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Diseases transmitted by inhalation - Coggle Diagram
Diseases transmitted by inhalation
Respiratory tract infections
Upper respiratory tract infection:
(involves the nose, pharynx and larynx)
Bacterial infections
Acute follicular tonsillitis
Causative organism
Streptococcus pyogenes
Gram-positive cocci arranged in chains
Mode of transmission
Droplets from a case or a carrier
Clinical picture
Pain, redness, and swelling of posterior pharynx, with greyish-white tonsillar exudate
Complications
Rheumatic fever and/or glomerulonephritis
Treatment
Penicillin
Prevention of rheumatic fever
Long-acting penicillin injection once a month to prevent rheumatic attacks.
Scarlet fever
Causative organism
Streptococcus pyogenes
Clinical picture
Pharyngitis
Red rash
Strawberry tongue
Diphtheria
Causative organism
Corynebacterium diphtheriae
Gram-positive bacilli arranged at angles having Chinese letters appearance
Mode of transmission
Droplet transmission from a case or a carrier
Clinical picture
The organism settles at the mucosa of the tonsils, or pharynx and produces a powerful exotoxin.
The lymph nodes are enlarged and oedematous giving the “bull-neck" appearance.
Local inflammation and necrosis cause the development of an adherent grey pseudo-membrane which bleeds on attempts to remove it.
Complications
The membrane may compress the airway leading to suffocation.
The organism produces a powerful toxin absorbed by the blood, which affects the heart, brain, or kidney.
Treatment
Rapid administration of antitoxin is life-saving (to neutralize the toxin).
It should be started if there is enough clinical suspicion without waiting for laboratory diagnosis. Care should be taken when giving antitoxin serum to avoid complications, such as hypersensitivity reactions.
Antibiotics should also be given to kill the organism.
Prevention
Active immunization by DPT vaccine (containing diphtheria toxoid) is given to infants at 2, 4, and 6 months.
Booster doses are given at the age of 18 months and school entry.
Whooping cough
Causative organism
Bordetella pertussis Gram-negative coccobacilli
Mode of transmission
Droplet transmission from a case
Treatment
Erythromycin is the drug of choice.
Clinical picture
The disease affects mainly children.
The organism produces many exotoxins that induce both local and systemic effects.
It begins with mild upper respiratory symptoms followed by attacks of cough, ending in an inspiratory "whoop" that may be followed by vomiting.
Prophylaxis
Killed Pertussis vaccine
A heat-killed vaccine is given to infants combined with the vaccine for diphtheria and tetanus (DPT). Killed Pertussis vaccine should not be given after the age of 6 years as it may cause encephalopathy.
Viral infections
Influenza
Causative organisms
Influenza viruses
Mode of transmission
Droplets and contact with contaminated surfaces
Clinical picture
The patient suffers from fever, headache, runny nose, and body aches.
Sore throat and cough.
It can occur in epidemic or even pandemic forms.
Recurrent attacks in the same season: due to antigenic variation.
Complications
(occur in old debilitated patients)
Pneumonia: viral or secondary bacterial
Treatment
Supportive (antipyretics, analgesics)
Prophylaxis
Vaccination:available
(reformulated annually because the virus mutates frequently).
Common cold
Causative organisms
Rhinoviruses and other viruses
Mode of transmission
Droplet inhalation and hand-to-hand contact followed by inoculation of the virus into the nose or conjunctiva.
Clinical picture
Fever, headache, rhinitis (runny nose), sore throat and cough
The virus usually becomes undetectable after 4 or 5 days.
Treatment
supportive (antipyretics, analgesics)
Prophylaxis
no Vaccines
Lower respiratory tract infections:(involves bronchi and lungs)
Bacterial or viral infections
Bronchitis
Causative organisms
Bacteria
Strept. pneumoniae, Haemophilus influenzae,Staphylococci and most of Gram-negative bacilli
Viruses
many viruses as respiratory syncytial virus
Clinical picture
The infection may be acute or chronic.
The infection may occur as a complication of upper respiratory tract infection.
Pneumonia
Causative organisms
Pneumococci
capsulated Gram-positive cocci arranged in pairs
Haemophilus influenzae
Gram-negative coccobacilli
Staphylococcus aureus
Gram-positive cocci arranged in groups
Streptococcus pyogenes
Gram-positive cocci arranged in chains
Klebsiella pneumoniae
capsulated Gram-negative bacilli
Mycobacterium tuberculosis
Chlamydia and Mycoplasma
bacterial organisms that cause atypical pneumonia
Clinical picture
Inflammation of the alveoli of the lungs
Fever, cough, expectoration, and shortness of breath
Systemic infections
Bacterial infections
Tuberculosis (TB)
Mode of transmission
Inhalation (airborne)
Ingestion of unpasteurized milk
Clinical picture
General symptoms and signs
Fatigue, weakness, loss of weight, loss of appetite, night sweats and night fever
Pulmonary symptoms and signs
Cough, expectoration of a large amount of sputum, and dyspnea.
Causative organism
Mycobacterium tuberculosis, acid-fast bacilli
Two important pathogenic types
human
and
bovine
types
Diagnosis
Direct detection
Microscopic examination of Z-N stained smear: red bacilli against a blue background
Culture
On Lowenstein Jensen (L-J) medium
The organism grows slowly and needs about 4-8 weeks for colonies to appear.
Specimen
Three early morning sputum samples on 3 successive days
Treatment
Antituberculosis drugs
Combined therapy for at least 6 months.
Note
The patient must comply totally with the treatment, otherwise, there will be relapse and the organism will acquire resistance to the drugs
Prevention
Avoid overcrowding and poor aeration
Early diagnosis and treatment of patients, as they are the source of infection.
Milk pasteurization or boiling
Vaccination: using live attenuated vaccine (BCG) given to children during the 1st month of life.
Meningitis
Causative organisms
Viruses
poliovirus coxsackievirus, mumps, rubella, rabies, herpes virus and arboviruses
Fungi
Cryptococcus neoformans and Candida
Bacteria
Neisseria meningitidis: which are Gram-negative cocci arranged in pairs.
H. influenzae, Penumococci, Proteus, Strept. pyogenes, E. coli,Klebsiella & Mycobacterium tuberculosis
Mode of transmission
The organism is transmitted by droplets from a case or a carrier. It settles in the nasopharynx and then travels via the bloodstream to reach the meninges.
Clinical picture
1- Fever and enlarged cervical lymph nodes
2- Skin rash
3- Signs & symptoms of increased intracranial pressure: severe headache, projectile vomiting, blurred vision, positive planter reflex & stiffness of back and neck muscles
Treatment
1- Using antibiotics that can pass the blood brain barrier, as sulphonamides and ciprofloxacin.
2- Antiviral drugs in cases of viral meningitis
3- Antifungal drugs in cases of fungal meningitis
Prophylaxis
Chemoprophylaxis
may be helpful for those exposed and unvaccinated by rifampicin for 2 days (in cases of meningitis caused by N. meningitidis)
Vaccination
Polysaccharide vaccine for N. meningitidis, H. influenzae & pneumococci
Viral infections
Mumps
Causative organism
Mumps virus (Man is the only host for the virus).
Mode of transmission
Droplets
Clinical picture
Fever and painful swelling of the parotid glands
The virus may also disseminate to other salivary glands, testes, ovaries, pancreas, and brain.
Prevention
MMR vaccine, combined with measles and rubella vaccines, is given to children at 15 months, and a booster dose is given at school age.
Immunity is life-lasting immunity after a single infection….WHY?
1.Only one stable antigenic type exists.
A stage of viraemia is present, so circulating virus-neutralizing antibodies (IgM and IgG) are protective.
Measles
Causative organism
Measles virus (Man is the only natural host for the virus)
Mode of transmission
Airborne
Clinical picture
High fever, sneezing, coughing and eye redness.
Koplik’s spots on the inside of the
Pink skin rash mainly on the trunk region
Complications
occur in debilitated children
Pneumonia, otitis media, and post-measles encephalitis.
Prevention
MMR vaccine, combined with mumps and rubella vaccines, is given to children at 15 months, and a booster dose is given at school age.
Life-long immunity is gained after a single infection due to:
Measles virus is of only one stable antigenic type.
A stage of viraemia is present, so circulating antibodies are protective.
German Measles (Rubella)
Causative organism
Rubella virus
Mode of transmission
Droplets
Clinical picture
1- Fever
2- Skin rash (starts on the face and spreads downwards for 2-3 days then disappears)
3- Cervical lymphadenopathy
Note
Congenital rubella syndrome:
Infection in a pregnant female may transmit the virus to the fetus transplacentally and lead to
1- Abortion or premature delivery
2- Congenital defects of the infant affecting the heart, CNS, eye & deafness
Prevention
MMR vaccine, combined with mumps and rubella vaccines, is given to children at 15 months, and a booster dose is given at school age.
Rubella vaccine alone is recommended for prepubertal girls and mothers in the immediate postpartum period (to help protect their babies).
Varicella (chicken pox)
Causative organism
Varicella-zoster virus
Mode of transmission
Airbirne and Contact
Clinical picture
(usually in children 4-10 years old)
The typical rash of varicella appears first on the trunk and then spreads to the face and limbs.
The skin rash is initially macular and rapidly evolves through papules to clear vesicles which change to pustules that dry and heal without scar formation.
Zoster (shingles) may result from reactivation of latent varicella infection in the neurons and manifests as painful vesicular eruption, unilateral and confined to one dermatome.
Prevention
Antiviral drugs: are given to immune-deficient children.
Specific immunoglobulin: given to contacts of cases to prevent the development of disease.
Varicella vaccine (Varivax): is given as one dose for children 1-12 years of age.
