Diagnosis of Carrion’s Disease by Direct Blood PCR in Thin Blood Smear Negative Samples.

Bartonella bacilliformis is the etiologic agent of Carrion’s disease. This disease has two well established phases, the most relevant being the so called Oroya Fever, in which B. bacilliformis infect the erythrocytes resulting in severe anemia and transient immunosuppression, with a high lethality in the absence of adequate antibiotic treatment. The presence of B. bacilliformis was studied in 113 blood samples suspected of Carrion’s disease based on clinical criteria, despite the absence of a positive thin blood smear, by two different PCR techniques (using Bartonella-specific and universal 16S rRNA gene primers), and by bacterial culture. The specific 16S rRNA gene primers revealed the presence of 21 B. bacilliformis and 1 Bartonella elizabethae, while universal primers showed both the presence of 3 coinfections in which a concomitant pathogen was detected plus Bartonella, in addition to the presence of infections by other microorganisms such as Agrobacterium or Bacillus firmus. These data support the need to implement molecular tools to diagnose Carrion’s disease

Signs and symptoms.^*

†<p>p<0.001††p<0.05 (Statistical significance established using the Fisher exact test).</p><p>* Symptoms considered on the basis of standard solicited data for the surveillance of Carrion’s disease.</p><p>¥Others: cyanosis, drowsiness, itching, back pain, chest pain, petechiae, congestion.</p

Information about culture and direct blood PCR in positive Samples.

<p>* All positive cultures but No. 76 were identified as <i>B. bacilliformis</i> or <i>B. elizabethae</i> (culture No. 28). Culture 76 was identified as <i>Bacillus firmus,</i> in accordance with direct blood PCR assays.</p

Characteristics of the population studied.

†<p>Positive samples using specific primers for <i>Bartonella 16S rRNA</i>.</p>††<p>Includes a <i>B. elizabethae</i> isolate.</p

Comparison of the techniques used to identify <i>Bartonella</i> spp.

<p>* Twenty-one <i>B. bacilliformis</i>, 1 <i>B. elizabethae.</i></p>†<p>Also include other microorganisms: <i>Rhodoccus</i> spp. (3 isolates) <i>Bacillus firmus</i> (3 isolates), <i>Achromobacter xylosoxidans,</i><i>Agrobacterium</i> spp., <i>Artrhobacter</i> spp, <i>Bacillus cereus</i>, <i>Blastococcus</i> spp., <i>Pseudomonas putida</i> and <i>Staphylococcus pettenkoferi</i>.</p

The primers and conditions used in this study.

†<p>The primer described in reference 14 has three more bases (GCCYCCTTGCGGTTAGCACAGCA).</p

Diagnosis of Carrion’s Disease by Direct Blood PCR in Thin Blood Smear Negative Samples

Bartonella bacilliformis is the etiologic agent of Carrion's disease. This disease has two well established phases, the most relevant being the so called Oroya Fever, in which B. bacilliformis infect the erythrocytes resulting in severe anemia and transient immunosuppression, with a high lethality in the absence of adequate antibiotic treatment. The presence of B. bacilliformis was studied in 113 blood samples suspected of Carrion’s disease based on clinical criteria, despite the absence of a positive thin blood smear, by two different PCR techniques (using Bartonella-specific and universal 16S rRNA gene primers), and by bacterial culture. The specific 16S rRNA gene primers revealed the presence of 21 B. bacilliformis and 1 Bartonella elizabethae, while universal primers showed both the presence of 3 coinfections in which a concomitant pathogen was detected plus Bartonella, in addition to the presence of infections by other microorganisms such as Agrobacterium or Bacillus firmus. These data support the need to implement molecular tools to diagnose Carrion’s disease