General information
Haemosporidia are common blood parasites in European songbirds and birds of prey (prevalence in blackbirds, for example, is close to 100%). The most important genera of these parasites include Plasmodium and Haemoproteus, which both produce malarial pigment and therefore belong to the malaria parasites, and Leucocytozoon. These 3 genera can be detected by our PCR test.
These parasites are globally distributed and very diverse, with well over 200 species currently described. Depending on the parasite species, the host spectrum ranges from highly specific (only one bird species affected) to generalised (various bird species from different, unrelated orders can be affected). Mixed infections are widespread in native songbirds.
The course of the disease ranges from peracute in susceptible bird species (e.g. penguins) to subclinical (e.g. blackbirds). The severity of the disease depends on the parasite species, the bird species as well as the age and the immune status of the host. Signs vary from reduced general condition, fatigue and anorexia to dyspnoea, anaemia, hepatomegaly, splenomegaly and pulmonary oedema. In penguins, sudden death is possible. Birds that survive the acute phase of infection may remain chronically infected for years. In these animals, the symptomatic phase of the disease can recur at any time if the animal is stressed or infected by another pathogen.