CHAPTER ONE

INTRODUCTION

1.1    Background of the study

Microsporidia are single-celled, obligate intracellular parasites that were recently reclassified from protozoa to fungi.  Microsporidia are a group of intracellular parasites which have attracted the interest of parasitologists for over 100 years. The first species, Nosemabombycis, was discovered in the middle of the 19th century as the cause of silkworm disease (i.e., pepper disease, pebrine disease), which nearly destroyed the silkworm industry in Southern Europe (Didier,2005; Franzen,2008).More than 1,400 microsporidian species have been described in both invertebrate and vertebrate hosts. Only eight genera and 15 species of microsporidia have been associated with human infections.

The first report on human microsporidia infection was in 1959 and described the case of a 9-year-old Japanese boy who presented with disseminated microsporidiosis associated with fever, headache, vomiting,and spastic convulsions, (Matsubayashet al.,1959). Interest in this group of parasites started with the development of the AIDS pandemic around the world in 1980’s. In 1985, a new species Enterocytozoonbieneusiwas found in an HIV-infected patient. Since then,species of microsporidia have been recognized worldwideas etiologic agents of opportunistic infections. The clinicalcourse of microsporidiosis depends on the immune statusof the patient and the site of infection. The groups at riskconstitute people with HIV/AIDS, organ transplant recipientsbeing treated with immunosuppressive drugs, travellers,children and the elderly, (Didier, 2000; Garcia, 2002;Rabodonirina, 2003; Wichro, 2005; Dworkin, 2007; Galvan, 2011).

Two microsporodiaEnterocytozoonbieneusi and Encephalitozoonintestinalis have been identified as possible causes of diarrhoeal illness in HIV-infected patients, (Mouraet al.,1993; Kotler, 1995).Over 40 million people are living with HIV/AIDS, the majority (more than 25 million) of whom live in sub-Saharan Africa. Up to 2.4 million deaths were recorded worldwide in 2005, (Akinboet al.,2009).

People in the advanced stages of HIV infection are vulnerable to secondary infections and malignancies that are generally termed as opportunistic infections as they take the advantage of the opportunity offered by a weakened immune system, (Saidu, et al.,2009). In HIV/AIDS positive patients, the most clinical manifestation is chronic diarrhoea and wasting due to enteric infection, (UNIADS 1998).This parasite is commonly observed in HIV-infected patients with CD4 Lymphocytes count of less than 50cells/mm3 who complain of chronic diarrhoea, nausea, malabsorption and severe weight loss but asymptomatic infection have also been reported in immunocompetentpersons,(Sak et al.,2011).

1.2       Justification

Microsporidiosisis a neglected tropical disease that is associated with chronic diarrhoea especially in persons living with HIV/AIDS, and in other immune-compromised individuals (elderly, organ transplant individuals, travellers). In developing countries like Nigeria, there has not been any serious efforts toward the eradication of Microsporidiosis. Infection rate of Microsporodiosis is on the increase in tropical and subtropical countries due to lack of health hygiene, access to public health centres, and knowledge of the disease. In Nigeria detection of microsporidia is not routinely performed in clinical practice, there is therefore dearth of information concerning Microsporidia in respect to prevalence, diagnosis, treatment and control.

Few cases of the disease has been reported in HIV/AIDS, and other immune-compromised individuals in Nigeria. However, epidemiology and prevalence of the disease has not been well documented for sustainable control. There is therefore a need for further study and understanding of the epidemiology of the parasite. Documenting the prevalence of the Infection will aid in management and control of the disease.

1.3       Aim

This study is aimed at assessing the prevalence of Microsporidia in HIV/AIDSpatients in Minna, Niger State.

1.4       Objectives

The specific objectives of this study are to determine:

1. The prevalence of Intestinal Microsporidia among HIV/AIDS patients of General Hospital Minna, Niger State.
2. The species of Microsporidiainvolved in relation to sex and age among HIV/AIDs patients of General Hospital Minna, Niger State
3. The association of CD4 Cell count and Microsporidia infection in HIV / AIDS patients.