CBM - Childhood Diseases

Question 1

Childhood Diseases

Polio

Answer 1

• Poliomyelitis is a notifiable infectious viral illness affecting the central nervous system.
• Poliomyelitis is an acute illness that follows invasion through the gastrointestinal tract by one of the three serotypes of polio virus (serotypes 1, 2 and 3)
• The polio virus replicates in the gut and has a high affinity for nervous tissue.
• Spread occurs by way of the bloodstream to susceptible tissues or by way of retrograde axonal transport to the central nervous system
• Most often the infection is clinically inapparent, or symptoms may range in severity from a fever to aseptic meningitis or paralysis.
• Headache, gastrointestinal disturbance, malaise and stiffness of the neck and back, with or without paralysis, may occur
• Ratio of inapparent to paralytic infections may be as high as 1000 to 1 in children and 75 to 1 in adults, depending on the polio virus type and the social conditions (1)
• Majority of cases (95%) are either asymptomatic or characterised by an abortive flu-like illness (2).
• Live attenuated vaccine virus retains the potential to revert to a virulent form that can rarely cause paralytic disease.
• This is called vaccine-associated paralytic polio (VAPP). When wild viruses have been eliminated, VAPP cases can occur rarely where live

Question 2

Childhood Diseases

Diptheria

Answer 2

Diphtheria is an acute infectious disease caused by the action of diphtheria toxin produced by toxigenic Corynebacterium diphtheriae or by Corynebacterium ulcerans .

• The disease may manifest as:
• an upper respiratory tract infection
• characterised by membranous pharyngitis (known as a pseudo-membrane)
• a cutaneous infection

Question 3

Childhood Diseases

Tetanus

Answer 3

Tetanus - clostridium tetani - anaerobic, flagellated, exotoxin-secreting, Gram-positive bacillus that forms a characteristic terminal spore (‘drumstick’). Spores are widespread in the environment (commonly found on soil, faeces and dust) surviving hostile conditions for long periods:

• spores introduced to the body after the contamination of abrasion or minor puncture wound (which may go unnoticed), injecting drug also through abdominal surgery
• organisms remain and multiply at the site of inoculation.
• but in around 20% of the patients, no entry site can be found
• produces a powerful exotoxin - tetanospasmin - acts on motor cells in CNS and is conveyed along the peripheral nerves directed from the affected part

Question 4

Childhood Diseases

Tetanus

Treatment?

Answer 4

Neutralization of unbound toxin

• human antitetanus immunoglobulin is given intramuscularly (IM) to neutralise the free circulating toxins
• 150units/kg of IM preparation may be given in multiple sites (IM preparations should not be given intravenously

Antibiotic therapy

• several antibiotics are useful against the tetanus bacterium
• Metronidazole - is the antibiotic of choice and has superseded penicillin, is used for 7 days (1g PR three times daily)
• the importance of penicillin in tetanus remains controversial : in a randomized, controlled trial mortality rate was higher in patients treated with penicillin when compared to metronidazole (24% vs 7%; P < 0.01)
• acceptable alternatives include - erythromycin, tetracycline, chloramphenicol and clindamyci

Question 5

Childhood Diseases

Pertussis?

Answer 5

• Caused by the gram negative organism Bordatella pertussis - upper respiratory tract infection with a characteristic, paroxysmal - whooping – cough.
• Organism found in the back of infected throat.
• Bordetella parapertussis also be responsible, not preventable with presently available vaccines.
• Transmission by droplets and is a highly contagious disease with direct contact with an infected person. Up to 90% of household contacts develops the disease.
• Recent studies have suggested that droplets can be dispersed to a distance of 6 feet (1.9 metres) during coughing

Question 6

Childhood Diseases

Smallpox

Answer 6

Smallpox (variola) is a DNA virus of the genus orthopox virus, which includes vaccinia and monkeypox.

• it is specifically a human disease with no reservoir in any animal species
• in normal environmental conditions (ambient temperature, ordinary levels of humidity and exposure to sunlight) the virus is very unlikely to survive for more than 48 hours