Acute respiratory infections (ARI) affect any part of the respiratory tract for less than 30 days and are a leading cause of death in children under five, particularly in low-income countries. Common causes include various bacterial and viral pathogens, and environmental factors such as air pollution and overcrowding increase susceptibility. Effective treatment early on can lead to full recovery, but delays in therapy increase mortality rates associated with ARI.

1. Acute Respiratory Infections
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Ali Abdulazeem
Mohammed Musa

2. Acute respiratory infections (ARI)
Indicate an infection of any part of respiratory tract of
less than 30 days duration and otitis media of less than 14
days duration.
It includes acute episode of running nose (cold), cough,
ear discharge, hoarseness of voice, breathing difficulty,
fast breathing and chest indrawing with or without fever.
On the other hand, chronic cough is one that lasts for 30
days or more. The common causes of chronic cough are
tuberculosis, asthma, foreign body, pertussis, HIV
infection etc.

3. Classification Of ARI
• Upper respiratory tract infections (AURI) include
common cold, pharyngitis, laryngitis,
tracheitis, epigiotitis
and otitis media.
• Lower respiratory tract infections
(ALRI) include bronchitis,
bronchiolitis and pneumonias.

4. 
It is currently the leading cause of death in young
children in low income Countries The World Health
Organization (WHO) estimates that one-third of all
deaths in children below the age of five years (4.3
million deaths in real terms in 1993) are due to ARI.

5. Major causes of death in neonates and
children under 5 years old around the world, 2013
(UNICEF A Promise Renewed: A Progress Report 2013 p. 22-23).

6. 
The highest death rates for ARI are seen in Africa,
especially sub-Saharan countries, followed by Asia
(excluding China) and then by Latin America and
China, and with much lower rates in North America
and Europe.

a ARI comprises 25-30 percent of hospital
consultations and 25 percent of total hospital
admissions. However, the incidence of ARI is
similar in industrialized and developing countries.

7. Global distribution of Acute Respiratory Infections
(Including pneumonia and influenza)
Accessed at: http://ih887.pbworks.com/w/page/5284030/Acute%20Respiratory%20Infection
World Lung Foundation

8. Epidemiology
Like other health problems studying by putting ARI in
epidemiological triangle
ARI

9. AGENT FACTORS

Acute respiratory infections are caused by a variety
of pathogens including bacteria and viruses.

The manifestations include influenza, sinusitis, acute
otitis media, nasopharyngitis, tonsillitis, epiglottitis,
laryngitis, tracheitis, acute bronchitis, bronchiolitis
and pneumonia.

10. VIRUSES

Enterovirus,

Influenza A, B, C,

Measles,

Parainfluenza 1, 2, 3,

RSV,

Rhinovirus,

Coronavirus

11. BACTERIA

Bordetella pertussis,

Corynebacterium diphtheriae,

Hemophilus influenzae,

Legionella pneumophila,

Strep. Pneumoniae,

Strep. pyogenes.

12. HOST FACTORS

Low birth weight: Infants born with low birth
weight, once infected, are more prone to death from
pneumonia.

Malnutrition: The average duration of
ARI illness in a malnourished child is
significantly longer. The complications
are more frequent and
the prognosis more grave.

13. 
Lack of immunization: Pneumonia is a common
complication associated with measles and whooping
cough which can be prevented by appropriate
immunization.

Antecedent viral infection: Such infections act by
impairing the child’s immune status. The bronchial
epithelium is damaged and thus the clearing of the
bacterial agent is impaired.

14. ENVIRONMENTAL FACTORS

Air pollution:
Air pollution, both indoor and outdoor, is
directly associated with an increased incidence of
ARI. The inhalants in polluted air cause damage to
tracheobronchial mucosa and bring about ciliary
paralysis which might increase susceptibility to
severe infection.

15. 
Passive smoking:
Passive smoking predisposes a child to
respiratory illness. Passive exposure to smoke in
childhood has an important bearing on the
development of respiratory function which, in turn,
may predispose a child to increased risk from
environmental agents later in life.

16. 
Pollution from biomass fuels:
Heavy exposure to smoke from cooking and
heating fires predisposes a child to severe ARI.

17. 
Overcrowding:
In conditions of continued close contact in
crowded families, an increased secondary attack rate
for respiratory infections has been
established.

18. TIME FACTOR
IN PROGNOSIS OF ARI

Respiratory infections, if treated early and
effectively, can be completely cured in nearly all
cases with normal life expectancy, which is often not
possible with other systemic diseases.

There is empirical evidence that the high mortality
in acute infections, including those affecting the
respiratory system, is mainly
attributable to gross delay
in institution of effective
therapy.

19. Viral Infections

Among the acute respiratory illness two-thirds to
three fourths are caused by viruses. Most of these
viral infections affect the upper respiratory tract, but
lower respiratory tract can be involved in certain
groups particularly in young age group and in
certain epidemiological settings. The illness caused
by respiratory viruses expressed into multiple
distinct syndromes, such as common cold,
pharyngitis, croup, tracheobronchitis, bronchiolitis,
pneumonia, etc.

20. COMMON COLD
(ACUTE CORYZA)

Almost everybody suffers from common
cold sometime in his life. It occurs more in
winter and in cold climates. It is an acute
infection of the respiratory tract
characterized by sneezing, running nose,
nasopharyngeal irritation and malaise
lasting two to seven days. Fever is rare.

The infectious agent is a rhinovirus with
more than 100 serotypes.

21. 
The patient is highly infective 24 hours preceding
and five days following the onset of the disease.
Transmission is by droplet method or through
fomites such as handkerchief. Susceptibility is
general. Immunity is shortlived and lasts for a month
or so. Incubation period is 12 to 72 (usually 24)
hours. There is no specific treatment. Cold vaccines
have been used but the results are not encouraging.

22. INFLUENZA

Influenza is an acute infectious respiratory disease
caused by RNA viruses of the family
orthomyxoviridae (the influenza viruses).
transmitted through respiratory droplets of coughs
and sneezes from an infected person, direct (skin to
skin) or indirect contact with infected material,
which ultimately enter through nasopharyngeal
route.

23. Seasonal risk areas for influenza

24. Clinical Features

Infection with influenza may be asymptomatic but
usually gives rise to fever and typical prostrating
disease, characteristic in epidemics. Usual
symptoms are flushed face, congested conjunctivae,
cough, sore throat, fever for two to three days,
headache, myalgia, back pains and marked
weakness. Pneumonia due to secondary bacterial
infection is the most common complication

25. 
Transmission of viruses starts one day before the
onset of symptoms and continue up to five to seven
days after the symptoms subsides.

Morbidity rate varies from 15 to 25 percent of the
population exposed to risk in case of large
communities. The rate may be as high as 40 percent
in case of closed populations.

26. 
The disease was first recognized in 1173; since then
80 epidemics have occurred. The epidemic lasts for
six to eight weeks at a place.

It is not known what happens to the virus between
the epidemics. However, there is evidence that
transmission of the virus to extrahuman reservoirs
(pigs, horses, birds, ducks) keeps the virus cycle
alive.

27. Changing
Nature Of Virus

Minor changes in the hemagglutinin and/or
neuraminidase antigens on the surface of the virus
which results from point mutation during viral
replication is called antigenic drift.

Antigenic drift explains why a person can be
infected by Influenza A viruses several times and
also why Influenza vaccine need to be updated every
year.

28. 
Antigenic shift is the major antigenic change that
results from genetic reassortment between two
different virus subtypes coinfecting the same cell
and developing a new subtype with completely new
hemagglutinin and neuraminidase antigen.

Antigenic shift is noted only with type A influenza
virus.

29. 
An example of antigenic shift involving both the
hemagglutinin and neuraminidase is that of 1957
influenza pandemic, when predominant sub type of
influenza A shifted from H1N1 to H2N2. The
population has got no immunity against the newly
emerged strain, which can then spread to cause an
‘Influenza pandemic’

30. Control Of Influenza

Influenza vaccination is the key strategy for the
prevention of influenza during the interpandemic
periods and a pillar of pandemic preparedness.
Antiviral drugs can only be used as an adjunct.
Resistant mutants of both the classes of antiviral
agents have been detected.

31. Types Of
Influenza Vaccines

Whole virus vaccines consisting of inactivated
viruses.

Split vaccines: This vaccines consisting of virus
particles disrupted by detergent treatment.

Subunit vaccines: Only the NA and HA proteins are
present and other internal and matrix proteins are
removed.

32. Prevention and control strategies

All symptomatic people should:
1. Avoid close contact (less than 1 meter) with
other people.
2. Cover their nose and mouth when coughing
or sneezing.
3. Use disposable tissues to contain respiratory
secretions and Immediately dispose off them.

34. CHICKENPOX (VARICELLA)
● Relatively mild disease in healthy children but may be life
threatening in immunosuppressed patients, neonates, and normal
adults, especially smokers-for whom the risk of varicella
pneumonia is high.
● attack is long lived, may be for life.
● Caused by a filtrable virus called the Varicella-Zoster virus
which is also responsible for herpeszoster (shingles). These two
diseases are now regarded as manifestations of different host
responses to the same etiological agent. Herpes zoster is more
common in adults and is rare in children.
● Chickenpox is spreads easily through the coughs and sneezes of
an infected person.

35. Clinical Manifestation

36. Prevention
-Passive Immunization:
Varicella-zoster immune globulin (VZIG) post exposure
prophylaxis is recommended for immunocompromised
children, pregnant women, and newborns exposed to
maternal varicella.
- Active Immunization:
Live virus vaccine is recommended for routine
administration in children at 12 to 18 months of age.

37. MENINGITIS
Meningococcal Meningitis:
Neisseria meningitidis is a
gram-negative Diplococcus
appears as kidney-shaped
pairs, Carriers, patients and
mild cases of nasopharyngitis
are the source of Infection

38. Prevention and Control
● Isolation: up to 24 hours after the start of appropriate
chemotherapy
● Protection of contacts:
Sulphadiazine for five days or rifampicin for two
days (adult dose: 600 mg bd) given as a
chemoprophylactic measure.
● Vaccine:
The meningococcal polysaccharide vaccine consists
of group-specific purified capsular polysaccharides

39. MEASLES
(RUBEOLA; MORBILLI)

Measles is endemic all over the world. Almost all
people suffer from it once. It occurs in epidemic
form every 2-3 years, more in winter months from
December to April. Measles is a leading cause of
childhood morbidity and mortality and nearly half
the global burden of vaccine preventable deaths.

40. 
The causative agent, measles virus, is a member of
the genus Morbillivirus of family Paramitoviridae.
Source of infection and modes of transmission are
same as in case of chickenpox. It is communicable
from four days before to five days after the
appearance of rash.

45. Prevention
1- The vaccine is a live attenuated vaccine.
2- When live attenuated vaccine is contraindicated,
human immune globulin (IG) may be given

46. 
The strategies to achieve the goal of measles
mortality reduction are:
- Achieving high routine measles vaccination
coverage of infants at 9 to 12 months of age;
- Establishing effective measles surveillance system
- Improving case management of measles cases
- Providing a second opportunity for measles
immunization to those who have not yet received
vaccine or who did not develop immunity after
vaccine administration.

47. MUMPS

Mumps is prevalent all over the world in endemic
form. The incidence rises in winter and spring. It is
caused by the virus—myxovirus parotiditis—which
has a predilection for glandular and nervous tissues.
The patient is infective seven days before the
swelling and for a week after that, Spread is by
droplet infection and through fomites

49. Prevention

Live mumps vaccines are available as monovalent
mumps vaccine, bivalent measles–mumps (MM)
vaccine, and trivalent measles–mumps–rubella
(MMR) vaccine.

50. RUBELLA
(GERMAN MEASLES)

Rubella is a common cause of childhood rash and
fever; The causative agent is a togavirus, The spread
of infection is mainly by droplet infection and direct
contact. A person is infective for two weeks— about
one week before and one week after the appearance
of skin rash

Clinical Features: Prodrome of low grade fever,
Lymphadenopathy in second week, Maculopapular
rash 14-17 days after exposure

51. Prevention
A live attenuated vaccine is available which
confers solid long-term immunity in 95 percent
cases.

52. PNEUMONIAS

They may be bacterial or viral in etiology. Among
bacterial pneumonias include those caused by S.
aureus, Staph pyogenes, Klebsiella and H.
influenzae

53. 
The pneumococcal pneumonia is an acute febrile
infection with cough, dyspnea and, often, pleural
pain. Pneumonia is usually lobar or segmental but a
bronchopneumonial involvement is common in
childhood and old age. The causative agent is
Streptococcus pneumoniae

54. Clinical Features

55. Vaccines

The pneumococcal polysaccharide vaccine (PPV).

56. Despite steady progress, pneumonia remains one of the single largest
killer of young children worldwide, 2015
Source: WHO and Maternal and Child Epidemiology Estimation Group (MCEE) provisional estimates 2015
Percentage of deaths among children under age 5 attributable to pneumonia

58. STREPTOCOCCAL
SORE THROAT

It is an acute inflammation of throat due, most
commonly, to Streptococcus hemolyticus, group A
(beta hemolytic) It is a very common ailment, more so
in children. Infection may be exogenous or
endogenous. Droplets, air, dust and fomites, all play a
part in its spread. Its important complications are
rheumatic fever and acute glomerulonephritis, hence it
should be treated early. It responds well to sulpha
drugs and penicillin.

59. DIPHTHERIA

Corynebacterium diphtheriae in severe cases can
cause pseudomembrane, it is gradually formed in the
throat, recognizable by their typical asymmetric,
grayish-white appearance and strong attachment to
the underlying tissue. Such pseudomembranes may
extend into the nasal cavity and the larynx causing
obstruction of the airways. Laryngeal diphtheria,
which sometimes occurs even without pharyngeal
involvement, is a medical emergency that often
requires tracheostomy

60. Prevention and Control

Early detection and notification

Isolation

Quarantine

Disinfection

Immunization: Active immunization is done by
using diphtheria toxoid

61. PERTUSSIS
(WHOOPING COUGH)

Prevalence is worldwide. The disease is more
common in temperate climate and in winters. It is
caused by Bordetella pertussis spread mainly by
droplets but also, to a small extent, through fomites.

63. 
Incidence and mortality are both higher in females.
Most deaths occur below one year age. Case fatality
ratio is 15 per 1000.3 There is no subclinical case
and no chronic carrier. Secondary attack rate is
about 90%.

64. Methods of Control:

Notification, isolation,Immunization for whooping
cough is usually done in the form of DPT, Both
whole cell and acellular pertussis vaccines are
widely used.

65. Distribution of communicable diseases cases in Azadi
teaching hospital during March, 2016
Total: 118
ARI: 31