Freqüência de anticorpos neutralizantes contra o vesiculovirus Piry, em doadores de sangue de Uberaba , Minas Gerais, Brasil

Na cidade de Uberaba, Estado de Minas Gerais, dos 162 doadores de sangue, 13 (8,0%) apresentaram anticorpos neutralizantes contra o vesiculovirus Piry. Nos indivíduos positivos foi estatisticamente mais freqüente o relato de residência anterior em área rural (p < 0,0001) e em cidades do Estado de São Paulo (p < 0,05).

Malaria serology: performance of six Plasmodium falciparum antigen extracts and of three ways of determining serum titers in IgG and IgM-ELISA

The study evaluated six Plasmodium falciparum antigen extracts to be used in the IgG and IgM enzyme-linked immunosorbent assays (ELISA), for malaria diagnosis and epidemiological studies. Results obtained with eighteen positive and nine negative control sera indicated that there were statistically significant differences among these antigen extracts (Multifactor ANOVA, p< 0.0001). Urea, sodium deoxycholate and Zwittergent antigen extracts performed better than did the three others, their features being very similar for the detection of IgG antibodies. Urea, alkaline and sodium deoxycholate antigen extracts proved to be better than the others for the detection of IgM antibodies. A straight line relationship was found between the optical densities (or their respective log 10) and the log 10 of antibody dilutions, with a very constant slope. Thus serum titers could be determined by direct titration and by two different equations, needing only one serum dilution. For IgM antibody detections, log 10 expression gave results that better correlated with direct titration (95% Bonferroni). For IgG antibody detections, the titer differences were not significant. The reproducibility of antibody titers and antigen batches was also evaluated, giving satisfactory results.

Detection of hepatitis B virus DNA by the polymerase chain reaction in anti-HBE positive chronic hepatitis B patients

Detection of HBV-DNA by PCR was compared with other serological markers (HBsAg, HBeAg and anti-HBe) in a series of49 Chronic Hepatitis B patients, including 12 with a spontaneous clearance of HBsAg. None of these HBsAg negative cases were PCR positive, but 33/37 (89.2%) HBsAg positive cases were PCR positive (p < 0.0001). Among HBsAg positive samples, nine cases were HBeAg positive and anti-HBe negative, all of them PCR positive. Other 3 patients were HBeAg and anti-HBe positive and these cases were also found PCR positive. A third group included 21 patients anti-HBe positive and HBeAg negative: 19 of them were PCR positive and 2 were PCR negative. The last 4 cases were HBeAg and anti-HBe negative, two of them were PCR positive. The detection of anti-HBe viremic cases in the present series suggest that preC variants could occur in our country. In conclusion, the integrated phase o f chronic hepatitis B seems to be less frequent than it was assumed, when only HBeAg or dot blot hybridization techniques were used. The new term "low replication phase" might favorably replace the former "integrated phase".

Cardiac sympathetic-parasympathetic balance in rats with experimentally-induced acute chagasic myocarditis

To clarify the mechanism responsible for the transient sinus tachycardia in rats with acute chagasic myocarditis, we have examined the cardiac sympathetic-parasympathetic balance of 29 rats inoculated with 200,000 parasites (Trypanosoma cruzi). Sixteen infected animals and 8 controls were studied between days 18 and 21 after inoculation (acute stage). The remaining 13 infected animals and 9 controls were studied between days 60 and 70 after inoculation (sub-acute stage). Under anesthesia (urethane 1.25 g/kg), all animals received intravenous atenolol (5 mg/kg) and atropine (10 mg/kg). Acute stage: The baseline heart rate of the infected animals was significantly higher than that of the controls (P < 0.0001). The magnitude of the negative chronotropic response to atenolol was 4 times that of the controls (P < 0.00001). This response correlated with the baseline heart rate (r= - 0.72, P < 0.001). The heart rate responses to the beta-blocker and to atropine, of the infected animals studied during the sub-acute stage, were not different from controls. These findings suggest that cardiac sympathetic activity is transiently enhanced and cardiac parasympathetic activity is not impaired, in rats with acute chagasic myocarditis. The transient predominance of cardiac sympathetic activity could explain, in part, the sinus tachycardia observed in the acute stage of experimentally-induced chagasic myocarditis.

VALIDATION OF 14C-UREA BREATH TEST FOR DIAGNOSIS OF Helicobacter pylori

The aim of this study was to validate the 14C-urea breath test for use in diagnosis of Helicobacter pylori infection. Thirty H. pylori positive patients, based on histologic test and thirty H. pylori negative patients by histology and anti-H. pylori IgG entered the study. Fasting patients drank 5 uCi of 14C-urea in 20 ml of water. Breath samples were collected at 0, 5, 10, 15, 20 and 30 min. The difference of cpm values between the two groups was significant at all the time intervals, besides time 0 (p<0.0001). At 20 min, the test gave 100% sensitivity and specificity with a cut-off value of 562 cpm. Females were higher expirers than males (p=0.005). 14C-urea breath test is highly accurate for Helicobacter pylori diagnosis. It is fast, simple and should be the non-invasive test used after treating Helicobacter pylori infection.

Randomized, double-blind trial comparing indinavir alone, zidovudine alone and indinavir plus zidovudine in antiretroviral therapy-naive hiv-infected individuals with CD4 cell counts between 50 and 250/mm3

Treatment with indinavir has been shown to result in marked decreases in viral load and increases in CD4 cell counts in HIV-infected individuals. A randomized double-blind study to evaluate the efficacy of indinavir alone (800 mg q8h), zidovidine alone (200 mg q8h) or the combination was performed to evaluate progression to AIDS. 996 antiretroviral therapy-naive patients with CD4 cell counts of 50-250/mm3 were allocated to treatment. During the trial the protocol was amended to add lamivudine to the zidovudine-containing arms. The primary endpoint was time to development of an AIDS-defining illness or death. The study was terminated after a protocol-defined interim analysis demonstrated highly significant reductions in progression to a clinical event in the indinavir-containing arms, compared to the zidovudine arm (p<0.0001). Over a median follow-up of 52 weeks (up to 99 weeks), percent reductions in hazards for the indinavir plus zidovudine and indinavir groups compared to the zidovudine group were 70% and 61%, respectively. Significant reductions in HIV RNA and increases in CD4 cell counts were also seen in the indinavir-containing groups compared to the zidovudine group. Improvement in both CD4 cell count and HIV RNA were associated with reduced risk of disease progression. All three regimens were generally well tolerated.

Use of selective medium for Burkholderia cepacia isolation in respiratory samples from cystic fibrosis patients

Burkholderia cepacia colonizes cystic fibrosis (CF) patients. We evaluated the impact of the use of a selective medium in the rate of B. cepacia recovery from respiratory samples of CF patients. During a 6-month period, respiratory samples were collected from 106 CF patients and cultivated on selective media including a B. cepacia selective medium. Confirmation of the identity of B. cepacia isolates was carried out by species specific PCR and determination of genomovar status performed by a sequential PCR approach. Results of B. cepacia isolation during this period were compared to the preceding two years, when the sample processing was identical except for the lack of the B. cepacia selective medium. B. cepacia was isolated in 11/257 (4.2%) of the samples using the selective medium, in contrast with the preceding two years, when it was isolated in 6/1029 samples (0.58%), p < 0.0001. Identity of all 11 isolates was confirmed by PCR and genomovar determination was accomplished in all but one isolate. These results suggest that the use of a selective medium increases recovery rate of B. cepacia from respiratory samples.

Seroprevalence of hepatitis B virus infection in individuals with clinical evidence of hepatitis in Goiânia, Goiás: detection of viral DNA and determination of subtypes

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.

Accidental tetanus: prognosis evaluation in a historical series at a hospital in Salvador, Bahia, Brazil

A total of 868 (84.89%) patients diagnosed with tetanus were studied, out of the 1,024 tetanus patients hospitalized at Couto Maia Hospital (Salvador, Bahia, Brazil), during the period between 1986 and 1997. Of this group (n = 868), 63.5% (n = 551) were discharged, 35.4% (n = 307) died, and 1.1% (n = 10) were transferred. The average age of the deceased patients (38.73 ± 23.31 years) was significantly greater (p < 0.0001) than the age of those who survived (29.21 ± 20.05 years). Analyzing the variables of the logistic regression model with statistic significance (p £ 0.25) for univariate analysis, we observed a greater association of risk for worst prognosis (death) in patients aged ³ 51 years; time of illness < 48 hours; time of incubation < 168 hours; neck rigidity; spasms; opisthotonos; body temperature ³ 37.7 ºC; heart beat ³ 111 beats/minute; sympathetic hyperactivity and association with pneumonia. Among the group of those who survived, patients with 1 to 5 of those variables (n = 398; 76.8%) were more frequent, while among patients of the group of the deceased, 70.3% (n = 206) presented 6 to 10 of those variables, with a highly significant difference (p < 10-8). In conclusion, the indicators described provide early information that may guide the prognosis and medical and nurse care.

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.

Frequency of toxocara infection in children attended by the health public service of Maringá, south Brazil

The lack of specific laboratorial diagnosis methods and precise symptoms makes the toxocariasis a neglected disease in Public Health Services. This study aims to determine the frequency of Toxocara spp. infection in children attended by the Health Public Service of Hospital Municipal de Maringá, South Brazil. To evaluate the association of epidemiological and clinical data, an observational and cross-section study was carried out. From 14,690 attended children/year aged from seven month to 12 years old, 450 serum samples were randomly collected from September/2004 to September/2005. A questionnaire was used to evaluate epidemiological, clinical and hematological data. An ELISA using Toxocara canis larval excretory-secretory products as antigen detected 130 (28.8%) positive sera, mainly between children from seven month to five years old (p = 0.0016). Significant correlation was observed between positive serology for Toxocara, and frequent playing in sandbox at school or daycare center (p = 0.011) and the presence of a cat at home (p = 0.056). From the families, 50% were dog owners which exposed soil backyards. Eosinophilia (p = 0.776), and signs and symptoms analyzed (fever p = 0.992, pneumonia p = 0.289, cold-like symptoms p = 0.277, cough p = 0.783, gastrointestinal problems p = 0.877, migraine p = 0.979, abdominal pain p = 0.965, joint pain p = 0.686 and skin rash p = 0.105) could not be related to the presence of anti-Toxocara antibodies. Therefore, two asthmatics children showed titles of 1:10,240 and accentuated eosinophilia (p = 0.0001). The authors emphasize the needs of prevention activities.

Lysozyme plays a dual role against the dimorphic fungus Paracoccidioides brasiliensis

In order to determine the role of lysozyme, an antimicrobial peptide belonging to the innate immune system, against the dimorphic fungus Paracoccidioides brasiliensis, co-cultures of the MH-S murine alveolar macrophages cell line with P. brasiliensis conidia were done; assays to evaluate the effect of physiological and inflammatory concentrations of lysozyme directly on the fungus life cycle were also undertaken. We observed that TNF-α-activated macrophages significantly inhibited the conidia to yeast transition (p = 0.0043) and exerted an important fungicidal effect (p = 0.0044), killing 27% more fungal propagules in comparison with controls. Nonetheless, after adding a selective inhibitor of lysozyme, the fungicidal effect was reverted. When P. brasiliensis propagules were exposed directly to different concentrations of lysozyme, a dual effect was observed. Physiologic concentrations of the enzyme facilitated the conidia-to-yeast transition process (p < 0.05). On the contrary, inflammatory concentrations impaired the normal temperature-dependant fungal transition (p < 0.0001). When yeast cells were exposed to lysozyme, irrespective of concentration, the multiple-budding ability was badly impaired (p < 0.0001). In addition, ultra-structural changes such as subcellular degradation, fusion of lipid vacuoles, lamellar structures and interruption of the fibrilar layer were observed in lysozyme exposed conidia. These results suggest that lysozyme appears to exert a dual role as part of the anti-P. brasiliensis defense mechanisms.

Validation of a rapid stool antigen test for diagnosis of Helicobacter pylori infection

The aim of this study was to validate the rapid lateral flow Helicobacter pylori stool antigen test (One step H. pylori antigen test, ACON laboratories, San Diego, USA; Prime diagnostics, São Paulo), using 13C-Urea Breath Test as the gold standard for H. pylori infection diagnosis. A total of 98 consecutive patients, asymptomatic or dyspeptic, entered the study. Sixty-nine were women, with a mean age of 45.76 ± 14.59 years (14 to 79 years). In the H. pylori-positive group, the rapid stool antigen test detected H. pylori antigen in 44 of the 50 positive patients (sensitivity 88%; 95% CI: 75.7-95.5%), and six false-negative; and in the H. pylori-negative group 42 presented negative results (specificity 87.5%; 95% CI: 74.7-95.3%), and six false-positive, showing a substantial agreement (Kappa Index = 0.75; p < 0.0001; 95% CI: 0.6-0.9). Forty four of fifty patients that had positive stool antigen were H. pylori-positive, the PPV of the stool antigen test was 88% (95% CI: 75.7-95.5%), and 42 patients with negative stool antigen test were H. pylori-negative, the NPV of the stool antigen test was 87.5% (95% CI: 74.7-95.3%). We conclude that the lateral flow stool antigen test can be used as an alternative to breath test for H. pylori infection diagnosis especially in developing countries.

Epidemiological profile of malaria in the state of Tocantins, Brazil, from 2003 to 2008

This study describes the epidemiological profile of malaria in the State of Tocantins, in the period 2003-2008, investigates the association between the frequency of malaria and population growth, classifies the cases by 'autochthonous' and 'imported', reports the indices of the disease and analyses the distribution of the cases by Plasmodium species, age and gender. The retrospective study was based on secondary data, stored in SIVEP-malaria and analyzed using the software Epi-Info 3.5.1. and Bioestat 5.0. 19,004 samples were investigated for malaria, 19% of them were positive, 73.32% with Plasmodium vivax, 21.80% with Plasmodium falciparum, 4.79% with mixed infections and only 0.08% with Plasmodium malariae. Male individuals accounted for 76.95% and predominated in all years and age groups, especially in the 15 to 49 years old group. From the overall cases, 34.27% were autochthonous and 65.73% were imported (χ2 = 356.8, p = 0.0001). The frequency of malaria decreased significantly during the entire series (rp = 0.96, p = 0.002) and the number of municipalities with autochthonous transmission also diminished. It was found that malaria is predominantly imported, related to land activities, which confirms the need for effective measures to maintain vigilance throughout the state and enhance educational activities in order to guide the population towards early treatment-seeking.

Safety and skin delayed-type hypersensitivity response in vervet monkeys immunized with Leishmania donovani sonicate antigen delivered with adjuvants

In this study, we report on the safety and skin delayed-type hypersensitivity (DTH), responses of the Leishmania donovani whole cell sonicate antigen delivered in conjunction with alum-BCG (AlBCG), Montanide ISA 720 (MISA) or Monophosphoryl lipid A (MPLA) in groups of vervet monkeys. Following three intradermal injections of the inoculums on days 0, 28 and 42, safety and DTH responses were assessed. Preliminary tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ) levels were also measured and these were compared with DTH. Only those animals immunized with alum-BCG reacted adversely to the inoculum by producing ulcerative erythematous skin indurations. Non-parametric analysis of variance followed by a post-test showed significantly higher DTH responses in the MISA+Ag group compared with other immunized groups (p < 0.001). The MPLA+Ag group indicated significantly lower DTH responses to the sonicate antigen compared with the AlBCG+Ag group. There was a significant correlation between the DTH and cytokine responses (p < 0.0001). Based on this study we conclude that Leishmania donovani sonicate antigen containing MISA 720 is safe and is associated with a strong DTH reaction following immunization.