1.0 Introduction
Malaria is one of the most prevalent human infections worldwide resulting in 225 million cases each year (WHO, 2010). It is caused by protozoa parasite of the genus plasmodium which infects and destroys red blood cells. Four species of plasmodia (P. falciparum, P. malariae, P. ovale and P. vivax) cause malaria in humans of which P. falciparum is the most common cause of morbidity and mortality (Taylor-Robinson, 1998; Das and Pan, 2006).Malaria kills an average of 1 million Patients in Africa annually, Snow et al., (2005). In Nigeria about 96 millionpeople are exposed to malaria, and out of these 64 million people get infected and almost 300,000 deaths are being reported annually in the general population, of which over 100,000 deaths are of Patients (Alaribe et al.,2006). Haematological parameters are measurable indices of blood that serve as a marker for disease diagnosis (Petel et al., 2004). Haematological abnormalities such as anaemia and thrombocytopaenia have been observed in patients with malaria (Ladhani et al. 2002; et al. 2007).
The key feature of the biology of the Plasmodium falciparum, the predominant malaria species, is the ability of the infected red blood cells to adhere to the lining of the small blood vessels (Richard et al., 1998). Such sequestered parasites provide considerable obstruction to tissue perfusion. In addition, it is becoming clear that in severe malaria there may be marked reductions in the deformability of uninfected RBCs (Dondorp et al., 2000). RBCs destruction is an inevitable part of malaria, and anaemia further compromises oxygen delivery. Severe anaemia may arise from multiple poorly understood processes including acute haemolysis of uninfected RBCs and dyserythropoeisis, as well as through the interaction of malaria infection with other parasites infection and with nutritional deficiencies (Dondorp et al., 2000). The aim of this study was to determine changes in the haematological parameters of Patients with malaria infection in Nigerian population of Africa. Alterations in the haematological indices may strengthen the suspicion of malaria, prompting more meticulous search for malaria parasite, and timely institution of specific therapy.
Malaria which is the most prevalent infectious disease in the tropical and subtropical regions of the world is of great public health importance (Mishra et al., 2003; Umar et al., 2007; Mia et al., 2011).The World Health Organization reports that malaria, the deadly parasitic disease is responsible for nearly ninety percent of death in Africa (Ogbodo et al., 2010). One-fifth of infants' death in Africa is caused by the scourge of malaria (Snow et al., 2005; WHO, 2010). In Nigeria, approximately 0.25 million deaths of Patients under the age of five is caused by malaria yearly (UNICEF, 2009). Typhoid fever which is also endemic in Africa is more severe in infants and the elderly (Preston and Boreszyk, 1994; Gatsing et al., 2006).
Both malaria and typhoid exhibit close symptomatology and epidemiology (Nsutebu and Ndumbe, 2001; Brian and Wahinuddin, 2006). The first case of malaria-typhoid co-infection occurred among American soldiers in 1862 (Bynum, 2002). The high incidence and prevalence of malaria-typhoid co-infection became popular almost ten years ago whereas the fact that malaria has been prevalently high is already recognized and accepted (Uneke, 2008). The onset and progression of the malaria infection is characterized by vast alterations in hematological and biochemical parameters (Bidaki and Dalimi, 2003). The World health Organization's (WHO) criteria acknowledges that some biochemical and hematological features should raise the severity of malaria (World Health Organization, 2000).
In different parts of the world including Nigeria, scientific materials on hematological and biochemical alterations in acute falciparum malaria are available (Mishra et al., 2003; Egwunyenga et al., 2004; Bidaki and Dalimi, 2003; Udosen, 2003), but none have really been reported from Sango-Ota, Ogun State, Nigeria and also scientific information on the impact of malaria-typhoid co-infection on hematological and biochemical parameters are scanty. This study examined the effect of malaria and malaria-typhoid co-infection on some hematological and biochemical indices. The study population includes only the febrile patients that have been clinically said to have malaria and malaria-typhoid co-infection from the results of their malaria and widal tests, respectively.
