CHAPTER ONE

INTRODUCTION

Background to the Study

Tuberculosis (TB) is a chronic infectious disease caused by bacteria generally referred to as mycobacterium tuberculosis; almost every organ in the body can be affected, but involvement of the lungs account for more than 80% of TB cases. Tuberculosis affecting the lungs is called Pulmonary Tuberculosis (PTB), while those affecting other organs are called Extra Pulmonary Tuberculosis (EPTB) (Federal Ministry of Health, 2010).

The most important source of infection is an untreated Pulmonary Tuberculosis (PTB) patient. When such a person coughs, spits or sneezes, tiny droplet nuclei containing the tubercles are released. Transmission is through inhaling these droplet nuclei (Federal Ministry of Health 2010).

Today tuberculosis remains a global public health problem of enormous dimension. It is estimated that there are I billion infected patients worldwide, with 10 million new cases and over 3 million deaths per year. Tuberculosis is responsible for more deaths than any other infectious disease (WHO, 2008).

It was estimated to cause a global emergency with estimates of 1.8 million deaths worldwide in 2008 out of over nine million cases. In the same year, the estimated global incidence rate fell to 139 cases per 100,000 populations after reaching its peak in 2004 at 143 per 100,000. However, this decline was not homogeneous throughout the World Health Organization (WHO) regions, with Europe failing to record a substantial decline, but rather appearing to have reached a stabilization rate (WHO, 2009).

In the WHO African region with a population estimate of 836,670,000 as at 2010, TB incidence was 2,300,000, prevalence of 2,800,000 and deaths of 250,000 (World Health Organisation, 20I0). Nigeria ranking the tenth among the 22 high TB burden countries in the world has the prevalence of 133 per 100,000 and 93,050 cases were registered in 2010. (Federal Ministry of Health, 2011)

Treatment success measured by a standardized process of treatment outcome monitoring (TOM) is one of the pillars of TB control and along with case detection, is recognized as a key programmatic output. It is against this rationale that World Health Assembly (WHA) resolution was passed in 1991, adopting two targets for global TB control to detect at least 70% of new infectious cases and to cure at least 85% of those detected. These targets were linked to the Millenium Development Goals, and stop TB partnership set the year 2005 as the dead line for achievement (Dye, Maher, Espinal and Raviglione, 2006).

Globally, the treatment success rate exceeded the 85% target for the first time in 2008 since the target was set in 1991, with a percentage of 87% for patients starting treatment in 2007 (WHO, 2009). Further, more treatment success rates were not maintained nor improved between 2006 and 2007 in all WHO regions with the exception of the European region which recorded the lowest success rate globally at 67% (WHO, 2009).

The importance of strengthening treatment outcome monitoring (TOM) in Europe has long been recognized. A statement put forward by the WHO and the International Union Against Tuberculosis, and Lung Disease underlined in 1998 the need for standardization and evaluation of treatment results for TB patients in the WHO European region