Chicken embryo related (CER) cell line for quantification of rabies neutralizing antibody by fluorescent focus inhibition test

Levels of rabies virus neutralization antibody in sera from vaccinated dogs and cattle were either measured by mouse neutralization test (MNT) or by rapid fluorescent focus inhibition test (RFFIT), performed on CER monolayers. The two tests were compared for their ability to detect the 0.5 International Units/ml (I.U.) recommended by the World Health Organization (WHO) as the minimum response for proof of rabies immunization. A significant correlation was found between the two tests (n = 211; r = 0.9949 in dogs and 0.9307 in cows, p < 0.001), good sensitivity (87.5%), specificity (94.7%) and agreement (96.6%) as well. RFFIT method standardized on CER cell system for neutralizing antibodies detection turns the diagnosis easier and less expensive, specially when a great number of samples must be tested from endemic areas as commonly found in Brazil. (c) 2005 the International Association for Biologicals. Published by Elsevier Ltd. All rights reserved.

Vaccine immune response and interference of colostral antibodies in calves vaccinated against rabies at 2, 4 and 6 months of age born from antirabies revaccinated females

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação da imunidade ativa de cães primovacinados (Fuenzalida & Palácios) no intervalo de campanhas anuais de vacinação contra a raiva no município de Botucatu/SP

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Circulação do vírus rábico em gambás (Didelphis albiventris e Didelphis aurita) nos municípios de Torre de Pedra, Bofete e Anhembi-São Paulo

Pós-graduação em Biotecnologia Animal - FMVZ

Humoral immune response in dogs and cats vaccinated against rabies in southeastern Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Imported human rabies in Switzerland, 2012: a diagnostic conundrum

Human rabies is rare in Western Europe. It is not easily recognized in the absence of a history of exposure. We describe the clinical course, diagnosis and follow-up of an imported human rabies case in Switzerland. The patient, a U.S. citizen, presented at an outpatient clinic in Iraq with pain in his right shoulder on July 5, 2012. On July 8 he was transferred to a hospital in the United Arab Emirates, where he exhibited progressive encephalitis with coma. On July 29, he was transferred to a hospital in Switzerland, where he died on July 31, 2012. The autopsy showed severe encephalitis. Rabies was diagnosed by the rapid fluorescent focus inhibition test (RFFIT) and confirmed by fluorescence antibody testing (FAT) in brain smears and immunohistochemistry on paraffin-embedded brain sections. The viral strain was characterized by RT-PCR followed by sequencing and phylogenetic analysis as an American bat rabies strain associated with Tadarida brasiliensis. Close contacts and exposed health care workers received postexposure prophylaxis (PEP).

Comparative assessment of seller’s staining test (SST) and direct fluorescent antibody test for rapid and accurate laboratory diagnosis of rabies.

Background: Rabies causes 55, 000 annual human deaths globally and about 10,000 people are exposed annually in Nigeria. Diagnosis of animal rabies in most African countries has been by direct microscopic examination. In Nigeria, the Seller’s stain test (SST) was employed until 2009. Before then, both SST and dFAT were used concurrently until the dFAT became the only standard method. Objective: This study was designed to assess the sensitivity and specificity of the SST in relation to the ‘gold standard’ dFAT in diagnosis of rabies in Nigeria. Methods: A total of 88 animal specimens submitted to the Rabies National Reference Laboratory, Nigeria were routinely tested for rabies by SST and dFAT. Results: Overall, 65.9% of the specimens were positive for rabies by SST, while 81.8% were positive by dFAT. The sensitivity of SST in relation to the gold standard dFAT was 81.0% (95% CIs; 69.7% - 88.6%), while the specificity was 100% (95% CIs; 76% - 100%). Conclusion: The relatively low sensitivity of the SST observed in this study calls for its replacement with the dFAT for accurate diagnosis of rabies and timely decisions on administration of PEP to prevent untimely deaths of exposed humans.

False-positive results of a rapid K39-based strip test and Chagas disease

Background: The definitive diagnosis of visceral. leishmaniasis (VL) requires invasive procedures with demonstration of amastigotes in tissue or promastigotes in culture. Unfortunately, these approaches require laboratory materials not available in poor countries where the disease is endemic. The correct diagnosis of VL is important, and made more difficult by the fact that several common tropical diseases such as malaria, disseminated tuberculosis, and enteric fever share the same clinical presentation. Serological tests have been developed to replace parasitological diagnosis in the field. A commercially available K39-based strip test for VL has been developed for this purpose. The endemic area of leishmaniasis in Brazil overlaps the endemic area of Chagas disease, a disease that can cause false-positive serological test results. The aim of this study was to evaluate the incidence of false-positive exams using a rapid test for VL in patients with Chagas disease. Methods: A rapid test based on the recombinant K39 antigen of Leishmania was used in: (1) 30 patients with confirmed Chagas disease, (2) 30 patients with a serological diagnosis of Chagas disease by ELISA, indirect immunofluorescence, indirect hemagglutination, and chemiluminescence, (3) 30 healthy patients from a non-endemic area as the control group, (4) 30 patients with confirmed VL, and (5) 20 patients with proved cutaneous leishmaniasis. Results: The sensitivity and specificity of the rapid strip test were 100% when compared with healthy volunteers and those with confirmed Chagas disease. One false-positive result occurred in the group with Chagas disease diagnosed by serological tests (specificity of 96%). Conclusion: The rapid test based on recombinant K39 is a useful diagnostic assay, and a false-positive result rarely occurs in patients with a serological diagnosis of Chagas disease. (C) 2008 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

An in vitro growth inhibition test for measuring the potency of Leptospira spp. Sejroe group vaccine in buffaloes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Detection of cross infections by Leishmania spp. and Trypanosoma spp. in dogs using indirect immunoenzyme assay, indirect fluorescent antibody test and polymerase chain reaction

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fluorescent antibody test, quantitative polymerase chain reaction pattern and clinical aspects of rabies virus strains isolated from main reservoirs in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

CDC Standard rubella hemagglutination-inhibition test /

Errata slip inserted.

Exposure to rabies virus in a population of free-ranging capuchin monkeys (Cebus apella nigritus) in a fragmented, environmentally protected area in southeastern Brazil

The aim of this study is to assess the frequency of rabies antibodies in free-ranging capuchin monkeys (Cebus apella nigritus) in a fragmented, environmentally protected, rural area of southeastern Brazil. Thirty-six free-ranging monkeys were tested by the rapid fluorescent focus inhibition test for detection of antibodies against rabies virus. Four individuals (11.11 %) had neutralizing antibody titers a parts per thousand yen0.25 IU/mL, demonstrating rabies virus exposure.

Evaluation of serological tests for the diagnosis of Neospora caninum infection in dogs: Optimization of cut off titers and inhibition studies of cross-reactivity with Toxoplasma gondii

Diagnosis of Neospora caninum infection in dogs is based on serological assays such as the indirect fluorescent antibody test (IFAT) and enzyme-linked immunosorbent assays (ELISA). This study evaluated two serological tests (IFAT and ELISA) for the detection of IgG antibodies to N. caninum in 300 serum samples of dogs through the optimization of cut off titers by using the two-graph receiveroperating characteristic (TG-ROC) curve. In addition, the identification of major cross-reactive antigens with Toxoplasma gondii was investigated by inhibition ELISA and immunoblotting (IB) assays. IFAT and ELISA results showed 74% agreement, with a good negative concordance (P-neg=0.83), but a poor positive concordance (P-pos=0.42). The great majority (86%) of sera with positive concordant results (IFAT+/ELISA+) recognized at least two out of three N. caninum immunodominant antigens, particularly the 29-32 and 35-37 kDa bands. Optimization of cut off titers in IFAT and ELISA was performed considering the reactivity to at least two out of three N. caninum immunodominant antigens as infection markers, obtaining a titer of 50 for IFAT and 200 for ELISA. Seropositivity to N. caninuin was significantly associated with T gondii-seropositive samples, particularly in ELISA (55.4%). Inhibition ELISA curves for N. caninum showed a partial heterologous inhibition, indicating some degree of cross-reactivity between N. caninum and T gondii antigens. Inhibition IB assays showed a moderate heterologous inhibition for N. caninum antigens above 45-50 kDa. These results indicate that ELISA should be used critically when crude tachyzoite antigen preparations are employed, due to possible cross-reactivity with other related parasites as T gondii. Also, the cut off dilution of 1:50 in IFAT showed to be the most appropriated for N. caninum serology in dogs. Therefore, we suggest that N. caninum immunodominant antigens, specially the 17 and 29-32 kDa proteins, should be selected markers in serological assays for canine neosporosis. (c) 2006 Elsevier B.V. All rights reserved.