Human herpesvirus-7 as a cause of exanthematous ilnesses in Belém, Pará, Brazil

We screened sera from 370 patients suffering from exanthematous illnesses in Belém, North Brazil, for the presence of human herpesvirus-7 (HHV-7) IgM and IgG antibodies. Samples were obtained from January 1996 to December 2002 and were processed by a HHV-7-specific indirect immunofluorescence assay (IFA). HHV-7-specific IgM and/or IgG antibodies were found in 190 (51.4%) of these patients, with similar prevalence rates (IgM+ and IgG+ subgroups taken together) for female and male subjects: 52.5% and 50.3%, respectively. Serological status as defined by IgG was identified in 135 (36.5%) patients. In 55 (14.9%) of the patients HHV-7 IgM antibodies were detected. HHV-7 IgM- and- IgG antibody rates were similar (p > 0.05) when male and female subjects are compared: 14.4% versus 15.3% and 38.1% versus 35.0%, respectively. Statistically significant difference (p = 0.003) was noted when HHV-7-IgM-positive female and male patients aged 5-8 months are compared. Prevalence rates ranging from 4.6% (female, 5-8 months of age) to 93.3% (female, > 10 years of age) and 12.2% (male, 5-8 months) to 80.0% (male, 8-10 years of age) were noted in the IgG- positive subgroups. A subgroup (n = 131) of patients with IgM or IgG HHV-7 antibodies were examined for the presence of DNA using a polymerase chain reaction/nested PCR. Recent/active HHV-7 infection occurred at a rate of 11.0% (6/55) among patients whose samples presented IgM+ specific antibodies. In a subgroup (n = 76) of patients with high HHV-7-IgG antibody levels (titre > 1:160) DNA could not be detected in sera examined by PCR/nested PCR. Of the six recent/active infections, four subjects with less than 1 year and two with 3 and 6 years of age, presented typical exanthem subitum (E.S), as defined by higher fever (> 38.0 ºC) with duration of 24 to 72 hours, followed by a maculopapular skin rash. Our results underscore the need for searching HHV-7 infection in patients with exanthematous diseases, particularly those presenting with typical E.S. HHV-7 appears therefore to emerge as a newly recognized pathogen of exanthem in our region.

Dapsone hypersensitivity syndrome in an adolescent during treatment during of leprosy

A 12 y old girl was admitted 24 days after start a WHO multidrug therapy scheme for multibacillary leprosy (dapsone, clofazimine and rifampicin) with intense jaundice, generalized lymphadenopathy, hepatoesplenomegaly, oral erosions, conjunctivitis, morbiliform rash and edema of face, ankles and hands. The main laboratory data on admission included: hemoglobin, 8.4 g/dL; WBC, 15,710 cells/mm³; platelet count, 100,000 cells/mm³; INR = 1.49; increased serum levels of aspartate and alanine aminotransferases, gamma-glutamyl transpeptidase, alkaline phosphatase, direct and indirect bilirubin. Following, the clinical conditions had deteriorated, developing exfoliative dermatitis, shock, generalized edema, acute renal and hepatic failure, pancytopenia, intestinal bleeding, pneumonia, urinary tract infection and bacteremia, needing adrenergic drugs, replacement of fluids and blood product components, and antibiotics. Ten days after admission she started to improve, and was discharged to home at day 39th, after start new supervised treatment for leprosy with clofazimine and rifampicin, without adverse effects. This presentation fulfils the criteria for the diagnosis of dapsone hypersensitivity syndrome (fever, generalized lymphadenopathy, exfoliative rash, anemia and liver involvement with mixed hepatocellular and cholestatic features). Physicians, mainly in geographical areas with high prevalence rates of leprosy, should be aware to this severe, and probably not so rare, hypersensitivity reaction to dapsone.

On the possibility of autochthonous Chagas disease in Roraima, Amazon region, Brazil, 2000-2001

Chagas disease has been almost entirely eradicated from the arid zones in Central and Northeastern Brazil where rare or no autochthonous cases have been reported. However, in the last 10 years the disease has increasingly been registered in the Amazon Region. Aiming to investigate the possibility of the occurrence of autochthonous cycle of Chagas disease in Roraima, triatomine collections, vectorial susceptibility studies (this one to be shown elsewhere), parasitological and serological analyses were conducted in three agricultural settlement areas (Rorainópolis, Passarão Project and Ilha Community). Blood-donor candidates were also investigated. This is the first epidemiological survey on Chagas disease conducted in agricultural settlements in Roraima. Triatomine species found were Triatoma maculata, Rhodnius pictipes, Rhodnius robustus and Panstrongylus geniculatus. Trypanosoma cruzi detection analyses included xenodiagnosis, indirect immunofluorescence, indirect hemaglutination, ELISA and kinetoplast PCR amplification. Natural triatomine infection was not found in intestinal contents. Twenty-five adult settlers (1.4% out of 1821, all > 15 year-old, 20 migrants) presented anti-T. cruzi antibodies. Two migrant settlers (from Minas Gerais and Maranhão) tested positive for more than two serological tests, besides either being positive for xenodiagnosis or PCR. Results show that Chagas disease is not endemic in the areas studied. However, all elements of the transmission cycle are present, demanding for an adequate and continuous vigilance.

Prevalence of IgG varicella zoster virus antibodies in the Kuikuro and Kaiabi indigenous communities in Xingu National Park, Brazil, before varicella vaccination

The purpose of the study was to estimate the prevalence of IgG antibodies against varicella zoster virus (VZV) in the two most populated indigenous ethnic groups from Xingu Indigenous National Park, in Brazil, prior to the introduction of vaccination against the disease, and to determine the positive and the negative predictive values of a history of varicella infection. In 2001, 589 inhabitants of two Kuikuro villages and three Kaiabi villages were evaluated and provided information concerning previous varicella infection. An indirect immunosorbent assay (ELISA) to detect IgG anti-VZV antibodies was performed in 224 blood samples - volunteer selection had no interference of anamnesis. IgG prevalence was 80.8% (95% Confidence Interval: 76% - 86%). The seroepidemiology of varicella in Xingu National Park prior to varicella vaccine introduction was comparable to the Brazilian national seroprevalence described in the literature, and so were the positive (98%) and the negative predictive value (41%) of the referred history.

St. Louis encephalitis vírus: first isolation from a human in São Paulo state, Brasil

This paper reports the isolation of St. Louis encephalitis virus (SLEV) from a febrile human case suspected to be dengue, in São Pedro, São Paulo State. A MAC-ELISA done on the patient's acute and convalescent sera was inconclusive and hemagglutination inhibition test detected IgG antibody for flaviviruses. An indirect immunofluorescent assay done on the C6/36 cell culture inoculated with the acute serum was positive for flaviviruses but negative when tested with dengue monoclonal antibodies. RNA extracted from the infected cell culture supernatant was amplified by RT-PCR in the presence of NS5 universal flavivirus primers and directly sequenced. Results of BLAST search indicated that this sequence shares 93% nucleotide similarity with the sequence of SLEV (strain-MSI.7), confirmed by RT-PCR performed with SLEV specific primers. Since SLEV was identified as the cause of human disease, it is necessary to improve surveillance in order to achieve early detection of this agent in the state of São Paulo and in Brazil. This finding is also an alert to health professionals about the need for more complete clinical and epidemiological investigations of febrile illnesses as in the reported case. SLEV infections can be unrecognized or confused with other ones caused by an arbovirus, such as dengue.

Questing one Brazilian query: reporting 16 cases of Q fever from Minas Gerais, Brazil

Q fever has been considered non-existing in Brazil where reports of clinical cases still cannot be found. This case-series of 16 patients is a result of a systematic search for such illness by means of clinical and serologic criteria. Serologic testing was performed by the indirect microimmunofluorescence technique using phase I/II C. burnetii antigens. Influenza-like syndrome was the most frequent clinical form (eight cases - 50%), followed by pneumonia, FUO (fever of unknown origin), mono-like syndrome (two cases - 12.5% each), lymphadenitis (one case - 6.3%) and spondylodiscitis associated with osteomyelitis (one case - 6.3%). The ages varied from four to 67 years old with a median of 43.5. All but one patient had positive serologic tests for phase II IgG whether or not associated with IgM positivity compatible with acute infection. One patient had both phase I and phase II IgG antibodies compatible with chronic Q fever. Seroconvertion was detected in 10 patients. Despite the known limitations of serologic diagnosis, the cases here reported should encourage Brazilian doctors to include Q fever as an indigenous cause of febrile illness.

Anti-Taenia solium metacestode IgG antibodies in serum samples from inhabitants of a central-western region of Brazil

A total of 354 serum samples from inhabitants who frequent the Clinical Laboratory in Catalão, Goiás, in the central-western region of Brazil, were collected from June to August, 2002. The samples were evaluated by indirect immunofluorescence antibody tests and an enzyme linked immunosorbent assay in order to detect anti-Taenia solium metacestode IgG antibodies. Reactive and inconclusive samples were tested by Western blotting (WB). Considering WB as a confirmation, the frequency of antibodies in the serum samples of the above population was 11.3% (CI 5.09 - 17.51). The immunodominant bands most frequently recognized in WB were 64-68 kDa (97.5%) and 47-52 kDa (80%). The percentage of seropositivity to cysticercosis was significantly higher for individuals residing in areas without sewage systems (p < 0.0001). In conclusion, the results indicate a probable endemic situation of cysticercosis in this population. These results reinforce the urgent need for control and prevention measures to be taken by the local public health services.

Seroepidemiology and occupational and environmental variables for leptospirosis, brucellosis and toxoplasmosis in slaughterhouse workers in the Paraná State, Brazil

Leptospirosis, brucellosis and toxoplasmosis are widely-distributed zoonosis, being the man an accidental participant of their epidemiological chains. The aim of this paper was to make a seroepidemiological report and identify occupational and environmental variables related to these illnesses in 150 workers in a slaughterhouse in the Northern region of Paraná. For the diagnosis of leptospirosis a microscopical seroagglutination test was applied; for brucellosis, the tamponated acidified antigen test and the 2-mercaptoetanol tests were used, and for toxoplasmosis the indirect immunofluorescence reaction test. For each employee an epidemiological survey was filled, which investigated occupational and environmental variables which could be associated with these infections. Positive results for leptospirosis were found in 4.00% of the samples, for brucellosis in 0.66% of samples and toxoplasmosis in 70.00%. From the three diseases researched, only the results for leptospirosis suggest occupational infection.

Seroprevalence of toxoplasmosis in a low-income community in the São Paulo municipality, SP, Brazil

Toxoplasmosis is one of the most common zoonoses worldwide. The seroprevalence for T. gondii in human population from Brazil might range from 40 to 80%. The aim of this paper was to study the seroprevalence of T. gondii infection in children from age one to 15 living in a low socioeconomic community, named community of Jardim São Remo in the year of 2002. The community is located in the West area of São Paulo municipality, São Paulo State, Brazil. Antibodies to T. gondii were found in 110 (32.4%, CI 95%: 27.5 - 37.7) of the 339 children tested with indirect immunofluorescent antibody test. The titration of the samples revealed 29 children with serum titer equal to 16, 14 children with 32, 18 children with 64, 21 children with 128, 20 children with 256 and eight children with serum titer > 512. The age dependence of the prevalence of T. gondii infection and the association between seroprevalence for T. gondii and seroprevalence for T. canis suggest that the infection is chiefly postnatal. Seroconversion in infant population of community Jardim São Remo occurs in children as young as two years old, earlier than in the children attended at health centers of São Paulo city. The seroprevalence of T. gondii in children from Jardim São Remo was compared to the prevalence in children from other urban centers of Brazil.

Echovirus 4 associated to hand, foot and mouth disease

Hand, foot and mouth disease (HFMD) is a contagious enteroviral infection occurring primarily in children and characterized by vesicular palmoplantar eruptions and erosive stomatitis. Echovirus 4 (EV-4) has been commonly associated with aseptic meningitis. The association of HFMD with EV-4 has not been reported previously. Two samples of a 14-month child who presented mild fever, sores in the mouth, rash with blisters on the palm of hands and soles of feet were sent to Enteric Viruses Laboratory of Adolfo Lutz Institute. Clinical samples were inoculated in three different cell lines, and those which presented cytopathic effect (CPE), were submitted to Indirect Immunofluorescence Assay (IFA) and "one step" RT-PCR. Agarose gel electrophoresis from RT-PCR product, showed a product with 437 bp, which is characteristic of Enterovirus group. Echovirus 4 was identified by IFA. Although HFMD is a viral infection associated mainly with Enterovirus 71 (HEV-71) and Coxsackievirus A16 (CV-A16), our results demonstrate a diversity of serotype related to HFMD and stress the importance of epidemiological surveillance to this disease and its complications.

Sensitivity of an immunoenzymatic test for detection of ant-L. brasiliensis antibodies compared to other tests used for the diagnosis of American cutaneous leishmaniasis

The diagnosis of American cutaneous leishmaniasis (ACL) is frequently based on clinical and epidemiological data associated with the results of laboratory tests. Some laboratory methods are currently being applied for the diagnosis of ACL, among them the indirect immunofluorescence reaction (IIFR), the Montenegro skin test (MST), histopathological examination, and the polymerase chain reaction (PCR). The performance of these methods varies in a considerable proportion of patients. After the standardization of an immunoenzymatic test (ELISA) for the detection of IgG in the serum of patients with ACL using a crude Leishmania braziliensis antigen, the results obtained were compared to those of other tests routinely used for the diagnosis. The tests revealed the following sensitivity, when analyzed separately: 85% for ELISA IgG, 81% for PCR, 64.4% for MST, 58.1% for IIFR, and 34% for the presence of parasites in the biopsy. ELISA was positive in 75% of patients with ACL presenting a negative MST, in 84.8% of ACL patients with negative skin or mucous biopsies for the presence of the parasite, and in 100% of cases with a negative PCR. Thus, ELISA presented a higher sensitivity than the other tests and was useful as a complementary method for the diagnosis of ACL.

Kinetics of growth of Leishmania (Leishmania) chagasi cycle in McCoy cell culture

The kinetics of growth of Leishmania performed in vitro after internalization of the promastigote form in the cell and the occurrence of the transformation of the parasite into the amastigote form have been described by several authors. They used explants of macrophages in hamster spleen cell culture or in a human macrophage lineage cell, the U937. Using microscopy, the description of morphologic inter-relationship and the analysis of the production of specific molecules, it has been possible to define some of the peculiarities of the biology of the parasite. The present study shows the growth cycle of Leishmania chagasi during the observation of kinetic analysis undertaken with a McCoy cell lineage that lasted for a period of 144 hours. During the process, the morphologic transformation was revealed by indirect immunofluorescence (IF) and the molecules liberated in the extra cellular medium were observed by SDS-PAGE at 24-hour intervals during the whole 144-hour period. It was observed that in the first 72 hours the promastigote form of L. chagasi adhered to the cell membranes and assumed a rounded (amastigote-like) form. At 96 hours the infected cells showed morphologic alterations; at 120 hours the cells had liberated soluble fluorescent antigens into the extra cellular medium. At 144 hours, new elongated forms of the parasites, similar to promastigotes, were observed. In the SDS-PAGE, specific molecular weight proteins were observed at each point of the kinetic analysis showing that the McCoy cell imitates the macrophage and may be considered a useful model for the study of the infection of the Leishmania/cell binomial.

An immunofluorescence test for diagnosis of ophthalmic herpes in a mouse corneal model

Herpes simplex virus type 1 (HSV-1) ophthalmic disease is the most common cause of corneal blindness in humans world-wide. Current culture techniques for HSV take several days and commercially available HSV laboratory based diagnostic techniques vary in sensitivity. Our study was conducted to evaluate the use of a quicker and simpler method to herpes ophthalmic diagnosis. Corneal smears were made by firm imprints of infected mouse eyes to glass slides, after smears were fixated with cold acetone, and an indirect immunofluorescence (IIF) method was performed using monoclonal antibodies in a murine model of ophthalmic herpes. Eye swabs from infected mice were inoculated in Vero cells for virus isolation. Cytology and histology of the eye were also performed, using hematoxylin-eosin routine. Mouse eyes were examined by slit-lamp biomicroscopy for evidence of herpetic disease at various times postinoculation. We made a comparative evaluation of sensitivity, specificity and speed of methods for laboratory detection of HSV. Our results indicate that this IIF method is quick, sensitive, specific and can be useful in the diagnosis of ophthalmic herpes as demonstrated in an animal model.

Mayaro virus: imported cases of human infection in São Paulo State, Brazil

Mayaro virus (MAYV) is an arbovirus (Togaviridae: Alphavirus) enzootic in tropical South America and maintained in a sylvan cycle involving wild vertebrates and Haemagogus mosquitoes. MAYV cases occur sporadically in persons with a history of recent activities inside or around forests. This paper reports three cases of MAYV fever detected in men infected in Camapuã, MS, Brazil. Serum samples collected at four days and two months after the onset of the symptoms and examined by hemagglutination inhibition test, revealed monotypic seroconversion to MAYV. Isolation of the virus was obtained from one of the samples by inoculation of the first blood samples into newborn mice. A suspension of the infected mouse brain was inoculated into C6/36 cells culture and the virus was identified by indirect immunofluorescent assay with alphavirus polyclonal antibodies. RT-PCR, performed with RNA extracted from the supernatant of C6/36 infected cells in the presence of alphavirus generic primers as well as specific MAYV primers, confirmed these results. The reported cases illustrate the importance of laboratory confirmation in establishing a correct diagnosis. Clinical symptoms are not always indicative of a disease caused by an arbovirus. Also MAYV causes febrile illness, which may be mistaken for dengue.

Seroprevalence of Toxoplasma gondii infection among indian people living in Iauareté, São Gabriel da Cachoeira, Amazonas, Brazil

The goal of this survey was to estimate the seroprevalence of Toxoplasma gondii infection in Iauareté, a multiethnic Indian community in the upper Rio Negro basin. We carried out a cross-sectional survey (n = 260), in order to obtain serum samples and demographic data. The sample was randomly selected, by family conglomerate analysis. Serodiagnosis was performed by an enzyme-linked immunosorbent assay and indirect immunofluorescence. Prevalence of reactivity was 73.5% (191/260), being higher in the older-age groups, reaching 95.7% (44/46) in the group aged 50 years or more. The majority of seropositive subjects had titers equal to or less than 1:64. Seroprevalence was greater in Indians belonging to the Hupda ethnic group (p = 0.03). According to the present survey, Indian people living in Iauareté have a high prevalence of antibodies to T. gondii. Demographic concentration and urbanization within low sanitation and poor hygiene backgrounds, as well as unfiltered water consumption, may be related to the high frequency of T. gondii seroprevalence observed in the studied area.