Immunology is the study of the immune system and is a very important branch of the medical and biological sciences. The immune system protects us from infection through

1. Presentation 12

2. Airborne diseases are diseases that are transmitted
through the air and affect the respiratory system.
In this course you will look at the following
airborne diseases:
 Upper respiratory tract infections
 Pneumonia
 Tuberculosis

3. An upper respiratory tract infection is an infection of
any of the structures of the upper airway. The
upper respiratory tract includes the sinuses, nasal
passages, pharynx, and larynx. These structures
direct the air you breathe from the outside to the
trachea and eventually to the lungs for respiration
to take place.

5. Upper respiratory infection is generally caused by the
direct invasion of the inner lining of the upper airway by
a virus or bacteria. Some of the common pathogens for
upper respiratory infection and their respective
incubation times are the following:
 Rhinoviruses, one to five days.
 Group a streptococci, one to five days.
 Influenza and parainfluenza viruses, one to four days.

6.  Respiratory syncytial virus (rsv), seven days.
 Pertussis (whooping cough), seven tob21 days.
 Diphtheria, one to10 days
 Epstein - Barr virus (ebv), four to six weeks (fauci
and longo, 2008).

7. The signs and symptoms of upper respiratory tract
infection are the following:
 Nasal congestion
 Runny nose (rhinorrhea)
 Nasal discharge (may change from clear to white to
green)
 Nasal breathing
 Sneezing

8.  Sore or scratchy throat
 Painful swallowing (odynophagia)
 Cough (from laryngeal swelling and post nasal drip)
 Malaise
 Fever (more common in children)

9.  Laboratory testing is generally not recommended in
the evaluation of upper respiratory infection. This
is because most upper respiratory infections are
caused by viruses, which do not have any specific
treatment.

10. Some important situations where specific testing may be
important include the following:
 Suspected strep throat (fever, lymph nodes in the neck,
whitish tonsils, absence of cough), necessitating rapid
antigen testing (rapid strep test) to confirm or rule out the
condition.
 Possible bacterial infection by taking bacterial cultures with
nasal swab, throat swab, or sputum.
 Prolonged symptoms, as finding a specific virus can prevent
unnecessary use of antibiotics (Fauci and Longo, 2008).

11. Treatment is normally symptomatic and it includes the following:
 Acetaminophen can be used to reduce fever and body aches.
 Non-steroidal anti-inflammatory drugs such as ibuprofen can be
used for body aches and fever.
 Antihistamines such as diphenhydramine are helpful in decreasing
nasal secretions and congestions.
 Nasal ipratropium (topical) can be used to diminish nasal secretions.
 Cough medications (antitussives) can be used to reduce cough.

12.  Steroids such as (dexamethasone (decadron ) and
prednisone orally (and nasally) are sometimes used reduce
inflammation of the airway passage and decrease swelling
and congestion.
 Decongestants such as pseudoephedrine (sudafed) actifed
oral, phenylephrine (neo-synephrine nasal) can be used to
reduce nasal congestion (generally not recommended in
children less than two years of age and not recommended
for individuals with high blood pressure).

13.  Oxymetazoline (afrin) nasal solution is a decongestant,
but should only be used for short-term.
 Combination medications containing many of these
components are also widely available.
 Antibiotics are sometimes used to treat upper
respiratory infections if a bacterial infection is
suspected or diagnosed. These conditions may include
strep throat, bacterial sinusitis, or epiglottitis.

14.  Antivirals may occasionally be recommended by
doctors in patients who are immunocompromised
(poor immune system). The treating doctor can
determine which antibiotic is the best option for a
particular infection (Fauci and Longo, 2008).

15. The important control and prevention measures of upper
respiratory tract infection are the following:
 Regular and thorough hand washing particularly after
touching the nose or mouth, and before handling food.
 Covering the mouth and nose when sneezing and
coughing. This helps to prevent the droplets loaded
with viruses from entering the air where they can infect
others.

16.  Do not share cups or kitchen utensils with others.
Use your own cup, plates and cutlery at mealtimes.
These are safe for others to use again after
washing them in the usual way (Fauci and Longo,
2008).

17. Pneumonia is an inflammatory condition of the lung
affecting primarily the microscopic air sacs known
as alveoli.

19. It is mainly caused by viruses or bacteria and less
commonly by other microorganisms, such as fungi.

20. Bacteria are the most common cause of community-
acquired pneumonia (CAP), with Streptococcus
pneumoniae isolated in nearly 50% of cases. Other
commonly isolated bacteria include haemophilus
influenzae in 20%, chlamydophila pneumoniae in
13%, and mycoplasma pneumoniae in 3% of cases;
Staphylococcus aureus; Moraxella catarrhalis;
Legionella pneumophila.

21.  In adults, viruses account for approximately a third
and in children for about 15% of pneumonia cases.
Commonly implicated agents include rhinoviruses,
coronavirus, influenza virus, respiratory syncytial
virus (RSV), adenovirus and parainfluenza.

22. The most common symptoms of pneumonia are the
following:
 Cough (with some pneumonias you may cough up
greenish or yellow mucus, or even bloody mucus).
 Fever, which may be mild or high.
 Shaking chills.
 Shortness of breath, which may only occur when
you climb stairs.

23.  Sharp or stabbing chest pain that gets worse when
you breathe deeply or cough.
 Headache.
 Excessive sweating and clammy skin.
 Loss of appetite, low energy, and fatigue.
 Confusion, especially in older people.

24. The main test is a chest x-ray (if the doctor suspects pneumonia).
Other tests include the following:
 CBC blood test to check white blood cell count.
 Arterial blood gases to see if enough oxygen is getting
into your blood from the lungs.
 CT (or CAT) scan of the chest to see how the lungs are
functioning.
 Sputum tests to look for the organism (that can be
detected by studying the spit) causing the symptoms.

25.  Pleural fluid culture if there is fluid in the space
surrounding the lungs.
 Pulse oximetry to measure how much oxygen is moving
through the bloodstream, done by simply attaching a
small clip to the patient’s finger for a brief time.
 Bronchoscopy, a procedure used to look into the lungs'
airways. It is performed when antibiotics are not
working well (Clark and Clark, 2006).

26.  Most cases of pneumonia can be treated at home.
However babies, children, and people with severe
pneumonia may need to be admitted to hospital for
treatment. Pneumonia is usually treated with
antibiotics, even if viral pneumonia is suspected as
there may be a degree of bacterial infection as well.

27. The type of antibiotic used and the way it is given is
determined by the severity and cause of the pneumonia.
Out-patient treatment usually includes the following:
 Antibiotics. They are given by mouth as tablets or liquid
capsule amoxicillin.
 Pain relieving medications.
 Paracetamol to reduce fever.
 Rest.

28. The preventive and control methods applied to
reduce occurrence of pneumonia include the
following:
 Stopping smoking. Smoking predisposes one to
pneumonia.
 Staying away from people who have colds, the flu,
or other respiratory tract infections.

29.  Avoiding people with measles or chickenpox especially
if one is not vaccinated against these diseases.
 Washing hands often. This helps prevent the spread of
viruses and bacteria that may cause pneumonia.
 Vaccinations: Children should get the pneumococcal
conjugate vaccine (Clark and Clark, 2006).