Feeding sources and trypanosome infection index of Rhodnius pallescens in a Chagas disease endemic area of Amador County, Panama

The sylvatic triatomine Rhodnius pallescens is considered to be the most important and widespread vector of Trypanosoma cruzi and Trypanosoma rangeli in Panama. However, its behavior and biological characteristics have only been partially investigated. Thus, to achieve sustainable and efficient control over Chagas disease in Panama, a better understanding of the ecology and biology of R. pallescens is essential. In this study we evaluated R. pallescens host feeding sources using a dot-blot assay, and the trypanosome infection index by PCR analysis in a Chagas disease endemic area of central Panama. It was found that in peridomestic palm trees, 20.3% of the examined bugs had fed on opossums (Didelphis marsupialis). However, we observed an increased anthropophagy (25.4%) for those bugs collected inside houses. Considering the domestic and peridomestic habitats as a whole, the proportion of collected R. pallescens infected with trypanosomes was 87.4%. In the two habitats the predominant infection was with T. cruzi (80-90%). Between 47-51% of the analyzed triatomines were infected with T. rangeli. Mixed infections (40-51%) were also detected. These findings provide a better basis for the implementation of a rational control and surveillance program for Chagas disease in regions where R. pallescens is endemic.

Seroprevalence of selected viral, bacterial and parasitic infections among inpatients of a public psychiatric hospital of Mexico

We sought to determine the frequency of serological markers of selected infections in a population of psychiatric patients in Durango City, Mexico, and to determine whether there are any epidemiological characteristics of the subjects associated with the infections. One hundred and five inpatients of a public psychiatric hospital of Durango were examined for HBsAg, anti-HCV antibodies, anti-HIV antibodies, anti-Brucella antibodies, rapid plasma reagin and anti-Cysticercus antibodies by commercially available assays. Anti-Cysticercus antibodies were confirmed by Western blot and HBsAg by neutralization assay. Epidemiological data from each participant were also obtained. Seroprevalences of HBsAg, anti-HCV, anti-HIV, anti-Brucella, rapid plasma reagin and anti-Cysticercus antibodies found were 0.0%, 4.8%, 0.9%, 0.0%, 1.9%, and 0.9%, respectively. Overall, 9 (8.6%) inpatients showed seropositivity to any infection marker. We concluded that our psychiatric inpatients have serological evidence of a number of infections. HCV is an important pathogen among our psychiatric inpatients. Health care strategies for prevention and control of infections in Mexican psychiatric patients should be considered.

Candida bloodstream infection: data from a teaching hospital in Mato Grosso do Sul, Brazil

The incidence of Candida bloodstream infection has increased over the past years. In the Center-West region of Brazil, data on candidemia are scarce. This paper reports a retrospective analysis of 96 cases of Candida bloodstream infection at a Brazilian tertiary-care teaching hospital in the state of Mato Grosso do Sul, from January 1998 to December 2006. Demographic, clinical and laboratory data were collected from medical records and from the hospital's laboratory database. Patients' ages ranged from three days to 92 years, with 53 (55.2%) adults and 43 (44.8%) children. Of the latter, 25 (58.1%) were newborns. The risk conditions most often found were: long period of hospitalization, utilization of venous central catheter, and previous use of antibiotics. Fifty-eight (60.4%) patients died during the hospitalization period and eight (13.7%) of them died 30 days after the diagnosis of candidemia. Candida albicans (45.8%) was the most prevalent species, followed by C. parapsilosis (34.4%), C. tropicalis (14.6%) and C. glabrata (5.2%). This is the first report of Candida bloodstream infection in the state of Mato Grosso do Sul and it highlights the importance of considering the possibility of invasive Candida infection in patients exposed to risk factors, particularly among neonates and the elderly.

Acute postsurgical suppurative parotitis: current prevalence at Hospital das Clínicas, São Paulo University Medical School

Postsurgical acute suppurative parotitis is a bacterial gland infection that occurs from a few days up to some weeks after abdominal surgical procedures. In this study, the authors analyze the prevalence of this complication in Hospital das Clínicas/São Paulo University Medical School by prospectively reviewing the charts of patients who underwent surgeries performed by the gastroenterological and general surgery staff from 1980 to 2005. Diagnosis of parotitis or sialoadenitis was analyzed. Sialolithiasis and chronic parotitis previous to hospitalization were exclusion criteria. In a total of 100,679 surgeries, 256 patients were diagnosed with parotitis or sialoadenitis. Nevertheless, only three cases of acute postsurgical suppurative parotitis associated with the surgery were identified giving an incidence of 0.0028%. All patients presented with risk factors such as malnutrition, immunosuppression, prolonged immobilization and dehydration. In the past, acute postsurgical suppurative parotitis was a relatively common complication after major abdominal surgeries. Its incidence decreased as a consequence of the improvement of perioperative antibiotic therapy and postoperative support. In spite of the current low incidence, we believe it is important to identify risks and diagnose as quick as possible, in order to introduce prompt and appropriate therapeutic measures and avoid potentially fatal complications with the evolution of the disease.

Clinical and epidemiological analysis of patients with HIV/AIDS admitted to a reference hospital in the northeast region of Brazil

The AIDS epidemic has become a worldwide phenomenon of enormous magnitude and extension, deeply transforming medical practices and public health initiatives. This retrospective survey aimed to analyze clinical and epidemiological characteristics of patients with HIV/AIDS admitted to the Institute of Tropical Diseases Natan Portella, Teresina, Piauí, Brazil, from January, 2001 through December, 2004. Of the 828 patients, 43% were from other states and 71.3% were men. Average patient age was 35.4 ± 11.5 years-old and 85.5% were illiterate or had primary education. The main form of exposure to HIV was heterosexual behavior (54.1%), while injectable drug use was confirmed by only 2.7% of registered cases. The most frequent infectious complications were candidiasis (42.4%) and pneumocystosis (22.2%). Sixty-eight cases (8.2%) of visceral leishmaniasis were registered. Using multivariate analysis, individuals aged over 40 years-old, patients with active tuberculosis, Pneumocystis carinii pneumonia and central nervous system cryptococcosis showed increased risk of death. In this study, young male adults with low educational levels predominated and the most frequent opportunistic infections were candidiasis and pneumocystosis.

Extended-spectrum beta-lactamases among Enterobacteriaceae isolated in a public hospital in Brazil

Extended-spectrum β-lactamases (ESBL) in enterobacteria are recognized worldwide as a great hospital problem. In this study, 127 ESBL-producing Enterobacteriaceae isolated in one year from inpatients and outpatients at a public teaching hospital at São Paulo, Brazil, were submitted to analysis by PCR with specific primers for blaSHV, blaTEM and blaCTX-M genes. From the 127 isolates, 96 (75.6%) Klebsiella pneumoniae, 12 (9.3%) Escherichia coli, 8 (6.2%) Morganella morganii, 3 (2.3%) Proteus mirabilis, 2 (1.6%) Klebsiella oxytoca, 2 (1.6%) Providencia rettgeri, 2 (1.6%) Providencia stuartti, 1 (0.8%) Enterobacter aerogenes and 1 (0.8%) Enterobacter cloacae were identified as ESBL producers. BlaSHV, blaTEM and blaCTX-M were detected in 63%, 17.3% and 33.9% strains, respectively. Pulsed field gel eletrophoresis genotyping of K. pneumoniae revealed four main molecular patterns and 29 unrelated profiles. PCR results showed a high variety of ESBL groups among strains, in nine different species. The results suggest the spread of resistance genes among genetically different strains of ESBL-producing K. pneumoniae in some hospital wards, and also that some strongly related strains were identified in different hospital wards, suggesting clonal spread in the institutional environment.

Rapid HIV diagnostic test in undocumented pregnant women applied at an inner-city teaching hospital

A significant number of Brazilian gestational-age women are still not tested for HIV, representing a high risk of transmission to their newborns. The current study sought to identify the number of pregnant women with no previous testing or undocumented for HIV referred to the Gynecology and Obstetrics Department of a Regional Teaching Hospital and included diagnosis of HIV infection determined by a rapid test and perinatal transmission in pregnancy. Medical records of all pregnant women admitted to hospital from January 2001 to December 2005 were reviewed. Pregnant women without HIV results were submitted to a rapid HIV test. Those who tested positive were further tested by ELISA and confirmed by indirect immunofluorescence assay (IIA) or Western blot (WB). The viral load from babies born to HIV-infected mothers was assessed by bDNA. Of the 16,424 pregnant women analyzed (6.6%), 1,089 were undocumented for HIV. Eleven women were positive in rapid testing and 10 were confirmed by ELISA, IIA or WB, with 0.9% seropositivity. Mother/infant pairs received zidovudine monotherapy prophylaxis and infant viral load was lower than 50 copies/mL. A higher number of pregnant women previously tested for HIV during antenatal care was verified, compared to that obtained nationwide.

Pseudo-outbreak of Clostridium difficile associated diarrhea (CDAD) in a tertiary-care hospital

The objective of this study was to describe a pseudo-outbreak of C. difficile in a hospital, following a change in the method used to detect the toxin. In February 2002, there were two cases of CDAD and in March 7 occurred, coinciding with a change of the test (from detection of toxin A to toxin A/B). An outbreak was suspected. Active surveillance and education of staff were started. A CDAD case was defined as a patient with acute onset of diarrhea (³ three episodes of liquid stools) and a positive stool test. They were classified as hospital or community-acquired. Stool samples were also collected for C. difficile culture and isolates were typed using AP-PCR. From March 2002 through December 2003 there were 138 cases of CDAD: 70% were hospital-acquired and among the 30% with CDAD present on admission, most (81%) came directly from the community (50% had no history of hospitalization). Fifty-two percent of hospital-acquired CDAD and 94% of cases on admission had already used antibiotics. The incidence of CDAD in hospitalized patients during surveillance was 3.3 per 1000 patient-admissions. The incidence of CDAD present on admission was 6.1/1000 patients. Sixteen isolates were typed and presented 13 different profiles. In conclusion, the CDAD increase in our study occurred due to change in diagnostic methods and not due to an outbreak, as suspected initially. The incidence in hospitalized patients was much lower than in reported outbreaks. There were 13 molecular types suggesting that an outbreak did not occur. CDAD was largely community-acquired.

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.

Discrepancies and consequences of indirect hemagglutination, indirect immunofluorescence and Elisa tests for the diagnosis of Chagas disease

Using the indirect hemagglutination (IH), indirect immunofluorescence (IIF) and enzyme linked immunosorbent assay (ELISA) tests for the diagnosis of Chagas disease, 4000 serum samples were examined. This study was conducted with different purposes: clinical interest, research support and parasitological monitoring of those patients with Chagas disease who were treated with heart transplantations. The tests occurred without patient selection and in accordance with the medical requests. The results showed discrepancies and brought about several questions, considering the different results that all three methods showed when considered together. What was found brought about concerns and we suggest the adoption of different measures, aiming to avoid these mismatches in the context of this disease.

Scientific authorships and collaboration network analysis on Chagas disease: papers indexed in PubMed (1940-2009)

Chagas disease is a chronic, tropical, parasitic disease, endemic throughout Latin America. The large-scale migration of populations has increased the geographic distribution of the disease and cases have been observed in many other countries around the world. To strengthen the critical mass of knowledge generated in different countries, it is essential to promote cooperative and translational research initiatives. We analyzed authorship of scientific documents on Chagas disease indexed in the Medline database from 1940 to 2009. Bibliometrics was used to analyze the evolution of collaboration patterns. A Social Network Analysis was carried out to identify the main research groups in the area by applying clustering methods. We then analyzed 13,989 papers produced by 21,350 authors. Collaboration among authors dramatically increased over the study period, reaching an average of 6.2 authors per paper in the last five-year period. Applying a threshold of collaboration of five or more papers signed in co-authorship, we identified 148 consolidated research groups made up of 1,750 authors. The Chagas disease network identified constitutes a "small world," characterized by a high degree of clustering and a notably high number of Brazilian researchers.

Effects of vitamin C supplementation on acute phase Chagas disease in experimentally infected mice with Trypanosoma cruzi QM1 strain

The tissue changes that occur in Chagas disease are related to the degree of oxidative stress and antioxidant capacity of affected tissue. Studies with vitamin C supplementation did not develop oxidative damage caused by Chagas disease in the host, but other studies cite the use of peroxiredoxins ascorbate - dependent on T. cruzi to offer protection against immune reaction. Based on these propositions, thirty "Swiss" mice were infected with T. cruzi QM1 strain and treated with two different vitamin C doses in order to study the parasitemia evolution, histopathological changes and lipid peroxidation biomarkers during the acute phase of Chagas disease. The results showed that the parasite clearance was greater in animals fed with vitamin C overdose. There were no significant differences regarding the biomarkers of lipid peroxidation and inflammatory process or the increase of myocardium in animals treated with the recommended dosage. The largest amount of parasite growth towards the end of the acute phase suggests the benefit of high doses of vitamin C for trypomastigotes. The supplementation doesn't influence the production of free radicals or the number of amastigote nests in the acute phase of Chagas disease.