Epidemiology of Tuberculosis

Epidemiologyof Tuberculosis

Epidemiologyof Tuberculosis

Tuberculosisor as it is popularly known TB is a potentially serious infectiousdisease that affects the lungs. The bacteria that cause TB are knownas Mycobacterium tuberculosis and are spread from one person toanother via minute droplets in the atmosphere resulting from cough orsneezing. The World Health Organization classifies TB as the secondlargest killer after HIV due to a single infectious cause. In 2013,there were 9 million cases of TB infection and 1.5 million peopledied from the disease. The disease can be prevented and can be cured(World Health Organization, 2014).

Thereare two types of TB latent and active TB. Latent TB is when the TBcausing bacteria is present in the body but in an inactive form. ThisTB is not contagious although it may become active, causing anindividual to become sick (WorldHealth Organization, 2013).Active TB on the other hand is TB in active form and makes a personsick and is contagious


TBis caused by Mycobacterium tuberculosis bacteria that spread from oneindividual to the other through small droplets exposed to theatmosphere through talking, spitting, sneezing, or coughing. Althoughit is contagious, one is not likely to get TB from a stranger, but aperson that one spends more time with including at home or workplace(Esmail,Barry &amp Wilkinson, 2012).People with active TB who have appropriate medical treatment forabout 2 weeks are not contagious.


ActiveTB is usually characterized by cough, fever, fatigue, chills, loss ofappetite and loss of weight as well as night sweats. Since the lungsare the major organs affected by TB, the symptoms include cough thatlasts for more than three weeks, chest pain experienced whilecoughing or breathing and sometimes blood while coughing or in thesputum.

Besideslungs, TB can affect other parts of the body including the kidney,the spine of even the brain. Symptoms for these attacks differdepending on the part of the body affected. For example, if thekidney is affected, there may be presence of urine in the urine(WorldHealth Organization, 2013).


TBcan be diagnosed through two main ways TB skin test and a bloodtest. However, these tests only tell if a person has the TB bacteria.To further establish whether one is sick with TB or active TB, othertest like sputum analysis or X-ray is administered (Esmail,Barry &amp Wilkinson, 2012).


Latentor inactive TB can be treated to prevent a person from getting TBdisease. TB disease is treated by medication taken from six to ninemonths. Drugs should be taken as advised for successful treatment. Ifnot taken correctly, the germs can develop resistance (Esmail,Barry &amp Wilkinson, 2012).

Multi-DrugResistant TB

TBgerms have over the years developed the ability to surviveantibiotics which 60 years ago were used to treat it. These germs arepassed through descendants. Drug resistant strain happens when anantibiotic cannot be able to kill the bacteria it is intended totarget. In 2013, 480,000 people developed multi-drug resistant TB(Esmail,Barry &amp Wilkinson, 2012).

Determinantsof Health and TB

Determinantsof health are those factors that influence the current state ofhealth of an individual. They may be physiological, socioeconomic,biological, psychological, behavioral, or psychosocial. The fivedeterminants of health include

Genesand biology

Theseare factors like sex and age of a person. TB can get any personregardless of their age or sex. For example 2013 had 550,000 childrenwith TB 80,000 of them dying of TB (World Health Organization, 2014).


Theseinclude behaviors that influence health such as smoking, alcohol useand drug abuse. The risk of getting TB increases in people who smoke.Long term use of drugs including alcohol also weakens the body immunesystem, making a person susceptible to TB (Glaziouet al., 2013).


Theseare social factors like gender, discrimination, income, educationamong others. People with low socioeconomic status or living in therural areas may not have access to health facilities and may not gettested for TB (Glaziouet al., 2013).In addition, lack of access to medical services causes many deaths ofTB patients.


Thisentails ecology and basically means the environment where one livesor works. People who rely on public transport such as train and busesfor transport and work in overcrowded places especially in thedeveloping countries are at an increased risk of TB. Refugee camps orurban informal settlement exposes people to risk of infection due toovercrowding (Glaziou,Falzon, Floyd &amp Raviglione, 2013).A person working in a crowded place like a market is also at anincreased risk of TB exposure.


Thisentails access to health care and having health cover. People withaccess to health facilities or have health insurance are betterpositioned to stay healthy (Glaziouet al., 2013).On the other hand, those with no access to health facilities ormedical care are at increased risk for TB. This includes the poor andthose living in the rural areas.

EpidemiologicTriangle As It Relates To TB

Epidemiologicaltriangle is a tool used by scientists to understand the spread of agiven disease in the community. It consists of an agent, host and theenvironment. For tuberculosis, the agent is Mycobacteriumtuberculosis which is an acid fast aerobic rod which reproducesgradually and is hypersensitive to ultraviolent light and heat. TBbasically affects the lungs and the respiratory system in general butcan also affect other organs. The disease is ranked the secondlargest killer after HIV. The TB death rate has dropped by 45 percentbetween 1990 and 2013 (World Health Organization, 2014).

Thetransmission of the TB bacteria is spread from one individual to theother through airborne droplets through sneezing, coughing, talkingor singing. The tiny the droplet the longer it can hang in the airafter the sick person has left the scene, thus increasing thelikelihood of infecting another person. It is easier to get infectedwith TB from a family member or a coworker than by a total stranger(WorldHealth Organization, 2013).Mycobacterium tuberculosis (the agent) is readily spread tovulnerable individuals (the host) through public settings or meetings(the environment). People with weakened immunity like those with HIV,diabetes mellitus, corticosteroid therapy or cancer are susceptibleto TB infection. TB can also affect healthy people especially thosewho remain exposed like health workers (Glaziouet al., 2013).

Roleof Community Health Nurse in TB Prevention

Communityhealth nurses play an important role in the prevention oftransmission of TB. The nurses should collaborate with the nursesfrom communicable disease control nurses (CDCNs) in developing aclient care plan (Glaziouet al., 2013).They investigate source incidences and contact, besides engaging ineducating patients, families and contacts about TB. They alsocoordinate directly observed therapy. They also point out patient’sbehavior that may hinder treatment and develop programs to promotecompletion of treatment.

WorldHealth Organization and Reducing TB Transmission

WHOis one of the organizations which has committed in the reduction ofTB transmission. In a 2008 guideline, WHO stipulated various elementsto achieving reduction of TB transmission.

Regularsurveillance of reported incidences and monitoring outcomes oftreatments should be the priority of assessing epidemiology control.All approaches should be strong in the carrying out of the systemsused for reporting of incidences of TB so as the data echoesaccurately the actual occurrence of TB and its trends (WorldHealth Organization, 2013).In addition, the evaluation procedure should be backed by suitableoperational empirical studies. Scrutiny of disaggregated surveillancedata should be supported in order to gather maximum information aboutTB epidemic and the influence of control procedures. Besides,appropriate computer application should be created and implemented toenhance routine recording and reporting.

In2006, WHO launched the new STOP TB approach, a worldwide strategy tostop TB. Since the launch, over 22 million TB patients have beentreated under direct observation therapy founded services. Generally,the strategy seeks to reduce TB prevalence by 50 percent based on1990 statistics and totally eradicating it by 2050 (WorldHealth Organization, 2013).A six step strategy exists to eradicate TB and include engaginghigh-quality DOTS development and enhancement, deal withTB/MDR/XDR-TB/HIV among other challenges, strengthening of healthsystems, involve all health care providers, enable and enhanceresearch, and empowering people with TB and the communities.


Esmail,H., Barry III, C. E., &amp Wilkinson, R. J. (2012). Understandinglatent tuberculosis: the key to improved diagnostic and noveltreatment strategies. Drugdiscovery today,17(9),514-521.

Glaziou,P., Falzon, D., Floyd, K., &amp Raviglione, M. (2013). Globalepidemiology of tuberculosis. SeminRespir Crit Care Med,34(1),3-16.

WorldHealth Organization (2014 October). Tuberculosis. FactSheet No.104.Retrieved http://www.who.int/mediacentre/factsheets/fs104/en/(Accessed December 20, 2014).

WorldHealth Organization. (2013). Globaltuberculosis report 2013.World Health Organization.