Presentation on theme: "Dr. Essam El Moghazy NTP Egypt. The Global burden of TB in 2010 1.3 million deaths in 2008 – 98% of these in developing world 11–13% of incident cases."— Presentation transcript:
Dr. Essam El Moghazy NTP Egypt
The Global burden of TB in million deaths in 2008 – 98% of these in developing world 11–13% of incident cases were HIV-positive 380,000 deaths due to TB/HIV cases MDR-TB 9.4 million new cases in 2009 – 80% in 22 high- burden countries
The burden of TB in Egypt 2010
WHAT IS TUBERCULOSIS? Tuberculosis is an infectious disease caused mainly by Mycobacterium tuberculosis. Tuberculosis can affect most organs in the body, but the lung is the main organ affected. If left untreated, each person with smear-positive pulmonary TB will infect, on average, between 10 and 15 persons in each year.
Those who will be infected with TB will not necessarily get the disease. The immune system walls off the TB bacilli, which can lie dormant for years. When someones immune system is weakened, chances of developing TB are increased. On average, 10 percent of the infected individuals develop the disease during their lifetime.
SOURCE OF INFECTION There are a number of Mycobacteria responsible for causing the disease in human beings: –Mycobacterium tuberculosis; –M. Africanum; and –M. Bovis.
TRANSMISSION OF INFECTION Inhalation: Inhalation of droplet nuclei, from a patient with smear positive pulmonary Tuberculosis, caused by sneezing or coughing is the most common way of transmission of TB infection. Ingestion: Infection usually occurs through milk contaminated with M. Bovis Coetaneous: Very rare and of no epidemiological importance (e.g. ear piercing; tattoos) Congenital: Very rare – the fetus acquires the infection from the diseased mother.
When to suspect TB? Tuberculosis should be considered if the patient has: –Persistent cough for two weeks or more; every individual presenting this symptom at the health facility should be considered a TB suspect –Production of sputum which may be blood-stained –Breathlessness and chest pain –General symptoms such as: loss of appetite; loss of weight; night sweats and fever –A history of contact with a TB patient The symptoms and signs of extra-pulmonary TB depend on the organ involved, e.g.: Chest pain in TB pleurisy and sharp angular deformity of the spine in Potts disease
The diagnosis of adolescents and adults with symptoms suggestive of pulmonary TB should be confirmed by detecting Acid Fast Bacilli (AFB) through the direct smear examination of the sputum.
A) Bacteriology 1. Detection of TB bacilli Direct smear microscopy The direct smear microscopy of sputum is a reliable and simple technique for detecting Mycobacteria in order to diagnose pulmonary TB. The method consists of microscopic examination of a specimen of sputum that has been spread on a slide, and stained by the Ziehl-Neelsen method.
Culture Culture of sputum is more sensitive than smear examination, but it takes 4 to 8 weeks before the result is known. It also requires well-equipped laboratories with skilled staff. Culture allows the study of anti-TB drug resistance.
2. Detection of the immune response to TB bacilli: Tuberculin skin Test (TST) When a healthy person is infected for the first time with the tubercle bacilli, the body will develop a specific immune response. This immune reaction (cell-mediated immunity) can be assessed by TST. Tuberculin is an antigen produced from dead tubercle bacilli, purified protein derivative PPD of. In the Mantoux test, 0.1 ml of tuberculin is injected intradermally. Most people infected by M. tuberculosis or vaccinated by BCG will react to TST and develop an induration at the site of injection. The diameter of this induration is measured after 48 to 72 hours.
3. Histo-pathological diagnosis of TB Through a biopsy of the suspected lesion e.g. lymph node biopsy and pleural biopsy. 4. Detection of metabolic end products of TB bacilli: BACTEC BACTEC is complicated and expensive, and is available only in specialized centers. 5. Detection of DNA of TB bacilli: polymerase chain reaction (PCR) PCR is 100% specific, but it its sensitivity is about 85 %. Moreover, it is expensive and requires specialized skills and equipment.
B) Radiography X-rays are not specific. TB can mimic any chest disease on the X-ray. Furthermore, it is difficult to differentiate in an X-ray between clinically active and inactive old lesions of pulmonary TB. It is not justified to start anti-TB treatment on radiographic basis. However, radiography can be of help in certain occasions, such as childhood TB; miliary TB; hilar lymphadenopathy; extra-pulmonary TB and, lack of sputum.
What determines case definition? The Three determinants of case definition are: –Site of TB disease. –Bacteriology (result of sputum smear). –History of previous treatment of TB. Note. Any person given treatment for tuberculosis should be recorded as a case. Incomplete "trial" tuberculosis treatment should not be given as a method for diagnosis.
New case A patient who has never had treatment for TB or who has taken drugs for less than one month Previously treated patients have received 1 month or more of anti-TB drugs in the past, may have positive or negative bacteriology and may have disease at any anatomical site. They are further classified by the outcome of their most recent course of treatment
Relapse A patient who is declared cured by a physician, after one full course of chemotherapy, and has become bacteriologically positive (indicates positive smear, culture or other newer means of identifying M. tuberculosis) Treatment failure A patient who, while on treatment, remained or became again smear- positive 5 months or later after commencing treatment; or, A patient who was initially smear-negative before starting treatment and became smear-positive after the second month of treatment
Treatment after interruption A patient who interrupts his treatment for 2 months or more (defaulter) and returns with smear positive sputum Others A patient who was either smear-negative pulmonary TB or extra-pulmonary TB, completed treatment and returned with symptoms and active disease or chronic cases. Chronic case: A patient who remained or became again smear-positive after completing a fully supervised retreatment regimen.
ContinuationInitialPatient Category Treatment category 4/HR2/EHRZ OR 2/SHRZ New smear +ve PTB. New smear –ve New forms of extra-Pulmonary TB. I
ContinuationInitialPatient Category Treatment category 5/HRE2/SHRZE then 1/HRZE Sputum smear +ve Relapse. Treatment failure. Treatment after interruption. II
Pulmonary Extra Pulmonary Positive Negative TAITAF Relapse New 2HRZES/1HRZE/5HRE 2HRZE(S)/4HR Re treatment cases TUBERCULOSIS