Chemokines and haematological profile in Sprague-Dawley rats infected with trichinella Zimbabwensis and Plasmodium berghei ANKA.

Abstract

Trichinellosis is an important re-emerging parasitic zoonosis caused by nematode species of the genus Trichinella and Plasmodium falciparum malaria is among the leading causes of mortality and morbidity in sub-Saharan Africa (SSA). Co-infection of the two diseases in rural communities is likely to be a common phenomenon although no reports have been made up to date. There is paucity of information on the consequence of co-infection regarding the clinical outcome of these diseases, especially malaria. Helminths, such as tissue-dwelling Trichinella spp larvae induce Th2 immune responses, while malaria induce Th1 immune responses as a survival strategy. On the other hand, chemokines are chemotactic cytokines produced by the host macrophages in order to elicit a protective immune response. Immuno-pathogenesis during co-infection remain obscure. It is against this background that this study aimed to determine host chemokine and haematological responses in male Sprague-Dawley rats during co-infection with Trichinella zimbabwensis and Plasmodium berghei. A 42 day follow up study was carried out, where 168 male Sprague-Dawley rats (90-150g) were randomly divided into four separate groups, control (n=42); malaria infected (n=42); Trichinella infected (n=42) and co-infected group (n=42). On day 0, male Sprague-Dawley rats were orally infected with 3 T. zimbabwensis muscle larvae per gram body weight. Followed at day 28 post-Trichinella infection with malaria induction using 105 P. berghei parasitized RBCs for the mono-infected group. While 42 male Sprague-Dawley rats were co-infected with T. zimbabwensis and P. berghei on day 0 and P. berghei infection occurred on day 28pi. Experimental animals were sacrificed on day 0,7,14,21,28,35 and 42 pi. Where whole blood and sera were collected. Plasmodium berghei percentage parastaemia, T. zimbabwensis adult worm count and muscle larvae load, haematological parameters and serum levels of IP-10, RANTES and EOTAXIN were determined. Co-infection with P. berghei and T. zimbabwensis showed elevated P. berghei percentage parastaemia, as well as upregulation of RANTES and EOTAXIN as a Th2 immune response, while IP-10 was downregulated as an effective immune response to parasitic infections. Mono-infection with P. berghei caused an upregulation of IP-10 as a Th1 immune response.