Prospective study of enteropathogens in two communities of Misiones, Argentina

Children under five years of age, from two communities of different socio-economic strata (97 from Zaiman and 55 from Las Dolores) were examined epidemiologically during 2 years, by means of quarterly visits of the working team, who carried out the collection of faecal samples. During the study, one or more enteropathogens were identified in 73.9% of samples in children from Zaiman and in 58.3% of the samples from Las Dolores, being associated to diarrhoea in 70.5% and to asymptomatic infections in 65.7%. The number of diarrheic episodes was higher in Zaiman (15.45%) than in Las Dolores (12.35%), being more frequent in the spring-summer seasons. In Zaiman, the bacterial enteropathogen proportion was relevantly higher (p< 0.005) in children with diarrhoea, whereas the presence of parasites was more frequent in asymptomatic children (p< 0.01). Rotavirus had an even distribution within diarrheic and asymptomatic children. In Las Dolores, no relevant differences were found in the detection of enteroparasites between diarrheic and asymptomatic children. Mixed infections were detected; enterotoxigenic Escherichia coli (ETEC)-rotavirus and ETEC-parasites being the most frequent ones. ETEC was involved in 85% of these infections. These data, together with the high enteropathogen carriage, suggest an elevated level of environmental contamination. The latter plays an important role in diarrheic diseases, and added to the most extreme poverty, it affects children's lives.

CRYPTOSPORIDIOSIS IN PEDIATRIC PATIENTS

Cryptosporidium was detected in 21 (3.8%) individual stool samples collected from 553 pediatric patients hospitalized in our center employing a Telemann concentration technique (formalinethercentrifugation) and stained with the modified Kinyoun method. The mean age of populations with Cryptosporidiosis (16 boys and 5 girls) was 11 months; 15 months for girls and 6.5 for boys. Ages of 81% of them were less than 19 months. Seventysix per cent of patients lived on the outskirts of Buenos Aires and 71% lacked pretreated running water at home. In 62% of the cases parasitological diagnoses coincided with warm seasons. At diagnosis mucous (63%) or watery (36%) diarrhea was presented in 90% of the patients with a median of 5 (38) bowel movements per day. Fever was presented in 66% of patients while abdominal pain and vomits in 60% and 52%, respectively. The median time from hospitalization up to parasitologic diagnosis was 20 days. Concomitant diseases observed were malnutrition, acute leukemia, bronchiolitis, HIV infection, anemia, celiac disease, myelofibrosis, vitelline sac tumor, neutropenia, osteosarcoma and dehydration. Cryptosporidiosis in our environment seems to occur more frequently in children younger than 18 months of age; who present diarrhea; are immunodeficient; come from a low socioeconomical background; and who live in poor sanitary conditions with no potable running water.

HEPATITIS B VIRUS INFECTION PROFILE IN CENTRAL BRAZILIAN HEMODIALYSIS POPULATION

Hepatitis B has proved to be a major health hazard in hemodialysis patients. In order to investigate the hepatitis B virus (HBV) infection profile in the hemodialysis population of Goiânia city - Central Brazil, all dialysis patients (N=282) were studied. The prevalence of any HBV marker (HBsAg, anti-HBs, and anti-HBc) was 56.7% (95% CI: 51.1-62.7), ranging from 33.3% to 77.7% depending on dialysis unit. HBV-DNA was detected in 67.6% and 88.2% of the HBsAg-positive serum samples, in 91.3% and 100% of the HBsAg/HBeAg-positive samples, and in 18.2% and 63.6% of the HBsAg/anti-HBe-reactive sera by hybridization and PCR, respectively. The length of time on hemodialysis was significantly associated with HBV seropositivity. Only 10% of the patients reported received hepatitis B vaccination. The findings of a high HBV infection prevalence in this population and the increased risk for HBV infection on long-term hemodialysis suggest the environmental transmission, emphasizing the urgent need to evaluate strategies of control and prevention followed in these units.

Total IgE detection in paired cerebrospinal fluid and serum samples from patients with neurocysticercosis

Neurocysticercosis (NC), the presence of Taenia solium metacestodes in tissues, is the most frequent and severe parasitic infection of the central nervous system. We investigated the presence of total IgE by an automated chemiluminescence assay in 53 paired cerebrospinal fluid (CSF) and serum samples from patients with NC (P) and in 40 CSF samples from individuals with other neurological disorders as the control group (C). Total IgE concentration ranged from 1.2 to 6.6 IU/ml (mean = 1.4 IU/ml, standard deviation-sd = 1.1 IU/ml) in 28.3% of CSF samples from the P group, a value significantly higher than for the C group (£1.0 IU/ml). The serum samples from the P group showed concentrations ranging from 1.0 to 2330.0 IU/ml (mean = 224.1 IU/ml, sd = 452.1 IU/ml), which were higher than the normal value cited by the manufacturer (<100.0 IU/ml) in 32.1% of the samples. A significant difference was observed in CSF samples from the P and C groups (p = 0.005) and in serum samples from the P group compared to the normal value (p = 0.005), with sera showing more frequent abnormal results.

The epidemiology of acute viral gastroenteritis in hospitalized children in Cordoba city, Argentina: an insight of disease burden

Information concerning the disease burden of viral gastroenteritis has important implications for the use and monitoring the impact of public health policies. The present study, carried out in Córdoba city, Argentina, documents the epidemiology of severe viral diarrhea as well as the burden of viral gastrointestinal disease in the hospital children admission. A total of 133 stools were collected from hospitalized children (Town Childhood Hospital) suffering from acute diarrhea and studied for the presence of Group A rotavirus, astrovirus and adenovirus 40/41 by enzyme-immuno assay, between November 1997 and October 1998. Enteric viruses accounted for 42.1% of the total diarrheal cases analyzed. Group A rotaviruses, astroviruses, adenoviruses 40/41 and mixed infections were found in 35.3, 4.5, 1.5, and 0.8% studied specimens respectively. We estimated that 1 in 27 children in the 0-35 month-old cohort/range would be annually hospitalized for a viral gastroenteritis illness. The major impact on viral diarrhea lies on rotaviral infection, accouting for 84.0% of the viral diarrheal cases analyzed and for approximately one third of severe diarrheas requiring hospital admission in Córdoba City, Argentina.

Snakebites by Bothrops spp in children in Campinas, São Paulo, Brazil

From January, 1984 to March, 1999, 73 children under 15 y old (ages 1-14 y, median 9 y) were admitted after being bitten by snakes of the genus Bothrops. Twenty-six percent of the children were classified as mild envenoming, 50.7% as moderate envenoming and 20.6% as severe envenoming. Two patients (2.7%) showed no signs of envenoming. Most of the patients presented local manifestations, mainly edema (94.5%), pain (94.5%) ecchymosis (73.9%) and blisters (11%). Local and/or systemic bleeding was observed in 28.8% of the patients. Before antivenom (AV) administration, blood coagulation disorders were observed in 60.7% (incoagulable blood in 39.3%) of the 56 children that received AV only in our hospital. AV early reactions, most of which were considered mild, were observed in 44.6% of these cases (in 15/30 patients not pretreated and in 10/26 patients pretreated with hydrocortisone and histamine H1 and H2 antagonists). The main clinical complications observed were local infection (15.1%), compartment syndrome (4.1%), gangrene (1.4%) and acute renal failure (1.4%). No deaths were recorded. There were no significant differences with regard to severity of envenoming versus the frequency of blood coagulation disorders among the three categories of envenoming (p = 0.75) or in the frequency of patients with AV early reactions between the groups that were and were not pretreated (p = 0.55). The frequency of local infection was significantly greater in severe cases (p < 0.001). Patients admitted more than 6 h after the bite had a higher risk of developing severe envenoming (p = 0.04).

Chagas disease in the Brazilian Amazon: IV. a new cross-sectional study

A new conglomerate family sample of 194 dwellings with 996 resident persons were studied in the town of Barcelos, State of Amazonas, in order to re-evaluate the risk of Chagas disease. During the survey the persons were interviewed and in this occasion we showed to them a collection of Panstrongylus, Rhodnius and Triatoma, asking if they recognized and eventually have been bitten by this kind of bugs. At this time we collected 500 ul of blood in microtainer® tubes from 886 interviewed persons who gave permission after informed consent. A screening test for T. cruzi antibodies based on agglutination of colored polymer particles, sensitized with three different synthetic peptides of T. cruzi (ID-PaGIA Chagas Test)®, showed 13.2% of sera positivity, but only 6.8% were confirmed by indirect immunofluorescence, and ELISA with purified T. cruzi antigens. Two hundred and six interviewed persons (20.7%) recognized the triatomines, as "piaçavas' lice" and 62 (30%) confirmed that have been bitten by the bugs, 25.8% of them had a positive serology for T. cruzi infection. Electrocardiographic alterations were shown in 9.3% of the seropositives and in 11.9% of the seronegative cases. This was considered not statistically significant.

Human toxocariasis: a seroepidemiological survey in the municipality of Campinas (SP), Brazil

The occurrence of human Toxocara infection was evaluated in three neighborhoods of the periphery of the Campinas municipality (Jardim Santa Mônica, Jardim São Marcos and Jardim Campineiro) in 1999. Forty residences and 138 residents were randomly selected by drawing lots and were submitted to a seroepidemiological survey, which included blood collection for the immunoenzymatic detection (ELISA) of anti-Toxocara antibodies and a blood count, and the application of a semi-structured questionnaire for the evaluation of epidemiological data. Significant levels of anti-Toxocara antibodies were detected in 23.9% of the 1999 samples. No significant difference in the frequency of infection according to age was observed. Environmental contamination with Toxocara eggs was observed in 12.3 and 14.0% of 57 soil samples collected in the same region in December 1998 and July 1999, respectively. Univariate analysis and multiple logistic regression of the data obtained from the questionnaires and of the results of the serological tests, suggest a significant influence of socioeconomic variables on the frequency of human infection with Toxocara under the conditions prevalent in the study area.

Evidence of active herpesvirus 6 (variant-A) infection in patients with lymphadenopathy in Belém, Pará, Brazil

A total of 323 patients with lymphadenopathy were selected in Belém, Brazil, between January 1996 and December 2001, and screened for the presence of human herpesvirus-6 (HHV-6) IgM- and- IgG antibodies by enzyme-linked immunosorbent assay (ELISA). When seroprevalence is analyzed by gender, similar rates are found for female (60.6%) and male (55.7%) individuals. Seventy-seven (23.8%) patients were HHV-6-IgM-and- IgG-positive (IgM+ subgroup), with positivity rates of 29.7% and 17.7% (p = 0.0007) for female- and male individuals, respectively. Sera from a subgroup (n = 120) of these subjects, with high HHV-6 antibody levels (either IgM+ or IgG+ reactivities), were subsequently processed for the presence of HHV-6 DNA by polymerase chain reaction (PCR)/nested PCR. Active infections (IgM+ and/or IgG+ high levels specific antibodies plus detection of viral DNA) were diagnosed in 20/77 (20.0%) and 8/43 (18.6%); subgroup of the 120 individuals suspected of having HHV-6 suggestive recent infection. All (n = 28) cases of active infection were found to be associated with HHV-6 variant-A (HHV-6A), as detectable by PCR/nested PCR, using variant-specific primer that amplify regions of 195 base pairs (bp) (HHV-6A) and 423 bp (HHV-6B). Rates of HHV-6 DNA detection between female and male patients were similar (p > 0.05) in the IgM+ and IgG+ groups: 20.4% versus 35.7% and 25.0% versus 13.0%, respectively. HHV-6 DNA was detected across < 5 through 41-50-year age-groups for patients whose serum samples were IgM+, with rates ranging from 7.7% (female subjects aged < 5 years) to 80.0% (male, 11-20 years). Among patients whose serological status was IgG+, HHV-6 DNA was detected in < 5, 6-10, 21-30 and > 50 age-groups at rates that ranged from 15.4% (male, < 5 years of age) to 100.0% (female aged 11-20 years). Swelling cervical lymph nodes were the most common sign, accounting for 9 (32.0%) cases in each gender group. Among patients (n = 28) with active infection by HHV-6A variant, duration of symptoms lasted 1-5 days in 35.7% of subjects, whereas in 64.3% of them the disease lasted 6-20 days. Our data suggest that it is worth seeking for HHV-6 infection whenever a patient (infant or adult) presents with lymphadenopathy as a prominent symptom in the course of an acute febrile illness.

p53 immunostaining pattern in Brazilian patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is an important type of cancer etiologically related to some viruses, chemical carcinogens and other host or environmental factors associated to chronic liver injury in humans. The tumor suppressor gene p53 is mutated in highly variable levels (0-52%) of HCC in different countries. OBJECTIVE: The objective of the present study was to compare the frequency of aberrant immunohistochemical expression of p53 in HCC occurring in cirrhotic or in non-cirrhotic patients as well as in liver cell dysplasia and in adenomatous hyperplasia. We studied 84 patients with HCC or cirrhosis. RESULTS: We detected p53 altered immuno-expression in 58.3% of patients in Grade III-IV contrasting to 22.2% of patients in Grade I-II (p = 0.02). Nontumorous areas either in the vicinity of HCC or in the 30 purely cirrhotic cases showed no nuclear p53 altered expression, even in foci of dysplasia or adenomatous hyperplasia. No significant difference was found among cases related to HBV, HCV or alcohol. CONCLUSION: The high frequency of p53 immunoexpression in this population is closer to those reported in China and Africa, demanding further studies to explain the differences with European and North American reports.

"Multiplex PCR" identification of the atypical and monophasic Salmonella enterica subsp. enterica serotype 1,4,[5],12:i:- in São Paulo State, Brazil: frequency and antibiotic resistance patterns

Salmonella spp. are the etiologic agents of salmonellosis, a worldwide spread zoonoses causing foodborne outbreaks and clinical diseases. By serological identification, Salmonella enterica subsp. enterica serotype 1,4,[5],12:i:- accounted for 8.8% of human and 1.6% of nonhuman Salmonella strains isolated in São Paulo State, during 1991-2000. A total of 28.6% of them amplified a fragment corresponding to H:1,2 (flagellar phase two) through PCR analysis and were further assigned as S. Typhimurium. Antimicrobial resistance was detected in 36.3% of the 369 PCR-negative strains tested, including the multiresistance to ampicillin, chloramphenicol, sulfonamides, tetracycline, and streptomycin.

Characterization of Cryptococcus neoformans isolated from urban environmental sources in Goiânia, Goiás State, Brazil

Cryptococcus neoformans is an opportunistic fungal pathogen that causes meningoencephalitis as the most frequent clinical presentation in immunocompromised patients, mainly in people infected by HIV. This fungus is an environmental encapsulated yeast, commonly found in soil enriched with avian droppings and plant material. A total of 290 samples of pigeon and the other avian droppings, soil, ornamental trees and vegetable material associated with Eucalyptus trees were collected to study environmental sources of Cryptococcus species in Goiânia, Goiás State. The determination of varieties, serotypes and the susceptibility in vitro to fluconazole, itraconazole and amphotericin B of C. neoformans isolates were performed. C. neoformans var. grubii (serotype A) was found in 20.3% (36/177) of pigeon dropping samples and in 14.3% (5/35) of samples of Eucalyptus. None of the environmental isolates of C. neoformans showed in vitro resistance to three antifungal agents. The knowledge of major route for human cryptococcal infection (inhalation of infectious particles from saprophytic sources) and a total of 60 C. neoformans isolates obtained from AIDS patients with cryptococcal meningitis between October 2001 and April 2002 justify the study of the habitats of these yeasts as probable sources of cryptococcosis in this city.

Cystoscopy in the diagnosis and follow-up of urinary schistosomiasis in Brazilian soldiers returning from Mozambique, Africa

The assessment of urinary schistosomiasis in individuals coming from endemic areas often requires diagnostic resources not used in areas of exposure in order to determine complications or to establish more precise criteria of cure. Cystoscopy and 24-hour urine examination were performed, after treatments with praziquantel 40 mg/kg body weight, single dose, on 25 Brazilian military men who were part of a United Nations peace mission to Mozambique in 1994. The median age of the individuals was 29 years and all presented a positive urine parasitological exam. The alterations detected by cystoscopy were hyperemia and granulomas in the vesical submucosa in 59.1% of the individuals and only granulomas in 40.9%. A vesical biopsy revealed granulomas in all patients and viable eggs in 77.3% even after a period during which the patients no longer excreted eggs in urine. Cystoscopy after treatment, followed by biopsy and histopathological evaluation, performed in areas where the evolution of the disease can be better monitored, was found to be a safe criterion of parasitological cure.

Intestinal parasitoses and environmental factors in a rural population of Argentina, 2002-2003

We evaluate the prevalence of intestinal parasites in 504 people and the degree of association between environmental variables and parasites found in population, soil and water in a rural area of Argentina during 2002-2003. A structured survey was used to evaluate the environmental variables and fecal-human, soil and water samples were analyzed. The prevalence of parasites was 45.4%. Most prevalent protozoa were Blastocystis hominis (27.2%) and Giardia lamblia (6.9%), while the most prevalent helminth was Ascaris lumbricoides (3.8%). The analyzed environmental variables showing association (p < 0.05) with presence of parasites in population were: cardboard-tin or wooden house, dirt floor, home or communal water pump, faucet outside the house or public faucet and cesspool or latrine. Parasite forms were found in 82.3% of the soil samples and in 84.2% of the water samples. In both samples we found parasites that were also found in people. In this study we have found deficient sanitary conditions associated with presence of parasites in population and we have evidenced that contaminated soil and water were the source of these parasites.

Benign and malignant neoplasias in 261 necropsies for HIV-positive patients in the period of 1989 to 2008

Considering that there are some studies with autopsies from AIDS describing only malignant neoplasias and that changes can occur after the introduction of Highly Active Antiretroviral Therapy (HAART), our objectives were to analyze the frequency of benign and malignant neoplasms in AIDS patients in the periods of both pre- and post-HAART. This is a retrospective study with 261 autopsies of HIV-positive patients between 1989 and 2008 in Uberaba, Brazil. Sixty-six neoplasms were found (39 benign, 21 malignant and six premalignant) in 58 patients. The most frequent malignant neoplasms were lymphoid, in 2.7% (four Non-Hodgkin lymphoma, one Hodgkin, one multiple myeloma and one plasmablastic plasmacytoma), and Kaposi's Sarcoma, in 2.3% (six cases). The most frequent benign neoplasms were hepatic hemangiomas in 11 (4.2%) of 261 cases and uterine leiomyoma in 11 (15.7%) of 70 woman. In the pre-HAART period eight (9.8%) benign neoplasias and four (4.9%) malignant occurred in 82 patients; in the post-HAART period, 29 (16.2%) benign and 17 (9.5%) malignant were present; however, the differences were not significant. We conclude that the introduction of HAART in our region doesn't look to have modified the frequency of neoplasms occurring in patients with HIV.