Rocky Mountain spotted fever, Panama

Abstract

We describe a fatal pediatric case of Rocky Mountain spotted fever in Panama, the first, to our knowledge, since the 1950s. Diagnosis was established by immunohistochemistry, PCR, and isolation of Rickettsia rickettsii from postmortem tissues. Molecular typing demonstrated strong relatedness of the isolate to strains of R. rickettsii from Central and South America.

Figure 1

Histologic and immunohistochemical evaluation of heart tissue. A) Lymphohistiocytic inflammatory cell infiltrates in the myocardium (hematoxylin and eosin stain; original magnification ×25). B) Immunohistochemical detection of spotted fever group rickettsiae (red) in perivascular infiltrates of heart (immunoalkaline phosphatase with naphthol-fast red substrate and hematoxylin counterstain; original magnification ×250.

Figure 2

Differentiation of Rickettsia rickettsii type strain Sheila Smith from Montana from R. rickettsii strains from Central and South America. A tandem repeat region corresponding to 563048–563028 nt of the strain Sheila Smith genome and flanking sequences were amplified with AF (5′-GTGATTGCTATATTTCGCTTT-3′) and AR (5′- CTAAGATTTGTTCCGTATAGG-3′) primers as described elsewhere (7). Repeat sequence (GCCTTAT, indicated with brackets) present in 3 copies in strain Sheila Smith, whereas only 2 copies were present in R. rickettsii isolates from Brazil, Colombia, Costa Rica, and Panama. Homologous sequences of these strains are deposited to GenBank under the following accession nos.: DQ666020, R. rickettsii strain Panama 2004; DQ666021, R. rickettsii strain Brazil; DQ666022, R. rickettsii strain Colombia; DQ666023, and R. rickettsii strain Costa Rica.