RADIOGRAPHIC ASSESSMENT OF CHEST REGION, FOCUS ON TUBERCULOSIS (A CASE STUDY OF 68 REFERENCE HOSPITAL YABA LAGOS).

ABSTRACT

Background: Tuberculosis is important global health problem. About one-third of the world’s population and 30% of HIV positive patients are infected with Mycobacterium tuberculosis. TB patients infected with HIV have radiographic patterns of both primary and post primary pulmonary tuberculosis.

Objectives:  This study aimed to make a Radiographic assessment of chest region, focus on tuberculosis(A case study of 68 reference hospital yaba Lagos).

Methodology:  Patients newly diagnosed with smear positive PTB were randomly selected, HIV tested and chest radiographic patterns were extracted from re-evaluation of original chest radiographs and their radiologic reports.

Results:A total of 170 patients were included among them 100 were males and 70 were females. Fifty four patients (31.8%) were HIV/PTB co-infected. Females were significantly more HIV/PTB co-infected than males (51.4% vs 18.0%, p-value= 0.000).  HIV/PTB co-infected patients compared to PTB only patients had significantly lesser cavities (44.4% vs 61.2%, p = 0.040), lesser alveolar consolidation (64.9% vs 81.7%, p =

0.04), HIV/PTB co-infected patients had more left and bilateral lung nodules 85.2% vs 60.9% (p = 0.023) and 70.4% vs 37.5% (p = 0.004) respectively, more miliary nodules (44.4% vs 15.6%, p = 0.003), more left upper, mid and lower zone nodules 59.3% vs 34.4% ( p = 0.028), 77.8% vs 54.7% (p-value = 0.039) and 66.7% vs 34.4% (p = 0.005) respectively. HIV/PTB co-infected patients with CD4 > 200µmol/l had more right mid zone consolidation (40,0% vs 4,5%, p = 0.007). No chest radiographic pattern which was highly associated with severe immunosuppression.

Conclusion: Most patients with smear positive pulmonary tuberculosis have abnormal chest radiographs. Pulmonary cavities and alveolar consolidation are highly associated with negative HIV status. HIV positive patient with smear positive PTB were more likely to have left or bilateral pulmonary nodules, milliary nodules and left upper, mid and lower zone nodules. Right mid zone consolidation in HIV patients was associated with CD4 counts > 200µmol/l. No radiographic pattern was highly associated with severe immunosuppression.

Recommendations: It is recommended that all HIV positive patients with pulmonary radiographic lesions to have sputum smear screening. Patients with pulmonary nodules should be evaluated for pulmonary tuberculosis and HIV. There is a need of more studies focusing on radiographic patterns among HIV positive and HIV negative patients using large community based sample.

 

CHAPTER ONE

INTRODUCTION

1.0 Introduction

This study aims to analyze the Radiographic assessment of chest region, focus on tuberculosis(A case study of 68 reference hospital yaba Lagos). The purpose of this introductory chapter is to provide an overview of the study. Again, the chapter introduces the problem of TB globally, in Africa and in Nigeria. It states the aim, research objectives and conceptual model defining the study and how significant this study will be. Finally this chapter presents a brief overview of how the chapters are presented in the thesis.

1.1Background to the study

Tuberculosis (TB) is a contagious airborne disease caused by the bacillus Mycobacterium tuberculosis and Mycobacterium africanum. It typically affects the lungs (pulmonary TB) but can also affect other organs of the body (extra pulmonary TB). In the case of Pulmonary tuberculosis (PTB), the disease can spread through air when an infected person expels the bacterium through cough, sneezing or spitting (Konstantinos, 2010; WHO, 2012a). TB remains a major global public health problem and persists as a major cause of human mortality and morbidity, affecting almost a third of the world‟s population (Dooley et al., 2011; WHO, 2002b). The World Health Organization (WHO) in 1993 declared TB a global emergency in recognition of the disease as a public health problem (Yahaya et al., 2014).

Tuberculosis (TB) continues to surge worldwide even after the availability of effective drugs for the treatment of the disease. The WHO estimates that in 2011, almost 8.7 million new TB cases occurred with 1.4 million mortality from the disease in the same year (WHO, 2012a). The consequences of TB on patients, families and communities through cost incurred on diagnosis, treatment, and transport to and from treatment centres and time lost from work cannot be under estimated (Barter et al., 2012; Ukwaja et al., 2013).

Global efforts to control TB were revived in 1991; this was as a result of the World Health Assembly‟s (WHA) recognition that TB is a major global public health problem (WHO, 1991). For effective TB control, the WHA subsequently sets global targets as part of its resolutions to include detection of at least 70% of new smear positive pulmonary TB cases and successful treatment of 85% of such cases, by the year 2000. The target date was later, revised to 2005 (WHO, 1991, 2002a, 2009b, 2009d) when it became clear that the WHA targets would not be met by 2000. The achievement of these targets would have resulted in the reduction of the prevalence, incidence, transmission and drug resistance to TB.

In 2006, progress in meeting the target numbers was substantial as case detection reached 59% (more than 57 countries met the case detection target), and treatment success reached 84% (more than 60 countries met the treatment target). Global TB epidemic declined by late 2006, however, only 25 countries have reached both the 1991 WHA targets for TB control with problem of low treatment success rates reported from Africa (72%) and Europe (75%) (Laserson & Wells, 2007; van Hest et al., 2013; WHO, 2006b). Notwithstanding the fact that the Millennium Development Goals (MDG) Report (2015) indicated declining TB incidence in all regions since 2000, the rate of decline is rather slow. The significant reduction in TB incidence with consequence reduction in the spread of the disease was expected to occur in all TB endemic areas by the year 2015. Globally, the number of people receiving tuberculosis treatment increased from 2.9 million in 1995 to 5.8 million in 2012, with treatment success rate improving each year. Indeed many developing countries exceeded in six succession years the target of 85%, set in 1991 (UN, 2015).

The burden of TB cannot be under estimated, as it remains a major public health problem in the world. It causes ill health among millions of people each year and ranks only second to HIV/AIDs as cause of death from infectious disease (WHO, 2012a). Statistics indicate that, there were about 9 million new cases in 2011 and 1.4 million TB deaths (990,000 among HIV-negative people and 430,000 HIV-associated TB deaths) (WHO, 2012a). This occurred notwithstanding the availability of effective treatment for the diseases. TB kills more youths and adults than other infectious diseases in the world (WHO, 2008b). The disease mostly affects the poor in the society. It also affects more males than females (WHO, 2013b).

Geographically, the burden of TB is highest in Asia and Africa. South-East Asia and Western Pacific regions account for 60% of total TB cases in the world. The African region has 24% of the world‟s cases and the highest rates of cases and deaths per capita.The WHO has also revealed that 3.7% of all new cases and 20% of previously treated cases were estimated to have multi-drug resistance tuberculosis (MDR-TB) worldwide (WHO, 2012a). The African region has approximately one quarter of the world‟s cases, and the highest rates of cases and deaths relative to population (WHO, 2012a). TB was declared an African emergency in August 2005 by WHO (Yahaya et al., 2014). Out of the 22 high TB burden countries in the world, nine are in Africa (WHO, 2012a). Almost 80% of TB cases among people living with HIV reside in Africa (WHO, 2012a). Africa carried the most severe burden with 281 cases per 100,000 population in 2014 compared with global average of 133 per 100,000 population (WHO, 2015a, 2016a, 2016b).

1.2 Problem Statement

Tuberculosis (TB) still remains a significant global health problem and the leading cause of morbidity and mortality from infectious diseases(Jagielski, et all 2010).  CXR is simple, low cost and gives large amount of information(Ashizawa, 2003). With wide availability of X-ray facilities throughout the country, CXR is important in evaluation of suspected or proven PTB (Awoyemi, et al 2009). Abnormal CXR features such as presence of cavities, upper lobe infiltrate and miliary pattern were associated with TB in different countries (Solari et al 2008). Hence an abnormal CXR has been helpful in diagnosis and for presumptive treatment of TB (Bakari et al, 2008).

Also finding of cavities on CXR of TB patient has been associated with presence of active TB hence high infectivity of the host (Gomes et al 2003). HIV seropositive patients with pulmonary tuberculosis and immunosuppression have atypical clinical features (52) also atypical radiographic patterns (Awoyemi et al, 2009).  Hence they may suffer from delays for treatment due to misdiagnosis or delays in diagnosis(Pallongyo 2003). Therefore they are likely to have increased morbidity or risk of death from an otherwise curable illness (ibid). On review of literature there are discrepancies in the occurrence of chest radiographic patterns among PTB patients with respect to HIV status and CD4 levels among HIV positive patients. Also there is no prior study in Tanzania that was done addressing chest radiographic patterns and their association with HIV status and CD4 levels. Therefore finding of most common radiographic presentation of PTB among PLHIV in our setting will be crucial to the timely diagnosis, proper treatment and management of TB patients in Nigeria.

1.3 Rationale

Chest radiography is cheap, safe and widely available imaging modality in assessing pulmonary manifestations of HIV/AIDS, and together with clinical and level of immunosupression will help to differentiate between typical and atypical PTB presentation (Ashizawa, 2003).

Chest X-ray facilities are widely available in all district hospitals all over Tanzania. In these facilities different health professionals such as MDs, AMOs and COs are involved in the investigation and management of TB suspects as well as TB patients. They all serve in TB screening sites but their knowledge and skill on interpretation of chest radiographic patterns and association with TB is varied hence this study will serve as the starting point on the demonstration of the chest radiographic findings in TB and their variation in HIV. Chest X-ray is used in the diagnosis, follow up and monitoring of patients with PTB especially in patients co-infected with HIV and in settings of smear negative PTB. Therefore common chest radiographic patterns of PTB gathered in this study will help towards better understanding of radiographic presentation of TB.

Upon dissemination of research findings, knowledge gathered in this study will help towards harmonization of interpretation radiographic patterns among health professionals. This will be crucial to the timely diagnosis, proper treatment and management of TB patients in Nigeria.

1.4 Broad Objective

To make a radiographic assessment of chest region, focus on tuberculosis(A case study of 68 reference hospital yaba Lagos).

1.4.1 Specific Objectives

1. To determine the distribution of adults with Tuberculosis in selected hospitals by socio-demographic factors in Yaba Lagos State.
2. To determine distribution of chest radiographic patterns among adults with Tuberculosis in selected hospitals in Yaba Lagos State.
3. To determine the association between chest radiographic patterns and HIV status among adults with Tuberculosis and HIV in selected hospitals in Yaba Lagos State.

To determine the association between chest radiographic patterns and level of CD4 counts among adults with Tuberculosis and HIV in selected hospitals in Yaba Lagos State.

1.5 Significance of the study

Tuberculosis (TB) is declining slowly each year and it was estimated that 37 million lives

were saved between  through effective diagnosis and treatment. Notwithstanding, given that most TB deaths are preventable, the death rate from the disease is still too high and all efforts to combat it must be accelerated. Incidence, prevalence and mortality rates are all falling in Africa, but not fast enough to meet global targets (WHO, 2014b).

These findings of the study are expected to provide a guide to programme implementers

(Health Directorates, the National Tuberculosis Control Programme (NTP), NonGovernmental Organizations (NGOs) and the Ministry of Health) in adopting innovative

strategies to improving the TB control programme in Nigeria.

Lastly, it is expected that the findings from this study become a challenge for further

studies and a guide for academics interested in the theme.

1.6 Scope of the Study

This study was Carried out in selected hospitals in Yaba, Lagos State.

1.7 Definition of key concepts

Bacteriologically confirmed TB case: Is a patient from whom a biological specimen is positive by smear microscopy, culture or WHO-approved rapid diagnostic test.

Clinically diagnosed TB case: Is a patient who does not fulfil the criteria for bacteriologically confirmed TB but has been diagnosed with active TB by a clinician or cases diagnosed on the basis of x-ray abnormalities or suggestive histology and extrapulmonary cases without laboratory confirmation.

Cavity is a lucent area within the lung that may or may not contain a fluid level and that is surrounded by a wall, usually of varied thickness.

Consolidation is as a homogeneous increase in pulmonary parenchymal attenuation that obscures the margins of vessels and airway walls of the lung associated with little or no loss of lung volume. The term in this study is used for alveolar, interstitial and mixed infiltrates.

Milliary nodules are widespread, tiny, discrete uniform round opacities measuring < 2mm.

Micro nodule is an oval or round pulmonary opacity measuring 2 to 5mm.

Macronodule is an oval or round opacity measuring 0.5 to 3cm.

Mass is an oval or round opacity measuring more than 3cm.

Pulmonary TB case: Is any bacteriologically confirmed or clinically diagnosed case of TB involving the lung.

Smear positive pulmonary TB case: A patient with one or more initial sputum smear examinations (direct smear microscopy) AFB-positive; or one sputum examination AFB positive plus radiographic abnormalities consistent with active pulmonary TB as determined by a clinician.

Smear negative pulmonary TB case: A patient with two sputum smear examinations negative for AFB but radiographic (X-ray) suggests TB and a decision by a clinician to  treat with anti-tuberculosis chemotherapy.

Extrapulmonary TB case: Is any bacteriologically confirmed or clinically diagnosed case of TB involving organs other than the lungs, e.g. abdomen, genitourinary tract, joints and bones, lymph nodes, meninges, pleura, skin.

TB/HIV co-infection: A patient who is infected with both TB and HIV.

DOTS: Is an internationally recognized strategy adopted for the implementation of the national tuberculosis control programme (NTP). The DOTS strategy has five main components, namely: case detection, directly observed treatment of patients with drugs, continuous supply of drugs, case (contact) tracing and recording systems and research.

Treatment supporter: Is a person selected by TB patients and who is trained to supervise the patient to take his or her TB drugs on daily basis. The role of the treatment supporter is to make sure the TB patient takes his or her drugs daily and regularly for the  required treatment duration. Sometimes, the treatment supporter collects the TB drugs from the health facilities for the TB patients.

1.8 Structure of the thesis

The study is compiled into five chapter. Chapter one is the introduction and addresses issues concerning background information of the study. The chapter also looks at the problem statement, the study research questions and objectives, conceptual model of the study, significance and justification.

In Chapter two, relevant literature from peer reviewed journals and other official documentation concerning this study is reviewed in line with the research questions to expose gaps that this study addressed and also emphases on the historical and  epidemiological perspective of tuberculosis (TB). Again, factors that influence compliance to TB treatment have also been reviewed and presented as well in the chapter two.

The chapter three addresses issues of the research methodology used in this study. This chapter describe the background of the study area, study type and design, population, study variables data collection procedure and data analysis. This chapter also looks at quality control and ethical considerations.

In chapter four, a presentation of the study results or findings both from the field and data review.  Chapter five involves discussions of results in relation to existing literature from other studies on the study subject, the summary of the findings, conclusion and recommendations are presented base on several issues that have being discussed.

 

CHAPTER TWO

LITERATURE REVIEW

2.0 Introduction

A literature review is an organised and systematic presentation of what has already been studied and published on a particular subject, with the purpose of informing the researcher on what is already known about that subject (Burns & Grove, 2005) and avoid unnecessary replication which wastes resources.

2.1 Definition, causes, symptoms and transmission of tuberculosis (TB)

2.1.1 Definition and causes of TB

Tuberculosis (TB) is a contagious and airborne disease caused by the bacillus Mycobacterium tuberculosis (M. tuberculosis) (Udwadia, 2012; WHO, 2012a). In a study, Konstantinos defined TB as a disease caused by Mycobacterium africanum (M. africanum) (Konstantinos, 2010). There are other related infectious mycobacterial species (M. bovis, M. microti, M. caprae, M. pinnipedii, M. canetti and M. mungi) which together form the M. tuberculosis complex, and most but not all of these species have been found to cause diseases in humans (CDC, 2013). The most frequent organism involved in human disease is the Mycobacterium tuberculosis (M. tuberculosis). Some studies conducted in Burkina Faso and Cameroun associate M. tuberculosis species as the main causative agent of pulmonary tuberculosis (Godreuil et al., 2007). Similarly, some studies conducted in Ghana have shown that M. tuberculosis accounted for about 73% of pulmonary tuberculosis cases whilst M. africanum and M. bovis accounted for about 23% and 3% respectively (Addo et al., 2007; Addo et al., 2010). People infected with TB bacilli may be asymptomatic yet may still require treatment to prevent TB disease from developing in the future (CDC, 2016). The main cause of infection is untreated smearpositive pulmonary tuberculosis (PTB) patient discharging the bacilli (WHO, 2012a). The disease most commonly affects the lungs (PTB), but sometimes affects other parts of the body (EPTB)  (CDC, 2005a). An individual only needs just a small amount of bacilli to be infected with TB. Although WHO (2013) asserts that TB is preventable and curable, the disease is still a major public health problem since its re-emergence in the 1990s and still persist as a major cause of human mortality and morbidity (Garrido et al., 2012;

WHO, 2002b). It is postulated that if stringent control measures are not implemented, approximately 1 billion people will become infected, 150 million will become symptomatic and 36 million will die from TB between 2002 and 2020 (Chung et al.,

2007). A comparatively small proportion of people infected with Mycobacterium tuberculosis will develop TB disease and the probability of developing TB is much higher among people infected with the human immunodeficiency virus (HIV) according to the WHO, (2012). It is also the position of the WHO that the disease is also more common among men than women, and affects mostly adults in the economically productive age groups; around two-thirds of cases are estimated to occur among people aged 15–59 years (Chennaveerappa et al., 2011; WHO, 2013b).

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