EPIDEMIOLOGY OF THREE COMMUNICABLE DISEASES IN SUB-SAHARAN AFRICA
In the book Public Health Medicine for the Tropics, Lucas and Gilles (2003) states that the term ‘epidemiology’ which originally meant ‘the study of epidemics’ employed techniques that were used in the study and control of epidemics but have now been usefully employed to include ‘study of non-communicable diseases and accidents’, ‘study of distribution of disease in human population’, ‘study of patterns of disease’ as well as ‘search for determinants of disease’. Furthermore, they stated that epidemiology ‘exploits the technologies from other disciplines – microbiology, parasitology, social sciences and new ...view middle of the document...
According to the WHO Treatment guideline on the treatment of TB, the following are the standard definition of a TB case (WHO, 2010).
Tuberculosis Suspect: Any person who presents with symptoms or signs sugges¬tive of TB. The most common symptom of pulmonary TB is a productive cough for more than 2 weeks, which may be accompanied by other respiratory symptoms (shortness of breath, chest pains, haemoptysis) and/or constitutional symptoms (loss of appetite, weight loss, fever, night sweats, and fatigue) (WHO, 2010).
Case of tuberculosis: A definite case of TB (defined below) or one in which a health worker (clinician or other medical practitioner) has diagnosed TB and has decided to treat the patient with a full course of TB treatment (WHO, 2010)..
Definite case of tuberculosis: A patient with Mycobacterium tuberculosis complex identified from a clinical specimen, either by culture or by a newer method such as molecular line probe assay. In countries that lack the laboratory capacity to routinely identify M. tuberculosis,some resource-limited settings, a pulmonary case with one or more initial spu¬tum smear examinations positive for acid-fast bacilli (AFB) is also considered to be a “definite” case, provided that there is a functional external quality assurance (EQA) system with blind rechecking (WHO, 2010)..
Tuberculosis is caused by Mycobacterium tuberculosis – a bacterium mostly found humans (Webber, 2012). The infection is also found in cattle as Mycobacterium bovis and naturally occurs in the environment and capable of infecting humans (WHO, 2013).
TB occurs in humans as Mycobacterium tuberculosis mostly affects the – a bacterium that mostly affects the lungs of humans (Webber, 2102) as is referred to as pulmonary TB. When found outside human lungs, it is referred to as extra-pulmonary TB and can occur as follows: skeletal tuberculosis, genital tract tuberculosis, urinary tract tuberculosis, CNS tuberculosis, gastrointestinal tuberculosis, adrenal tuberculosis, scrofula and cardiac tuberculosis (Web Path, 2014). TB occurs in cattle in the form of Mycobacterium bovis and natarally occurs in the environment (WHO, 2013).
TB is spread from person to person through the air. When people with lung or pulmonary TB cough, sneeze or spit releasing TB germ into the air, other people may become infected if and when they inhale these germs. About a third of the world's population has latent TB, which means people have been infected by TB bacteria but are not (yet) ill with TB disease and cannot transmit the disease. It is pertinent to note that 10% of the people infected with Mycobacterium tuberculosis have a lifetime risk of falling ill. There is a higher risk and/or disease progression is faster among people living with HIV, diabetics, tobacco smokers, who have their immune system compromised as a result of their illness or habit (WHO, 2013).
The symptoms of active TB is usually mild for many months in persons that...