MDR Tuberculosis: Role of Agent, Host and Environment Factors, and Potential Policy Responses

This paper analyzes the role of agent connected with MDR TB, evaluates the host and environmental factors related to the disease, and provides potential policy responses for the treatment of MDR TB.

MDR Tuberculosis
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Table of Contents
Introduction......................................................................................................................................2
Role of Agent...................................................................................................................................2
Host and Environment Factors........................................................................................................5
Potential Policy Responses..............................................................................................................8
Conclusion.....................................................................................................................................11
References......................................................................................................................................12

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Introduction
MDR Tuberculosis (MDR TB) is a particular type of TB which does not respond to the treatment
of TB. The bacteria of TB infect those persons who are resistant to two medicines, isoniazid as
well as rifampicin. Consequently, it becomes difficult for them to treat and need specialized
treatments. The paper will analyze the role of agent connected with MDR TB. It will also
evaluate the host and environmental factors related to the disease. Moreover, it will provide
potential policy responses for the treatment of MDR TB for helping the people to deal with the
impact of the disease.
Role of Agent
The Tuberculosis (TB) is a vital infectious disease and also public health concern all over the
world. The emergence of drug resistance has worsened the situation since, from the year 2012,
more than 450,000 cases of MDR TB and almost 170,000 people have died due to MDR TB. It is
caused by the bacteria known as Mycobacterium Tuberculosis (M Tb) which are resistant to
isoniazid (INH) and rifampicin (RMP) that are the two vital drugs used for treating the disease
(Ahmad Khan et al., 2016). One of the key factors is that the early detection of drug resistance in
TB can reduce and minimize the spreading of this disease.
RMP was launched in the year 1972 as an agent of anti-TB and is one of the most effective
antibiotics for anti-TB and along with INH makes the base of regimen for multidrug treatment
for tuberculosis (Bonnet et al., 2016). RMP is active against both non-growing as well as
growing bacilli. The action mode of RMP in M TB is by binding to β-subunit of the RNA
polymerase. Most of RMP-resistant medical isolates of M Tb harbor mutations in the rpoB gene

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which codes for the β-subunit. Due to this, some changes take place and reduce the affinity for
the drug and lead towards developing the resistance. INH was launched in the year 1952 as an
agent of anti-TB and together with RMP remained as the base of treating TB. In comparison to
RMP, INH is active only against metabolically active replicating bacilli. It is a pro-drug which
needs activation by either inhA genes or katG genes for exerting its effects. Both the mutations
are not connected directly, and thus, individual mutations are needed for organisms for changing
from drug-susceptible isolate towards MDR TB.
M Tb enters into the human body when an individual breathes in expelled droplets from another
individual with active infection from MDR TB. The bacteria is spread through prolonged contact
with any individual with active infection from MDR TB such as sharing a long car ride or a
home with an individual with active infection from MDR TB can lead to catch the bacteria. It is
the misconception that M Tb can spread through making contact with toilet seats, shaking hands,
kissing, sharing toothbrushes and sharing drinks or foods (Dheda et al., 2018). The bacteria
could only enter into the human body through air droplets either through sneezing, coughing,
singing or speaking. It has been seen when an individual inhales, the bacteria enters in the lungs
and then harms the body parts. If it is not treated, the bacteria could spread in areas like brain,
spine and kidneys and could be life-threatening. A positive culture of M Tb needs to be created
for MDR TB.
When the bacteria infect the human body, it affects the immune system, and the immune
response of the human body becomes critical regarding the progress of the disease. It either helps
the body to fight against the bacteria, or if some molecules get involve with it, the bacteria can
exacerbate the infection. Usually, an individual with weak immune systems such as children
under five years, the persons receiving chemotherapy and with AIDS or HIV are at higher risks

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of the development of MDR TB (Dudnyk et al., 2017). When a person breathes in the bacteria of
TB, the bacteria get into their lings and begin to increase since their immune systems could not
fight the M Tb. Those persons develop the disease with few weeks or days after the infection.
In healthy people, they might get infected by the latent TB, but active disease might not develop
till several months or years. It may develop when their immune systems become weakened for
other causes, and they could not fight against the germs. When an individual gets the active
disease of TB, it implies that the bacteria are multiplying as well as attacking the lungs or other
body parts like skin, spine, brain, kidneys, bones and the lymph nodes (Isaakidis et al., 2015)
The M Tb move from the lungs to various parts of the human body through the lymphatic system
or the blood. The symptoms consist of loss of appetite and weight, cough, night sweats, chills,
fever and also symptoms connected with the functions of particular affected system or organ
such as sputum in the lungs, coughing of blood or pain in bones if M Tb attacks the bones.
The disease remains a crisis for public health and a threat to health security. It has been estimated
by WHO that 558, 000 new cases with resistance to RMP have emerged which is the most active
first-line medicine out of which more than 80% have MDR-TB (John et al., 2018). The two
causes for MDR TB to be continued to develop as well as spread are person-to-person
transmission and mismanagement of the treatment of TB. If the individuals neglect the treatment
of TB, the bacteria increases in the human body and lead towards MDR TB.

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Host and Environment Factors
MDR TB is becoming more widespread in the present environment and is the more aggressive
form of TB. MDR TB has increased from the year 2012 and more than 450, 000 cases of MDR
TB and almost 170, 000 people have died due to MDR TB. The primary hosts of this aggressive
form of TB are human beings. Human beings are only known host where M Tb lives naturally as
well as reproduces (Kuaban et al., 2015). The bacteria is spread basically like an air borne
droplets from the persons in the infectious phase of TB, even though gastrointestinal (GI) and
transdermal transmissions are even possible. The leading cause of MDR TB is a bacteria known
as Mycobacterium Tuberculosis (M Tb). However, MDR TB can pose risks to both human
beings and animals all over the world, but the bacteria is considerably high in human beings,
guinea pigs and other primates.
According to the World Health Organization (WHO), M Tb enters into the human body when an
individual breathes in expelled droplets from another individual with active infection from MDR
TB. The bacteria of TB that that enter the body of the animals is known as Mycobacterium bovis
(M bovis). Cats, cattle and rabbits are susceptive of M bovis and resistant to M Tb. The wild
hoofed stocks are susceptive of M bovis but there are also some reports of isolation of M Tb in
them (Kundu et al., 2018). Dogs and swine are susceptive of both M Tb and M bovis. Thus,
these animals are also regarded are the hosts of MDR TB.
Human beings have an only small percentage of M bovis but the bacteria is present both in
domestic and wild animals all over the world particularly in nations where very little data is
available of the existence of M bovis in human beings. So, it can be said that both human beings
and animals are the hosts of MDR TB. M Tb is transmitted in airborne particles known as droplet

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nuclei which have a diameter of 1 to 5 microns. The infectious airborne particles are generated
when individuals those who have laryngeal or pulmonary TB sneeze, cough, sing or shout and is
circulated through the air from people to people and depend on the atmosphere (Lange et al.,
2018). The people who inhale in the air that contain the bacteria of TB can also be infected with
MDR TB.
The environmental factors connected with MDR Tuberculosis are summarized below:
Air Pollution
Outdoor Air Pollution - The rapid industrialization and urbanization are making more people
being exposed to air pollution in their day-to-day lives. The WHO has reported that more than
90% of the population of the world lives in places with levels of air quality beyond the air quality
standards of WHO. It has also been informed more than three million people have died
prematurely all over the world due to air pollution with 88% of deaths taking place in low as well
as middle-income nations, particularly in the South East Asia and Western Pacific areas.
Prolonged exposure to outdoor air pollution for long-term has major impacts on health and could
increase the risk of MDR TB (Loveday et al., 2015).
The toxic gases in air pollution play a vital role in maximizing MDR TB. The key air pollutants
with potential adverse impacts on human health are carbon monoxide (CO), nitrogen dioxide
(NO2), sulfur dioxide (SO2) and ozone (O3) (Meressa et al., 2015). The carbon monoxide (CO)
maximizes M Tb, which is the causative agent of MDR TB in shifting to drug-resistant state
from active infection state. It is known as latency which is a global issue and leads in MDR TB
to escape detection as well as detection and also contributes to the overall transmission of MDR
TB.

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Exposure to SO2 is prone to MDR TB in only men, perhaps due to the lifestyles of the men like
occupational factors that involve exposure to SO2 and time spent outdoors (Metcalfe et al.,
2019). This gas synergistically maximized the acute mortality and morbidity which signifies that
particles in the gas are more toxic. This gas is highly soluble and is acknowledged as an irritant
of the respiratory tract, which could penetrate towards airways and reduce the functions of the
lungs. It damages the clearance of mucociliary as well as causes infection, which considerably
maximizes the risks of MDR TB. NO2 is also positively connected with MDR TB. O3 can cause
damages in the body of human beings in even healthy people.
Indoor Air Pollution - Indoor air pollution is a recognized environmental factor for the
development of MDR TB. The relationship between this disease and indoor air pollution was
submitted in the year 1911. The studies between 1858 and 1902 in Paris showed that death due to
this disease was connected with the number of windows in each house. From then onwards,
several studies have published the connection between this disease and indoor air pollution
(Muñoz-Torrico et al., 2017). The people cooking with biomass stoves are connected with a 2.4-
times higher chances of development of this disease. A meta-analysis revealed that air pollution
in the indoors had increased the incidences of MDR TB, with a relative risk Cigarette smoking,
exposure to secondhand tobacco and fossil gas cooking are strongly related with the increase of
rates of MDR TB.
Potential Policy Responses
Earlier, MDR TB has the tendency to take place in areas where there were sufficient aces to first-
line drugs, but the control programs were not adequately funded or were not strong enough to
make sure of the adherence to standardized practices and therapy (Olaru, Lange and

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Heyckendorf, 2015). The treatment practices involved with MDR TB vary widely in low to
middle-income nations such as Argentina and former Soviet Republics and the treatments often
take place in the private medical centres such as India. Recently, the spread of MDR TB has
been fueled by immunosuppression that is associated with HIV and as a result, it plays a
subsequent and vital function in the morbidity of MDR TB in sub-Saharan Africa (Pang et al.,
2016.
WHO as well its global partners, over the last decade, have maximized their focus on
recognizing, treating and managing the transmission of MDR TB as a part of overall policy for
global TB controls. The strategic component of this global policy for stopping TB is called
Directly Observed Treatment Short-course (DOTS) (Rao et al., 2019). It is a globally
recommended program for controlling MDR TB and has been identified as a cost-efficient and
highly effective strategy. This policy is a method of assisting people in the course of their
treatment. Rather than sending home with their medicines, they may visit their local pharmacy or
hospital or a nurse could come to their house. It implies the individuals have somebody to talk to,
and they could ensure that the individuals take their treatment properly.
DOTS is accessible to any person who has TB (Rendon et al., 2016). If they find it difficult to
take their medicines regularly, the policy can work well for them. In the case of MDR TB, the
doctor might suggest this method for helping them in their treatment with more medicines than
usual TB for more than six months. It has five elements and they are calls for the commitments
of financial and political resources, usage of quality mycobacteriology for diagnosing MDR TB,
usage of regimens of standardized treatment with proper supervision and assistance for
adherence, assurance of sufficient supply of anti-TB medicines and monitoring as well as
evaluation of the program.

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 Commitments of Financial and Political Resources - MDR TB could be cured and the
epidemic can be reversed if sufficient administrative support and resources for controlling
TB are given (Rigouts et al., 2015)
 Usage of Quality Mycobacteriology for Diagnosing MDR TB - If the symptomatic of the
chest is examined by this method, it can help to reliably search the infectious patients
 Usage of Regimens of Standardized Treatment with Proper Supervision and Assistance
for Adherence - It can help to make sure that the correct medicines are taken at the correct
time during the time of the treatment (Saravanan et al., 2017)
 Assurance of Sufficient Supply of Anti-TB Medicines - It can ensure that a credible
national program for MDR TB does not have to depend on anybody away
 Monitoring as well as Evaluation of the Program - It can help in keeping track on each of
the patients individually and monitoring the overall performance of the program
The challenges involved with it are the development of sustainable capability for the culture of
sputum and drug susceptibility tests, avoidance of risks connected with possible increase in
resistance of drugs by using standardized protocols of retreatments in the absence of drug
susceptibility tests and assurance of aces to best-quality first as well as second-line medicines
and sufficient controls for infection in the healthcare employees (Somoskovi et al., 2015). The
policies which can be beneficial efforts for controlling MDR TB and preventing more emergence
of resistance to drugs are given below:
 Making sure of the infrastructure which can support cost-efficient approaches for controls by
expanding the coverage of DOTS
 Stopping transmission of HIV and mitigation of the related population-level immuno-
suppression, particularly in TB-endemic areas

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 Solving the requirements of other special groups such as indigenous and incarcerated
 Reinforcing infrastructure of the health systems
 Promoting social mobilization, community involvement and advocacy for preventing,
treating and controlling TB
 Forming and applying strong, inexpensive and simple tests for detecting TB as well as
resistance to drugs
 Finding, testing as well as using new and safe regimens for medicines which will
successfully treat both drug-resistant and drug-susceptible strains
 Making more efficient vaccines which can protect against infection and progress towards
active TB (Tiberi et al., 2016
These efforts make the crucial components of the global strategy for stopping TB. This initiative
would need the commitments of human and financial resources as well as political will at local,
regional and global levels and also cooperation among the private and academic biomedical
centers, national governments, and nongovernmental organizations. The Global Plan to End TB
2016 to 2020 and WHO End TB Strategy aims to eradicate TB (Tiberi et al., 2016). They held
meetings, wrote documents and set targets. It was assumed that there is a need for a paradigm
shift and a radical change to view TB but differently. Both the policies will be operated as per
the plan so that the targets can be met. It has been seen that WHO has not explained why this
time the policies will be different.

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Conclusion
The paper concluded that an aggressive form of TB that affect half a million individuals each
year and leads to a higher rate of deaths than those who are prone to drugs. The disease is
increasing in some nations, with only 3% of infected people are treated as per the standards
established by the WHO. It is caused by the bacteria known as M Tb and can pose risks to both
the human beings and animals all over the world but the bacteria is considerably high in human
beings, guinea pigs and other primates. The host and environmental factors related to the disease
were evaluated. The potential policy responses for MDR TB by WHO aims to eradicate the
disease from the world.

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