RESUMO
Bartonella bacilliformis causes bartonellosis, a potentially life-threatening emerging infectious disease seen in the Andes Mountains of South America. There are no generally accepted serologic tests to confirm the disease. We developed an indirect fluorescence antibody (IFA) test for the detection of antibodies to B. bacilliformis and then tested its performance as an aid in the diagnosis of acute bartonellosis. The IFA is 82% sensitive in detecting B. bacilliformis antibodies in acute-phase blood samples of laboratory-confirmed bartonellosis patients. When used to examine convalescent-phase sera, the IFA is positive in 93% of bartonellosis cases. The positive predictive value of the test is 89% in an area of Peru where B. bacilliformis is endemic and where the point prevalence of infection is 45%.
Assuntos
Anticorpos Antibacterianos/sangue , Infecções por Bartonella/diagnóstico , Infecções por Bartonella/epidemiologia , Bartonella/imunologia , Doenças Endêmicas , Técnica Indireta de Fluorescência para Anticorpo/métodos , Antígenos de Bactérias/imunologia , Infecções por Bartonella/microbiologia , Humanos , Peru/epidemiologia , Valor Preditivo dos Testes , PrevalênciaRESUMO
OBJECTIVE: To study the etiology and seroepidemiology of cat-scratch disease (CSD) in Hawaii. METHODS: Blood and fine-needle aspirate (FNA) from the lymph nodes of 39 consecutive patients with clinical CSD were cultured for Bartonella henselae, and blood samples from index cats, stray cats, and dogs were cultured and their sera were tested by indirect fluorescence antibody test for antibodies to B. henselae and Afipia felis. Sera from age- and sex-matched human subjects without cat exposure served as controls. RESULTS: Warthin-Starry staining showed positive results in only 4 of 32 FNAs, and B. henselae was isolated from only one FNA specimen. All of 38 patients who had two or more sera tested had elevated titers of antibody to B. henselae. Only 1 of 48 human control sera had antibody to B. henselae. Of 31 kittens, 21 had positive blood culture results and elevated antibody titers to B. henselae. Of three adult cats, all had negative blood culture results, but they had serologic evidence of past infection. Of 23 adult stray cats, 18 had elevated titers of antibody to B. henselae, but in only one was the blood culture result positive. Results of IFA tests were marginally positive for A. felis in 1 of 29 patients with CSD and in one adult stray cat and one dog. CONCLUSIONS: This study shows that the B. henselae IFA test is both highly sensitive and specific for the detection of infection caused by B. henselae and for the laboratory diagnosis of CSD, and that FNA is seldom helpful in confirming the diagnosis. We further demonstrated that CSD in Hawaii is due to B. henselae and that infection is directly linked to the scratch or bite of a kitten. Older cats seldom have bacteremia but often have serologic evidence of past infection. Our study fails to implicate dogs in the epidemiology of CSD in Hawaii, and A. felis was not etiologically implicated in CSD in the human subjects and animals we studied.