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ORIGINAL ARTICLE
Year : 2022 | Volume
: 11
| Issue : 4 | Page : 356-363
Risk factors associated to multidrug-resistant tuberculosis in patients attending the deido district hospital of Douala – Cameroon
Djuikoue I Cecile1, Ndjip Ndjock S. Alex2, Nzenya D Jolle1, Nana S Cedric1, Chounna T Noemy1, Wandji G Irene3, Mfongouot P Leila2, Ketchaji Alice4, Nguedia Assob J. Clement5, Pokam Thumamo D. Benjamin6
1 Department of Medical Microbiology and Public Health, Faculty of Health Sciences, Université des Montagnes, Bagangté, Douala, Cameroon
2 Department of Applied Health Sciences, University and Strategic Institute of the Estuary, Douala, Cameroon
3 Coastal Regional Delegation of Public Health, Regional Technical Group for the Fight against Coastal Tuberculosis, Douala, Cameroon
4 Department for the Control of Diseases, Epidemics and Pandemics, Ministry of Health, University of Buea, Buea, Cameroon
5 Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
6 Department of Medical Laboratory Science, Faculty of Health Sciences, University of Buea, Buea, Cameroon
Correspondence Address:
Pokam Thumamo D. Benjamin
Department of Medical Laboratory Science, Faculty of Health Sciences, University of Buea, P.O. Box 63, Buea
Cameroon
Source of Support: None, Conflict of Interest: None
CheckDOI: 10.4103/ijmy.ijmy_136_22
Background: Multidrug-resistant tuberculosis (MDR-TB) is defined as resistance to at least isoniazid and rifampicin. In Cameroon, the prevalence is estimated at 150 cases/100,000 inhabitants or 6000 cases out of an estimated population of 3 million. Objective: The aim of the present study was to determine the risk factors associated with MDR-TB at Deido District Hospital located in the littoral region of Cameroon. Methods: This was a cross-sectional and analytical retrospective study. Our sample included all TB patients undergoing treatment at the Diagnostic and Treatment Center of the hospital from January 2019 to August 2020. Identified risk factors of MDR-TB were analyzed using the SPSS software version 20.0. Results: A total of 304 participants were enrolled with a predominance of 185 (60.8%) men. The average age was 35 years (29–43 years). About 122/304 (40%) of the patients suffered from MDR-TB. The significant factors associated with MDR-TB were occupation (adjusted odd ratio [aOR] = 61.46), monthly income (aOR = 0.11), history of TB (aOR = 5.3), alcohol consumption (aOR = 12.7); self-medication (aOR = 5.4) and consultation of traditional healers for any cure (aOR = 155.84). Conclusion: The emergence of MDR-TB associated with several risk factors in the study area is worrisome and can be prevented by improving the living conditions of patients and putting in place appropriate treatment strategies.
Keywords: Cameroon, Douala, littoral region, multidrug-resistant tuberculosis, risk factors
Tuberculosis (TB) is an infectious disease caused by Mycobacterium TB or Koch's Bacillus. Its transmission is always direct, from the infected symptomatic pulmonary subject to a healthy one. Africa, with its 11% of the world's population, bears 27% of the global burden of TB. It is a common and fatal infectious disease despite the existence of effective treatment. Today, it represents a major public health problem on a global scale.[1] Multidrug-resistance (MDR) organisms occur when they are no longer susceptible to the two most effective anti-TB drugs, isoniazid and rifampicin.[2],[3] In developing countries, the diagnosis of pulmonary TB is mainly based on the isolation of acid-fast bacilli by the direct examination of sputum.[4] For other forms of TB (extrapulmonary), diagnosis is often difficult and late, especially when resources are limited, which is the cause of high mortality.[5] Each year, nearly 440,000 people contract MDR-TB and 150,000 people die from this form of the disease.[6] The World Health Organization (WHO) estimates 600,000 cases of resistance to rifampicin, the most effective first-line drug, of which 490,000 are MDR-TB. In 2016, 10.4 million people contracted this disease and 1.7 million died from it (of which 0.4 million also had human immunodeficiency virus [HIV]). More than 95% of deaths from TB occurs in low- and middle-income countries.[4] Cameroon was ranked 25th in the world, with a specific mortality reaching 2.89%, or 6267 deaths in total according to the WHO.[7] Despite the availability of active drugs and vaccines, the prevalence of multidrug-resistance (MDR) and extremely drug resistance has only increased these recent years.[8] Drug-resistant TB (DR-TB) is an ongoing health threat.[9] Therefore, it is necessary to determine the risk factors leading in the rise of MDR strains. Several factors over the past decade have led to the increase in the incidence of TB, particularly in Africa, and include among others the deterioration of the social conditions of the inhabitants and the mixing of populations linked to armed conflicts, the spread of HIV infection and the weak capacities of national TB programs.[10] Little attention has been paid on these factors in Douala, the cosmopolitan and economic capital of Cameroon located in the Littoral and coastal region of the country.
MethodsThis was a cross-sectional and analytical retrospective study. The sample included all TB patients undergoing treatment at the Diagnostic and Treatment Center (DTC) of Deido Hospital from January 2019 to August 2020.
Type of sampling and reasons for selection
In our study, a nonprobability sampling technique was used because our sample size was obtained using only the TB patient management register.
Both a collection form and phone calls were used to obtain data from the archives as well as missing data from participants, respectively. Participant data were analyzed using a logistic regression model (univariate and multivariate analysis) to identify the risk factors for MDR-TB. The association between the variables studied and MDR-TB was estimated by the adjusted odd ratio (aOR) and the significant P value (P) set at < 0.05 (95% confidence interval [CI]). The analysis was performed using the IBM SPSS Statistics Desktop 20.0 Windows Multilingual eAssembly (CRG2LML), IBM, 1 New Orchard Road Armonk, New York 10504-1722 United States.
Ethical approval and consent to participate
Ethical clearance (No. 2398 CEI-UDo/09/2020/M) and administrative authorisations were obtained before the start of the study from the Institutional Ethics Committee of the University of Douala and the Coastal Health Delegation respectively.
ResultsMultidrug-resistant tuberculosis prevalence among different types of tuberculosis patients
A total of 304 participants were included in the study with a predominance of 185 men (60.8%). The average age was 35 years (29–43 years). The overall prevalence of MDR-TB was 122/304 (40.1%), whereas 182/304 (59.9%) had drug-sensitive TB. Seven (2.3%) MDR patients were new cases. Relapse cases represented 9.2% (28/304), transferred 4.6% (14/304), retirees after failure 7.5% (23/304), retirees after abandonment 12.2% (37/304), and others not specify 4.3% (13/304) [Figure 1].
Figure 1: Prevalence of MDR-TB by patients TB types in the study area. MDR-TB: Multidrug-resistant tuberculosis-TuberculosisSociodemographic characteristics of multidrug-resistant patients
The most represented age group was between (29 and 43) with 133 (43.7%) participants against the (1–15) age group with 10 (3.2%). Of the 304 participants, the male was predominant with 185 (60.8%) against 119 (39.1%) female and 52 (17.1%) of the (43–57) age group had developed MDR-TB.
Majority of the 304 participants worked in the formal sector (128 [42.1%]) and the minority were retirees 2 (0.6%). The patients (63/105 [60%]) in the informal sector were four times at risk of acquiring MDR-TB (odd ratio [OR] 3.986; 95% CI 2.29–6.91; P = 0.000). Married people represented the majority with 136 (44.7%) individuals against 102 (33.5%) single ones of the 304 participants. However, the latter (50/102 (49%) group was significantly (OR 1.763; 95% CI 1.04–2.97; P = 0.034) affected with MDR-TB. Equally, of the 304 participants, 158 (51.9%) had a monthly income below the minimum wage known as the Guaranteed Minimum Interprofessional Salary-GMIS, which showed that this group of individuals was more at risk of developing MDR-TB [OR 1.607; 95% CI 1.01–2.55; P = 0.045, [Table 1]].
Table 1: Sociodemographic characteristics of multidrug-resistant patients at the study areaRisk factors of multidrug-resistant tuberculosis infection
[Table 2] shows that of the 304 participants, 224 (73.7%) consumed alcohol compared to 80 (26.3%) nondrinkers. Multidrug resistance developed in 98/224 (43.8%) of consumers compared to 24/80 (30%) of nonconsumers (OR 1.815; 95% CI 1.05–3.13; P = 0.032).
Table 2: Risk factors of multidrug-resistant tuberculosis infection among patients at the Deido District HospitalA total of 206/304 (67.7%) participants used tobacco compared to 98/304 (32.3%) of nontobacco users. Only 80 (38.8%) of the 206 smokers developed MDR-TB (P = 0.504). The same held among drug users and respondents with a history of imprisonment with 21/40 (52.5%) and 5/7 (71.4%) who developed multidrug resistance to TB, respectively [Table 2].
Comorbidities and multidrug-resistant tuberculosis association
Overall, 101 (33.2%) comorbidities were observed in the 304 participants. Eighty-four (27.6%) of the 304 were HIV infected and 33/84 (39.2%) developed MDR-TB. Seven (2.3%) of the 304 were diabetic patients, of which 4/7 (57.1%) suffered from MDR-TB. Diabetes increased the risk of developing MDR-TB by 4.3 times (OR 4.308; 95% CI 1.58–11.74; P = 0.004). Cancer patients represented 4/304 (1.3%) of our respondents and 2 (50%) of whom developed MDR-TB. Other comorbidities such as obesity, heart failure, and high blood pressure represented 6 (1.9%) of our 304 respondents with 5/122 (83.3%) being MDR-TB patients [Table 3].
Table 3: Association of multidrug-resistant tuberculosis and comorbidities in patients at the study areaTreatment follow-up and multidrug-resistant tuberculosis infection
Of the 304 participants, 194 (63.8%) had interrupted their treatment against 110 (36.2%), and MDR-TB patients represented 87/194 (71.3%) among these former group. Treatment interruption thus increased the risk of developing MDR-TB (OR 1.742; 95% CI 1.06–2.84; P = 0.027). A total of 128/304 (31.2%) did not adhered to the time of medication intake, of which 31/128 (24.2%) suffered from MDR (OR 0.299; 95% CI 0.18–0.49; P = 0.000). Amongst the 304 respondents, 166 (54.6%) had poor compliance compared to 138 (45.4%) patients and 79/166 (47.5%) patients with poor compliance had a double risk of developing MDR-TB (OR 2.006; 95% CI 1.25–3.21; P = 0.004). Reasons for the failure to adhere fully to treatment in 165 (54.3%) of the 304 patients were attributed among others to drugs adverse effects, stigmatization, and forgetfulness, of which 14/46 (30.4%); 28/50 (56%); and 1/4 (25%) were MDR-TB patients respectively. Others included lack of drugs and/or voluntary stops with 38/139 (27.3%) developing MDR-TB [Table 4].
Table 4: Treatment follow-up and multidrug-resistant tuberculosis infection among patients at the Deido District HospitalPatients' clinical characteristics and multidrug-resistant tuberculosis
Of the 304 participants, 117 (38.5%) had a history of TB of which 80 (68.3%) developed MDR-TB compared to 42 (22.4%). People with a history of TB thus had a 7.46- fold increased risk of developing MDR-TB (OR 7.465; 95% CI 4.44–12.54; P = 0.000). Having been in contact with a person infected with TB represented 91 (29.9%) of the 304 respondents, of whom 37 (40.6%) developed MDR-TB. Self-medication was practiced by 138 (45.3%) of the 304 respondents, of whom 84 (60.8%) suffered from MDR. The self-medication factor multiplied the risk of getting MDR-TB by 5.2 times (OR 5.24; 95% CI 3.18–8.62; P = 0.000). A total of 124 (40.8%) of the 304 participants admitted having consulted a traditional healer to find a cure. [Table 5] further indicates that 102 (61.4%) of those who sought care in these healers had an increased risk of contracting TB by 37.09 times [OR 37.091; 95% CI 19.27–71.36; P = 0.000, [Table 5]].
Table 5: Association of patients' clinical characteristics and multidrug-resistant tuberculosis at the Deido District HospitalMultivariate analysis of risk factors associated with multidrug-resistant tuberculosis in patients
[Table 6] obtained from the multivariate analysis shows the risk factors associated with the disease.
Table 6: Multivariate analysis of risk factors associated with multi-drug resistant-tuberculosis in patients at Deido District HospitalThe sociodemographic characteristics showed that, occupation and monthly income were linked to MDR-TB, (aOR 61.46; 95% CI 11.84–319.02; P = 0.0001/aOR 0.112 95% CI 0.02–0.45; P = 0.002), respectively. People who reached out to traditional healers in search for a cure had a 155-fold risk of developing MDR-TB (aOR 155.845; 95% CI 40.59–598.29; P = 0.000). Similarly, self-medication was a significant factor of MDR-TB (aOR 5.397; 95% CI 2.08–13.99; P = 0.001).
DiscussionTB, though preventable and curable, remains a global health problem, ranked one of the top causes of death worldwide, despite the WHOs strategies.[11] Recurrence of TB is still a major problem in high-burden countries, where there is lack of resources and no special attention is being given to this issue.[12] Despite the efforts made by the national TB control program (NTCP) in Cameroon, MDR-TB still remains a matter of concern in the country. According to the WHO in 2021, MDR-TB continues to pose a public health crisis and threat to health security. There were an estimated 500,000 new cases of rifampicin resistance in the world in 2020.[2] To overcome this problem, some measures have been undertaken by the NTCP-Cameroon, such as to provide large centres (65 DTCs) with molecular diagnostic device. Thus, all health facilities (public and private) will contribute in the active search of suspicious cases of TB across the country.[13] In our study, a prevalence of 2.3% MDR-TB was found among new cases. This is slightly below a study conducted by Meriki et al. in the Northwest and Southwest region of the country which found a 5.7% prevalence.[14] Kuaban et al. in their study in the city of Yaoundé in Cameroon found 27.7%, while other studies conducted in Ouagadougou-Burkina-Faso (2015), Lisbon and Vale do Tejo-Portugal (2012), and Zhejiang Province-China (2013) were 55.5%, 24%, and 27%, respectively.[15],[16],[17],[18]
In the present study, age and gender were not identified as risk factors. This result is similar to a Moroccan and Congolese study.[17],[18] In addition, some authors have demonstrated a significant association between the age group (35–54 years) and (19–40 years) and the male gender with MDR-TB.[19],[20]
In the Littoral region, almost half (42.6%) of MDR-TB cases occurred in the 29–43 age group. This result is in line with WHO's claim that TB mostly affects adults during their most productive years, but all age groups are at risk.[7] The predominance of adults here can be explained by the fact that they are more predisposed to the conditions of life more specifically in the search of financial stability.
A significant association was found between occupation and MDR-TB. These data agree with a study carried out in Guinea Conakry which showed that workers in the informal sector was the most affected group with 20.83%.[21] Some authors such as Pai et al. in their study conducted in India also identified occupation as a risk factor of TB.[22] Our results showed that people working in the informal sector were about 4 times at risk of contracting MDR-TB unlike retirees. This could be explained by the fact that many inhabitants in Douala, the economic capital of Cameroon, come from other regions of the country in search of a living means and stay overcrowded in slums doing menial jobs. In line with a study carried out in Burundi, occupation such as caregivers and cleaners multiply the risk of being infected with TB by seven times.[23] However, a study carried out in Morocco found no association between TB and occupation.[17]
There were 2.3 million new cases of TB worldwide in 2020 due to undernutrition, and this risk is three times greater in undernourished people.[7] In our study, MDR-TB was significantly associated with people whose monthly income was lower than the minimum wage (36,270 XAF). These results corroborate with two studies carried out in Morocco, Tunisia and India, which show that the low socioeconomic level is a risk factor of MDR-TB.[17],[24],[25] Low socioeconomic level favors the spread of MDR-TB because, despite the fact that the direct cost of treatment is not covered by the patients (treatments are delivered free of charge to all treatment centres), they bear the indirect costs linked to the duration of the treatment. Considering the little monthly income of the patients, they are even unable to get to the health facility because of lack of money for transportation.
Globally, 830,000 new cases of TB were attributed to alcohol abuse and 860,000 to smoking in 2020. Alcohol abuse and smoking increase the risk of contracting the disease by 3.3 and 1.6 times, respectively.[7] Our study found that alcohol abuse significantly increases the risk of MDR-TB, corroborating a Malaysian and Indian studies.[26],[27]
Smoking did not however increase the risk of MDR-TB in our study unlike a Bhutan study.[28] A nonsignificant association between contacts of patients with MDR-TB occurrence was equally found in this study, contrary to two observations which have shown that the risk of developing MDR-TB was associated with the presence of a contact subject with MDR-TB.[7],[17],[29] However, it should be noted that this variable was almost unknown in most of our participants.
People with a history of TB had 5.6 times the risk of developing MDR-TB. These results agree with those of Tenzin et al. whose study showed that taking anti-TB drugs in the past multiplied the risk of MDR-TB acquisition by 5 times.[28] The increase in resistance to anti-TB drugs, particularly MDR-TB, is the result of the mismanagement and misuse of anti-TB drugs during treatment. This misuse includes the administration of inappropriate doses and poor regimens (use of only one drug, poor quality of drugs, or poorly stored and premature discontinuation of treatment) added to the inability to ensure that patients complete their treatment.[7],[14] This has equally been shown in the two other studies.[17],[18]
Another reason for increase in TB drug resistance is the self-medication and the consultation of traditional healers practiced by TB patients as shown in this study with a 5.4 and 155.85 times of developing MDR-TB, respectively. Douala, the economic city of the country with an overcrowded population where everyone wants to make money by all means, have quacks and drugs hawkers deceiving patients. TB patients could have been victims or ignorant, hence contributing to the development of multidrug resistance.
Various studies and reviews reported that host factors including smoking, alcohol abuse, low body mass index, comorbidity (e.g., HIV infection, diabetes mellitus [DM], chronic renal failure, malignancy, chronic obstructive pulmonary disease [COPD], silicosis) can predispose to the development of TB. Several of these factors were associated with poor treatment outcomes (e.g., alcohol abuse, HIV infection, DM), TB relapse (e.g., HIV infection, DM) and the development of MDR-TB (e.g., alcohol abuse, HIV infection, DM, COPD) significantly. Coexisting diseases are continuously being identified as a vital factor in the control of TB. It is believed that the improvement of the host's health status, both timely identification and effective treatment of comorbidity, may alleviate the development of TB and reduce the spread of DR-TB.[12],[30] Our observations corroborate with other studies who found significant associations between MDR-TB and co-morbidities such as HIV and diabetes.[17],[27],[31]
This result is consistent with a systematic review and meta-analysis in which HIV was associated with an increased pooled relative risk of unsuccessful treatment outcome in MDR-TB patients,[32] contrary to two previous studies who found no significant difference in people with HIV or diabetes.[3],[33] A study in Dubai-United Arab Emirates (2020) instead identified diabetes as a risk factor of TB drug resistance, but failed to find a significant association between HIV co-infection and TB drug-resistance.[34]
ConclusionOur study has shown that MDR-TB still represents a major public health problem in the littoral region of Cameroon and in the city of Douala. The 23–43 years' age group was the most affected with a predominance of men. Singles, people working in the informal sector and those with an income below the minimum wage were the most exposed to MDR. MDR-TB was found associated with risk factors such as monthly income, previous TB infection, alcohol consumption, self-medication, and consultation of traditional healers for any cure. However, sociodemographic conditions and poor treatment management were the main risk factors found. The emergence of MDR-TB in the study area as well as within the country can be prevented by improving the living conditions of the patients and putting in place appropriate treatment strategies.
Limitations of the study
The treatment records of TB patients in the study area were not complete and as such, some data on the various potential risk factors were not fully assessed. Equally, some patients' information such as distance from the health facility and their household, as well as different adverse events related to first-line anti-TB treatment leading to treatment discontinuation were unavailable. Moreover, the retrospective aspect of the study did not allow the assessment of patients' knowledge of MDR-TB.
Acknowledgments
We appreciate the guide and contributions of the director of the Regional Technical Group and her team, as well as all DTCs staff at Deido District Hospital.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
References
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