Positive correlation between hemosporidian parasitemia and likelihood of PCR detection in co-infected birds.

Abstract

As shown previously, the nested PCR method of detection of avian blood parasites, commonly referred to as Waldenström's method, sometimes amplifies only 1 parasite species of the several that may be present in the same bird, and not always the one with the highest parasitemia. This result raises questions regarding the use of the molecular method for the identification of bird parasites. Additionally, it is unclear whether the amplified parasite, among the several present in the same host, reflects the intensity of infection. However, I performed statistical analyses on a dataset in which there were multiply infected birds and showed that the parasites with the highest parasitemia are the most likely to be amplified. Such a positive correlation between the likelihood of amplification and the parasitemias of the different blood parasites supports the use of Waldenström's method for the comparison of the parasite content of groups of birds exposed to the same parasites.