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Challenges of Tuberculosis in Iran


1 Infectious and Tropical Disease Research Center, Tabriz University of Medical Sciences, Tabriz, IR Iran
2 Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, IR Iran
3 Drug Applied Research Center, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, IR Iran
*Corresponding author: Hossein Samadi Kafil, Assistant Professor, Drug Applied Research Center, Faculty of Medical Sciences Tabriz University of Medical Sciences, Tabriz, Iran. Tel: +98-9127184735, Fax: +984133364661, E-mail: Kafilhs@tbzmed.ac.ir.
Jundishapur Journal of Microbiology. 10(3): e37866 , DOI: 10.5812/jjm.37866
Article Type: Review Article; Received: Apr 21, 2016; Revised: Jan 12, 2017; Accepted: Jan 18, 2017; epub: Feb 1, 2017; collection: Mar 2017

Abstract


Background: Despite the implementation of the national control program, tuberculosis is one of the greatest health problems in Iran. The prevalence of different strains in specific ethnic populations suggests that Mycobacterium tuberculosis transmission has been limited and restricted to close contact.

Objectives: In the present review, we describe the epidemiology of tuberculosis in Iran.

Methods: In this review article, databases including Scopus, PubMed, and Google scholar were used to search for the epidemiology of tuberculosis in Iran.

Results: Since 1996, tuberculosis incidence has been decreased as the national tuberculosis control program was established in Iran. However, due to the emergence of drug-resistant strains, recurrence of the disease, and association of tuberculosis with HIV pandemic, tuberculosis is becoming a health problem in Iran like many other parts of the world. Moreover, several other factors such as poverty, homelessness, inadequate access to health services, and lack of infrastructure in public health play an important role in worsening the situation. The distribution of the disease is not similar in all parts of Iran and it is higher in the western and eastern parts than the central areas.

Conclusions: Review of the studies revealed that levels of multidrug-resistant tuberculosis among new tuberculosis patients are increasing in Iran and the vaccination system needs to be reformed. Because of the increasing number of patients coming from neighboring countries with multidrug-resistant tuberculosis, this area needs more stewardship and control in order to prevent the outbreak of multidrug-resistant tuberculosis. Finally, by improving the healthcare system, it is trusted that a more noteworthy number of these patients will be cured in Iran.

Keywords: Epidemiology; Surveillance; Multidrug resistance; Mycobacterium tuberculosis

1. Background


Tuberculosis has claimed its victims throughout the history. Tuberculosis’s notoriety as one of the the most important bacterial terrors of humanity alongside typhoid, typhus, plague, cholera, and diphtheria has led to descriptors such as “the captain of all those men of death” and “great white plague”. More than a decade after the declaration of world health organization (WHO) about the global health emergency of tuberculosis, it is still a major health concern worldwide (1). Tuberculosis occurs in every nation all around the world; but, the most noteworthy frequency is found in Africa and Asia, while lately, it has re-emerged as a major public health issue in Russia and other eastern European nations (2).


Considering the importance of tuberculosis, especially in developing countries such as Iran with a large number of Afghan immigrants, changes in age range, and growing population, it is necessary to acquire comprehensive information about this disease in order to adopt appropriate control strategies and achieve WHO’s goals. This type of information may include drug resistance, outbreak rate, underlying factors such as smoking and diabetes, socio-cultural factors, and mortality rate. Other factors that play an important function in the spread of tuberculosis are age, male gender, homelessness, immigration, asthma, smoking, family history of close contact with tuberculosis or human immunodeficiency virus (HIV) patients, making the outbreak of tuberculosis more likely in the impoverished provinces. We believe that the present review can provide comprehensive information regarding the epidemiology of Mycobacterium tuberculosis infection in Islamic Republic of Iran.

2. Objectives


In the present study, we describe the epidemiology of tuberculosis in Iran. In this review article, Scopus, Pubmed, and Google scholar databases were used to study the epidemiology of tuberculosis in Iran.

3. Evidence Acquisition


In the literature review process, Scopus, Pubmed, and Google scholar databases were searched to study the epidemiology of tuberculosis, drug resistance, molecular epidemiology, multidrug-resistant tuberculosis, and HIV/tuberculosis co-infection in Iran.

4. General Status of Tuberculosis in Iran


With close attention to the fact that tuberculosis is still one of the biggest killers among the infectious diseases, Iran, like other countries of the world, uses a live attenuated vaccine [Bacille Calmette-Guerin (BCG)] and several antibiotics, which are essential to gain better understanding of the pathogenicity and virulence factors of M. tuberculosis (3). Due to the introduction of vaccination program in 1988 to immunize all children at birth, the incidence of tuberculosis in Iran reduced from 20,308 cases in 1990 to 15,545 cases in 2006 as well as the mortality rate declined from 2,358 cases to 1,839 cases per year. In addition, a comprehensive review has been conducted in Iran on directly observed therapy short-course (DOTS) program, and surveillance and laboratory quality assurance involving healthcare providers for controlling tuberculosis have been strengthened as well (4). The aim of this program is to be ascertained of patients’ adherence to therapy by observing them to swallow each dose of medication (5). However, one important problem in carrying out the DOTS strategy by healthcare workers is the inconvenience of the patients in terms of obtaining the drugs from a health center frequently a week. Therefore, the performance of this strategy under the control of family members could be an alternative (5).

5. Incidence and Prevalence


The distribution of tuberculosis is not uniform; the incidence and prevalence of the disease are higher in the regions near the borderlines and lower in the central parts of the country (Figure 1). The borderline areas of Iran including the provinces of Sistan and Baluchestan, Golestan, Khorasan, East Azerbaijan, West Azerbaijan, and Kurdistan are endemic regions by giving 10% - 13% multidrug-resistant isolates among 141 TB cases per 100,000 (6).


Figure 1.
A General View of the Prevalence of TB in Different Parts of Iran

It is currently estimated that over 2 billion people worldwide are exposed to M. tuberculosis, with over 8.7 million new infections in 2012, leading to 2.5 to 3 million cases of mortality per year; this makes tuberculosis the foremost cause of death by infection (7). In Asia, it is not exactly known when tuberculosis initially spread. However, the prevalence of the disease in the continent was high until the end of the nineteenth cent