1 - Paeds - Resp - Chest infections - TB Flashcards
why is incidence rising?
spread by?
3 RFs?
due to HIV infection and multi-drug resistant strains
spread - resp route
RFs - lose proximity, infectious load, underlying immdef
how is tb infection different to Tb disease?
tb infection (latent TB) is more likely to progress to disease in infants and young kids
however - children vs adults??
kids generally not infectious vs adults, kids usually acquire it from an infected adult in the household
Clinical features - primary infection can be one of two things? % of infants + older kids show Sx+signs?
aSx and Sx
~50% of infants and 90% of older children will show minimal signs/Sx of infection
what limits Sx progression? disease does what? may do what? what may become +ve ? what then? what does CXR show?
local inflam reaction
disease remains latent and may activate later
Mantoux test may become +ve (>10mm or >15mm with BCG) - initiate treatment
CXR can showed marked hilar lymphadenopathy
what happens if local host response fails to contain inhaled tubercle bacilli?
it spreads by lymph to regional LNs. Lung lesion + LN = Ghon (primary) complex
how long does host cellular immune response take to respond? what slows and what develops?
3-6 weeks
mycobacterial replication slows but Sx develop -> fever, anorexia, weight loss, cough, CXR changes
What happens to primary complex ? inflam reaction may lead to what? what may also be present?
usually heals and may calcify
local enlargement of peribronchial LNs > bronchial obstruction > collapse and consolidation of affected lung
pl effusions may also be present
if its not halted by host immune response what happens?
local dissemination to other lung regions. primary infection may involve other organs eg gut, skin
2 steps before post primary TB?
dormancy + dissemination > reactivation > post primary TB
Miliary TB - sites? whats likely in paeds? causing?
bones, joints, kidneys, pericardium, CNS - CNS seeding is likely, causing tuberculous meningitis - sig mort and morb if not treated early
Initial treatment? examples?
what next?
triple, quad therapy (rifampicin, Isoniazid, Pyrazinamide, Ethambutol) initially
decreased to rif and ison after 2 months
length of treatment ? when is longer needed?
6m usually for uncompx pulm or LN TBif TB meningitis, or disseminated disease
what if pt is post puberty?
pyridoxine is given weekly to prevent peripheral neuropathy from isoniazid
what else in TB meningitis?
dexamethasone given for 1 month to reduce long term sequelae - ensure adherence
