Trends of Mycobacterium Tuberculosis and Rifampicin resistance in Adigrat General Hospital, Eastern zone, Tigray Region, Northern Ethiopia

Background: Tuberculosis is an infectious disease usually caused by Mycobacterium tuberculosis bacteria. The global emergence of mono- or multidrug-resistant tuberculosis and extensively drug-resistant forms of tuberculosis poses a considerable challenge to tuberculosis control programs. There has been no reliable and organized data on trends and drug resistance of Mycobacterium tuberculosis in the study area. Therefore, this study aimed to determine the trends of Mycobacterium tuberculosis and Rifampicin resistance in the Adigrat General Hospital, eastern zone, Tigray, Northern Ethiopia. Methods: A hospital-based retrospective cross-sectional study was conducted at Adigrat General Hospital from January 2015 to 2018. Data were collected retrospectively from the Genexpert TM TB registration books using a data extraction format. Data was entered into Epi-Info 3.1 and subsequently exported and analyzed using SPSS Version 20. The results were summarized using descriptive statistics, tables, and figures. P values < 0.05 were considered statistically significant. Result : A total of 5,944 Mycobacterium tuberculosis presumptive patients were included in the study. The majority of the study participants were male (58.1%) with participants’ median age of 40.0 (IQR 57, 26) years, the majority were 30-44 years. The overall positive cases of Mycobacterium tuberculosis was 24.3% (1446) with a total of 132 (9.1%) found to be resistant to rifampicin. Within the total Rifampicin resistant sub-group, 129/132 (97.7 %) were newly identified cases and the rest were previously treated, tuberculosis patients. Age, the reason for diagnosis, site of presumptive tuberculosis, and/or being HIV infected showed significant association with our dependent variable; however, only age and being HIV infected were associated with rifampicin resistance. Conclusion: In our study, the overall trends of Mycobacterium tuberculosis and rifampicin


Introduction
Tuberculosis (TB) is caused by a bacterium called Mycobacterium tuberculosis. The bacteria usually attack the lungs, but TB bacteria can attack any part of the body such as the kidney, spine, and brain. Not everyone infected with TB bacteria becomes sick. As a result, two TB-related conditions exist: latent TB infection (LTBI) and TB disease. If not treated properly, TB disease can be fatal. Tuberculosis is spread from person to person through the air. When people with lung TB cough, sneeze or spit, they propel the TB germs into the air. A person needs to inhale only a few of these germs to become infected.
Tuberculosis is curable and preventable [1 & 2]. A relatively small proportion of people infected with Mycobacterium tuberculosis will go on to develop TB disease; however, the probability of developing TB is much higher among people with immune suppression or compromise. About one-quarter of the world's population has latent TB, which means people have been infected with TB bacteria but are not yet ill with the disease and cannot transmit the disease [2].
. Tuberculosis (TB) has existed for millennia and remains a major global health problem. It causes ill-health of approximately 10 million people each year and is one of the top ten causes of death worldwide [3]. According to the Global Tuberculosis Report (2017), 10.4 million people have estimated the incidence to have all forms of TB in 2016 while an estimated 1.3 million people died from TB, excluding deaths attributed to TB/HIV in 4 combination. In addition, an estimated 4.1% of these new TB cases and 19% of the previously treated cases are believed to harbor drug resistant-TB with an estimated 240,000 deaths annually due to multi-drug resistant tuberculosis (MDR-TB) [3]. The World Health Organization (WHO) estimates that 4.5 million people are co-infected with Human Immunodeficiency Virus (HIV) and TB globally [4].
Ethiopia is among the 30 highest TB, HIV, and MDR-TB burden countries, which accounted for 80% of all estimated TB cases worldwide. Ethiopia had an annual estimated TB incidence of 207/100,000 populations and a death rate of 33  Ethiopia is implementing a comprehensive TB/Leprosy and TB/HIV control programs and has achieved a lot in the past decade. However, In Ethiopia, the case detection rate was very low using smear microscopy in the past, but in its commitment against TB, the Ethiopian government has joined the post-2015 Global TB Strategy called "END TB strategy" which will increase case detection & further reduce the burden of this disease.
To achieve these strategies Ethiopia endorsed many advanced technologies concordantly with WHO recommendations, including the implementation of the GeneXpert™ MTB/RIF assay. The assay detects Mycobacterium tuberculosis and rifampicin resistance by 5 identifying mutations using three specific primers and five unique molecular probes through a rapid (2 hour) process with minimal bio-safety requirements and training [10].
Ethiopia is one of the high burden countries, reflected both in its TB incidence and the estimated rates of MDR-TB [11]. However, there is limited information regarding the trend analysis of TB and rifampicin resistance in our study area. To date, there are no studies conducted that have reviewed documents systematically to identify the trends in Mycobacterium tuberculosis and rifampicin resistance using GeneXpert™ in Adigrat General Hospital. Therefore, this study aimed to determine the trends in Mycobacterium tuberculosis and rifampicin resistance using GeneXpert™ among TB-presumptive cases at Adigrat General Hospital, northern Ethiopia.

Study design, setting, and time
A retrospective cross-sectional study design was used to collect the secondary data from Hospital, 5 primary Hospital and 37 health centers. Adigrat General Hospital is serving as a referral for surrounding health centers and primary hospitals, and teaching center for medical and health science students. The hospital has about 120 beds and more than 250 health care providers. Adigrat General Hospital is the only hospital that testing sputum using Genexpert and treated the MDR-TB for surrounding 7 districts in the Eastern zone Tigray.

Inclusion criteria
Those who had completed data in the GeneXpert TM TB registration book were included during the study period specified.

Exclusion criteria
Those cases with indeterminate and/or invalid GeneXpert™ results were excluded from the study.

Independent variable
Sex, residence, age, co-infection, site of presumptive TB, reason for diagnosis and year of diagnosis

Operational Definition
Presumptive-TB: An individual who presents with symptoms or signs suggestive of TB like sweating, coughing more than two weeks, loss of appetite, weight loss and weakness. MDR presumptive patient: Is a patient who relapses for TB, lost to follow up patients and having close contact with drug-resistant TB infected persons.

Sample size
Retrospectively all presumptive TB patients from a Genexpert TB registration book from January 01, 2015, to December 31, 2018, were included.

Laboratory investigation
Adigrat General Hospital TB Clinic operates under the national TB-and leprosy-control program of Ethiopia, in which the diagnosis of TB is followed by GeneXpert TM MTB/RIF assay for rifampicin resistance. Samples were processed by GeneXpert TM MTB/ RIF (Cepheid) assay according to the manufacturer's manual.

Data collection
The data were collected retrospectively from TB registration books in Adigart General Hospital at The Directly Observed Treatment [short course clinic] (DOTS). Data was collected using a pre-developed checklist.

Quality of data
The quality of data was maintained by checking the completeness of necessary information; the obtained data were cross-checked and double entered and re-checked to ensure the quality of data.

Statistical analysis and interpretation
Data obtained through the checklist and laboratory test results were double entered into the Epi-Info 3.1 software. Data analysis was performed using SPSS™ 20. Descriptive analysis, frequencies, and figures were used to explain the findings. Chi-square analysis was used to correlate categorical variables. In all cases, p-values less than 0.05 were considered statistically significant.

Results
A total of 5944 presumptive TB and drug resistance TB patients was retrospectively included in this study. Among these patients, the majority were male 3455 (58.1%). The

Discussion
The WHO continues to search for innovative technologies to enhance accurate and reliable laboratory diagnosis of TB to curb Mycobacterium tuberculosis and DR-TB worldwide.
However, the emergence of drug-resistant forms of TB, which need more resources to detect, treat, and effectively reduce the burden of disease is a wicked problem.

GeneXpert™ MTB/RIF assay is a new automated real-time Nucleic Acid Amplification
Technology that overcomes many of the current operational difficulties in TB diagnosis [12].
TB affects mostly adults in the economically productive age groups with approximately two-thirds of cases estimated to occur among people aged 15-59 years [1].

Conclusion
In our study, the overall trends of Mycobacterium tuberculosis and rifampicin resistance were found to be high and gradually increasing. HIV co-infected and previously treated patients were more likely to develop rifampicin resistance. Therefore, maximizing early detection of drug-resistant Mycobacterium tuberculosis and strengthening tuberculosis infection control activities are recommended to reduce the burden of this contagious and potentially deadly disease as well as further study is needed to detect MDR-TB in the study area.

Limitation of the Study
As we collected retrospective data from Genexpert TB logbooks, we encountered data missing and incompleteness. Variables included for associated factors were also limited.

Acknowledgements
First of all we would like to thank the Research Approving and Ethics committee, which provided approval to conduct this research and Adigrat General Hospital laboratory for documented information about GeneXpert™.
We also wish to express our sincere thanks and appreciation to Dr. Chernet Gebre, Medical In the last but not the least we would like to thank for Professor Pammla Petrucka, from university of Saskatchewan Canada for revising this manuscript and English language editing.

Authors' contributions
GK conceived and designed the study, performed the analysis, interpreted data, and drafted the manuscript. BH assisted with the design, proposal preparation, data collection, performed analysis and interpretation of data, and critically prepared and reviewed the manuscript. All authors read and approved the submitted version of the manuscript.

Funding Statement
Not applicable.

Availability of data
The findings of this study are generated from the data collected and analyzed based on the stated methods and materials. All the data are found in the manuscript and there are no supplementary files. The original data supporting this finding will be available upon request through the corresponding author.

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This study was reviewed and approved by research and community service Ethical Review Board (RERB) of Adigart University, College of Medicine and Health Sciences and after discussion of the purpose and aim of the study permission was obtained from Adigrat General Hospital Chief Executive Officer and Laboratory Head to access the registration book. Written informed consent was not sought from the study participants as secondary data were used. Confidentiality of the results were maintained through anonymous data set and not communicated for other purposes.    Figure 1 Trends of Mycobacterium tuberculosis and rifampicin resistant in Adigrat General

Conflicts of Interest
Hospital, Tigray, Northern, Ethiopia