Directly Observed Treatment Short Course
(DOTS): Treatment for TB
About Dr Zahid Masood Khan
What is TUBERCULOSIS (TB)?
Tuberculosis is a specific communicable disease caused by Mycobacterium
Tuberculosis.
Causative Agent
Mycobacterium Tuberculosis which is an acid fast bacilli (AFB).
1- Typical Mycobacterium Tuberculosis
They are 3 in number.
a- Human. b- Bovine. c- African.
2- Atypical.
Organs Effected
T.B. does not spare any organ. It is classified as:
1- Pulmonary T.B:
It is infected form to the others.
2- Extra pulmonary:
T.B. is also an important cause of Infertility.
Pathology of Disease
Organ effected by T.B. undergoes caseous necrosis and granuloma formation and
cavities are formed. Caseous necrosis & cavity formation are more in
Mycobacterium T.B.
Diagnosis of T.B.
It is based upon:
a- History. b- Clinical
examination
c- Direct microscopy (Z.N. staining of sputum smear).
d- Montoux test. e- X-Ray Chest.
BUT Tuberculosis should never be diagnosed exclusively on X-Ray Chest.
Fancy Test for T.B.
a- ICT T.B.
b- Micodot test.
c- ANDA test.
d- G.A. T.B. test.
e- PCR: Initially thought to be highly specific but now its specificity
regarding disease is questionable.
" Still the golden standard for T.B. diagnosis is direct microscopy &
culture ".
Some Facts & Figures about T.B.
T.B. is as old as mankind. It s a top killing disease in world. Pakistan stands
no. 5 in world as regards to T.B. burden. Incidence of T.B. in Pakistan is more
than 250 cases/100,000 population (In suburban area more than 50 cases of T.B.
are added to existing load at Union Council level).
In 1993 it is declared as global emergency. In 1997 WHO said ' Pakistan seems to
be losing war against tuberculosis and knowledge of Doctors about T.B. is so
poor and as a result number of drug resistant strains are increasing alarmingly
'.
In 1999 whole world provided data to WHO regarding T.B. except 4 countries:
1- Afghanistan.
2- Congo.
3- Zimbabwe.
4- Pakistan.
T.B. gives significant mortality & morbidity and in Pakistan it still
effects working age group.
T.B. is second (2nd) deadliest infection in world
and half of its population is infected with Mycobacterium. Upto 2020 one billion
people will be infected, 200 million will become sick & 70 million will die
worldwide.
Control & Treatment of T.B.
Diagnosis & Treatment of T.B. is not a problem now. Rather the problem is
lack of organization of services to ensure widespread detection and cure of T.B.
To solve this problem, the treatment of T.B. is now modified to DOTS i.e. "
Directly Observed Treatment Short Course ".
What does it mean?
As the name gives two concepts itself:
1- Directly observed treatment means medicine to the patient should be given in
front of some medicinal personnel.
2- Second is short course. It means good results can be achieved through this
strategy in a short period of time.
Key Components of DOTS
In Pakistan it has been launched in 1999. The key points of DOTS are:
1- Government commitment to sustain T.B. control activity.
2- Case detection by sputum smear microscopy among symptomatic patients. Self
reporting to health services.
3- Standardized treatment regimen of 6-8 months for all confirmed sputum smear
positive cases with DOTS for at least initial 2 months.
4- A regular uninterrupted supply of all essential anti-tuberculous drugs.
5- A standardized recording and reporting system that allows assessment of
treatment result for each patient and of T.B. control programme.
Basic Management Unit of DOTS
It is an important feature of DOTS covering a population of 100,000 to 150,000.
It has,
* Staff.
* Resources to diagnose, to initiate treatment and to manage the drug supply.
DOTS Strategy Today
It has following aspects,
* Technical.
* Logistical.
* Operational.
* Political aspects.
These all work together to ensure its success and applicability.
1- Technical Aspect
It deals with:
a- Case detection & diagnosis by direct microscopy.
b- Treatment - Standardized short course.
In DOTS, watching patient taking medicine is essential, at least during
intensive phase of treatment. To ensure that drugs are in right combination and
for proper duration. Anybody can be an observer but he must be accountable to
T.B. Control services.
c- Recording and reporting of progress and cure.
2- Logistical Aspect
It deals with:
a- Sure drug supply and means 6 month stock of drugs must be present with
additional 3 months stock.
b- Network of smear microscopy laboratories.
c- Supervision & training uptil Primary health care workers.
3- Operational Aspect
It deals with inflexibility and implication of technical
aspects.
WHO Recommended Anti-Tuberculus Drugs
Drug
Dose
INH
(H)
5mg/kg daily.
Rifampicin
(R)
10mg/kg daily
PZA
(Z)
25mg/kg daily
Streptomycin
(S)
15mg/kg daily
Ethambutol
(E)
15MG/KG DAILY
Ethambutol is only bacteriostatic drug.
Drugs for T.B. Treatment according to its
Category
Category I
It includes cases
* New smear positive pulmonary T.B.
* Smear negative pulmonary T.B. with extensive parenchymal disease.
* New extra pulmonary smear forms.
Treatment Schedule
2 R.H.E.Z.
G.H.E.
or 4 R.H.
Category II
It includes cases
* Sputum smear positive relapse.
* Treatment failure.
* Drug defaulters (Takes 1 month or more treatment and then returns to facility
after gap of 2 months).
Treatment Schedule
2 S.H.R.E.Z.
1 H.R.Z.E.
and then
5 H.R.E.
Category III
* New smear negative pulmonary
* T.B. other than Category I.
* New less severe forms of extra pulmonary forms.
Treatment Schedule
2 H.R.Z.
G.H.E.
or
2 H.R.Z.
4 H.R.
Prevention of Disease
* Breakage of chain of Transmission.
* T.B. contact training.
* Drug Prophylaxis.
* BCG Vaccination.
Advantages of DOTS
* DOTS is the cost effective T.B. treatment. Only
Rs.2,500/- are needed in this treatment while MDR (Mycobacterium drug resistant)
cost is Rs.100,000/- in minimum.
* Prevents development of MDR forms of AFB.
Successful both in large & small, rich & poor countries.
No need of hospitalization.
* Due to short period of treatment no side effects of the drugs.
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