flu and TB Flashcards
influenza
- upper and lower respiratory tract illness
- cannot be flu without respir involvement
- systemic si/sx with sudden onset
flu has increased morbidity and mortality in which populations
- pregnant women
- kids
- > 65
- pts with comorbidities
types of the flu
- A
- B
- C
subtypes of flu
- based on hemagglutin (H) and neuramidinase (N) antigens
- A has 16 H and 9 N subtypes
major subtypes of the flu that affect humans
- H1, H2, H3
- N1, N2
antigenic shift
- major change in H and N
- causes pandemics and epidemics
- change in RNA of virus
antigenic drift
- point mutations if RNA
- small changes
- happen almost annually -> outbreaks of varied extent and severity
clinical manifestations of flu
- sudden onset
- HA
- fever- usually high grade
- myalgia
- cough
- sore throat
dx of flu
- rapid influenza antigen tests
- immunofluorescence- not used often
- RT-PCR- used more in research
who should be tested for flu
- Immunocompetent at risk for flu complications with acute febrile illness within 5 days onset
- Immunocompromised with febrile respiratory illness regardless of onset
- Inpatients with febrile respiratory illness
- Acute respiratory illness after admission
- Local surveillance
- Health care workers, residence, or visitors to institution with outbreak
- Linked to flu outbreak i.e. on cruise ship
ddx for flu
- strep pharyngitis
- mononucleosis
- pneumonia
- acute bronchitis
what is the first line tx for flu
- oseltamivir (tamiflu)
- given BID X 5 days for tx
- give QD X 7 days for prophylaxis
alt treatments for flu
- zanamivir (relenza)- inhaled
- peramivir (rapivab)- IV
- baloxavir (xofluza)- given as 1x weight based dose
who should get treated for flu and when?
- everyone should be treated
- greatest benefit in first 24-30 hours but can still treat
- especially want to target populations at risk for complications
pts who are at risk for complications from flu
- chronic disease and immunocompromised
- > 65
- kids <5
- pregnant women and 2 weeks post partum
- american indians and alaska natives
- nursing home residents
- morbid obesity- BMI > 40
TB
- bacterial infection with mycobacterium tuberculosis
- generally impacts lungs but can affect other body parts
- if left untreated kills 50% of pts
where is TB prevalent
- Sub-Saharan Africa
- india
- islands of southeast Asia and micronesia
reasons for resurgence of TB
- drug resistance
- poverty
- HIV
risk factors for TB
- substance abuse
- HIV
- poor nutrition, low SES
- men > women
- household contact
- born in endemic region
- community setting
- minority
how is TB transmitted
- respiratory droplets
risk factors for TB transmission
- active untreated disease
- cavitary disease
- sputum pos for m. tuberculosis, acid fast bacilli
risky procedures for pt with TB
- intubation
- bronchoscopy
- sputum induction
- chest PT
- admin aerosolized drugs
- irrigation of TB abscess
- autopsy
outcome of m. tuberculosis inhalation
- immediate clearance
- primary disease- immediate onset sx
- latent infection- pos PPD but no sx
- reactivation- onset of active disease many years after latent infection
when is the greatest risk for progression of TB to active disease?
- within first 2 years of infection
clinical manifestations of TB
- cough 3+ weeks
- chest pain
- hemoptysis
- fatigue, weakness
- weight loss, anorexia
- low grade fever, chills
- night sweats
- latent TB is asymptomatic
screening for TB
- mantoux tuberculin skin test (TST)
- purified protein derivative (PPD)
- pos PPD supports dx but is not diagnostic
- BCG can interfere- neg result does not r/o TB
when is 5 mm PPD test pos
- HIV infected*
- recent contact with TB case
- fibrotic changes on CXR
- pts who are immunocompromised
when is a 10 mm PPD test pos
- residence or employees of high risk setting
when is 15 mm PPD test pos
- majority of population
BCG vaccine
- TB vaccine used in high risk countries
- prevents childhood TB
- not recommended in US
- can cause false pos PPD
who gets a CXR for TB dx
- anyone with suspected TB
- pos PPD
- pos IGRA
- doesnt establish dx but can r/o TB
IGRA
- TB blood testing
- good specificity
- preferred in pts with BCG vaccine
- can use in pts who wont or cant return for PPD reading
what is the gold std for TB dx
- sputum culture
main drugs used to treat TB
- isoniazid (INH)
- rifampin (RIF)
- pyrazinamine (PZA)
- ethambutol (EMB)
- +/- streptomycin
how long are most TB treatments
- 9 months
tx for active TB
- intensive phase: INH + RIF + PZA + EMB X 2 months
- Continuation phase: INH + RIF for 18 weeks
tx for active TB in pregnancy
- Intensive phase: INH, RIF, EMB X 2 mo
- Continuation phase: INH + RIF X 7 mo
- do not use streptomycin or pyrazinamide in pregnancy
treatment for LTBI
- INH + RIF X 3 months weekly
- Not recommended if <2, HIV, resistant TB, or pregnant
treatment for LTBI in pregnancy
- INH QD or 2X week for 9 mo
- Supplement with pyridoxine (B6)
MDR- TB
- resistant to at least isoniazid and rifampin, possibly other drugs
XDR- TB
- resistant to at least isoniazid, rifampin, and one of three injectable second line drugs
- Capreomycin, kanamycin, amikacin
