A PCR test for avian malaria in Hawaiian birds

Area of Science:

• Ecology
• Parasitology
• Conservation Biology

Background:

• Native Hawaiian forest birds face decline due to habitat loss and introduced species.
• Hawaiian honeycreepers are vulnerable to avian malaria (Plasmodium sp.), particularly at lower elevations.
• High-elevation refuges are crucial for honeycreeper survival, but malaria presence there is poorly understood.

Purpose of the Study:

• To develop a sensitive diagnostic test for Plasmodium detection in Hawaiian birds.
• To quantify the prevalence of avian malaria in high-elevation native bird populations.
• To assess the conservation implications of widespread avian malaria.

Main Methods:

• Development of a polymerase chain reaction (PCR) based diagnostic test to detect Plasmodium rRNA genes in avian blood.
• Quantitative competitive PCR (QC-PCR) used to determine test sensitivity.
• Comparison of PCR test results with standard histological methods.

Main Results:

• The developed PCR test demonstrated high sensitivity, exceeding that of human malaria DNA blot tests.
• PCR detected a higher prevalence of malaria compared to histology, especially at mid-elevations.
• Avian malaria was confirmed in seven native bird species across high-elevation sites on Hawaii and Maui.

Conclusions:

• Avian malaria is more prevalent in Hawaiian forests than previously recognized.
• The PCR diagnostic test is a valuable tool for monitoring and managing malaria in threatened bird populations.
• Findings underscore the urgent need for conservation strategies addressing avian malaria in native Hawaiian birds.