Mycobacterium avium complex (MAC) isolated from AIDS patients and the criteria required for its implication in disease

Before the AIDS pandemia, the Mycobacterium avium complex (MAC) was responsible in most cases for the pneumopathies that attack patients with basic chronic pulmonary diseases such as emphysema and chronic bronchitis36. In 1981, with the advent of the acquired immunodeficiency syndrome (AIDS), MAC started to represent one of the most frequent bacterial diseases among AIDS patients, with the disseminated form of the disease being the major clinical manifestation of the infection8. Between January 1989 and February 1991, the Section of Mycobacteria of the Adolfo Lutz Institute, São Paulo, isolated MAC from 103 patients by culturing different sterile and no-sterile processed specimens collected from 2304 patients seen at the AIDS Reference and Training Center and/or Emilio Ribas Infectology Institute. Disseminated disease was diagnosed in 29 of those patients on the basis of MAC isolation from blood and/or bone marrow aspirate. The other 74 patients were divided into categories highly (5), moderately (26) and little suggestive of disease (43) according to the criteria of DAVIDSON (1989)10. The various criteria for MAC isolation from sterile and non-sterile specimens are discussed.

Drug resistance of M. Tuberculosis isolated from patients with HIV infection seen at an AIDS Reference Center in São Paulo, Brazil

M. tuberculosis-positive cultures were obtained from 228 patients seen in our service and drug sensitivity assays were carried out from January 1992 to December 1994. A survey of the medical records of these patients showed resistance to one or more drugs in 47 (20.6%), 25 of whom (10.9%), who reported previous treatment, were considered to have acquired resistance. Among the antecedents investigated, only previous treatment and alcoholism were the factors independently associated with the occurrence of resistance. The survival of patients with resistant strains was lower than that of patients attacked by non-resistant M. tuberculosis. We conclude that in the present series M. tuberculosis resistance to tuberculostatic agents was predominantly of the acquired type.

Detection of Toxoplasma gondii soluble antigen, SAG-1(p30), antibody and immune complex in the cerebrospinal fluid of HIV positive or negative individuals

Active infection by T. gondii was evaluated by immunoassay for soluble SAG-1 (p30), the major surface antigen from T. gondii, specific antibodies and immune complexes in human cerebrospinal fluid (CSF) samples. A total of 263 samples of CSF were collected from hospitalized patients presenting neurological disorders and analyzed for antibodies to HIV. Patients were divided into two groups: HIV positive (n = 96) or HIV negative (n =167). The results of the assays showed that 45% of all samples were positive for soluble SAG-1. Toxoplasma Ag/Ab immune complexes were detected in 19% of the CSF samples and 62% were positive for T. gondii- specific IgG. A combination of these assays in the presence of clinical findings consistent with active Toxoplasma infection may predict the presence of toxoplasmic encephalitis. Moreover, detection of soluble SAG-1 in the CSF of these individuals appears consistent with active infection.

Acute renal failure after massive honeybee stings

Two clinical cases of patients who survived after numerous attacks of Africanized bees (600 and 1500 bee stings, respectively) are reported. Clinical manifestation was characterized by diffuse and widespread edema, a burning sensation in the skin, headache, weakness, dizziness, generalized paresthesia, somnolence and hypotension. Acute renal failure developed and was attributed to hypotension, intravascular hemolysis, myoglobinuria due to rhabdomyolysis and probably to direct toxic effect of the massive quantity of injected venom. They were treated with antihistaminic, corticosteroids and fluid infusion. One of them had severe acute renal failure and dialysis was required. No clinical complication was observed during hospital stay and complete renal function recovery was observed in both patients. In conclusion, acute renal failure after bee stings is probably due to pigment nephropathy associated with hypovolemia. Early recognition of this syndrome is crucial to the successful management of these patients.

Canine visceral leishmaniasis in Barra de Guaratiba, Rio de Janeiro, Brazil: assessment of risk factors

Barra de Guaratiba is a coastal area of the city of Rio de Janeiro where American visceral leishmaniasis (AVL) is endemic. Although control measures including killing of dogs and use of insecticides have been applied at this locality, the canine seroprevalence remains at 25% and during 1995 and 1997 eight autochthonous human cases were notified. In order to evaluate factors related to the increase of the risk for Leishmania (Leishmania) chagasi infection in dogs we have screened 365 dogs by anti-Leishmania immunofluorescent antibody test (IFAT) and captured sandflies in the domestic and peridomestic environment. Some variables related to the infection were assessed by uni- and multivariate analysis. The distance of the residence from the forest border, its altitude and the presence of the opossum Didelphis marsupialis in the backyard, were found predictor factors for L. (L.) chagasi infection in dogs in Barra de Guaratiba. The presence of Lutzomyia longipalpis in the peridomestic environment indicates the possibility of appearence of new human cases. Our data also suggest the presence of a sylvatic enzootic cycle at this locality.

Early diagnosis of relapse in borderline leprosy: two case reports

Two cases of relapse in borderline leprosy were reported. Despite the late-reversal, reaction-like feature, the suspicion of relapse in both was based on persistent and slow-developing skin lesions and an absence of acute neuritis or reaction during one year of follow-up. The authors have considered this possible occurrence in lepromatous borderline-treated patients after their immune cellular restoration and defend that not all Type 1 reactions would be an inflammatory answer to persistent Mycobacterium leprae, but that they could be. Therefore, a relapse diagnosis could be applied and it is more advisable, as one year of Multi-Drug Therapy (MDT) is less dangerous and more efficient for these cases than one year of corticosteroids.

Genetic diversity and primary resistance among HIV-1-positive patients from Maringá, Paraná, Brazil

The objective of this study is to identify subtypes of Human Immunodeficiency Virus type 1 (HIV-1) and to analyze the presence of mutations associated to antiretroviral resistance in the protease (PR) and reverse transcriptase (RT) regions from 48 HIV-1 positive treatment naïve patients from an outpatient clinic in Maringá, Paraná, Brazil. Sequencing was conducted using PR, partial RT and group-specific antigen gene (gag) nested PCR products from retrotranscribed RNA. Transmitted resistance was determined according to the Surveillance Drug Resistance Mutation List (SDRM) algorithm. Phylogenetic and SimPlot analysis of concatenated genetic segments classified sequences as subtype B 19/48 (39.6%), subtype C 12/48 (25%), subtype F 4/48 (8.3%), with 13/48 (27.1%) recombinant forms. Most recombinant forms were B mosaics (B/F 12.5%, B/C 10.4%), with one C/F (2.1%) and one complex B/C/F mosaic (2.1%). Low levels of transmitted resistance were found in this study, 2/48 (2.1% to NRTIs and 2.1% for PI). This preliminary data may subsidize the monitoring of the HIV evolution in the region.

PREVALENCE OF DRUG RESISTANCE AND VIRULENCE FEATURES IN Salmonella spp. ISOLATED FROM FOODS ASSOCIATED OR NOT WITH SALMONELLOSIS IN BRAZIL

Salmonella is the most common etiological agent of cases and outbreaks of foodborne diarrheal illnesses. The emergence and spread of Salmonella spp., which has become multi-drug resistant and potentially more pathogenic, have increased the concern with this pathogen. In this study, 237 Salmonella spp., associated or not with foodborne salmonellosis in Brazil, belonging mainly to serotype Enteritidis, were tested for antimicrobial susceptibility and the presence of the virulence genes spvC, invA, sefA and pefA. Of the isolates, 46.8% were sensitive to all antimicrobials and 51.9% were resistant to at least one antimicrobial agent. Resistance to more than one antimicrobial agent was observed in 10.5% of the strains. The highest rates of resistance were observed for streptomycin (35.9%) and nalidixic acid (16.9%). No strain was resistant to cefoxitin, cephalothin, cefotaxime, amikacin, ciprofloxacin and imipenem. The invA gene was detected in all strains. Genes spvC and pefA were found in 48.1% and 44.3% of strains, respectively. The gene sefA was detected in 31.6% of the strains and only among S. Enteritidis. Resistance and virulence determinants were detected in Salmonella strains belonging to several serotypes. The high rates of antibiotic-resistance in strains isolated from poultry products demonstrate the potential risk associated with the consumption of these products and the need to ensure good food hygiene practices from farm to table to reduce the spread of pathogens relevant to public health.

PREVALENCE OF ANTIBODIES AGAINST INFLUENZA VIRUS IN NON-VACCINATED EQUINES FROM THE BRAZILIAN PANTANAL

The prevalence of antibodies against Equine Influenza Virus (EIV) was determined in 529 equines living on ranches in the municipality of Poconé, Pantanal area of Brazil, by means of the hemagglutination inhibition test, using subtype H3N8 as antigen. The distribution and possible association among positive animal and ranches were evaluated by the chi-square test, spatial autoregressive and multiple linear regression models. The prevalence of antibodies against EIV was estimated at 45.2% (95% CI 30.2 - 61.1%) with titers ranging from 20 to 1,280 HAU. Seropositive equines were found on 92.0% of the surveyed ranches. Equine from non-flooded ranches (66.5%) and negativity in equine infectious anemia virus (EIAV) (61.7%) were associated with antibodies against EIV. No spatial correlation was found among the ranches, but the ones located in non-flooded areas were associated with antibodies against EIV. A negative correlation was found between the prevalence of antibodies against EIV and the presence of EIAV positive animals on the ranches. The high prevalence of antibodies against EIV detected in this study suggests that the virus is circulating among the animals, and this statistical analysis indicates that the movement and aggregation of animals are factors associated to the transmission of the virus in the region.

Prevalência da doença de Chagas em banco de sangue através da reação de fixação de complemento e imunofluorescência indireta: discrepâncias entre as reações e possibilidade de falhas na seleção de doadores

Utilizando a Reação de Fixação de Complemento (FC) e Imunofluorescência Indireta (IF) os AA. encontraram no Banco de Sangue do Hospital Universitário de Londrina, Paraná, Brasil, 7,4% de reações sorológicas positivas para doença de Chagas em 3.000 candidatos a doadores de sangue sendo concordantes em 97,1% e discordantes em 2,9%. A IF se mostrou mais sensível que a FC, sendo o risco de se encontrar um resultado positivo na IF quando esse era negativo ou duvidoso na FC estimado como sendo 15 vezes maior que o risco de se encontrar um resultado positivo na FC quando esse era negativo ou duvidoso na IF. A segurança das provas sorológicas aumentam quando se consideram os resultados duvidosos ou anticomplementares como positivos. Em outro grupo de candidatos a doador que já haviam doado sangue anteriormente, 450 tinham de uma a seis reações de FC prévias feitas em outro laboratório. Desses encontraram-se 10 indivíduos (2,2%) com reação positiva ou duvidosa em pelo menos uma oportunidade, o que mostra a relatividade da seleção de doadores apenas pela reação sorológica, discute-se a utilização alternativa da violeta de genciana pelos serviços de hemoterapia.

Estudo parasitológico e anátomo-patológico da fase aguda da doença de Chagas em cães inoculados com duas diferentes cepas do Trypanosoma cruzi

Cães jovens foram infectados com as cepas Y e CL do T. cruzi usando-se como inóculos 107 formas sangüíneas inoculadaspor via intraperitoneal e 2 x 10³ tripomastigotas metacíclicos obtidos do inseto vetor e inoculadospor via conjuntival. As cepas Ye CL induziram nos cães curvas deparasitemia totalmente distintas, confirmando dados parasitológicos obtidos em camundongos e coelhos. Com a cepa CL a parasitemia, com ambos os inóculos, foi gradualmente ascencional ao passo que com Y a parasitemia foi extremamente baixa, irregular e, com freqüência, subpatente. Com ambas as cepas o parasitismo e as lesões predominaram no miocárdio. Entretanto, com a cepa Y a miocardite foi sempre intensa desde as fases mais precoces da infecção, ao passo que com a cepa CL o processo inflamatório tomou-se acentuado somente a partir do 20.° dia. Freqüentemente a intensidade da miocardite observada em alguns animais não guardava relação com a parasitemia; em alguns cães com parasitemia subpatente, nos quais a infecção só foi diagnosticada pelo xenodiagnóstico, a intensidade da miocardite foi comparável àquela observada nos animais com parasitemia patente. Idêntica correlação também não foi assinalada em relação ao parasitismo tissular. Esses achados sugerem a participação de mecanismo imunológicos na gênese das lesões, ainda na fase aguda da infecção.

Aspectos da função renal em portadores do vírus da imunodeficiência humana

Verificou-se a ocorrência de alterações em alguns parâmetros da função renal de indivíduos infectados pelo virus da imunodeficiência humana (HIV), assintomáticos. Foram estudados 47 indivíduos, realizando-se provas funcionais renais: depuração de creatinina endógena, depuração de água livre, depuração osmolar, reabsorção tubular proximal e distal de sódio, excreção fracional de sódio e potássio e pH urinário. Os resultados revelaram diferenças significantes (p < 0,05) no pH urinário, maior no grupo HIV (6,36 ± 0,41), do que nos controles (6,02 ± 0,41); na depuração de água livre, que indicou reabsorção de água maior no grupo HIV (1,00 ± 0,64ml/min), do que nos controles (0,53 ± 0,48ml/min) e na depuração osmolar, que foi 2,00 ± 0,83ml/min no grupo HIV e 1,57 ± 0,48ml/min nos controles. O restante dos indicadores de função renal estudados não se mostraram diferentes estatisticamente entre um e outro grupo. Concluiu-se que essas diferenças são significativas, apesar de os valores absolutos estarem dentro da normalidade, pois podem estar associadas a alterações evolutivas tardias da doença, tais como o aumento na frequência de infecções do trato urinário e a hiponatremia dilucional. Mais estudos são necessários para se confirmarem essas hipóteses.

Epidemiologia dos acidentes por Thalassophryne nattereri (niquim) no Estado do Ceará (1992-2002)

No Estado do Ceará (1992 a 2002), 16 casos de envenenamento com o Thalassophyne nattereri ocorreram no litoral, a maioria (87,5%) em praias de Fortaleza e 12,5% do interior. Noventa e quatro por cento eram do sexo masculino e 6% feminino. Com relação à idade, 75% estavam na faixa etária de 21 a 40 anos, 19% entre 41 e 60 anos e 6% entre 1 a 10 anos. O tempo de exposição foi de 1 a 5 horas (4), 6 a 12 (3), mais de 12 horas (4), 5 pacientes não informaram o tempo decorrido entre o acidente e o atendimento. Manifestações clínicas observadas foram dor, edema local, isquemia transitória, parestesia, equimose e sensação de queimação local. O tratamento consistiu de antiinflamatórios e analgésicos. Em alguns casos, foram usados anestésicos, água morna, debridamento cirúrgico e anti-histamínicos. Em 75% dos casos, observou-se cura confirmada e em 12% a cura não foi confirmada, em dois a evolução foi ignorada. Provavelmente, o número de acidentes ocorridos é maior do que o encontrado devido a subnotificação.

Detecção do genótipo 4 do vírus da hepatite C em Salvador, BA

É descrito o primeiro caso de detecção do genótipo 4 do vírus da hepatite C (VHC) em Salvador, BA. Foram utilizados os testes de RT-PCR para detecção do VHC-RNA, e o LIPA para genotipagem. O genótipo 4 responde mal ao tratamento, sendo portanto importante a busca ativa dos contactantes.