M.tuberculosis,lab diagnosiss and clinical manifestations.pptx

all about M.tuberculosis

1. Clinical manifestations and laboratory diagnosis of Tuberculosis M.Sc. III Semester St. Xavier’s College Shyam Prasad Pant

2. CLINICAL MANIFESTATIONS Pulmonary tuberculosis : Symptoms: Chest pain Cough for more than 3weeks Weight loss Sputum production Haemoptysis Breathlessness/ Dyspnoea Fever and night sweating Tiredness Loss of appetite II. Extra pulmonary tuberculosis: Extra pulmonary TB occurs in the sites other than lungs such as lymph nodes, larynx, pleura (membrane surrounding the lungs), brain, kidneys, bones or joints. Depending on the site of infection, extrapulmonary infections may be: Genitourinary tuberculosis Tubercular meningitis Gastrointestinal tuberculosis Skeletal tuberculosis Tubercular lymphadenitis Miliary tuberculosis/ disseminated tuberculosis: This occurs when the bacilli enter bloodstream and are carried to all parts of body, where they grow and cause disease in multiple sites. This condition is rare but fatal. Miliary refers to the radiograph appearance as of millet seeds scattered throughout the lungs. It is most common in children below 5 years of age and in severely immunocompromised individuals.

3. CLINICAL MANIFESTATIONS Genitourinary tuberculosis Symptoms : The typical symptoms include dysuria, increased frequency of urination, and flank pain. The condition in men may manifest as epididymitis or a growth in the scrotal area . In women , the condition may manifest as pelvic inflammatory disease. Genitourinary tuberculosis is responsible for approximately 10% of sterility of women. Tubercular meningitis This is one of the most severe complications of tuberculosis. This condition may manifest headache, which is either intermittent or persistent. Gastrointestinal tuberculosis The clinical manifestation of the condition depends on the site affected in the gastrointestinal tract. For example, infection of stomach or duodenum manifests as abdominal pain mimicking peptic ulcer disease. Whereas infection of large intestine manifests as pain in abdomen, diarrhoea etc. Skeletal tuberculosis In skeletal tuberculosis spine is the most common site resulting pott’s disease. Tubercular lymphadenitis Tuberculous lymphadenitis (or tuberculous adenitis) is a chronic specific  granulomatous  inflammation of the lymph node  with  caseation   necrosis , caused by infection with  Mycobacterium tuberculosis  or  Mycobacterium bovis . It is most commonly involves the neck along the sternocleidomastoid muscle.

4. CLINICAL MANIFESTATIONS Complication of tuberculosis Miliary disease, disseminated tuberculosis, and tubercular meningitis are the most serious complications of primary tuberculosis. Pleural effusion and pneumothorax are other pulmonary complications of tuberculosis. Intestinal perforation, obstruction and malabsorption are the complication of tuberculosis of small intestine. Hydronephrosis and autonephrectomy are the renal complication. Paraplegia  (impairment in motor or sensory function of the lower extremities). Tuberculosis with HIV HIV patients with tuberculosis are more likely to progress to disseminated disease. These patients usually do not have cavitary pulmonary disease or upper lobe infiltrates in the lung. Patients with tuberculosis should be tested for HIV and those with HIV need to be tested periodically for tuberculosis by tuberculin skin test and chest radiography. HIV patients with a positive tuberculin skin test usually develop active tuberculosis at a rate of 3-16% per year. HIV reactivates latent tuberculosis infection and make the disease more serious and make treatment ineffective. The patient with both HIV and tuberculosis on treatment with antirectroviral therapy develop various clinical manifestations which includes fever, lymphadenopathy and noninvasive pulmonary infiltrates.

5. LABORATORY DIAGNOSIS Collection of the Specimen: Pulmonary TB: sputum Meningitis: CSF Kidney: urine Others: pus samples, laryngeal swabs, pleural fluid For sputum sample/pulmonary tuberculosis Collect 2 Sputum Samples as follows: 1. Supervised spot sputum specimen at the first visit. 2. Early morning sputum specimen on the next day. Out of two samples at least one must show AFB by microscopy. Good container: Disposable, clean, unbreakable, leak proof, wide mouthed plastic container. Plastic container SHOULD BE TRANSPARENT Newspaper and a used vial of streptomycin must not be used for the sample of culture and drug susceptibility test Every specimen container must be labelled with a serial number

6. INSTRUCTIONS TO THE PATIENT FOR SPUTUM COLLECTION Explain to the suspects (respiratory symptomatic patient) about the reason for sputum examination -Explain how many sputum samples are needed Give instructions on how to collect the sputum Instructions should be as follows to get sufficient sputum: Gargle to remove any thing remained inside mouth Continue to take breaths as deep as possible. Drink a glass of warm water, or black tea with pepper or ginger. Let the head down and cough up. Cough should come from as deep down in the chest as possible. Do not give saliva or nasal mucus. The early morning sputum must be collected before eating anything. The patients who are taking anti-tuberculosis drugs do not need to stop taking drugs before collection, but they must gargle well to remove the food and anti-tuberculosis drugs remaining in the mouth just before collection of sputum for culture and susceptibility test.

7. b. Microscopy: Procedure for microscopy: Sputum smears preparation (1cm × 2cm) by using a bamboo stick/applicator stick ↓ Acid fast staining ↓ Observe under microscope ↓ Acid fast bacilli; red rod slightly curved; often branching appearance

8. c. Culture: It is more sensitive than AFB staining technique and can detect 10-100 bacilli per field as observed in microscope. The culture is also required for antibiotic susceptibility test. For culture of sputum specimen, at first it is digested and decontaminated (other microbes in the sputum). Modified Petroff´s Methods for digestion and decontamination   (X) ml of sputum + 2 (X) ml of 4% NaOH in a capped test tube ↓ Allow to stand for 15 mins at room temperature to digest sputum ↓ Centrifuge at 3000 rpm for 15mins ↓ Decant supernatant ↓ Resuspend the residue in sterile normal saline ↓ Re-centrifuge at 3000rpm for 15 mins ↓ ↓ Residue Decant supernatant 0.1ml residue , which contains tubercle bacilli, is inoculated in LJ or Ogawa medium. LJ medium →rough, buff coloured and tough colonies Ogawa medium →head of cauliflower like colony

9. d) Biochemical tests: Rate of growth: slow grower Catalase: positive Niacin test: positive Growth on medium with p-nitrobenzoic acid: negative Pigment production: negative Tween 80 hydrolysis: negative Urease: positive Other methods: DNA probes PCR Bactec 460 TB rapid radiometric culture method Bactec 9000 MB system ESP culture