Respiratory Tract Infections PDF

Respiratory tract infections  Upper Respiratory System Nose Nasal cavity...

Respiratory tract infections  Upper Respiratory System Nose Nasal cavity Sinuses Tongue Pharynx Esophagus Lower Respiratory System Clavicle Larynx Trachea Bronchus Bronchioles Smallest bronchioles Ribs Right Left lung lung Alveoli Diaphragm © 2015 Pearson Education, Inc. URTI LRTI Common cold Laryngotracheobronchitis Oral thrush (Croup) Pharyngitis Bronchitis Sinusitis Bronchiolitis Epiglottitis Pneumonia Diphtheria Tuberculosis Otitis media Viruses are the most Bacteria are the most common causes common causes in adults Transmission route https://www.nature.com/articles/s41579-021-00535-6/figures/1  Common cold The most common URTI Peak in winter Caused by >200 viruses Rhinovirus causes most cases in adults Coronavirus, parainfluenza, adenovirus and respiratory syncytial virus (RSV) are more common in children Symptoms include cough, sneeze, sore throat, runny nose, fever Symptoms are self-limited No treatment available, but drugs are available that can relieve the symptoms  Oral thrush Caused by Candida albicans (a yeast) Whitish lesions in the oral cavity In patients who undergo prolonged chemotherapy, have diabetes, have taken broad spectrum antibiotics (e.g. tetracycline)  Pharyngitis In young children and adults, viruses are the most cause of pharyngitis In older children (5-15yrs), Streptococcus pyogenes is the most common cause, followed by viruses and Mycoplasma pneumoniae  Strep throat Caused by Streptococcus pyogenes (Group A -hemolytic Streptococcus) Should be treated by antibiotics, because it can lead to severe complications including sinusitis, otitis media, rheumatic fever, post-streptococcal glomerulonephritis Penicillin or amoxicillin are the first choice  Scarlet fever A complication of “Strep throat” Some strains of S pyogenes contain an erythrotoxin which causes reddening of the skin Rash on the neck, chest, elbows and inner thighs Most often in children aged 5 to 15 years. Was a major cause of deaths before development of penicillin Strawberry tongue  Sinusitis Inflammation of mucous membrane of nasal sinuses Signs and symptoms: Blocked or stuffy nose Pain, swelling, tenderness and pressure around eyes, cheeks, noses or forehead Headache, toothache, fever Common causes are: Streptococcus pneumoniae Haemophilus influenzae Streptococcus pneumoniae alpha (a)-hemolytic streptococci (partially hemolyze red blood cells) Cocci in pairs Can cause severe infections including otitis media, meningitis, sepsis Slide showing S. pneumoniae with capsule ( white halo surrounding cell) Image Source: Pinterest Pneumococcal vaccines Pneumococcal conjugate vaccines PCV13: serotypes of 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F and 23F PCV15: 2 additional serotypes of 22F and 33F; induced higher immunogenicity against serotype 3 than PCV13/PCV20 PCV20: 5 additional serotypes (8,10A, 11A, 12F and 15B), approved for use in adults only (18+years) Pneumococcal polysaccharide vaccine (23vPPV) Recommendation of pneumococcal vaccines in Hong Kong for high-risk populations as of 27 September 2023 Children can receive PCV15 with two primary doses given at 2 and 4 months of age followed by a booster dose at 12 months (2p+1). A single dose of 23vPPV for elders 65 years of age and older without high risk conditions. High-risk individuals aged 2 years or above to receive a single dose of PCV15, followed by a single dose of 23vPPV one year later. For those who have already received PPV23, a single dose of PCV15 should be administered one year later. For those who have already received any PCV15, a single dose of 23vPPV should be administered one year later. Haemophilus influenzae Haemophilus influenzae type b (Hib) is the common cause in young children (