Multi-drug-Resistant Tuberculosis: The Burden on Middle and Low Income Countries
Author: Macquin Anduwan - Bachelor of Oral Health
One of the most deadly infectious diseases in the world is tuberculosis (TB). Each day nearly 4 500 people lose their lives and about 30 000 people contract tuberculosis [1]. Even those on treatment are unable to live normal lives for the next few months. Tuberculosis is an air-borne disease that is caused by the bacteria Mycobacterium tuberculosis and can infect patients in multiple regions of their body such as their brain, kidneys, or the spine [2]. Most often though, it manifests in the lungs, causing patients to experience difficulty in breathing, weight loss, and general fatigue. Though a general fall in TB cases has been reported globally, the past decade has also seen a global rise in multidrug-resistant TB (MDR TB), which has raised major public health concerns [3]. Currently, many reports link TB as a heavy burden in low to middle income countries.
A few years ago in the year 2016, approximately 490,000 people worldwide had reportedly developed multidrug-resistant TB, most of which were from middle and low income countries [4], [5]. Recent statistics suggest that approximately 4.6% of patients presenting with TB globally are diagnosed with MDR TB [3]. These statistics represent the one-in-three people who are fortunate to be diagnosed with MDR TB and of these, only about every quarter of them are treated [5]. Of the estimated 10 million cases of TB each year, the World Health Organization (WHO) estimates that about 60 per cent of new cases occur in the Indo-Pacific region [6].
Each year approximately 15 000 to 20 000 people are diagnosed with tuberculosis in the Pacific [7]. Papua New Guinea (PNG), one of the Pacific Island Countries, has a very high prevalence of tuberculosis, including multidrug-resistant tuberculosis. The treatment success rate was registered, based on 2016 reports, at only 62% [8]. With an estimated incidence rate of 432 per 100 000 people, PNG has the highest rate in the Pacific [8]. Other countries like Kiribati and Marshall Islands also had high reported cases at about 330 per 100 000 and 255 per 100 000 respectively [9].
An article published in 2012 underlined the role of socioeconomic status and health system development in regards to tuberculosis in the Asia and Pacific region [10]. In that article, tuberculosis was shown to have a higher incidence, prevalence and mortality rate in countries that had a lower human development index, gross domestic product (GDP) per capita, corruption perception index, and countries where more people were malnourished [10]. Health system variables included total health expenditure per capita, hospital beds, and improved water and sanitation had strong links to tuberculosis [10]. The study concluded that socioeconomic determinants and health system development played a large role in controlling TB in the region [10].
At the moment, many governments in the Pacific currently work in line with the internationally recommended Directly Observed Treatment Short-course (DOTS) strategy. This strategy is one of the six elements that make up the World Health Organization’s STOP TB campaign in the Western Pacific 2006 -2010 [11].
Tuberculosis, in most cases, is treatable and many patients may recover fully. Treatment usually involves a strict six-month drug regimen. Any premature interruption or inappropriate antimicrobial drug can lead to the development of multidrug-resistance, which can then pass on from person-to-person [4]. A person is, therefore, said to have developed multidrug-resistant TB (MDR TB) when resistance has been developed to at least isoniazid and rifampin, two very potent drugs used to treat people with TB [2].
According to the World Health Organization, there are two reasons why multiple drug resistance continues to surface and spread, and that is because of mismanagement of TB treatment and person-to-person transmission [4].
Treatment for MDR TB is usually much longer than the 6-month regimen for drug-susceptible TB. Patients may be under treatment for 9 to 24 months with a lower rate of recovery [4].
Often the combination of great distances, limited resources, and long treatment periods presents a challenge to the inhabitants of the Pacific [12]. In some of the countries, these challenges makes treating multidrug-resistant TB very difficult. Treatment options are expensive as it is and many times the recommended medicines are not always available [4]. Drug resistance needs to be detected using special laboratory tests such as Xpert MTB/RIF (GeneXpert), molecular type, or Susceptibility testing on AFB cultures [4]. Currently, molecular types have been working well even in low resource settings. [4]
At present, middle to low income countries face challenges in ensuring TB patients receive proper treatment, especially in remote and underdeveloped locations. The way forward now is to prevent MDR TB, and ultimately TB, by a cooperative effort between health care workers following up on patients regularly to make sure medication is taken effectively and also by patients taking the onus to make sure they complete their treatment course. Where possible, precautions should always be taken to avoid risk of infection through contact with diagnosed patients or suspected cases. Testing and diagnosis must also be done as soon as possible and local public health systems should ensure health care workers are properly trained to deal with presenting patients. The burden in low income centres can be relieved, as long as the above are carefully followed, and governments and non-profit organizations continue to support public health efforts in these centres.
References
[1] "Tuberculosis in the Western Pacific," World Health Organzation, [Online]. Available: https://www.who.int/westernpacific/health-topics/tuberculosis. [Accessed 1 August 2020].
[2] "Drug-Resistant TB," Centers for Disease Control and Prevention, 17 January 2017. [Online]. Available: https://www.cdc.gov/tb/topic/drtb/default.htm. [Accessed 2 August 2020].
[3] C. Lange, K. Dheda, D. Chesov, A. M. Mandalakas, Z. Udwadia and C. R. Horsburgh Jr., "Management of drug-resistant tuberculosis," The Lancet, vol. 394, no. 10202, pp. 953-966, 2019.
[4] "What is multidrug-resistant tuberculosis (MDR-TB) and how do we control it?," World Health Organization, 16 January 2018. [Online]. Available: https://www.who.int/news-room/q-a-detail/what-is-multidrug-resistant-tuberculosis-(mdr-tb)-and-how-do-we-control-it. [Accessed 2 August 2020].
[5] The Economist Intelligence Unit, "It's Time to End Drug-Resistant Tuberculosis: The case for action," 2019. [Online]. Available: https://www.eiu.com/graphics/marketing/pdf/its-time-to-end-drug-resistant-tuberculosis-full-report.pdf. [Accessed 2 August 2020].
[6] "$13 million to combat tuberculosis in our region," Australian Ministers Department of Health, 7 August 2019. [Online]. Available: https://www.health.gov.au/ministers/the-hon-greg-hunt-mp/media/13-million-to-combat-tuberculosis-in-our-region. [Accessed 2 August 2020].
[7] K. Viney, D. Hoy, A. Roth, P. Kelly, D. Harley and A. Sleigh, "The epidemiology of tuberculosis in the Pacific, 2000 to 2013," Western Pacific Surveillance and Response Journal, vol. 6, no. 3, 2015.
[8] "Public Health Action supplement highlights operational challenges and successes in TB programmes in Papua New Guinea," The Union, 2 October 2019. [Online]. Available: https://www.theunion.org/news-centre/news/public-health-action-supplement-highlights-operational-challenges-and-successes-in-tb-programmes-in-papua-new-guinea. [Accessed 1 August 2020].
[9] Commonwealth Health Partnerships, "Burden of TB in the Pacific: Strategic planning and public health action," 2014. [Online]. Available: http://www.commonwealthhealth.org/wp-content/uploads/2014/05/4-TB-Pacific-SPC.pdf. [Accessed 1 August 2020].
[10] J. Wu and K. Dalai, "Tuberculosis in Asia and the Pacific: The Role of Socioeconomic Status and Health System Development," International Journal of Preventive Medicine, vol. 3, no. 1, pp. 8-16, 2012.
[11] J. O'Connor, A. Wiegandt and K. Vinney, "Tuberculosis surveillance in the Pacific Island countries and territories," 2010. [Online]. Available: https://spccfpstore1.blob.core.windows.net/digitallibrary-docs/files/1c/1c1d3e688a5ae8e446a67fcd2cf19c6e.pdf?sv=2015-12-11&sr=b&sig=tafmKnAcqxegITGY5EnysI4LDItcRu4y3l1%2B%2FJT1e9A%3D&se=2021-01-31T03%3A26%3A51Z&sp=r&rscc=public%2C%20max-age%3D864000%2C%20. [Accessed 2 August 2020].
[12] "Fighting drug-resistant TB in the Pacific," World Health Organization, 18 November 2018. [Online]. Available: https://www.who.int/westernpacific/news/feature-stories/detail/fighting-drug-resistant-tb-in-the-pacific. [Accessed 2 August 2020].