The 24th of March is a day set aside to raise awareness and educate the public about the worldwide epidemic of tuberculosis (TB), its impact and the efforts in place to eradicate the disease (WHO, 2020). On this day, millions of people around the world come together to commemorate the day in 1882 when Dr. Robert Koch revealed his discovery of “Mycobacterium tuberculosis”- the bacterium that causes TB- opening the way towards its diagnosis and cure (Barberis et al., 2017).
This year’s theme “It’s Time”, focuses on speeding up TB response to save lives and calls on the government, health-care providers and affected communities to join forces under the banner “Find. Treat. All. #EndTB” to make sure no one is left behind (WHO, 2020).
Tuberculosis is a contagious disease caused by Mycobacterium tuberculosis (MTB), a bacteria which usually attacks the lungs, but can also attack other parts of the body such as the kidney, spine, and brain (Barberis et al., 2017). Not everyone infected with the TB bacteria becomes ill and as a result of this, two TB-related conditions exist: latent or inactive TB infection and active TB or TB disease.
Source: AIDSInfo, 2019
Despite the fact that 90% to 95% of people infected with M. tuberculosis remain asymptomatic and do not develop active TB, approximately 5% to 10% of such latent infections advance to active disease- which if not treated properly- kills about half of those affected (Jilani et al., 2019). The common symptoms of active TB are persistent coughs with blood-containing mucus, fever, chills, sweating at night, and weight loss (CDC, 2016).
TB is globally widespread, with more than two billion people (approximately 30% of the world’s population) suspected to be infected with M. tuberculosis (Haddad et al., 2018). The worldwide incidence of TB attained its peak in 2003 but has been gradually declining since then.
In 2016, an estimated 10.4 million people became infected with TB, of which about 1.7 million died (Haddad et al., 2018; Jilani et al., 2019). The majority of new TB cases in 2016 reportedly emerged from Asia (about 45%), and Africa (about 25%), where Nigeria accounted for 8% out of the 25% (or 407 cases per 100,000 people) (WHO, 2016; 2017; Ogbo et al., 2018). .
TB continues to be a major public health issue in low and middle-income countries (LMIC) and is ranked above human immunodeficiency virus and acquired immune deficiency syndrome (HIV/AIDS) as the major cause of death from a single transmissible disease (WHO, 2017).
Globally, younger people (ages 15-24) have the highest rates of active TB, however in developed countries, older individuals experience the highest rates. Generally, adults of all age groups are at risk of progressing from latent to active TB (Narasimhan et al., 2013). The risk factors to contract active TB include:
- HIV infection (20 to 30 times more likely to develop active TB than those without).
- Medical treatments and immunosuppressive agents (such as corticosteroids).
- Persistent/long-term lung diseases.
- Use of tobacco products.
- Babies and infants
- Elderly people (weak immune systems)
- People previously infected
- Healthcare workers
- People living in crowded environments
- Alcohol use (greater than 40 g per day).
- Indoor pollution.
- Kidney disease
Drug Resistant Tuberculosis
Drug-resistant TB (DR-TB) is caused by M. tuberculosis that are resistant to anti-TB drugs, and it usually occurs when the drugs used for TB treatment are wrongly used or mishandled (CDC, 2017). Multidrug-resistant TB (MDR-TB) is a specific type of DR-TB which occurs when the M. tuberculosis that a person is infected with are resistant to two of the major TB drugs: isoniazid (INH) and rifampicin (RMP).
Approximately 9% of people with MDR-TB, have “extensively drug-resistant TB” (XDR-TB) which is a very rare form of DR-TB. XDR-TB is basically MDR-TB with additional resistance to any fluoroquinolone and to at least one of three injectable agents (i.e. amikacin, kanamycin, or capreomycin) (Kurz, 2016). When a person becomes ill with any of these types of resistant TB, it means that the drugs prescribed would not work and other drugs would need to be taken by the person if they are to be cured (WHO, 2014; Kurz, 2016).
The WHO drug resistance surveillance data showed about 240,000 deaths from MDR/RR-TB in 2016. In addition, 8 000 patients with extensively drug-resistant TB (XDR-TB) were reported globally. So far, 123 countries have reported at least one XDR-TB case, and on an average, approximately 6.2% of people with MDR-TB have XDR-TB (WHO, 2017).
The burden of Tuberculosis in Nigeria
As previously stated, TB continues to exist as a significant health issue in many LMICs especially Nigeria which is ranked 7th among the 30 high TB burden countries and second in Africa (GHE, 2020). Nigeria was also one of the top 3 (out of 10) countries that was responsible for 80% of the total gap between TB incidence and reported cases in 2017 (Ogbuabor and Onwujekwe, 2019). No more than an estimated 20% of active cases in Nigeria are notified despite it having one of the highest TB burdens in Africa (WHO, 2014).
In Nigeria, the prevalence of TB among HIV-negative people was 27% (Fig.1), the TB incidence rate was 158 per 100,000 population, and the total number of TB mortality was 39,933 (Fig.2) in 2016 (Ogbo et al., 2018). As shown in Fig.1, TB prevalence was highest in people aged 50–69 years and lowest in children under 5 years.
In 2017, approximately 75% of the estimated 418,000 incident cases of TB in Nigeria were neither notified nor diagnosed and TB mortality (leaving out Human Immunodeficiency Virus + TB) was 63 per 100,000 people (WHO, 2018; Ogbuabor and Onwujekwe, 2019).
For more than 20 years, Nigeria has been classified as one of the countries with a high burden of TB so as to encourage focused interventions, advocacy for funding and policies to improve the control of TB. Some factors related to this high TB burden are a high proportion of patients with drug-resistant TB (4.3% of new cases and 25% of previously-treated cases); and inadequate health systems that are incapable of supporting the effective scale-up of TB services (Onyedum et al., 2017). The National Tuberculosis & Leprosy Control Program (NTBLCP)- established by the Government of Nigeria- was launched as a part of the Ministry of Health to manage the funding for all TB-related work in Nigeria. Its commision is to coordinate TB and Leprosy control activities in all states within the country, and to reduce the public burden of both diseases. Significant progress has been made by the Ministry of Health in drafting the National Strategic Plan for Tuberculosis Control which seeks to ensure “universal access to prevention, diagnosis and treatment by 2020” in accordance with its commitments to the WHO (WHO, 2015).
Several challenges influencing the success of the National Strategic plan exist, such as insufficient financial provisions, access to areas that are hard to reach, missing or unreported TB cases and barely sufficient technical capacity of human resources. Nevertheless, well-meaning Nigerians continue to use the opportunity which World TB day presents to prompt the government to make efforts towards ensuring a further reduction in TB disease burden, as well as improve the health and well-being of Nigerians. This will require an extensive approach that includes increased funding and appropriate monitoring, health system strengthening and increased national and subnational surveillance for TB disease.
Let the government and citizens alike play their parts to strengthen TB education and awareness; and end stigma and discrimination against TB. It’s time !!
- Barberis, I., Bragazzi, N. L., Galluzzo, L., and Martini, M., 2017. The history of tuberculosis: from the first historical records to the isolation of Koch’s bacillus [pdf]. Available at:<https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5432783/pdf/2421-4248-58-E9.pdf>
- Ogbo F. A., Ogeleka P.,, Okoro A., Olusanya B. O., Olusanya J., Ifegwu K. I., Awosemo A. O.,, Eastwood J., and Page, A., 2018. Tuberculosis disease burden and attributable risk factors in Nigeria, 1990–2016. Trop Med Health 46, 34 (2018). https://doi.org/10.1186/s41182-018-0114-9
- Jilani TN, Avula A, Zafar Gondal A, et al. Active Tuberculosis. [Updated 2019 Sep 9]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available at:< https://www.ncbi.nlm.nih.gov/books/NBK513246/>
- Haddad, M. B., Raz, K. M., Lash, T. L., Hill, A. N., Kammerer, J. S., Winston, C. A., Castro, K. G., Gandhi, N. R., & Navin, T. R. (2018). Simple Estimates for Local Prevalence of Latent Tuberculosis Infection, United States, 2011-2015. Emerging infectious diseases, 24(10), 1930–1933. https://doi.org/10.3201/eid2410.180716
- Onyedum CC, Alobu I, Ukwaja KN (2017) Prevalence of drug-resistant tuberculosis in Nigeria: A systematic review and meta-analysis. PLoS ONE 12(7): e0180996. https://doi.org/10.1371/journal.pone.0180996
- Narasimhan, P., Wood, J., Macintyre, C. R., & Mathai, D. (2013). Risk factors for tuberculosis. Pulmonary medicine, 2013, 828939. https://doi.org/10.1155/2013/828939
- Kurz, S. G., Furin, J. J., & Bark, C. M. (2016). Drug-Resistant Tuberculosis: Challenges and Progress. Infectious disease clinics of North America, 30(2), 509–522. https://doi.org/10.1016/j.idc.2016.02.010
- Ogbuabor, D.C., Onwujekwe, O.E. Governance of tuberculosis control programme in Nigeria. Infect Dis Poverty 8, 45 (2019). https://doi.org/10.1186/s40249-019-0556-2
- World Health Organization. (2014). First National TB Prevalence Survey 2012 Nigeria.
- Ogbo, F.A., Ogeleka, P., Okoro, A. et al. Tuberculosis disease burden and attributable risk factors in Nigeria, 1990–2016. Trop Med Health 46, 34 (2018). https://doi.org/10.1186/s41182-018-0114-9