“Tuberculosis (TB) is an infectious disease caused by bacteria, Mycobacterium tuberculosis. It claims the highest rate of mortality. Each year.” Developments and concerns in Tuberculosis treatment.
This article has been published as submitted by the writer without any editing by Chillibreeze so you can critique it, in its original format. Please feel free to rate and comment on this article.
Submit your article and be rated by other Indian writers
Scroll down to the bottom to rate this article.
Author: Resham Sinha
Tuberculosis (TB) is an infectious disease caused by bacteria, Mycobacterium tuberculosis. It claims the highest rate of mortality. According to WHO estimates 1.77 million people in the world died of tuberculosis (figures include HIV associated TB deaths) in the year 2007. A vast majority of this number belong to the developing nations.
Symptoms
Tuberculosis is symptomatic and is diagnosed when the under-mentioned symptoms are observed. However clinicians have reported Tuberculosis cases accidentally while investigating other ailments. This is common in countries where there is less awareness and a disorganized health care system.
- The first symptom of Pulmonary TB is persistent cough and if not treated timely it can spread from lungs to other parts of the body.
- Night sweats, weight-loss, breathlessness and chest-pain are few other symptoms which indicate TB.
- A person may show different symptoms and signs depending on the organ infected. For instance a patient, whose kidney gets infected, will show blood streaks in his urine. A person with bone-TB will have features of inflammation in the bone.
Causes of spread
- TB is an air-borne disease and can spread through air droplets when an individual with active TB, coughs or sneezes.
- Careless spitting in public places or using sputum to count notes and flip pages are some common traits that can spread the disease if the subject suffers from active TB.
- Non-pasteurized milk or cattle infected with Mycobacterium bovis can also lead to TB however, this is less common.
- Emergence of HIV-associated TB has resulted in an extensive spread of the disease.
Major hurdles in the eradication of the disease
Emergence of multi-drug resistant, TB (MDR-TB), extremely drug resistant tuberculosis (XDR-TB) and latent TB have been the major constraints in the eradication of TB.
- Latent TB – When a person infected with the bacteria does not show any visible symptom of the disease, the person is said to have latent or dormant infection. Latent infection can turn into active TB when the person is immunocompromised. A person with active TB will show symptoms of the disease and can also spread the disease. Latent TB cannot be treated and 90% of patients infected with latent TB do not show any symptom during there lifetime.
- MDR-TB – TB is curable if the patient is immuno-competent. There are five drugs available to combat TB and a combination therapy of these drugs is administered to the patient for 6 months after a drug-susceptibility test. Isoniazid and Rifampicin are the two major drugs used in the treatment of TB. A patient who is resistant to these two drugs are said to have multi-drug-resistant TB (MDR-TB). People infected with MDR-TB are treated with second line drugs for almost 2 years and suffer severe side effects. MDR-TB generally does not spread through contact. It is common in HIV patients as they have a weak immune system wherein weak strains of bacteria are not under any selection pressure and hence easily replicate to mutant forms. Improper chemotherapy due to misdiagnosis, incomplete treatment due to non-availability of drugs, disease relapse are some of the reasons for the emergence of MDR-TB.
- XDR-TB – XDR-TB is defined as resistance to at least isoniazid, rifampicin in addition to fluoroquinolones and at least one of the three injectible drugs capreomycin, kanamycin, and amikacin. Although incidence appears to be low WHO has recorded half a million cases by 2004. Treatment requires all six classes of second line drugs. Countries that have good TB control programmes have been able to achieve about 50% to 60% success in the treatment of XDR-TB.
TB patients have to follow an arduous chemotherapy but at the end of it gets cured. Unfortunately due to lack of awareness it is considered a social stigma and open cases of TB which need to be isolated (diagnosed positive on microscopic examination of sputum) are not disclosed. This results in further spread of disease. Lack of awareness is one of the major hurdles in TB eradication.
New developments
- BCG vaccine (for TB) currently administered against infection only reduces the risk of TB in infants but offers no protection against pulmonary TB and infection in adolescence or adulthood. A new TB vaccine, developed at the Oxford University called MVA85A/AERAS-485 holds promise. It has entered Phase II b trial in April 2009 and is being carried out in South Africa.
- The advent of RNA–based PCR detection method has brought down the diagnosis time from eight weeks (microbiology culture method) to a few hours. However in developing countries, traditional methods (Microscopy and Culture method) are used, as rapid diagnostic techniques are unaffordable.
- A commendable approach of government is the RNTP (Revised national tuberculosis program) in which many volunteers have come forward to eradicate the disease by helping to implement the DOTS (Directly observed treatment, short-course). The volunteer completely monitors the patient from diagnosis to cure. They ensure a steady supply of drug to the patient and observe the patient swallowing the drug in there presence.
- Most recently in May 2009 a new antibiotic Moxifloxacin has completed phase II trial and is expected to reduce the drug regimen by several months.
- A complete genome sequence of mycobacteria is available now, this breakthrough has helped in epidemiological studies and could lead to discovery of new drugs, vaccines, and better diagnostic techniques.
- A global consortium of scientists are studying the 3-dimensional structure of different mycobacterial proteins this can help in identifying the drug target protein and proteins essential for the bacteria’s survival and thus help in the discovery of new drugs.
- Several different strains of bacteria are being studied and helped development of molecular markers. These markers have been helpful in studying gene deletions leading o alteration in phenotypes like virulence.
- A large number of molecular markers have helped epidemiological and evolutionary studies which can further help in devising methods for intervention against the disease.
- Frog mobile health partnership, Project Masiluleke is an innovative approach in South Africa to spread awareness for HIV-TB. This program sends Sms on mobile phones and guides a person through diagnosis, treatment and prevention. If the model succeeds it can be used at several other countries with high incidence of the disease.
A few areas of future research
- Mutations in the drug target gene results in resistant strains of bacteria. Understanding the mechanism of drug resistance at the molecular level and developing highly effective anti-TB medication.
- Drugs which take care of latent bacteria, MDR and XDR.
- A single dose or shorter dose therapy.
- Molecular methods are being used to study the epidemiology of the disease. Studies are aimed at what makes a host susceptible to infection? Does age, sex, poverty, genetic make-up influence infection.
- Research in animal models has shown some strains are more infectious than others. This observation can help in new vaccine development.
- Molecular epidemiology (ME) studies on correlation between host of different genetic make-up and bacteria of different strains, and genes which provide immunity to TB.
- ME studies aimed to study transmission dynamics of the disease.
Concerns
- There have been rapid diagnostic techniques available today but what is the use if we don’t have any novel compound to treat the disease. We are using drugs developed 40 years ago that are of no help against the soaring MDR’s and XDR’s with the advent of HIV.
- TB drug (Rifampicin) cannot be taken with anti-retroviral therapy. How are we going to help TB- HIV co-infected individuals.
- TB research and control suffers major funding deficit there is a need to increase the investment 5 –fold and R&D needs to be well coordinated at national and international levels.
- Strain specific epidemiology studies have thrown light on the fact that different strains of bacteria elicit different host immune response this truth has further complicated new vaccine design.
- Most of the ME studies are done in geographical areas which are affluent countries and have a low TB burden. Therefore inference drawn from these studies will hardly bear less relevance to the scenario in countries with poor economic condition and less health awareness.
Conclusion
New-age research has made possible rapid diagnostic tests and better therapy. However, they are beyond reach of the developing countries which bear the major burden of the TB-affected individuals. In order to eradicate the disease completely, all nations should come together and divide areas of research. Developed nations must take a moral responsibility to help the developing nations financially for research, diagnosis and treatment.
Several non-government organisations have made a beginning in this direction. Bill Gates Foundation is one such organisation providing funding for TB research and facilitating the development of new vaccine. In august 2009, Clinton Foundation announced partnership with two pharma companies, Matrix and Pfizer, to lower the cost of TB and HIV-drugs. STOP TB partnership is a WHO (World Health Organisation) initiative which aims to drastiacally reduce global TB burden by 2015. Drug resistant strains, poor drug compliance, difficult isolation of infectious cases, poor health awareness, Incompetency of public health personnel, Poor nutritional state of masses are some of considerations which need to be addressed to the earliest.
A united effort to eradicate the disease from our planet can help us reach our goal at the earliest.
More on Chillibreeze
Read, rate and comment on more such articles by Indian writers
Take advantage of our confidential and professional article review services to get your writing rated by an expert critic
Check out our Writing Courses and Writing Assessments
Want to work on client projects? Read more about our screening process.
Related posts:
Chillibreeze on Twitter: 
Connect with our Writers Section Manager, Priya: 
Become a fan of Chillibreeze: 
