African Journal of Malaria and Tropical Diseases

Full Length Research Paper

Survival strategies of malaria episode, outcome and implications of treatment interventions

Erasto V. Mbugi¹*, Benezeth M. Mutayoba ¹, Sakurani T. Balthazary¹, Allen L. Malisa², Thomas B. Nyambo³ and Hassan Mshinda⁴

¹Department of Veterinary Physiology, Biochemistry, Pharmacology and Toxicology, Faculty of Veterinary Medicine,

Sokoine University of Agriculture (SUA), P.O. Box 3017, Morogoro, TANZANIA.

²Department of Biological Sciences, Faculty of Science, Sokoine University of Agriculture P.O. Box 3038, Morogoro, Tanzania

³Department of Biochemistry, School of Medicine, Muhimbili University College of Health Sciences (MUCHS), P.O. Box 65001, Dar es Salaam, TANZANIA.

⁴Ifakara Health Research and Development Centre (IHRDC), Off Mlabani Road, P.O. Box 53, Ifakara, Kilombero District, Morogoro, TANZANIA

*Corresponding authors E-mail: [email protected]. Tel: +255 272 753 982. Fax: +255 272 753 982. Mobile: +255 748 586 869.

Accepted 04 April, 2015

Abstract

Polymorphism and antigenic variation are important biological survival strategies of malaria parasites determining the episode, outcome and implications of treatment interventions. In P. falciparum, polymorphic antigens are associated with the asexual blood-stage; merozoite surface protein 2 (MSP2). The MSP2 genes have been invaluable in post-treatment discrimination of parasite resurgence from new infection, especially in high transmission areas. We performed polymerase chain reaction (PCR) on DNA extracted from blood samples of 141 malaria-infected infants, followed by restriction fragment length polymorphism (RFLP) of PCR products. The findings showed multiplicity of infections of single to six infections with an average of 2.58 infections per patient. Single infections of either 3D7 or FC27 allelic families of the MSP2 gene occurred in 51 patients (50.5%) out of all PCR- RFLP successful samples (n = 101). Out of 15 (10.6%) follow up samples with resurgent parasitaemia, 3 (20%) samples had recrudescent infections while 12 (80%) had variable results. Our findings provide an insight on the prevalence of the genetic determinants of suphadoxine-pyrimethamine (SP) resistance in Mlimba during the study period, and in the face of rapidly spreading resistance, calls for the periodic surveillance in order to timely detect early warning signal of the deteriorating SP cure rate.

Key words: Malaria, Plasmodium falciparum, MSP2 genes, Multiplicity of infections, Mlimba, Tanzania.