Serodiagnosis of Bartonella bacilliformis Infection by Indirect Fluorescence Antibody Assay: Test Development and Application to a Population in an Area of Bartonellosis Endemicity

Abstract

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 toB. 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%.

The Epidemiology of Bartonellosis in Peru

“…Based on IFA serological testing in February 1998. 42% of participants had IgG antibodies to B. bacilliformis as was reported previously (Chamberlin et al. 2000).…”

“…Giemsa-stained peripheral thin smears, blood culture, PCR and serologic testing were presented previously (Chamberlin et at, 2000). Briefly, blood samples for culture were collected in sodium.citrate tubes and transported to lima where they were cultured in sealed flasks using a modified F-1 media with liquid overlay of RPMIJ1 0 % fetal bovine serum and then observed for eight weeks at 28°C without additional C02.…”

“…A few studies have presented cross-sectional. serologic data of populations with epidemic and endemic bartonellosis that show high rates of prior infection (Chamberlin et al. 2000)…”

“…blood culture, peR. or a 4-fold rise in Bartonella-specific immunoglobulin G antibody titer using paired sera (Chamberlin et at, 2000).…”

Production of Recombinant Protein Pap31 and Its Application for the Diagnosis of Bartonella bacilliformis Infection

“…The current gold standard method, indirect fluorescence assay (IFA), uses irradiated whole-cell antigen preparation from cocultivated Vero cells. 5 The method is sensitive, but costly, and requires expertise to achieve reproducible results. Because B. bacilliformis is the causative agent of Oroya fever and verruga peruana, where mortality can be exceptionally high, improved methods to detect B. bacilliformis exposure are needed over existing procedures.…”