Control of Tuberculosis - Research Paper Example

Introduction Tuberculosis is in the forefront of infectious disorder epidemiology. Though tuberculosis was contemplated not a serious health problem,the disease is not yet virtually died out. As the global environment is changing at fast pace, the paths of disease transmission are also varying and therefore, offering more challenges when international eradication is concerned. To control tuberculosis two important tools are: knowledge of epidemiology, and good management. The control of tuberculosis has posed varied problems in the past decades. In commissioning and contracting for this contagious disease, several management issues have to be considered. Technical and financial amenities should be used by the developed countries to prevent resurgence of this infectious disease. The people who do not want to follow preventive education are the most vulnerable to risk factors. To reduce the enormous global burden and long-term goal of better control of this communicable disease, there is a need for international surveillance. The pathogen Mycobacterium tuberculosis is responsible for tuberculosis (TB). The person carrying the dormant tuberculosis germs is prone to tuberculosis, if they become active and multiply. The dormant state of infection in the body is refereed as ‘latent TB infection’ (O’Donoghue 2006). Then, the infection can be easily transferred to the other person in contact with the individual carrying the disease. This is an airborne disease and people exposed to infected droplet nuclei get easily infected. It spreads through activities like cough, sneeze, laugh, sing etc. of the disease carrying person. It has been estimated that around 33% of world population is infected with tuberculosis germs. It has been reported that about 9 million people can suffer from tuberculosis disease in a year. The disease is most prevalent in resource-limited countries, but since it has not yet been completely uprooted, the chances of outbreak of the disease in other countries including United States can not be neglected (LoBue, Sizemore, & Castro 2009). When the tuberculosis infection in the person gets successfully treated, it is referred as ‘primary tuberculosis’. This cured person still contains noninfectious, but live mycobacterium. This ‘primary inactive tuberculosis’ could follow one of the three paths in the future. It might remain inactive throughout the life span of the infected person, or it might develop into ‘active tuberculosis’ from its own infection, or the same person might get exposed to new infection called ‘reinfection tuberculosis’ which would have again above two possibilities (Jekel, Katz & Elmore 2001). HIV infected individuals not only have high chances of developing TB infection, but also are the most vulnerable people to develop active TB disease, making TB and HIV a deadly combination (Palomino, Leão, & Ritacco 2007). State of knowledge The disease Tuberculosis has undergone many transformations over human history. Tuberculosis is also referred as the white plague, wasting diseases or consumption. Until the mid-1800s, it was assumed that Tuberculosis was genetic disorder. People were not aware of its air borne character and its infectious power. It was observed in 1865 by a French surgeon that TB was a communicable disorder. The pathogenic organism of tuberculosis was discovered in 1882. The people were unaware until 1950s of the fact that tuberculosis person might be able to lead healthy life in the future, if properly treated. People diagnosed with tuberculosis were admitted to unpolluted atmosphere of sanatoriums and special rest homes. They were assigned daily activities. It remained unclear about the real utility of sanatoriums. The people, who were uncomfortable due to cost factor of sanatorium, expired at home. In 1943, an American scientist, Selman Waksman, was found out a treatment to destroy tuberculosis pathogen. Then, in a decade two more drugs were discovered. This innovation helped many tuberculosis patients to recover. These breakthroughs decline the mortality rate in the United States. It was thought an ultimate treatment for tuberculosis, and the death rate was continuously decreasing with the years. Most tuberculosis sanatoriums were shut down by the mid-1970s. It was thought that within two decades the disease would die out or get completely eradicated effortlessly. But it was a complete shock when resurgence of the tuberculosis was found in the mid-1980s. There was a dramatic increase in TB patients until 1992. The multi drug resistant cases were also on rise. WHO announced TB a global public health crisis in 1993. The upsurge in communicable disease was attributed to several factors like HIV epidemic in 1980s, aging of the world population, immigration to developed countries from countries where TB is common, the spread of TB in certain settings (for example, correctional facilities and homeless shelters), change in social structure and inadequate funding for TB control and other public health efforts i.e. deterioration of health care system (Dias-Baptista et al 2008). Then it was realized that there was a need for genuine preventive measures by health departments and other organizations to prevent and control the disease. The pandemic had given rise to international surveillance. Then the states created modern TB detection labs. US Centers for Disease Control and Prevention (CDC) supplemental funding for lab was increased. Then, from 1993 onwards the rate of infected TB patients began to fall. This decline could be directly attributed to augmented federal resources for TB control and other public health efforts. Innovative TB prevention and TB control programs in state and local health departments were established. The patients were monitored through directly observed therapy (DOT) to get complete drug treatment. A timeline of major events in the history of TB is shown in Figure 1. The history clarifies that since the disease has not yet been completely uprooted; long-term goal of better control of this communicable disease is a necessity. Figure 1 Timeline of major events in the history of TB (http://www2.cdc.gov/phtn/tbmodules/modules1-5/m1/con4.htm) Methods used for control The deadliest disease tuberculosis causes 2 million deaths annually. The figure is indicative of 7% TB deaths, if all the deaths globally are considered. Out of this more than 25% deaths could be prevented. TB infected individual can transmit the infection to almost 10 to 15 other people annually (Johnson 2009).To control this potential source of pathological infection and reduce public-health burden, proper measures have to be taken. Policies and Programs The objective of World Health Organisation (WHO) policies is to offer clear guidance to successfully handle all TB patients (adults and children, new and retreatment cases, sputum smear-positive and smear-negative, pulmonary and extrapulmonary). The main strategy established by WHO is termed as DOTS (Directly Observed Treatment Strategy). The aim of this strategy is to resist the development of drug-resistance. DOTS ensures that patient’s compliance is directly observed to achieve reliable results of the treatment with complete efficacy. WHO policies emphasis on Global Partnership to Stop TB. This has to be accomplished through working together of various TB control groups, synergistic efforts of all stakeholders in tuberculosis control to ensure worldwide accesss to effective implementation of DOTS care, and to investigate novel tuberculosis techniques (new drugs, vaccines and advanced diagnostic methods) (Maher, Blanc, & Raviglione 2004). TB control programs are designed to arrest and prevent spread of TB, prohibit emergence of drug resistant TB; and reduce mortality rate, disability, illness, distress, emotional trauma, family disruption, and social discrimination (Connecticut Department of Public Health 2009). The tuberculosis control Program is broadly separated into two functional parts: surveillance and prevention. Active disease reporting, collection, and interpretation of data and monitoring of mycobacteriology laboratory reports come under surveillance activities. Prevention methods comprises of supporting targeted testing, providing medications, professional education, and consultation (Copyright Iowa Department of Public Health, IDPH). The principle approach to prevent and Control TB in the United States is explained below (Taylor, Nolan, & Blumberg 2005). It is categorized into four strategies. Early diagnosis coupled with a rapid assessment of TB infectious patients is the first step to control TB. The clinical manifestation shown by the patients should be detected fast before the disease progresses by primary health care providers. Detected TB cases should be reported to jurisdictional public health agency for surveillance purposes. This facilitates early intervention treatment plans and case-management services. In the second step, the close contacts of TB patients with other individuals are avoided to control transmission of TB infection and disease. Contact evaluation is an important technique to detect further cases of TB disease and recognition of early stages of latent tuberculosis infection. In the next step, appropriate action should be taken to prevent TB infection turn into TB disease in latent TB infection population. This is achieved by targeted testing and administration of a curative course of treatment in TB germs carrying patients. For increasing targeted testing and treatment of infection carrier individuals, the issue is addressed in two ways. Firstly, high risk patients such as human immunodeficiency virus (HIV) infected or diabetes mellitus patients should be tested for TB infection (Taylor, Nolan, & Blumberg 2005). Secondly, task oriented programs should be enacted. The task is to reach the persons who have an increased prevalence of dormant TB infection and/or an increased risk for developing active disease in infected persons. The last step is to decrease TB cases from recent pathogenic transmission. The new settings (correctional facilities, homeless shelters, bars, newly recognized social settings etc.) as well as known settings which are most vulnerable to infection are recognized and effective infection control measures are implemented to reduce the TB risk burden (Taylor, Nolan, & Blumberg, 2005). This method of control was used in US during the 1985-1992, when reemergence of TB outbreak was there. TB morbidity caused due to transmission of TB bacteria continues to be a prominent part of the epidemiology of the disease in the United States. Implementation of Institutional infection-control measures in health care facilities in 1990s had a positive outcome during 1985-1992 TB outbreak (Taylor, Nolan, & Blumberg 2005). Effective implementation and success of the TB control programs in many developing countries is necessary in addition to socioeconomic conditions, technology and policy. Treatment First drug discovery for the treatment of TB is an antibiotic streptomycin in 1947, followed by isoniazid (1952) and p-aminosalicylic acid, led to progress in the direction of chemotherapeutic treatment. The development of new drugs and preventive measures delivered better results in terms of declining TB infected population and associated mortality. The treatment has multimodal approach which includes curing the TB patient, preventing mortality from active TB or latent infection, preventing relapse of TB, reducing the chances of transmission, and preventing the development of resistance. The treatment should prevent the selection of resistant bacilli in infectious individuals. Antituberculosis drugs could exhibit bactericidal activity, sterilizing activity, and the ability to prevent resistance. Recently WHO introduced the standard chemotherapy regimen to combat TB on a global scale. This consists of a short-course combination therapy inclusive of four anti-TB drugs. The treatment is given as per DOTS strategy (Dias-Baptista et al. 2008). Essential antituberculosis drugs are tabulated in Table 1 with their recommended dosages. First line treatment drugs are isoniazid, rifampicin, Pyrazinamide and streptomycin etc. Bactericidal drugs isoniazid and rifampicin act on all types of TB pathogenic bacilli. Rifampicin has the most potent sterilizing activity. Pyrazinamide and streptomycin act on mycobacteria within the macrophages. Streptomycin inhibits the growth of rapidly multiplying bacilli. Ethambutol (bacteriostatic) and thiocetazone prevents emergence of resistant bacilli. The drugs used for Second line treatment are mostly expensive and includes, para-aminosalicylic acid, Ethionamide, Cycloserine, Capreomycin, Kanamycin. The extrapulmonary TB patents are operated and also corticosteroids are prescribed (Alves-Dunkerson & Dunkerson). Table 1 Essential Antituberculosis drugs (WHO, 2004) Prevention The objective of primary prevention technique is reducing an individuals susceptibility to disease by teaching people, vulnerable groups and health care providers about the TB disease and transmission. To reduce propagation of TB, legislative, political, and cultural factors are considered to fund educational programs and improve living conditions of the most vulnerable population. Financial and nutritional back up, HIV counseling, and to reduce obstacles in TB prevention and treatment programs are also considered very important issues (Alves-Dunkerson J. & Dunkerson D.). Bacillus Calmette Guerin (BCG) vaccine is prepared from live attenuated mycobacterium. Cost effective BCG is used for primary prevention of tuberculosis in most of the developing countries except United States. It is mostly administered to infants and children; and gets protection for around 5 to 10 years once injected. But since its protection capacity is not 100%, BCG vaccine is not usually used in US. BCG vaccinated individual might also give false positive tuberculin test. People who had this prophylactic vaccine in the past for about more than 10 years could become again susceptible to TB infection. They could have a positive TB test indicating TB infection (James F. Jekel, David L. Katz, Joann G. Elmore, 2001). In the secondary prevention method, screening methods are employed and then diagnostic tests are executed to check the TB infection. Here, preventive therapies are employed mainly to prohibit inactive TB infection to turn into active TB disease. If Purified Protein Derivative (PPD) reaction is >15 mm, the patient has TB infection. Isoniazid administered for 6 month in inactive primary tuberculosis patients could reduce chances of reactivation tuberculosis by 50%. For HIV patients the therapy might continue for a year. US public health service employs use of isoniazid treatment for positive tuberculin test patients who are under 35 years. Directly observed prevention therapy (DOPT) is followed to check for patient’s compliance to take the medicine as per the prescription and observe possible side effects of the treatment. If the patient is resistant to one drug then drug strategy is changed, and combination therapy approach might be followed. Suspected multi drug resistant TB patients are tested and treated in negative pressure rooms in the hospitals to prevent transmission of resistant strains. In the tertiary prevention methods, patients with active TB disease are treated with standard antituberculosis agents. Special precautionary measures are employed to isolate infectious individual from transmitting TB to others (Alves-Dunkerson J. & Dunkerson D.). In the institutions, special multitude precautionary TB prevention measures should be taken. Primary prevention method comprises of prohibition of overcrowding, maintenance of good ventilation, setting up ultraviolate radiation wherever possible to kill mycobacteria in the surrounding. The secondary methods of prevention are chest X-ray and tuberculin skin testing. The tertiary methods of prevention consist of combination therapy, DOT therapy, and use of negative pressure rooms (James F. Jekel, David L. Katz, Joann G. Elmore, 2001). Weakness and improvements Inspite of such developments in drug treatment and strategies tuberculosis is still considered as dreaded disease. This is based on the evidence of the WHO reported TB cases. Drug-resistant tuberculosis and virulent strains has offered unmet challenges with little assistance from the recent drugs. Dr. Margaret Chan, the director-general of the World Health Organization has expressed worry about the uncontrollable future of TB. Age old diagnostic tests are used to detect TB infection. 85 year old BCG vaccine is still in use without any recent introduction of new TB drugs in the market. Once considered miracle drugs (40 years old) are becoming increasingly ineffective due to their misuse, improper use, large number of tablets for long duration to be taken at one time, and patient’s noncompliance to the dosage regime. The outbreaks of antimicrobial resistance are most common in India, China, Russia, South Africa and Bangladesh. It is worrisome that extensively resistant pathogens giving rise to extensively drug-resistant tuberculosis (XDR-TB) are not responding to two primary anti TB drugs (isoniazid, rifampicin) and not even more expensive second-line drugs like fluoroquinolones and at least one of three injectable second-line drugs used to treat TB (amikacin, kanamycin, or capreomycin) (LoBue, Sizemore, & Castro 2009). By the end of 2007, this devastating epidemic with fatal strains has spread to 54 countries. Chinas Ministry of Health has introduced innovative pilot program for TB prevention to reduce pill intake, encourages doctors to monitor TB patients by giving incentives and funding for novel TB diagnostic tests. Old diagnostic methods like specimen handling, smear staining, adenosine diaminase activity, culture identification etc. might get replaced with new sophisticated diagnostic tools like automated culture methods, nucleic acid amplification methods, gentic identification methods, nonconventional phenotypic diagnostic methods (Palomino, Leão, & Ritacco 2007). Sending messages to patient’s mobile, medicine kits with built-in reminder alarms are also novel ideas to improve patient’s compliance. New high risk settings should be found out to implement effective TB preventive and control measures (Johnson, 2009). WHO has plans to seriously target elimination by 2050 and it necessitates use of novel drug therapies. WHO’s new Stop TB Strategy based on DOTS, Stop TB Partnerships and the International Standards for quality tuberculosis care are new strategies in direction of hope to fight TB globally. The Global Plan (2006–2015) to stop and eliminate TB is in the right direction; and 27 medicines, 15 diagnostics and 8 vaccines are in the production pipeline at various stages ranging from product development to clinical trials. Successfully clinically approved drugs should immediately come into the market with fast licensing, adoption. “Retooling” process would help for widespread use of new tools and treatment strategies. Recognition of the critical delay factors for adoption and implantation of new tools is also considered one of the important factors for immediate effect. This improved quality care would also address the changing nature of the epidemic and to meet the requirements of most vulnerable communities with or at risk of TB. A task force on retooling is established to monitor and accelerate the development of new tools, drugs and vaccines (recombinant BCG vaccine), to plan framework to improve participation of policy-makers and practitioners at global and national levels for introduction of new improved TB treatment strategy, and to enhance fruitful interaction among all working groups about retooling (WHO, 2007). Conclusion Tuberculosis is in the forefront of infectious disorder epidemiology. TB control programs are designed to arrest and prevent spread of TB, prohibit emergence of drug resistant TB; and reduce mortality rate, disability, illness, distress, emotional trauma, family disruption, and social discrimination The treatment has multimodal approach which includes curing the TB patient, preventing mortality from active TB or latent infection, preventing relapse of TB, reducing the chances of transmission, and preventing the development of resistance. Inspite of developments in drug treatment and strategies tuberculosis is still considered as dreaded disease. Drug-resistant tuberculosis and virulent strains has offered unmet challenges with little assistance from the recent drugs. The coordinated efforts of local, state, and federal action with synergistic national strategy and availability of ample resources can deliver dramatic reduction in tuberculosis cases at the end of this century. The Global Plan (2006–2015) to stop and eliminate TB is in the right direction; and 27 medicines, 15 diagnostics and 8 vaccines are in the production pipeline at various stages ranging from product development to clinical trials. Recognition of the critical delay factors for adoption and implantation of new tools is also considered one of the important factor for immediate effect. WHO’s new Stop TB Strategy based on DOTS, Stop TB Partnerships and the International Standards for quality tuberculosis care are new strategies in direction of hope to fight TB globally. References LoBue, P. Sizemore, C. & Castro K. G. (2009) Plan to Combat Extensively Drug-Resistant Tuberculosis Recommendations of the Federal Tuberculosis Task Force. February 13, 2009 / 58(RR03); pp1-43. Palomino, J. C. Leão, S. C. Ritacco, V. (2007) Tuberculosis: From basic science to patient care. www.TuberculosisTextbook.com, First Edition. O’Donoghue, C. (2006) Guide to Surveillance, Reporting and Control, Massachusetts Department of Public Health, Bureau of Communicable Disease Control, Tuberculosis, 2nd edition, June 2oo6, pp. 869-877. Copyright Iowa Department of Public Health, (IDPH), Tuberculosis Control Program, www.idph.state.ia.us/adper/tb_control.asp Department Of Health And Human Services, Centers for Disease Control and Prevention, (CDC) Transmission and Pathogenesis of Tuberculosis: History of TB, Module1, p. 4 http://www2.cdc.gov/phtn/tbmodules/modules1-5/m1/con4.htm I. M. F. Dias-Baptista et al. (2008) Trends In Multidrug-Resistant Tuberculosis, J. Venom. Anim. Toxins incl. Trop. Dis., 14 (2), 2008, pp. 203-223. Johnson, T. (2009) Drug-resistant TB may ‘spiral out of control, U.N. says, McClatchy Newspapers. Posted on Wednesday, 04.01.09. http://www.miamiherald.com/news/world/AP/story/979014.html Taylor, Z. Nolan, C. M. & Blumberg, H. M. 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Blanc, L. Raviglione, M. (2004) WHO policies for tuberculosis control, The Lancet, 363 (9424), 5 June 2004, p. 1911. Alves-Dunkerson J. & Dunkerson D. The dental learning network, Chapter 8: Prevention and Treatment of Tuberculosis http://www.dentallearning.org/course/fde0014/c8/index.htm. Read More