Co-infection with multiple different parasites is a common phenomenon in both human and animals. Among parasites that frequently co-infect the same hosts, are the filarial worms and malaria parasites. Despite this, the mechanisms underlying the interactions between these parasites is still relatively unexplored with very few studies available on the resulting pathologies due to co-infection by filarial nematodes and malaria parasites. Hence, this study investigated the histopathological effect of Brugia pahangi and Plasmodium berghei ANKA (PbA) infections in gerbil host. Gerbils grouped into B. pahangi-infected, PbA-infected, B. pahangi and PbA-coinfected, and uninfected control, were necropsied at different time points of post PbA infections. Brugia pahangi infections in the gerbils were first initiated by subcutaneous inoculation of 50 infective larvae, while PbA infections were done by intraperitoneal injection of 106 parasitized red blood cells after 70 days patent period of B. pahangi. Organs such as the lungs, kidneys, spleen, heart and liver were harvested aseptically at the point of necropsy. There was significant hepatosplenomegaly observed in both PbA-infected only and coinfected gerbils. The spleen, liver and lungs were heavily pigmented. Both B. pahangi and PbA infections (mono and coinfections) resulted in pulmonary edema, while glomerulonephritis was associated with PbA infections. The presence of both parasites induced extramedullary hematopoiesis in the spleen and liver. These findings suggest that the pathologies associated with coinfected gerbils were synergistically induced by both B. pahangi and PbA infections.
Malaria and lymphatic filariasis (LF) are two leading and common mosquito-borne parasitic diseases worldwide. These two diseases are co-endemic in many tropical and sub-tropical regions and are known to share vectors. The interactions between malaria and filarial parasites are poorly understood. Thus, this study aimed at establishing the interactions that occur between Brugia pahangi and Plasmodium berghei ANKA (PbA) co-infection in gerbils. Briefly, the gerbils were matched according to age, sex, and weight and grouped into filarial-only infection, PbA-only infection, co-infection, and control group. The parasitemia, survival and clinical assessment of the gerbils were monitored for a period of 30 days post Plasmodium infection. The immune responses of gerbils to both mono and co-infection were monitored. Findings show that co-infected gerbils have higher survival rate than PbA-infected gerbils. Food and water consumption were significantly reduced in both PbA-infected and co-infected gerbils, although loss of body weight, hypothermia, and anemia were less severe in co-infected gerbils. Plasmodium-infected gerbils also suffered hypoglycemia, which was not observed in co-infected gerbils. Furthermore, gerbil cytokine responses to co-infection were significantly higher than PbA-only-infected gerbils, which is being suggested as a factor for their increased longevity. Co-infected gerbils had significantly elicited interleukin-4, interferon-gamma, and tumor necrotic factor at early stage of infection than PbA-infected gerbils. Findings from this study suggest that B. pahangi infection protect against severe anemia and hypoglycemia, which are manifestations of PbA infection.