TUBERCULOSIS

PRESENTATION BY - V.LAXMI PRASANNA. 12BU1R0025

CONTENTS. INTRODUCTION. DEFINITION SIGNS AND SYMPTOMS CAUSES RISK FACTORS. MECHANISM DIAGNOSIS TREATMENT PREVENTION HISTORY SOCIETY AND CULTURE

INTRODUCTION.

Tuberculosis,MTB or TB, in the past also called phthisis,phthisis pulmonalis is a wide spread,infectious disease caused by various strains of mycobacteria,usually Mycobacterium tuberculosis.

Robert Koch discoverer of Micobacterium Tuberculosis.so it is also called as koch disease.

TB is the leaading cause of death in the world from a bacterial infectious disease.

The disease affects 1.8 billion people per year ,which is equal to 1/3 rd of entire world population and new infections occur in aabout 1%of the population every year.

among all the diseases tb is considered as "KING OF DISEASES".

DEFINTION.

Tuberculosis is a potentially fatal contagious disease that can affect almost any part of the body but is mainly an infection of the lungs.It is caused by a bacterial microorganism,the tubercle bacillus or Mycobacterium tuberculosis.

SIGNS AND SYMPTOMS.

TUBERCULOSIS may infectbany part of the body,but most commonly occurs in yhe lungs[known as pulmonary tuberculosis].

Extra pulmonary tb occurs when tuberculosis develop outside of the lungs,although extra pulmonary tb may co exist with pulmonary tb as well.

GENERAL SIGNS AND SYMPTOMS include:- -prolonged cough for more than 3 weeks.

-blood in sputum.-weight loss

-loss of appetite.-night sweat.

-fever.-chills.

-fatigue.-chest pain.

-Significant nail clubbing may also occur.

PULMONARY-- If a tuberculosis infection does become active,it most commonly involves the lungs. symptoms may include chest pain,producing sputum,prolonged cough. Abot 25% of of people may not have symptoms.Occasionally people may cough up blood in small

amounts and in very rare cases infection may errode into pulmonary artery resulting in massive bleeding

EXTRA PULMONARY--In 15-20% of active cases,the infection spreads outside the lungs causing other kinds of TB.These are collectively denoted as "extra pulmonary tuberculosis".it occurs more commonly in immuno supressed persons and young children.

notable infection sites are pleura[tuberculous pleurisy],cns[tuberculous meningitis],lymphatic system[scrofula of neck],genitourinary system[urogenital tuberculosis],bones and joints[pott disease of spine]tuberculosis ulcer.

A potentially more serious ,wide spread form of TB is called disseminated TB, commonly known as miliary tuberculosis.

miliary TB makes up about 10% of extra pulmonary cases.

CAUSES.

Main cause of TB is Mycobacterium tuberculosis,a small ,aerobic,non motile bacilus.it is characterised by formation of tubercles in lungs and other tissues.

The high lipid content of this pathogen accounts for many of its unique clinical characteristics. It divides every 16-20 hours,it has outer membrane bilipid layer.

It can withstand weak disinfectants and survive in dry state for weeks. Other known pathogenic mycobacteria include M.leprae,M.avium,M.kansasii.the

latter two species are classified as non tuberculous mycbacteria[NTM]. NTM cuse neither TB nor leprosy ,but they do cause pulmonary diseases that

resemble TB.

RISK FACTORS.

A number of factors make people more susceptable to TB infections. The most important risk factor globally is HIV. Tuberculosis is closely linked to both over crowding and malnutrition,making

it one of the principal disease of poverty. Chronic lung disease is another significant risk factor.those who smoke

cigarettes have nearly twice the risk of TB compared to non smokers. Alcoholism,diabetes mellitus also increase risk of developing tuberculosis. Cetrain medications such as corticosteroids and infliximab are becoming

increasingly important risk factors ,especially in developed world. Genetic susceptibility also exists as a risk factor.

MECHANISM.

TRANSMISSION:- when people with active TB cough,sneeze,sing or split,they expel infectious aerosol droplets 0.5-5.0micrometer in diameter.each droplet may transmit the disease.

people with close contact with people with tb are particularly high risk of becoming infected.

probability of transmission from one person to other depends on several factors-ventilation,virulence of strain,level of immunity of uninfected person,number of droplets.

PATHOGENESIS:-About 90% of those infected with M. tuberculosis have asymptamatic, latent TB infections (sometimes called LTBI), with only a 10% lifetime chance that the latent infection will progress to overt, active tuberculous disease.

when bacteria enters into body,it enters into alveoli present in lungs. In alveoli macrophages are present ,when bacteria enters alveolr macrophages,they

get replicated. Bacterial cells are picked up by dendritic cells which doesn’t allow replication of

bacteria,but allow transfer of bacteria from lungs to other tissues. Then it enters into lymph nodes and then blood dtreamand distributed to other

parts.this infection is called as secondary infection. primary site of infection is ghons focus,present in upper part of lower lobe and lower

part of upper lobe.

each part in our body is effect by this type of bacteria-----brain,pancreas,liver,thyroid,bones,heart,skeletal muscles,lymphnodes,respiratory track.

TB is also considered as granulomatous condition. Macrophages present in order to form granuloma surrounded by

lymphocytes Cells present in granuloma are epitheloid cells.these unite to form gaint

cells.results in formation of tubercles.

In center of granuloma white cheesy material is seen,which is called as " soft tubercle",this is called as "caseous necrosis".

In case of hard tubercle,along with fibroblasts,epetheloid cells are present.

epetheloid cells combine to form gaint cells. Finally to minimize the infection,tubercles get healed by formation of

scars and calcification.

DIAGNOSIS.

diagnosis based on symptoms is signs and symptoms is difficult. main test is chest X-ray is taken to identify tubercles,primary and

secondary infection. microbiological tests- sputum test,urine test are done to identify

bacteria. If a person is seriously infected then blood test is done immediatedly. skin tests-- heaf test

montaux test. ct scan to diagonise tb.

skin test-- in this tests,take the purified protein derivative,quantity of ml

differs,but procedure is same. PROCEDURE- -ppd solution is taken and injected into skin in fore arm.

- wait for 48-72 hours - if patient is really suffering from TB,we can observe red bump on fore arm. -based on red bump,they conform the tuberculosis.

TREATMENT.

treatment is taken for about 6 months to 1year period. Drugs used to treat are called as anti tubercular drugs.these are

classified into 1st line drugs and 2nd line drugs.

1st line drugsINH[isonicotinic

acid]RifampicinEthambutol

PyrazinamideStreptomycin.

2nd line drugsClarythromycin

ethionamidePAS[para amino salicylic acid].

When compared to 2nd line drugs,1st line drugs have more efficacy and lower toxicity.

treatment period is 6months -1 year. 1st 2 months-drugs used are INH,refampcin,ethambutol,pyrazinamide. for the next four months-drugs used are INH,refampicin.

In order to get rid of resistance/minimize the resistance,drugs are given in combinations for treatment.

PREVENTION.

TB can be prevented by giving a vaccine called BCG[Bacillus Calmette Guerin],which is also used to prevent leprosy.

It is the most widely used vaccine worldwide, with more than 90% of all children being vaccinated.

As tuberculosis is uncommon in most of Canada, the United Kingdom, and the United States, BCG is administered to only those people at high risk.

DOTS-directly observed treatment strategy- doctors checks and superwise patients to minimize tb.

PUBLIC HEALTH:-The World Health Organization declared TB a "global health emergency" in 1993, and in 2006, the Stop TB Partnership developed a global plan to stop Tuberculosis, that aims to save 14 million lives between its launch and 2015.

A number of targets they have set are not likely to be achieved by 2015, mostly due to the increase in HIV-associated tuberculosis and the emergence of multiple drug-resistant tuberculosis.

HISTORY.

Tuberculosis is an ancient disease spinal Tuberculosis in Egyptian mummies. Genetic studies suggest TB was present in the America from about 100 AD Before the Industrial revolution, folklore often associated tuberculosis with

vampires. When one member of a family died from it, the other infected members would lose their health slowly. People believed this was caused by the original person with TB draining the life from the other family members.

Although the pulmonary form associated with tubercles was established as a pathology by Dr Richard Morton in 1689, due to the variety of its symptoms, TB was not identified as a single disease until the 1820s. It was not named "tuberculosis" until 1839, by J. L. Schönlein.

The bacillus causing tuberculosis, M. tuberculosis, was identified and described on 24 March 1882 by Robert Koch. He received the Nobel Prize in physiology or medicine in 1905 for this discovery.

Hopes of completely eliminating TB from the population were dashed after the rise of drug resistance strains in the 1980s. The subsequent resurgence of tuberculosis resulted in the declaration of a global health emergency by the World Health Organization in 1993.

SOCIETY AND CULTURE.

The World Health Organization, Bill and Melinda Gates Foundation, and US government are subsidizing a fast-acting diagnostic tuberculosis test for use in low- and middle-income countries.MARCH 24rth is world tb day.many campaigns were held to bring awarenes about tb and its treatment.

ANY QUESTIONS??