
Full text loading...
Category: Clinical Microbiology
Emerging Perspectives on Human Babesiosis, Page 1 of 2
< Previous page | Next page > /docserver/preview/fulltext/10.1128/9781555816988/9781555812164_Chap11-1.gif /docserver/preview/fulltext/10.1128/9781555816988/9781555812164_Chap11-2.gifAbstract:
Babesial parasites have special historical significance because the babesial agent of Texas cattle fever, characterized by Smith and Kilborne in 1893, was the first arthropod-transmitted pathogen described in vertebrates. The first case of human babesiosis in an individual from the eastern United States was reported in 1969 and attracted the interest of the medical community because it was a fulminating case in a spleen-intact patient. The first clinical studies of human babesiosis described erythema chronicum migrans-like lesions in the early stages of disease. Awareness of human babesiosis has prompted the identification of new human cases worldwide. Reports of human babesiosis around the world underscore the likelihood that many such cases go undetected, possibly because of unfamiliarity of physicians with the disease. Similarly, in South Africa, two human cases initially diagnosed as malaria were later recognized as cases of human babesiosis after reexamination of blood smears revealed merozoites in erythrocytes without pigment but with nonstaining vacuoles and many multiply infected erythrocytes, all of which are charactersitic of babesial infections. An increasing population of immunocompromised individuals will result in an increase in the number of human babesiosis cases. Parasitemias in human infection with Babesia divergens range from 1 to 50% of the erythrocytes. In chronically infected individuals, the sensitivity of the PCR technique targeting the 18S ss rRNA gene would be low due to the small number of parasites in a sample and the small number of target genes present in Babesia spp.
Full text loading...
Phylogenetic tree inferred from neighbor-joining analysis of piroplasm species using an alignment of the entire 18S ss rRNA gene sequence. Numbers above the lines represent the percentage of replicates out of 500 bootstrap samplings in which the given branching pattcrn was obtained. GenBank accession numbers for the sequences used are noted in parentheses after the isolate name.
Phylogenetic tree inferred from neighbor-joining analysis of piroplasm species using an alignment of the entire 18S ss rRNA gene sequence. Numbers above the lines represent the percentage of replicates out of 500 bootstrap samplings in which the given branching pattcrn was obtained. GenBank accession numbers for the sequences used are noted in parentheses after the isolate name.