Novel Chronic Anaplasmosis in Splenectomized Patient, Amazon Rainforest

Abstract

We report a case of unusual human anaplasmosis in the Amazon rainforest of French Guiana. Molecular typing demonstrated that the pathogen is a novel Anaplasma species, distinct to all known species, and more genetically related to recently described Anaplasma spp. causing infections in rainforest wild fauna of Brazil.

Keywords: Amazon rainforest; French Guiana; anaplasmosis; bacteria; vector-borne infections; zoonoses.

Figure 1

Anaplasma phylogenies for the Candidatus Anaplasma sparouinense species characterized from French Guiana and reference sequences. Trees were constructed by using maximum-likelihood estimations based on best-fit approximation for the evolutionary model Hasegawa-Kishino-Yano plus invariant sites for 16S rDNA with 485 unambiguously aligned bp (A) and ITS2 sequences with 387 unambiguously aligned bp (B). Bold indicates Anaplasma species and strains specific to the Neotropics. GenBank accession numbers of sequences used in analyses are shown on the phylogenetic trees. Numbers at nodes indicate percentage support of 1,000 bootstrap replicates. The scale bar is in units of substitution per site.

Figure 2

Thin films of a blood sample collected in October 2019 from a patient in French Guiana. Inclusions of Candidatus Anaplasma sparouinense are located at the periphery of the red blood cells as small round dots of 0.3–0.4 µm (arrowheads). Other red blood cells contain Howell-Jolly bodies of various shapes and sizes >1 µm (arrows). Some Howell-Jolly bodies are found in the background of the smears. Wright-Giemsa stain; original magnification ×100.