Repositório RCAAP

Histiocytic necrotizing lymphadenitis, or Kikuchi's lymphadenitis (KL), is an unusual form of lymphadenitis, generally with self-limited clinical course. KL has been reported in rare patients infected with the human immunodeficiency virus (HIV). Pathogenesis of the lesion is probably related to an impaired immune function. The purpose of the present article is to report on one case in which KL was diagnosed in an HIV-infected patient. Histomorphology and immunophenotype were similar to previous reports, but a focus of activated CD30+ macrophages was seen, what might be due to the immunological status of the patient. EBV was not detected on the sections using the in situ hybridization technique. Although rare, the occurrence of KL in HIV-infected subjects must be emphasized, because of the potential misdiagnosis of malignancy, especially in the presence of CD30+ cells.

Knowledge of anemophilous fungi in a given city or region is important for the ecological diagnosis and specific treatment of allergic manifestations induced by inhaled allergens. In order to diagnose the presence of anemophilous fungi, several qualitative and quantitative techniques are used depending on the study place. This study of fungal air spores was performed with a Rotorod Sampler®, an equipment which samples the air through a plastic rod attached to an electric engine that makes it spin fast enough to collect the particles in the air. The samples were collected once a week during 24 hours using the standard cycle of the manufacturers. A total of 52 samples were obtained from April 2000 through March 2001. The results revealed prevalence of ascosporos (50.49%), Cladosporium (17.86%), Aspergillus/Penicillium (15.03%), basidiosporos (3.84%), rusts (3.82%), and Helminthosporium (2.49%), and a lesser frequency of Botrytis (1.22%), Alternaria (1.19%), smuts (0.90%), Curvularia (0.87%), Nigrospora (0.61%), and Fusarium (0.08%). Also, 1.59% of the spores detected here could not be identified by the systematic key used. More fungal spores were observed during the summer than during the autumn.

Lesions observed in chronic chagasic cardiopathy frequently produce electrocardiographic alterations and affect cardiac function. Through a computerized morphometrical analysis we quantified the areas occupied by cardiac muscle, connective and adipose tissues in the right atrium of dogs experimentally infected with Trypanosoma cruzi. All of the infected dogs showed chronic myocarditis with variable reduction levels of cardiac muscle, fibrosis and adipose tissue replacement. In the atrial myocardium of dogs infected with Be78 and Be62 cardiac muscle represented 34 and 50%, fibrosis 28 and 32% and adipose tissue 38 and 18%, respectively. The fibrosis observed was both diffuse and focal and mostly intrafascicular, either partially or completely interrupting the path of muscle bundles. Such histological alterations probably contributed to the appearance of electrocardiographic disturbances verified in 10 out 11 dogs which are also common in human chronic chagasic cardiopathy. Fibrosis was the most important microscopic occurrence found since it produces rearrangements of collagen fibers in relation to myocardiocytes which causes changes in anatomical physiognomy and mechanical behavior of the myocardium. These abnormalities can contribute to the appearance of cardiac malfunction, arrythmias and congestive cardiac insufficiency as observed in two of the analyzed dogs. Strain Be78 caused destruction of atrial cardiac muscle higher than that induced by strain Be62.

We have compared the searching of the presence of "honeycomb" structures by direct microscopy on wet mount preparations with the direct immunofluorescence (DIF) for the diagnosis of Pneumocystis carinii pneumonia (PCP) in 115 bronchoalveolar (BAL) fluids. The samples belonged to 115 AIDS patients; 87 with presumptive diagnosis of PCP and 28 with presumptive diagnosis other than PCP. The obtained results were coincident in 114 out of 115 studied samples (27 were positive and 87 negative) with both techniques. A higher percentage of positive results (32.18%) among patients with presumptive diagnosis of PCP with respect to those with presumptive diagnosis other than PCP (3.57%) was observed. One BAL fluid was positive only with DIF, showed scarce and isolated P. carinii elements and absence of typical "honeycomb" structures. The searching for "honeycomb" structures by direct microscopy on wet mount preparations could be considered as a cheap and rapid alternative for diagnosis of PCP when other techniques are not available or as screening test for DIF. This method showed a sensitivity close to DIF when it was applied to BAL fluids of AIDS patients with poor clinical condition and it was performed by an experienced microscopist.

Cranial CT scans of eleven immunocompetent children with central nervous system (CNS) infection due to Cryptococcus neoformans var. gattii were retrospectively reviewed. These children had an average age of 8.8 years and positive culture for C. n. var. gattii in cerebrospinal fluid. The most common signs and symptoms were headache, fever, nuchal rigidity, nausea and vomiting. No normal cranial CT was detected in any patient. Hypodense nodules were observed in all patients . The remaining scan abnormalities were as follows: nine had diffuse atrophy, six had hydrocephalus, and five had hydrocephalus coexistent with diffuse atrophy.

Hepatitis A virus (HAV) infection constitutes a major public health problem in Brazil. The transmission of HAV is primarily by fecal-oral route so the water is an important vehicle of HAV dissemination. There is a great incidence of acute cases of hepatitis A in some areas of Brazil however the seasonal variation of these cases was not documented. The aim of this study was to determine the seasonality of HAV infection in Rio de Janeiro. From January 1999 to December 2001, 1731 blood samples were collected at the National Reference Center for Hepatitis Viruses in Brazil (NRCHV). These samples were tested by a commercial enzyme-immunoassay to detect anti-HAV IgM antibodies. Yearly positive rates were 33.74% in 1999, 32.19% in 2000, and 30.63% in 2001. A seasonal variation was recognized with the highest incidence in spring and summer. Furthermore a seasonal increase in incidence of HAV infection was found during the rainy season (December to March) because the index of rains is very high. It is concluded that HAV infections occur all year round with a peak during hot seasons with great number of rains.

The present study was carried out to evaluate the Malar-CheckTM Pf test, an immunochromatographic assay that detects Plasmodium falciparum Histidine Rich Protein II, does not require equipment, and is easy and rapid to perform. In dilution assays performed to test sensitivity against known parasite density, Malar-CheckTMwere compared with thick blood smear (TBS), the gold standard for diagnosis. Palo Alto isolate or P. falciparum blood from patients with different parasitemias was used. The average cut-off points for each technique in three independent experiments were 12 and 71 parasites/mm³ (TBS and Malar-CheckTM, respectively). In the field assays, samples were collected from patients with fever who visited endemic regions. Compared to TBS, Malar-CheckTMyielded true-positive results in 38 patients, false-positive results in 3, true-negative results in 23, and false-negative result in 1. Malar-CheckTMperformed with samples from falciparum-infected patients after treatment showed persistence of antigen up to 30 days. Malar-CheckTM should aid the diagnosis of P. falciparum in remote areas and improve routine diagnosis even when microscopy is available. Previous P. falciparum infection, which can determine a false-positive test in cured individuals, should be considered. The prompt results obtained with the Malar-CheckTM for early diagnosis could avoid disease evolution to severe cases.

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Serotype, mating type and ploidy of 84 strains of Cryptococcus neoformans isolated from 61 AIDS and 23 non-AIDS patients admitted in a tertiary teaching hospital in São Paulo, Brazil were examined. Among 61 strains isolated from AIDS patients, 60 strains were var. grubii (serotype A). Only one strain was var. gattii (serotype B). No var. neoformans (serotype D) was found. Among 23 strains isolated from non-AIDS patients, 15 were var. grubii (serotype A) and the remaining 8 were var. gattii, all of which were serotype B. Seventy-three of the 75 serotype A strains were the heterothallic alpha type (MATalpha) and the remaining 2 were untypable (asexual). Most of the MATalpha strains (69/73) were haploid and the remaining 4 strains were diploid. Similarly, both of the 2 asexual strains among the 75 serotype A strains were haploid. There were no alpha-mating type (MATalpha) strains among the 84 isolates. All of the 8 var. gattii strains were serotype B and haploid. Among a total of 84 strains tested, neither serotype AD nor serotype D were found. Neither triploid nor tetraploid were found. These results suggest that the serological, sexual and ploidy characteristics in C. neoformans strains isolated from AIDS patients in São Paulo were rather simple, whereas strains isolated from non-AIDS patients presented serotype A and B with predominance of serotype A.

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.

Serum samples from 497 children and adults inhabiting two neighbourhoods (Guamá and Terra Firme) in Belém, Pará, North Brazil were screened for the presence of human herpesvirus 8 (HHV-8) antibody using an enzyme-linked immunosorbent assay. An overall 16.3% prevalence was found for these urban communities. Taken both genders together, prevalence rates of HHV-8 antibody increase gradually, across age-groups, ranging from 12.0% to 33.3%. When seroprevalence is analysed by gender, similar rates are found for female (18.4%) and male (14.0%) individuals. In the former gender group, seroprevalence rates increased from 10.3%, in children ;£; 10 years of age, to 30.0% in adults 41-50 years of age. Conversely, among male subjects, the prevalence of HHV-8 antibodies decreased from 13.3% in children/young adults aged ;£; 10 to 20 years of age to 6.1% in adults aged 21-30 years. From the 31-40 year-old group male onwards, seropositivity rates increased gradually, ranging from 8.3% to 66.7%. A significant difference in seropositivity rates was noted when comparing 21-30 age groups for female and male subjects: 23.3% and 6.1%, respectively (P = 0.03). Geometric mean optical densities were found to increase slightly from the lower to the higher age-groups. Our data suggest that transmission of HHV-8 occurs frequently in the general urban population of Belém, and that prevalence of antibody seems to increase with age.

Phenotypic and genotypic characteristics of Salmonella Typhi were studied in 30 strains, isolated in different years, from some areas in Brazil. Conventional typing methods were performed by biochemical tests, Vi phage-typing scheme, and antimicrobial susceptibility test. Molecular typing methods were performed by analysis of plasmid DNA and by random amplified polymorphic DNA (RAPD-PCR). For the latter, an optimization step was performed to ensure the reproducibility of the process in genetic characterization of S. Typhi. The predominance of 76.7% of biotype I (xylose +, arabinose -) was noticed in all studied areas. Three phage types were recognized, with prominence for the phage types A (73.3%) and I+IV (23.3%). All the strains were susceptible to the drugs used. However, 36.7% of the strains contained plasmids, with predominance of the 105 Kb plasmid. RAPD was capable of grouping the strains in 8 genotypic patterns using primer 784, in 6, using primer 787 and in 7, using primer 797. Conventional phenotypic typing methods, as well as the DNA plasmid analysis, presented nonsignificant discriminatory power; however, RAPD-PCR analysis showed discriminatory power, reproducibility, easy interpretation and performance, being considered as a promising alternative typing method for S. Typhi.

A investigação laboratorial de botulismo durante 1982-2001, confirma a ocorrência de surtos/casos de botulismo no Brasil. Dentre estes, a toxina botulínica tipo A foi encontrada em 7. O material biológico de 1 caso (soro e fezes) foi positivo para a primeira etapa do bioensaio, mas a quantidade do material não foi suficiente para a sua tipificação. Um surto, ocorrido em 2001, foi negativo para a presença de toxina botulínica em amostras de soro, lavado gástrico e fezes coletadas antes de 8 dias da instalação dos sintomas na pessoa afetada com diagnóstico clínico compatível com a doença. Outros 2 casos com diagnóstico clínico compatível foram negativos, porém nestes a coleta de amostras foi (1) depois da administração de anti-soro ao paciente e (2) em período superior a 8 dias do início dos sintomas. A investigação laboratorial foi realizada por bioensaio em camundongo, conforme descrito no "Compendium of Methods for the Microbiological Examination of Foods" (compilado por "American Public Health Association - APHA")11, e pelo uso de anti-soros específicos do "Centers for Disease Control (CDC)", Estados Unidos.

Cat-Scratch Disease (CSD) is a benign lymphadenitis that may progress to severe or recurrent forms, and it is occasionally associated with morbidity. Between January of 1998 and March of 1999, forty-three suspected CSD patients were assessed in the Hospital Cayetano Heredia and the Instituto de Salud del Niño, in Lima, Peru. Twelve patients had a confirmed diagnosis, 8 of whom were women, and the mean age was 10 years old. The majority (53%) of the cases were encountered in the summer. All patients reported having had contact with cats. Fever, malaise, lymphadenopathy and skin lesions were the most frequent clinical features. Twelve patients had indirect immunofluorescence antibody test titers of between 1/50 and 1/800 for Bartonella henselae and Bartonella clarridgeiae. Two lymph node biopsies were histologically compatible with CSD. No positive blood cultures could be obtained. This is the first Peruvian prospective study able to identify B. henselae and B. clarridgeiae in pediatric patients.

The presence of serological markers for hepatitis B virus (HBsAg, anti-HBc IgM and Anti-HBc total) was investigated in the serum of 1,396 individuals who had clinical suspect of hepatitis. It was observed that 50.7% of the individuals were positive and, from the total of the studied individuals, 14.5% were positive for HBsAg. From these, 8.5% were also positive for anti-HBc IgM. The analysis in relation to gender showed a higher seroprevalence index among male individuals (p < 0.0001). It was observed the occurrence of subtypes adw2 (62.7%), ayw3 (23.5%), ayw2 (9.8%) and adw4 (3.9%). The viral DNA was detected in 61 (33.9%) HBsAg positive samples and in one sample positive only for anti-HBc total. These results indicate an important incidence of the HBV infection in this population, and reinforce previous studies regarding this virus in the central west region of Brazil.

A leptospirosis clinical-epidemiological study was made in humans and reservoirs in the state of Yucatán, México. Interviews and serological analyses were made on 400 persons from an open population, 439 probable cases of leptospirosis and 1060 animal reservoirs (cows, pigs, dogs, rats and opossums). IgM Leptospira DipstickTM and Microscopic Agglutination Test (MAT) was used to detect human antibodies to leptospiras and serovar respectively. Leptospirosis incidence in humans was 2.2/100,000 inhab. in 1998, 0.7/100,000 in 1999 and 0.9/100,000 in 2000. Overall seroprevalence was 14.2%, relatively unchanged from seroprevalences observed 20 years ago. Highest seropositivity was found in people over 56 years of age, predominating males over females. Predominant serovars in the open population were tarassovi, hardjo, pomona and panama. Leptospirosis cases were most frequent in rural areas, and the anicteric course predominated over the icteric. The panama, icterohaemorrhagiae and pomona serovars predominated in both anicteric and icteric courses. Dogs, pigs and rodents had the highest seropositivity among the reservoirs. Contact with rodents and natural water sources were significant factors (p ;&pound;; 0.05). Human cases (74%) occurred during the rainy season. It is concluded that leptospirosis is still a serious illness with important clinical and epidemiological implications in the state of Yucatán, Mexico.

Perinephric and renal abscesses are rare in childhood, but they must be remembered in the differential diagnosis of fever and abdominal or flank pain. This paper reports three cases whose solution was found after clinical and surgical treatment. The importance of ultrasound and computerized tomography (CT) in prompt diagnosis is highlighted in this work. The use of these methods along the improved antimicrobial therapy may result in decrease in mortality due to this pathology.

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