Gizelda Katz

Probable transfusion-transmitted Zika virus in Brazil

Zika virus (ZIKV) is an emerging arthropod‐borne flavivirus transmitted by Aedes mosquitoes. Recent commentaries regarding ZIKV routes of transmission describe a potential transmission by transfusion. Herein, we report a probable case of transfusion‐transmitted ZIKV infection through a platelet transfusion that was detected from postdonation information.

Brazilian spotted fever: a case series from an endemic area in southeastern Brazil: epidemiological aspects.

Abstract:  Brazilian spotted fever (BSF) is the most important tick‐borne disease in Brazil and is caused by Rickettsia rickettsii and transmitted by the Ixodid tick Amblyomma cajennense, its main vector. We present epidemiologic aspects of a case series of patients admitted to the Hospital das Clínicas da UNICAMP from 1985 to 2003 with a confirmed diagnosis of BSF either by a fourfold rise in indirect immunofluorescence (IFA) titers of IgG antibodies reactive with R. rickettsii or isolation of R. rickettsii from blood or skin specimens. Seasonal variation of case occurrence seems to be associated with the life cycle of the tick. The recent reemergence of cases seems to be associated with the growing numbers of the capybara (Hydrochaeris hydrochaeris) and their expansion into urban areas.

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 Sao Pedro, Sao Paulo State. A MAC-ELISA done on the patients 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 Sao 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.

Brazilian Spotted Fever: A Case Series from an Endemic Area in Southeastern Brazil

Abstract:  This case series study is based on a retrospective review of medical records and case notification files of patients admitted to The Hospital das Clínicas da UNICAMP from 1985 to 2003 with a confirmed diagnosis of BSF either by fourfold rise in indirect immunofluorescence assay (IFA) titers of IgG antibodies reactive with R. rickettsii or isolation of R. rickettsii from blood or skin specimens. A median lethality of 41.9 % was observed between 1985 and 2004. The case‐fatality ratio of 30 % in our study, lower than the overall São Paulo state ratio, could be explained by a higher index of suspicion and a larger experience in our hospital, a regional referral center for BSF. The presence of the classical triad of fever, rash, and headache as described in RMSF was observed in fever than half (35.2%) of our patients.

Features of Brazilian spotted fever in two different endemic areas in Brazil.

Brazilian spotted fever (BSF) caused by Rickettsia rickettsii is the most important rickettsiosis and the only reportable tick-borne disease in Brazil. In Brazil, the hard tick Amblyomma cajennense is the most important BSF vector; however, in São Paulo State, A. aureolatum was also recognized as a vector species in remaining Atlantic forest areas near the metropolitan area of São Paulo city. We analyzed clinical and epidemiological features of BSF cases from two distinct areas where A. cajennense (Area 1) and A. aureolatum (Area 2) are the incriminated vectors. The clinical features demonstrate the same severity pattern of BSF in both endemic areas. Differences in seasonality, patient characteristics (median age and gender), and epidemiological risk factors (animals host contact and vegetation characteristics) were observed and possibly could be attributed to the characteristics of each vector and their typical biological cycle (hosts and environment).

Brazilian spotted fever: two faces of a same disease? A comparative study of clinical aspects between an old and a new endemic area in Brazil

Nucleo de Vigilância Epidemiologica, Servico de Epidemiologia Hospitalar, Hospital das Clinicas, Universidade Estadual de Campinas ⁄UNICAMP, Campinas ⁄ SP, Brazil, Diretoria de Vigilância Epidemiologica-SES ⁄ SC, Florianopolis ⁄ SC, Brazil, Divisao de Biologia Medica, Servico de Virologia, Setor de Riquetsias, Instituto Adolfo Lutz-SES ⁄ SP, Sao Paulo ⁄ SP, Brazil, Secretaria de Vigilância em Saude, Ministerio da Saude-SVS ⁄MS, Brasilia ⁄DF, Brazil, Centro de Vigilância Epidemiologica ‘‘Prof. Alexandre Vranjac’’-SES ⁄ SP, Sao Paulo ⁄ SP, Brazil and Disciplina de Molestias Infecciosas, Faculdade de Ciencias Medicas, Universidade Estadual de Campinas ⁄UNICAMP, Campinas ⁄ SP, Brazil and Epidemiology Group Novartis Vaccines and Diagnostics s.r.l., Siena, Italy

Evaluation of dengue NS1 antigen detection for diagnosis in public health laboratories, São Paulo State, 2009

The present work evaluated the diagnostic accuracy of detection of Dengue NS1 antigen employing two NS1 assays, an immunochromatographic assay and ELISA, in the diagnostic routine of Public Health laboratories. The results obtained with NS1 assay were compared with virus isolation and, in a subpopulation of cases, they were compared with the IgM-ELISA results obtained with convalescent samples. A total of 2,321 sera samples were analyzed by one of two NS1 techniques from March to October 2009. The samples were divided into five groups: groups I, II and III included samples tested by NS1 and virus isolation, and groups IV and V included patients with a first sample tested by NS1 and a second sample tested by IgM-ELISA. Sensitivity, specificity, positive and negative predictive values, Kappa Index and Kappa Concordance were calculated. The results showed that NS1 testing in groups I, II and III had high sensitivity (98.0%, 99.5% and 99.3%), and predictive values and Kappa index between 0.9 - 1.0. Groups IV and V only had Kappa Concordance calculated, since the samples were analyzed according to the presence of NS1 antigen or IgM antibody. Concordance of 92.1% was observed when comparing the results of NS1-negative samples with IgM-ELISA. Based on the findings, it is possible to suggest that the tests for NS1 detection may be important tools for monitoring the introduction and spread of Dengue serotypes.

Clusters of Brazilian spotted fever in São Paulo State, southeastern Brazil. A review of official reports and the scientific literature.

Nucleo de Vigilância Epidemiologica, Hospital das Clinicas, Universidade Estadual de Campinas ⁄UNICAMP, Campinas, Sao Paulo, SP, Centro de Vigilância Epidemiologica ‘‘Prof. Alexandre Vranjac’’-SES ⁄ SP, Sao Paulo, SP, Instituto Adolfo Lutz, Secretaria de Estado da Saude de Sao Paulo, Sao Paulo, SP, Coordenadoria de Vigilância em Saude, SMS ⁄Campinas, Campinas, Sao Paulo, SP, Servico de Controle de Infeccao Hospitalar, Santa Casa de Vinhedo, Vinhedo, Sao Paulo, SP, Secretaria de Estado da Saude de Sao Paulo, Sao Paulo, Disciplina de Molestias Infecciosas, Faculdade de Ciencias Medicas, Universidade, Estadual de Campinas ⁄UNICAMP, Campinas, Sao Paulo, SP, Brazil and Epidemiology Group Novartis Vaccines and Diagnostics s.r.l., Siena, Italy

Brazilian spotted fever in the paediatric age-segment in the State of São Paulo, southeastern Brazil, 2003–2006

Nucleo de Vigilância Epidemiologica ⁄ Servico de Epidemiologia Hospitalar ⁄Hospital das Clinicas ⁄Universidade Estadual de Campinas, Campinas, Sao Paulo, SP, Centro de Vigilância Epidemiologica ‘Prof. Alexandre Vranjac’, Secretaria de Estado da Saude de Sao Paulo, Sao Paulo, SP, Disciplina de Molestias Infecciosas ⁄Departamento de Clinica Medica ⁄ Faculdade de, Ciencias Medicas ⁄Universidade Estadual de Campinas, Campinas, Sao Paulo, SP, Brazil and Epidemiology Group Novartis Vaccines and Diagnostics s.r.l., Siena, Italy

Brazilian spotted fever: Real-time PCR for diagnosis of fatal cases

Suspicion of Brazilian spotted fever (BSF) should occur in endemic regions upon surveillance of the acute febrile icteric hemorrhagic syndrome (AFIHS). However, limitations associated with currently available laboratory tests pose a challenge to early diagnosis, especially in fatal cases. Two real-time PCR (qPCR) protocols were evaluated to diagnose BSF in 110 fatal AFIHS cases, collected in BSF-endemic regions in 2009-2010. Of these, 24 were positive and 86 negative by indirect immunofluorescence (IFA) assay (cut-off IgG and/or IgM ≥ 128). DNA from these samples was used in the qPCR protocols: one to detect Rickettsia spp. (citrate synthase gene) and another to determine spotted fever group (SFG) Rickettsia species (OmpA gene). Of the 24 IFA-positive samples, 5 (21%) were positive for OmpA and 9 (38%) for citrate synthase. In the IFA-negative group (n=86), OmpA and citrate synthase were positive in 23 (27%) and 27 (31%), respectively. These results showed that the 2 qPCR protocols were about twice as sensitive as the IFA test alone (93% concordance). In conclusion, qPCR is a sensitive method for the diagnosis of fatal BSF cases and should be considered for routine surveillance of AFIHS in places like Brazil, where spotted fever-related lethality is high and other endemic diseases like dengue and leptospirosis can mislead diagnosis.