. O conjunto total das diferentes abordagens utilizadas neste trabalho contribuiu para aumentar o conhecimento do papel das enzimas de destoxificação durante a passagem do parasita da malária pelo mosquito vector.

Clinical and epidemiological aspects of HTLV-II infection in São Paulo, Brazil: presence of Tropical Spastic Paraparesis/HTLV-Associated Myelopathy (TSP/HAM) simile diagnosis in HIV-1-co-infected subjects

In this study, the epidemiological and clinical features observed in solely HTLV-II-infected individuals were compared to those in patients co-infected with HIV-1. A total of 380 subjects attended at the HTLV Out-Patient Clinic in the Institute of Infectious Diseases "Emilio Ribas" (IIER), São Paulo, Brazil, were evaluated every 3-6 months for the last seven years by infectious disease specialists and neurologists. Using a testing algorithm that employs the enzyme immuno assay, Western Blot and polymerase chain reaction, it was found that 201 (53%) were HTLV-I positive and 50 (13%) were infected with HTLV-II. Thirty-seven (74%) of the HTLV-II reactors were co-infected with HIV-1. Of the 13 (26%) solely HTLV-II-infected subjects, urinary tract infection was diagnosed in three (23%), one case of skin vasculitis (8%) and two cases of lumbar pain and erectile dysfunction (15%), but none myelopathy case was observed. Among 37 co-infected with HIV-1, four cases (10%) presented with tropical spastic paraparesis/HTLV-associated myelopathy (TSP/HAM) simile. Two patients showed paraparesis as the initial symptom, two cases first presented with vesical and erectile disturbances, peripheral neuropathies were observed in other five patients (13%), and seven (19%) patients showed some neurological signal or symptoms, most of them with lumbar pain (five cases). The results obtained suggest that neurological manifestations may be more frequent in HTLV-II/HIV-1-infected subjects than those infected with HTLV-II only.

Methylene blue vital staining for Trypanosoma cruzi trypomastigotes and epimastigotes

The morphological identification of Trypanosoma cruzi is currently considered to have a high specificity, but its sensitivity, which depends on the volume of the sample examined, is rather low. Trypanosome developmental stages suspended in blood, reduviid feces, and culture media are routinely searched for by means of fresh film examination (about 2 µL). High speed centrifugation of blood samples separates the buffy coat, where most trypomastigotes concentrate. As the parasites are transparent and colorless, their detection is mostly dependent on their motility. The fluorescent vital stain acridine orange has been used to enhance image contrast, as exemplified by the QBC (Quantitative Buffy Coat) technique. Staining blood, buffy coat, reduviid feces, and culture media samples with methylene blue (also a vital dye) is a means of producing sharp, well contrasted images of motile or non-motile T. cruzi developmental stages, only standard laboratory microscopes being required. Slides previously coated with a thin layer of methylene blue are used to stain fresh blood films. Photomicrographs exemplify the results of methylene blue staining applied to living and fixed parasites.

Antiretroviral treatment for HIV infection/AIDS and the risk of developing hyperglycemia and hyperlipidemia

A cross-sectional study with internal comparison groups was conducted to describe sociodemographic characteristics, as well as verify the association between the type of antiretroviral treatment used and hyperglycemia and hyperlipidemia, with special attention to the use of HIV protease inhibitors. The data was obtained through an interview questionnaire, as well as blood and urine samples that were collected for the laboratory exams. A total of 418 patients were interviewed. 46 of these, however, met the exclusion criteria. The sample was therefore composed by 372 HIV positive patients, attended at the laboratory of the Correia Picanço State Hospital for the collection of blood, to estimate the HIV viral load and/or TCD4 cell counts from August to November 2000. The association between the variables was tested using the chi-square test and the p-value. A multiple logistic regression analysis was carried out to adjust for potential confounding factors. A greater frequency of patients with high glucose levels was observed among those making use of antiretroviral therapy without protease inhibitors, but the number of patients limited the comparisons. An association was verified between the total serum cholesterol level and the use of HIV protease inhibitors (p = 0.047) even after controlling for age. An association was also observed between the triglyceride levels and the use of HIV protease inhibitors, which remained after adjustment for age, sex and creatinine levels (p < 0.001). The levels of glucose and TSH, the presence of proteinuria and the practice of physical activity were not associated either with the levels of cholesterol or with the levels of tryglicerides thus they were not confounders of the associations described.

High prevalence of malaria infection in Amazonas state, Venezuela

This study was carried out to determine the incidence of malaria in an endemic region of Amazonas State, Venezuela. For this, 200 random samples were collected from symptomatic and asymptomatic individuals from San Fernando de Atabapo and Santa Barbara. Epidemiological factors were related to malaria infection, which was diagnosed by microscopy observation and amplification of the 18S rDNA sequence by PCR. Malaria prevalence in these populations was 28.5%, whilst P. vivax and P. falciparum prevalences were 12 and 17%, respectively. No infection by P. malariae was found. A mixed infection was found on an asymptomatic individual. Prevalence patterns differed between age groups depending on the Plasmodium species. We found that 34.8% of the P. vivax and 15.2% of the P. falciparum infections were asymptomatic. The use of nets was helpful to prevent P. vivax infection, but did not protect against P. falciparum infection. The results suggest the presence of more than one mosquito vector in the area, displaying a differential pattern of infection for each Plasmodium species. There appear to be risk factors associated with malaria infections in some individuals. The population based approach and PCR diagnosis improved the accuracy of the statistical analysis in the study.

Detection of parvovirus B19 infection in formalin-fixed and paraffin-embedded placenta and fetal tissues

Parvovirus B19 infection was first discovered in 1975 and it is implicated in fetal death from hydrops fetalis the world over. Diagnosis is usually made through histological identification of the intranuclear inclusion in placenta and fetal organs. However, these cells may be scarce or uncharacteristic, making definitive diagnosis difficult. We analyzed histologically placentas and fetal organs from 34 cases of non-immune hydrops fetalis, stained with Hematoxylin and Eosin (HE) and submitted to immunohistochemistry and polymerase chain reaction (PCR). Of 34 tissue samples, two (5.9%) presented typical intranuclear inclusion in circulating normoblasts seen in Hematoxylin and Eosin stained sections, confirmed by immunohistochemistry and PCR. However, PCR of fetal organs was negative in one case in which the placenta PCR was positive. We concluded that parvovirus B19 infection frequency is similar to the literature and that immunohistochemistry was the best detection method. It is highly specific and sensitive, preserves the morphology and reveals a larger number of positive cells than does HE with the advantage of showing cytoplasmic and nuclear positivity, making it more reliable. Although PCR is more specific and sensitive in fresh or ideally fixed material it is not so in formalin-fixed paraffin-embedded tissues, frequently the only one available in such cases.

Natural infection of phlebotomines (Diptera: Psychodidae) in a visceral-leishmaniasis focus in Mato Grosso do Sul, Brazil

The main purpose of this study was to investigate natural infection by Leishmania in phlebotomine females in a visceral-leishmaniasis focus in Antonio João county in Mato Grosso do Sul State, Brazil. Between June and October 2003, the digestive tracts of 81 females captured in Aldeia Campestre, Aldeia Marangatu and Povoado Campestre were dissected. The females were separated by species, location, area and date of capture into 13 groups and kept in ethanol 70%. To identify the Leishmania species using the PCR technique, amplifications of the ribosomal-DNA (rDNA) and mini-exon genes were analyzed. Of the 81 specimens, 77 (95%) were Lutzomyia longipalpis, making this the most common species; only one specimen of each of the species Brumptomyia avellari, Evandromyia cortelezzii, Evandromyia lenti and Nyssomyia whitmani was found. Trypanosomatids were identified in eight of the nine groups of Lutzomyia longipalpis (10.39%) one group from Aldeia Campestre, one from Aldeia Marangatu and six from Povoado Campestre; of the eight groups, one from Aldeia Marangatu and another, with promastigotes forms also confirmed by dissection (1.23%) from Povoado Campestre, were identified by PCR as Leishmania chagasi (2.6%). The other groups gave negative results. These findings indicate that there is a high risk of leishmaniasis transmission in this area.