An outbreak of acute bartonellosis (Oroya fever) in the Urubamba region of Peru, 1998.

Abstract

During May 1998, we conducted a case-control study of 357 participants from 60 households during an outbreak of acute bartonellosis in the Urubamba Valley, Peru, a region not previously considered endemic for this disease. Blood and insect specimens were collected and environmental assessments were done. Case-patients (n ϭ 22) were defined by fever, anemia, and intra-erythrocytic coccobacilli seen in thin smears. Most case-patients were children (median age ϭ 6.5 years). Case-patients more frequently reported sand fly bites than individuals of neighboring households (odds ratio [OR] ϭ 5.8, 95% confidence interval [CI] ϭ 1.2-39.2), or members from randomly selected households Ն 5 km away (OR ϭ 8.5, 95% CI ϭ 1.7-57.9). Bartonella bacilliformis isolated from blood was confirmed by nucleotide sequencing (citrate synthase [gltA], 338 basepairs). Using bacterial isolation (n ϭ 141) as the standard, sensitivity, specificity, and positive predictive value of thin smears were 36%, 96%, and 44%, respectively. Patients with clinical syndromes compatible with bartonellosis should be treated with appropriate antibiotics regardless of thin-smear results.

Identification of Bartonella bacilliformis Genotypes and Their Relevance to Epidemiological Investigations of Human Bartonellosis

“…Outbreaks of bartonellosis not only continue in recognized regions of endemicity but are also now being reported with increasing frequency in areas where the disease has not previously been encountered (8,15). The public health impact of bartonellosis in these areas is at least as significant as it is in regions of endemicity.…”

An Evaluation Study of Enzyme-Linked Immunosorbent Assay (ELISA) Using Recombinant Protein Pap31 for Detection of Antibody against Bartonella bacilliformis Infection among the Peruvian Population

“…The specificity of the test is very high (96%) but the sensitivity remains fairly low (36%) for detection of the organism. 9,10 In addition, B. bacilliformis is difficult to isolate in laboratory cultures, as it requires special media and a long incubation time of up to 8 weeks. The PCR assay requires special equipment, dedicated laboratory space, and highly skilled personnel.…”

Population Genetic Analysis ofBartonella bacilliformisIsolates from Areas of Peru Where Carrion's Disease Is Endemic and Epidemic

“…It has been widely presumed that the limited geographic distribution was a function of the limited range of the sand fly vector, Lutzomyia verrucarum (3,18). However, recent reports have documented human B. bacilliformis infections over a much larger area than previously reported, including the Andean highlands and the Amazona region east of the Andes mountains, as well as in historically recognized areas where B. bacilliformis is endemic (1,9,16,17). These studies have indicated that in addition to B. bacilliformis occurring over a broader geographical range than previously recognized, the spectrum of symptoms associated with B. bacilliformis infection is highly variable.…”

“…In addition, in areas outside the range of L. verrucarum, the presence of B. bacilliformis-associated disease implies disease transmission by previously unrecognized vector species; this suggests either recent changes in vector competence or previously unrecognized infection cycles (9).…”

“…Recent studies have used limited gene sequence data to compare new isolates with existing reference isolates (4,9). We analyzed nucleotide sequence diversity at three loci: a fragment of the citrate synthase gene or gltA (commonly used for Bartonella species phylogenetic analysis), the invasion-associated locus B (ialB), and the flagellin locus.…”