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


Autoria(s): Pereira dos Santos, Fabiana Cristina; Mendes do Nascimento, Elvira Maria; Katz, Gizelda; Angerami, Rodrigo Nogueira; Colombo, Silvia; de Souza, Eliana Rodrigues; Labruna, Marcelo Bahia; da Silva, Marcos Vinicius
Contribuinte(s)

UNIVERSIDADE DE SÃO PAULO

Data(s)

04/11/2013

04/11/2013

2012

Resumo

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 (cutoff 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. (C) 2012 Elsevier GmbH. All rights reserved.

Identificador

TICKS AND TICK-BORNE DISEASES, JENA, v. 3, n. 41430, supl. 1, Part 3, pp. 311-313, 42156, 2012

1877-959X

http://www.producao.usp.br/handle/BDPI/40839

10.1016/j.ttbdis.2012.10.027

http://dx.doi.org/10.1016/j.ttbdis.2012.10.027

Idioma(s)

eng

Publicador

ELSEVIER GMBH, URBAN & FISCHER VERLAG

JENA

Relação

TICKS AND TICK-BORNE DISEASES

Direitos

closedAccess

Copyright ELSEVIER GMBH, URBAN & FISCHER VERLAG

Palavras-Chave #REAL-TIME PCR #DIAGNOSIS #BRAZILIAN SPOTTED FEVER #FATAL CASES #RICKETTSIOSIS #SAMPLES #TICKS #ASSAY #SERUM #AREA #INFECTIOUS DISEASES #MICROBIOLOGY #PARASITOLOGY
Tipo

article

original article

publishedVersion