Analysis of Toxoplasma gondii antigens with sera from toxoplasmosis patients

Some proteins of the Toxoplasma gondii are recognized by IgG, IgM and IgA antibodies in patients with acute and chronic toxoplasmosis, depending on the strain and stage of the Toxoplasma. Sixty-nine sera from immunocompetent individuals were studied through the Western-Blot Test: 20 has an acute infection, 29 has a chronic toxoplasmosis infection and 20 were healthy (seronegatives). The protein analysis revealed by IgG and IgM antibodies were performed through the Immunoplot method in order to know their recognition frequency (f) and be valued as infection markers. In the acute phase, the IgM antibodies showed a recognition frequency (f = 0.60) for the 60kDa protein, and in the chronic phase the IgG antibodies showed a recognition frequency (f = 0.68) for the 12kDa protein. Seronegatives revealed no type of band. The protein of 12kDa can be a diagnostic marker of the chronic phase while protein 60kDa of the acute phase of toxoplasmosis.

How prevalent is Plasmodium malariae in Rondônia, Western Brazilian Amazon?

We have compared results of Plasmodium species identification obtained with conventional on-site microscopy of Giemsa-stained thick smears (GTS) and a semi-nested polymerase chain reaction (PCR) in 96 malaria patients from Rondônia, Western Brazilian Amazon. Mixed-species infections were detected by PCR in 30% patients, but no such case had been found on GTS. Moreover, P. malariae infections were detected in 9 of 96 patients (10%) by PCR, but were not identified by local microscopists. The potential impact of species misidentification on malaria treatment and control is discussed.

Clonal structure of Trypanosoma cruzi Colombian strain (biodeme Type III): biological, isoenzymic and histopathological analysis of seven isolated clones

The clonal structure of the Colombian strain of Trypanosoma cruzi, biodeme Type III and zymodeme 1, was analyzed in order to characterize its populations and to establish its homogeneity or heterogeneity. Seven isolated clones presented the basic characteristics of Biodeme Type III, with the same patterns of parasitemic curves, tissue tropism to skeletal muscle and myocardium, high pathogenicity with extensive necrotic-inflammatory lesions from the 20th to 30th day of infection. The parental strain and its clones C1, C3, C4 and C6, determined the higher levels of parasitemia, 20 to 30 days of infection, with high mortality rate up to 30 days (79 to 100%); clones C2, C5 and C7 presented lower levels of parasitemia, with low mortality rates (7.6 to 23%). Isoenzymic patterns, characteristic of zymodeme 1, (Z1) were similar for the parental strain and its seven clones. Results point to a phenotypic homogeneity of the clones isolated from the Colombian strain and suggest the predominance of a principal clone, responsible for the biological behavior of the parental strain and clones.

Duffy blood group genotypes among malaria patients in Rondônia, Western Brazilian Amazon

We have compared Duffy blood group genotype distribution, as determined by polymerase chain reaction with allele-specific primers, in 68 Plasmodium vivax-infected patients and 59 non-vivax malaria controls from Rondônia, Brazil. Homozygosity for the allele Fy, which abolishes Duffy antigen expression on erythrocytes, was observed in 12% non-vivax controls but in no P. vivax patient. However, no significant association was found between Fy heterozygosity and protection against P. vivax. The Fy x allele, which has recently been associated with very weak erythrocyte expression of Duffy antigen, was not found in local P. vivax patients.

Response to chemotherapy with benznidazole of clones isolated from the 21SF strain of Trypanosoma cruzi (biodeme Type II, Trypanosoma cruzi II)

Susceptibility to chemotherapy with benznidazole was investigated of 5 clones isolated from the 21 SF strain (biodeme Type II, Trypanosoma cruzi II). Swiss mice were infected with the parental strain for each clone and submitted to chemotherapy with benznidazole (100mg/kg/day during 90 days). Treatment determined negativity of the parasitemia. Cure rates were evaluated by parasitological cure tests. Serology was evaluated for treated animals (titers from negative to 1:640) and untreated controls (1:160 to 1:640). Cure rates varied from 30 to 100% for the 5 clones, and were 25% for the parental strain. Results suggested that the variability of response to treatment of the clonal populations of Trypanosoma cruzi II strains is responsible for the high variation in the response to chemotherapy with benznidazole and nifurtimox by strains of this biodeme.

Prevalence of hepatitis A virus infection: the paradoxical example of isolated communities in the western Brazilian Amazon region

This study evaluated the prevalence of hepatitis A virus infection in the rural area of Lábrea, in the western Brazilian Amazon region. Communities and households were selected randomly. Serum samples were analyzed by means of the immunoenzymatic method for the presence of total antibodies against HAV. The study included 1,499 individuals. The prevalence of anti-HAV was 74.6% (95% CI 72.3-76.8). Univariate analysis showed associations with age (chi-square for linear trend = 496.003, p < 0.001), presence of outside toilet (p < 0.001), history of hepatitis (p < 0.001) and family history of hepatitis (p = 0.05). After adjusting for age, HAV infection also showed an association with the number of people in the family (p = 0.03). The overall prevalence rates were high, but not more than 60% of the children under the age of ten years had already been infected. Very high prevalence was detected only within older cohorts, thus paradoxically defining this as a region with intermediate endemicity, even under the conditions of poverty encountered.

Evaluation of the use of real-time PCR for human T cell lymphotropic virus 1 and 2 as a confirmatory test in screening for blood donors

INTRODUCTION: HTLV-1/2 screening among blood donors commonly utilizes an enzyme-linked immunosorbent assay (EIA), followed by a confirmatory method such as Western blot (WB) if the EIA is positive. However, this algorithm yields a high rate of inconclusive results, and is expensive. METHODS: Two qualitative real-time PCR assays were developed to detect HTLV-1 and 2, and a total of 318 samples were tested (152 blood donors, 108 asymptomatic carriers, 26 HAM/TSP patients and 30 seronegative individuals). RESULTS: The sensitivity and specificity of PCR in comparison with WB results were 99.4% and 98.5%, respectively. PCR tests were more efficient for identifying the virus type, detecting HTLV-2 infection and defining inconclusive cases. CONCLUSIONS: Because real-time PCR is sensitive and practical and costs much less than WB, this technique can be used as a confirmatory test for HTLV in blood banks, as a replacement for WB.

High prevalence of methicillin-resistant Staphylococcus aureus with SCCmec type III in cystic fibrosis patients in southern, Brazil

INTRODUCTION: Bacterial colonization of the lungs is the main cause of morbidity in cystic fibrosis (CF). Pathogens such as Staphylococcus aureus are very well adapted to the pulmonary environment and may persist for years in the same patient. Genetic determinants of these bacteria, such as the presence of SCCmec have recently emerged as a problem in this population of patients. METHODS: Staphylococcus aureus isolates obtained from different clinical materials coming from CF and non-CF patients attended at a cystic fibrosis reference hospital were compared according to SCCmec type and antibiotic susceptibility profile. RESULTS: Three hundred and sixty-four single-patient Staphylococcus aureus isolates were collected, of which 164 (45%) were from CF patients. Among the latter, 57/164 (44.5%) were MRSA, and among the non-CF patients, 89/200 (35%) were MRSA. Associated pathogens were found in 38 CF patients. All 57 MRSA from CF patients harbored the multiresistant cassette type III. In contrast, 31/89 MRSA from non-CF patients harbored SCCmec type I (35%) and 44/89 harbored type III (49%). The antibiotic susceptibility pattern was similar between CF and non-CF patients. CONCLUSIONS: The high prevalence of multiresistant SCCmec type III among CF patients compared with non-CF patients in our institution may make it difficult to control disease progression through antibiotic therapy for promoting the survival of this kind of patient.

Sand fly captures with Disney traps in area of occurrence of Leishmania (Leishmania) amazonensis in the state of Mato Grosso do Sul, mid-western Brazil

INTRODUCTION: The work was conducted to study phlebotomine fauna (Diptera: Psychodidae) and aspects of American cutaneous leishmaniasis transmission in a forested area where Leishmania (Leishmania) amazonensis occurs, situated in the municipality of Bela Vista, State of Mato Grosso do Sul, Brazil. METHODS: The captures were conducted with modified Disney traps, using hamster (Mesocricetus auratus) as bait, from May 2004 to January 2006. RESULTS: Ten species of phlebotomine sandflies were captured: Brumptomyia avellari, Brumptomyia brumpti, Bichromomyia flaviscutellata, Evandromyia bourrouli, Evandromyia lenti, Lutzomyia longipalpis, Psathyromyia campograndensis, Psathyromyia punctigeniculata, Psathyromyia shannoni and Sciopemyia sordellii. The two predominant species were Ev bourrouli (57.3%) and Bi flaviscutellata (41.4%), present at all sampling sites. Two of the 36 hamsters used as bait presented natural infection with Leishmania. The parasite was identified as Leishmania (Leishmania) amazonensis. CONCLUSIONS: Analysis of the results revealed the efficiency of Disney traps for capturing Bichromomyia flaviscutellata and the simultaneous presence of both vector and the Leishmania species transmitted by the same can be considered a predictive factor of the occurrence of leishmaniasis outbreaks for the human population that occupies the location.

Humoral immune response of patients bitten by the snake Bothrops erythromelas

INTRODUCTION: Snake envenomings are a health problem in rural areas of tropical and subtropical countries, but little is known regarding the immune response presented by bitten individuals. The IgM production of patients bitten by Bothrops erythromelas snake was analyzed to identify the effectiveness of treatment in this type of envenomation. METHODS: Bothrops erythromelas venom was submitted to electrophoresis and transferred to a nitrocellulose sheet, following incubation with patients' sera. RESULTS: A 38 KDa protein was detected before and 24 h after therapy. CONCLUSIONS: The result suggests that this protein could be used as a marker for individuals envenomed by Bothrops. erythromelas.

Cryptococcus gattii molecular type VGII as agent of meningitis in a healthy child in Rio de Janeiro, Brazil: report of an autochthonous case

Cryptococcus gattii causes meningoencephalitis in immunocompetent hosts, occurring endemically in some tropical and subtropical regions. Recently, this fungus was involved in an outbreak in Vancouver Island and British Columbia (Canada). In this temperate region, the VGII type is predominant. The paper describes an autochthonous case of meningoencephalitis by C. gattii VGII in a previously health child in Rio de Janeiro, considered nonendemic region of Brazil. The fungus was identified by biochemical tests and the molecular type was determined by URA5-RFLP. The present report highlights the need for clinical vigilance for primary cryptococcal meningitis in nonendemic areas.

Vertical transmission of HIV-1 in the western region of the State of São Paulo

INTRODUCTION: This study aimed to determine the prevalence of vertical HIV-1 transmission in the western region of the State of São Paulo, Brazil. METHODS: The study analyzed the medical records of HIV-1-infected mothers and infant pairs living in the municipalities of São Paulo Regional Health Departments DRS II (Araçatuba) and DRS XI (Presidente Prudente). From March 2001 to March 2006, blood samples were collected and referred to the Molecular Biology Unit of the Adolfo Lutz Institute (ALI), Presidente Prudente. HIV-1-RNA viral load was determined by bDNA assay. RESULTS: The number of births (109/217, 50.2%) and vertical HIV-1 transmissions (6/109, 5.5%) that occurred in DRS II was similar to births (108/217, 49.8%) and vertical transmissions (7/108, 6.5%) in DRS XI (p > 0.05). Although 80% (4/5) of the infected children were male in DRS II, while in DRS XI, 75% (6/8) were female, no differences between sex regarding infected and noninfected children in the regions of Araçatuba and Presidente Prudente were verified. The overall vertical HIV-1 transmission rate was 6%. No consistent reduction in the prevalence of vertical HIV-1 transmission occurred over the years. About 20% of mothers did not know the HIV-1 status of their newborns eight months after delivery. CONCLUSIONS: In the present study, MTCT prevalence rates were about 70% higher than those previously determined in the State of São Paulo, with noreduction throughout the period.Furthermore, a significant number of mothers did not know the HIV-status of their newborns eight months after delivery.

Occurrence of 102 cases of paracoccidioidomycosis in 18 months in the Itaipu Lake region, Western Paraná

INTRODUCTION: The study investigated the incidence of disease and death events among patients with paracoccidioidomycosis who were residents in the Itaipu Lake region from 2008 to 2009. METHODS: A review of patient records was conducted at the Department of Tuberculosis of the Epidemiology Center of the City of Foz do Iguaçu, Paraná. RESULTS: The results identified 102 new cases of paracoccidioidomycosis in the period described, 72 men and 30 women, and 15 deaths were recorded during the study. CONCLUSIONS: It can be concluded that the Itaipu Lake region is an endemic region.