Tuberculosis (TB) - PDF

Tuberculosis Tuberculosis (TB) is an airborne infectious disease caused by Mycobacterium tuberculosis, an acid-fast aerobic bacterium that is capable of remaining alive outside the host for a relatively long time. Certain medical conditions and other factors increase the risk that Latent T...

Tuberculosis Tuberculosis (TB) is an airborne infectious disease caused by Mycobacterium tuberculosis, an acid-fast aerobic bacterium that is capable of remaining alive outside the host for a relatively long time. Certain medical conditions and other factors increase the risk that Latent TB will progress to active TB. The risk may be 3x greater to those with DM and 100X greater to those with HIV infection compared to those that do not.  Clinical Presentation Persons who have been infected with Mycobacterium tuberculosis but do not have active disease (LTBI) are completely asymptomatic Signs and Symptoms Fatigue, anorexia Dry cough progressing to productive and sometimes blood tinged Weight loss, low grade fever Night sweats  Diagnostics Screening is the first step in diagnostic evaluation of TB, it is performed to identify infected persons at high risk for TB and those with TB needing treatment Definite diagnosis by NAAT culture of M. tuberculosis x3 QuantiFERON-TB Gold blood test AFB smears are presumptive evidence of active TB but not diagnostic. Small homogeneous infiltrate in upper lobes by CXR PPD shows exposure: Not diagnostic for active disease: repeat CXR in 6 months Upper lobe with cavitation (black round holes), fibrosis (scarring), and pulmonary infiltrates (fluid) in active TB disease  Differential Diagnosis Tuberculosis Pneumonia Acute Bronchitis Carcinoma  Pharmacologic Treatment Initially, Isoniazid(INH) 300 mg, Rifampin(RIF) 600 mg, Pyrazinamide 1.5 to 2.0 gm and ethambutol 15 mg/kg daily for 3-4 months Isoniazid: Give Vitamin B6 (pyridoxine) to decrease risk of neuritis, neuropathy, hepatitis and seizures Ethambutol: should be tested for visual acuity and red-green perception. Rifampin: Orange colored urine, hepatitis, thrombocytopenia Liver function studies, CBC, serum creatinine should be obtained at baseline If the isolate proves to be fully susceptible to INH and RIF then the 4th drug may be dropped Continue the first 3 drugs daily for two months then four more months of INH and RIF daily Persons with HIV should be treated for nine months  Management Notify Local health department of all cases of TB Hospitalizations is NOT required but should be considered if patient is non-compliant or is likely to expose susceptible individuals Use of negative pressure room for a hospitalized patient with active TB Monitor patient with Pulmonary TB weekly with sputum smears and cultures for the first 6 weeks after initiation of therapy, then monthly until negative cultures are documented Continued symptoms or positive cultures after 3 months should raise the suspicion of drug resistance  Important facts to recall! Those with a positive skin test should receive 6 months of INH: A positive test is 5 mm for HIV infected persons, contacts of a known case or persons with a chest film typical for TB, organ transplant A positive test is 10 mm for immigrants from high prevalence areas, those in high risk groups or health care workers, incarcerated, has diabetes and a healthy patient > 4 years A positive test is 15 mm for all others not in high prevalence groups  Pulmonary Function Tests (PFTs) PFTs access how well the lungs take in and release air. PFTs also measure how well the lungs transfer O2 from the atmosphere into a person’s circulatory systems. The PFTs specifically measure the following: FVC Volume of gas forcefully expelled from lungs after maximal inspiration FEV1 Volume of gas expelled in the 1st second of the FVC maneuver FEV 25-75 Maximal mid-expiratory airflow rate PEFR Maximal airflow rate achieved in FVC maneuver TLC Volume of gas in lungs after maximal inspiration FRC Functional residual capacity RV Volume of gas remaining in lungs after maximal expiration Barkley (2015)  Pertussis Also known as “Whooping Cough” is a highly contagious respiratory disease. It is caused by the bacterium Bordetella pertussis. Pertussis is known for uncontrollable, violent coughing which often makes it hard to breathe. Pertussis causes coughing fits, someone with pertussis often needs to take deep breaths, which result in a “whooping” sound. Pertussis can affect people of all ages, but can be very serious, even deadly, for babies less than a year old. The best way to protect against pertussis is by getting vaccinated  Clinical manifestations Early symptoms last for 1-2 week Runny nose low-grade fever occasional cough Late-stage symptoms can last for 10 weeks or longer Paroxysms followed by a “whoop sound” Vomiting during and exhaustion after coughing fits  Pertussis and Pregnant Women CDC recommends all women receive a Tdap vaccine during the 27th through 36th week of each pregnancy, preferably during the earlier part of this time period This will protecting the baby with high levels of antibodies before birth and the first 2 months prior to receiving vaccination.  Diagnosis and Treatment Diagnosis of Pertussis is made through: PCR (Polymerase chain reaction) – Rapid detection of B. pertussis and B. Para pertussis from nasopharyngeal swabs Treatment Antibiotic therapy Within first 3 weeks of infection- Azithromycin, Clarithromycin, Erythromycin Do not use cough medication Fluids to prevent dehydration Small frequent meals to prevent vomiting Pregnant women should get Tdap in third trimester of each pregnancy to prevent transmission  Gerontology Considerations Pulmonary Changes in the Elderly Lungs become stiffer, respiratory strength and endurance diminishes Chest wall becomes more rigid, Increased AP diameter Hyperresonance to percussion Alveolar surface decreases up to 20% reducing O2 uptake Alveoli collapse more easily Number of mucus-producing cells increase, cough reflex decreases PEARLS in the Elderly regarding Pneumonia At least 50% of all cases are among adults over 65 years of age Those in Long-term care facilities have 30% risk for pneumonia over 2 years period Streptococcus pneumoniae, gram negative bacilli and staph aureus most common CXR findings may have multiple presentations based on the offending  A patient has a chronic swelling of theparotid gland that is unresponsive to antibiotics and which has not increased in size. Which diagnostic test is indicated? a. Computed tomography b. Fine-needle aspiration c. Magnetic resonance imaging d. Plain film radiography  ANS: B Chronic lesions may represent tuberculosis or malignancies, so fine-needle aspiration is indicated to rule out these diseases. Radiological studies are used to identify theextent of disease but are usually not diagnostic