The Pathogen Mycobacterium Tuberculosis - Research Paper Example

Tuberculosis Tuberculosis Tuberculosis (TB) is in the forefront of infectious disorder epidemiology. Though tuberculosis was once a serious health problem, the disease has not yet died out. As the global environment is changing at a fast pace, the paths of disease transmission are also varying and therefore, offering more international eradication challenges. To control tuberculosis two important tools are the knowledge of epidemiology and good management. The control of tuberculosis has posed varied problems in the past decades. Consideration in commissioning and contracting for this contagious disease requires several management issues. Technical and financial amenities by developed countries are available for use 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 the germs become active and multiply. ‘Latent TB infection’ (O’Donoghue, 2006), is the dormant state of infection in the body. Those with latent infection can easily transfer the disease to another person through contact. Ease of infection of this airborne disease is caused by exposure to infected droplet nuclei. It spreads through activities such as cough, sneeze, laugh, singing, etc. of the disease-carrying person. Approximate estimated figures show that the incidence of TB effects around 33% of world population. Reports show that about nine million people can suffer from tuberculosis disease in a year. Resource-limited countries have the highest prevalence of the disease and because it has not yet been completely uprooted, the chances of outbreak of the disease in other countries including the U.S. cannot be (LoBue, Sizemore, & Castro, 2009). In the “primary tuberculosis”, the patient can recover completely. 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’ (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 to as the white plague, wasting diseases, or consumption. Until the mid-1800s, it was assumed that Tuberculosis was a genetic disorder. People were not aware of its airborne character and its infectious power. In 1865, a French surgeon theorized that TB was a communicable disorder. In 1882, the scientist reported the pathogenic organism of tuberculosis. The public was unaware until the 1950s that a tuberculosis-infected person might be able to lead a healthy life in the future, if properly treated. Prior to that time, people diagnosed with tuberculosis were admitted to the unpolluted atmosphere of sanatoriums and special rest homes. The people, who were uncomfortable due to the cost factor of sanatorium, expired at home. In 1943, an American scientist, Selman Waksman, found a treatment to destroy the tuberculosis pathogen. Then in the next decade, scientists discovered two more drugs. This innovation helped many tuberculosis patients to recover. These breakthroughs decline the mortality rate in the United States and the death rate continuously decreased. Most tuberculosis sanatoriums were shut down by the mid-1970s. The WHO thought that within two decades the disease would die out or get completely eradicated effortlessly. Complete shock ensued when resurgence of tuberculosis was found in the mid-1980s and there was a dramatic increase in TB patients until 1992. The multi-drug resistant cases of TB were also on rise. The World Health Organization (WHO) announced a TB global public health crisis in 1993. The upsurge in communicable disease in United States was attributed to several factors such as: the HIV epidemic in the 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, inadequate funding for TB control and deterioration of health care system (Dias-Baptista, 2008). Then public health agencies understood 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. The agencies created modern TB detection labs with the supplemental funding from Center for Disease Control and Prevention (CDC). From1993 onwards, the rate of infected TB patients began to fall due to augmented federal resources for TB control and other public health efforts. State and local health departments established innovative TB prevention and TB control programs. Directly observed therapy (DOT) monitored the patients to get complete drug treatment. A timeline of major events in the history of TB is shown in Figure 1. The history clarifies the existence of the disease; therefore the long-term goal of better control of this communicable disease is a necessity. Figure 2 is epidemiological fact sheet for tuberculosis for Duval County, FL (2007). Figure 01 Timeline of major events in the history of TB (CDC, 2008) Figure 2 2007 Tuberculosis Fact Sheet, Duval County In 2007, Duval County ranked 5th for tuberculosis morbidity in Florida. 1 o 7% (71/980) of Florida’s TB cases in 2007 resided in Duval County 2 o 17% (12/71) of TB cases were co-infected with HIV 3 o 31% (22/71) of cases were in the foreign-born population 4 o 11% (8/71) reported excessive use of alcohol within the past year 5 o 6% (4/71) reported drug use within the past year 6 o 10% (7/71) of TB cases were among the homeless Gender: 1 o Males represented 58% (41/71) of all Duval County’s TB cases. 2 o 37% (15/41) of males were 25-44 years of age 3 o 32% (13/)41 of males were non-Hispanic White 4 o 15% (6/41) of males were Asian 5 o 49% (20/41) of males were non-Hispanic Black 6 o 5% (2/41) of males were Hispanic (all races) Age-Group: 1 o Ages 25-44 reflected 34% (24/71) of Duval County’s TB morbidity. 2 o 17% (2/12) of HIV/TB co-infections were 25-44 years old o 45% (10/22) of foreign-born cases and 29% (14/49) of U.S. born cases were 25-44 years of age Race/Ethnicity: Non-Hispanic Blacks represented 52% (37/71) of TB cases in Duval County. 1 o 38% (14/37) of TB cases in Blacks were 25-44 years in age 2 o 54% (20/37) of TB cases in Blacks were male 3 o 50% (10/20) of TB cases in Black males were age 25-44 4 o 83% (10/12) of all TB/HIV cases were Blacks 5 o 27% (10/37) of TB cases among Blacks were co-infected with HIV 6 o 15% (3/20) of TB cases among Black males were HIV positive Hispanics (all races) represented 4% (3/71) of Duval County’s 2007 TB cases. 1 o 33% (1/3) of TB in Hispanics were 25-44 years in age 2 o 67% (2/3) of TB in Hispanics were male 3 o 50% (1/2) of TB cases among Hispanic males were age 25-44 4 o 0% (0/12) of all TB/HIV cases were among Hispanics 5 o 0% (0/3) of TB among Hispanics were co-infected with HIV 6 o 0% (0/2) of TB cases among Hispanic males HIV positive. Methods used for control Tuberculosis causes 25% of preventable deaths from two million annual deaths. A 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 should be taken. Policies and Programs The objective of WHO policies is to offer clear guidance to handle successfully 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 the DOTS (Directly Observed Treatment Strategy). The aim of this strategy is to resist the development of drug-resistance. DOTS ensure the patient’s compliance to achieve reliable results of the treatment with complete efficacy. WHO policies emphasis on Global Partnership to Stop TB can be accomplished through working together of various TB control groups, synergistic efforts of all stakeholders in tuberculosis control to ensure worldwide access 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 focuses on arresting and preventing spread of TB, prohibiting emergence of drug resistant TB; and reducing mortality rate, disability, illness, distress, emotional trauma, family disruption, and social discrimination (Connecticut Department of Public Health, 2009). The tuberculosis control program separates 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. The principle approach to prevent and Control TB in the United States consists of (Taylor, Nolan, & Blumberg, 2005) four strategies. Early diagnosis coupled with a rapid assessment of TB infectious patients is the first step to control TB. Immediate detection of the clinical manifestation shown by the patients before the disease progresses is necessary. Report the detected TB cases 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 from turning into TB disease in the latent TB infection population. By targeted testing and administration of a curative course of treatment in TB could be achieved. Increasing targeted testing and treatment of infection carrier individuals, the issue is addressed in two ways. It is necessary to check first high-risk patients, such as human immunodeficiency virus (HIV) infected or diabetes mellitus patients for TB infection (Taylor, Nolan, & Blumberg, 2005). Second, task oriented programs encompasses of reaching the persons who have an increased prevalence of dormant TB infection and an increased risk for developing active disease in infected persons. The last step is to decrease TB cases from recent pathogenic transmission. Recognize the new settings (correctional facilities, homeless shelters, bars, newly recognized social settings, etc.) as well as known settings, which are most vulnerable to infection, and implement effective infection control measures to reduce the TB risk burden (Taylor, Nolan, & Blumberg, 2005). US implemented this method of control during 1985-1992, when a reemergence of TB occurred. TB morbidity, 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 the 1990s had a positive outcome during 1985-1992 TB outbreak (Taylor, Nolan, & Blumberg, 2005). Effective implementation and success of TB control programs in many developing countries is necessary in addition to socioeconomic conditions, technology, and policy. Treatment The first drug discovery for the treatment of TB was 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 a multimodal approach that 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. 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 as per DOTS strategy (Dias-Baptista 2008). Table 1 lists the essential antituberculosis drugs with their recommended dosages. The drugs used for Second line treatment are mostly expensive and includes, para-aminosalicylic acid, Ethionamide, Cycloserine, Capreomycin, Kanamycin. 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. The legislative, political, and cultural factors play crucial role to fund educational programs and improve living conditions of the most vulnerable population. Primary prevention of tuberculosis in most of the developing countries except the United States includes use of cost-effective BCG in infants and children. Bacillus Calmette Guerin (BCG) vaccine is from live attenuated mycobacterium. BCG vaccine gives protection for around five to ten years once injected. The draw back of this vaccine is that its protection capacity is not 100%. This prophylactic activity of the vaccine only lasts for 5-10 years and vaccinated individuals could become susceptible again to TB infection. In the secondary prevention method, after screening methods, diagnostic tests confirm the TB infection. Here, preventive therapies mainly inhibit inactive TB infection to turn into active TB disease. If Purified Protein Derivative (PPD) reaction is >15 mm, the patient probably has TB infection. Isoniazid administered for six month in inactive primary tuberculosis patients could reduce chances of reactivation tuberculosis by 50%. For HIV patients the therapy might continue for one year. Public health services employ use of isoniazid treatment for positive tuberculin test patients who are under 35 years. Directly observed prevention therapy (DOPT) checks 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, physician changes his/her drug strategy to a combination therapy. Healthcare provider tests suspected multi drug resistant TB patients and treats them in the negative pressure rooms in the hospitals to prevent transmission of resistant strains. The tertiary prevention methods treat patients with active TB disease with standard antituberculosis agents. Special precautionary measures include isolation of infectious individuals (Alves-Dunkerson J. & Dunkerson D.). In institutions, a special multitude of precautionary TB prevention measures should be taken. Primary prevention method comprises of prohibition of overcrowding, maintenance of good ventilation, and setting up ultraviolet radiation to kill mycobacterium in the surrounding area. 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 In spite of such developments in drug treatment and strategies, tuberculosis is still a dreaded disease according to the evidence of 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 WHO has expressed worry about the uncontrollable future of TB. Age-old diagnostic tests to detect TB infection and 85-year-old BCG vaccine are still in use without any recent introduction of new TB drugs in the market. Once considered miracle drugs (40 years ago) 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. Sending messages to patient’s mobile, medicine kits with built-in reminder alarms are also novel ideas to improve patient’s compliance. The outbreaks of antimicrobial resistance are most common in India, China, Russia, South Africa, and Bangladesh. Extensively resistant pathogens give rise to extensively drug-resistant tuberculosis (XDR-TB) are not responding to primary anti TB drugs and not even more expensive second-line drugs. By the end of 2007, this devastating epidemic with fatal strains has spread to 54 countries. WHO has plans to target elimination by 2050. 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. 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. WHO has established a task force on retooling 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 TB control programs focuses on arresting and preventing spread of TB, prohibiting emergence of drug resistant TB; and reducing 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. In spite of developments in drug treatment and strategies, tuberculosis is still a 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 factors for immediate effect. WHO’s 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 Connecticut Department of Public Health, Tuberculosis Control Program (2009). Retrieved November 1, 2009 from http://www.ct.gov/dph/cwp/view.asp?a=3136&q=388584 Department Of Health And Human Services, Centers for Disease Control and Prevention, (CDC) Transmission and Pathogenesis of Tuberculosis: History of TB, Module1, p. 4. Retrieved October 31, 2009 from http://www2.cdc.gov/phtn/tbmodules/modules1-5/m1/con4.htm Dias-Baptista (2008) Trends In Multidrug-Resistant Tuberculosis, J. Venom. Anim. Toxins incl. Trop. Dis., 14 (2), 2008, pp. 203-223. Jekel, J. F. Katz, D. L. & Elmore J. G. (2001) Epidemiology, biostatistics, and preventive medicine, 2nd edition. Elsevier. Johnson, T. (2009) Drug-resistant TB may ‘spiral out of control, U.N. says, McClatchy Newspapers, April 1, 2009. Retrieved October 31, 2009 from http://www.miamiherald.com/news/world/AP/story/979014.html LoBue, P. Sizemore, C. & Castro K. G. (2009). Plan to combat extensively drug-resistant tuberculosis recommendations of the federal tuberculosis task force, pp1-43. Maher, D. Blanc, L. Raviglione, M. (2004). WHO policies for tuberculosis control, The Lancet, 363 (9424), 5 June 2004, p. 1911. O’Donoghue, C. (2006) Guide to Surveillance, Reporting and Control, Massachusetts Department of Public Health, Bureau of Communicable Disease Control, Tuberculosis, 2nd edition. Retrieved October 30, 2009 from EBSCO. Palomino, J. C. Leão, S. C. Ritacco, V. (2007) Tuberculosis: From basic science to patient care. Retrieved October 31, 2009 from http://www.tuberculosistextbook.com/ Taylor, Z. Nolan, C. M. & Blumberg, H. M. (2005) Controlling Tuberculosis in the United States, Recommendations from the American Thoracic Society, CDC, and the Infectious Diseases Society of America, 4 November 2005, 54(RR12), pp. 1-81. Retrieved October 31, 2009 from http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5412a1.htm World Health Organization (2004). Treatment of tuberculosis: Guidelines for national programs. Retrieved October 31, 2009 from http://www.who.int/tb/publications/stag_report_2005.pdf World Health Organization (WHO) (2007) New Technologies for tuberculosis control: A framework for their adoption, introduction and implementation. Retrieved November 1, 2009 from http://www.stoptb.org/retooling/assets/documents/New%20Technologies%20 for%20TB%20Control%20Final%20version%20with%20design%2025May2007.pdf 2007 Tuberculosis Fact Sheet, Duval County. http://www.doh.state.fl.us/Disease_ctrl/tb/Trends-Stats/Fact- Sheets/Florida/Big%206/Fact_Sheet_Duval_07.pdf . Read More