THE IMMUNIZATION OF FOWLS AGAINST MOSQUITO-BORNE PLASMODIUM GALLINACEUM BY INJECTIONS OF SERUM AND OF INACTIVATED...

Area of Science:

• Veterinary Parasitology
• Immunology
• Infectious Diseases

Background:

• Avian malaria, caused by Plasmodium gallinaceum, poses a significant threat to domestic fowls.
• Effective immunization strategies are crucial for controlling disease transmission and mortality in poultry.

Purpose of the Study:

• To evaluate the efficacy of different immunization methods against Plasmodium gallinaceum infection in domestic fowls.
• To assess the impact of inactivated sporozoite vaccination, serum injections, and combined treatments on malaria mortality and infection intensity.

Main Methods:

• Fowls were subjected to vaccination with inactivated homologous sporozoites.
• Injections of normal sheep serum or serum from chronically infected fowls were administered.
• A combined treatment group received both sporozoite vaccine and serum injections.
• Mortality rates, infection intensity (percentage of infected red blood cells), and prepatent periods were recorded and compared to control groups.

Main Results:

• All tested prophylactic treatments reduced the normal malaria death rate (55.4%).
• The combined treatment (sporozoite vaccine + serum) demonstrated the most significant reduction in mortality (7.3%).
• Combined treatment also led to the lowest average percentage of infected red blood cells (15.0%) compared to vaccination (20.5%) or serum treatment (17.9%) alone.

Conclusions:

• Prophylactic treatments, particularly the combination of sporozoite vaccine and serum, effectively reduce mortality and infection severity in avian malaria.
• The findings suggest a synergistic interaction between cellular (vaccine) and humoral (serum) immunity in conferring protection against Plasmodium gallinaceum.