By Kareen Atekem, MPH
[dropcap type=”circle” color=”#FFFFFF” background=”#8C212A”]T[/dropcap]uberculosis (TB), a disease caused by the organism Mycobacterium tuberculosis, and transmitted through infectious droplets, remains one of the world’s deadliest communicable diseases. According to the latest WHO data on TB published in May 2014, Cameroon was ranked 25th in the world, with TB related deaths reaching 2.89%, or 6,267 in total. According to the Cameroon National Tuberculosis Strategic Plan for 2010-2014, the population aged fifteen to forty-four years (the economically active group) is the one most affected by TB. Per WHO guidelines, treatment of TB requires a period of six months whereby patients are required to take three to four drugs on a daily basis. Given the need to take so many pills, some patients may miss the requisite times for drug intake and appointment dates for drug collection at treatment centers, thereby leading to treatment interruption, relapse, and, worst of all, drug resistance. Anti-tuberculosis drug resistance is considered a public health challenge and a major obstacle in the fight against TB in Cameroon, the major problem arising from multidrug-resistant tuberculosis (MDR-TB).
Anti-TB Drug Resistance Burden in Cameroon
Globally, 3.5% of new TB cases and 20.5% of previously treated cases are estimated to have MDR-TB (WHO, 2014). In 2012, an estimated 450,000 people developed MDR-TB, and there were an estimated 170,000 deaths from MDR-TB. Meanwhile, in 2013, there was an estimated increase of 480,000 new cases of MDR-TB worldwide, and a further increase of approximately 210,000 deaths from MDR-TB. According to the study Drug Resistance in Africa by Alwyn Mwinga, Cameroon recorded the second highest drug resistance in patients with no history of prior treatment with 38.1%, following Ghana with 54.5%. The prevalence of MDR to TB drugs in a study in Yaoundé by Kuaban et al, was observed to be 27.6%. Furthermore, the prevalence of resistance to at least one anti-TB drug was 27.7%, and multi-drug resistance was 5.9% in a study conducted in the North West and South West regions of the country (Meriki et al., 2013).
Economic Burden of Tuberculosis Drug Resistance
The emergence of MDR-TB is of great concern because it requires the use of second-line drugs that are difficult to procure, and are much more toxic and expensive than those of the first-line regimen (Espinal et al., 2001). The economic cost is not directly borne by the patients; treatments for TB is delivered free of charge at all treatment centers. However, patients encounter indirect costs such as extended periods of treatment (an intensive phase lasting a minimum of eight months with total treatment duration of at least twenty months). The Global TB Report for 2014 indicates there has been a marked increase in funding for MDR-TB, most notably proceeding 2009. The cost-per-patient treated for drug-susceptible TB was generally in the range of US $100 ? $1,000, and for MDR-TB, the cost-per-patient treated ranged from an average of US $9,235 in low-income countries, to US $48,553 in upper middle-income countries. The average cost of first-line drugs to treat drug-susceptible TB was US $46, compared to a much higher average cost of US $5,240 for second-line drugs required to treat a patient with MDR-TB. By the end of this year, 2015, about 20% of the US $8 billion required by low and middle income countries for TB care and control will be needed for MDR-TB treatment, a 0.6% increase of funding available for 2013 (WHO 2013 update on MDR-TB).
The increase in TB drug resistance, particularly MDR-TB, is a result of the improper use of anti-TB drugs during the treatment course of TB patients with drug-susceptible strains. This improper use includes the administration of inappropriate treatment regimens and failure to ensure that patients complete the full course of treatment. Hence, WHO urges the use of DOTS (directly observed treatment, short course) as a priority for effective TB control, and as a means of reducing the development of drug resistance. Health personnel working at treatment centers have to administer and directly observe patients swallowing their drugs before leaving the treatment center. Unfortunately, this is not done in most of the treatment centers due to shortage of healthcare personnel, and the fact that a good number of TB patients come to collect their drugs on a daily basis following their appointment dates.
The government has put some tools into place to curb the disease. This is the case of the National Tuberculosis Control Program (PNLT), established in 1996, whose aim is to fight TB, reduce its incidence and prevalence through training and staff supervision, and to design, monitor, and provide tuberculosis data collection and reporting tools. The PNLT program also provides anti-TB drugs, laboratory supplies, and microscopy to district hospitals.
Surveillance – A Major Challenge
Surveillance of MDR-TB through data reporting and public awareness has been a challenge to the program. Cameroon has no data on national drug resistance surveillance. The Ministry of Public Health, in collaboration with District Health Services, need to improve the availability of data and estimates of trends in MDR-TB, both important aspects to battling anti-TB drug resistance. This collaborative effort will support and strengthen the capacity for surveillance and health system strengthening. Additionally, critical health system challenges such as: limited number of treatment centers, poor access to diagnostic and treatment services, shortage of health personnel, weak-to-ineffective systems of patient follow-up during treatment, and the interrupted supply of anti-TB drugs significantly hinder efforts to identify and effectively treat drug-resistant TB cases.
Conclusion and Proposed Solutions
In conclusion, anti-TB drug resistance ranges from a single drug-resistant TB, to MDR-TB, as well as the extensively drug-resistant TB (XDR-TB), that has resistance to some of the most effective anti-TB drugs. Extensively drug-resistant TB arises after the mismanagement of individuals with MDR-TB, and is associated with a much higher mortality rate than that of MDR-TB; a result of a reduced number of effective treatment options. The key actions to combat the drug-resistant TB problem in Africa (Cameroon inclusive) include developing and up scaling programmatic management of drug-resistant TB, establishing laboratory-based surveillance systems, and implementing TB infection control measures to diagnose and monitor MDR and XDR TB. Inaction in establishing strong TB programs with sound policies for drug-resistant TB may lead to a new epidemic with serious consequences for public health.
The WHO has seen the need to assess the nine-month Bangladesh regimen in other settings following the outcome of the clinical trial on the evaluation of a standardized treatment regimen of anti-tuberculosis drugs for patients with multi-drug resistant tuberculosis (STREAM) in Bangladesh (Nunn et al., 2014). The STREAM is a multi-center randomized trial design comparing a nine-month regimen to the treatment currently recommended by WHO (fourteen to twenty months). The reduced length of the treatment regimen would reduce the challenges of MDR-TB treatment for both patients and health systems, thereby producing better results.