adenoviruses Flashcards
what are adenoviruses
Adenoviruses are non-enveloped, icosaheadral viruses, containing
Double Standard linear DNA.
what diseases do adenoviruses cause
They commonly causes diseases such as
- respiratory infections
- conjunctivitis
- gastroenteritis .
how were adenoviruses first discovered
Adenoviruses – were 1st discovered during
- screening of throat washings
- cultures of adenoids and tonsils - performed in the search for the common
cold virus.
how many serotypes are of human adenoviruses are known
Nearly 40 serotypes (genotypes) of human adenoviruses are known.
Several different types of adenoviruses cause infections to the people
what is the pathogenesis of adenoviruses
- The site of the clinical syndrome is generally related to the mode of virus transmission.
For ex. Most adenoviruses cause respiratory disease - by the respiratory route.
However, most adenoviruses also replicate efficiently and asymptomatically in the
intestine.
- Some serotypes of adenoviruses can be isolated from the stool (after respiratory tract infection).
Similarly, ocular infections are transmitted by direct inoculation of the eye –- virus-contaminated hands
- ophthalmologic instruments
- bodies of water - groups of children swimming together.
The viruses are viable for a week at 37°C.
Inactivated at 50°C & resist ether and bile salts.
what is the clinical significance of adenoviruses
Clinical significance
Adenoviruses replicate well in epithelial cells
They cause diseases and symptoms which are related to the killing of these cells.
what are the types of adenoviruses commonly associated with disease
But certain types are more commonly associated with disease,
1) Respiratory tract infection
2) Eye infection
3) Gastrointestinal tract infection
what are the types of adenoviruses less commonly associated with disease
Less commonly associated with disease
4) Urinary tract
5) Heart
what is the most common respiratory tract infection of adenoviruses
i) Acute Febrile Pharyngitis - Most common manifestation in infants
& young children
characterized by - cough, tonsillitis
- sore throat
- nasal congestion
- fever
what does adenoviruses type 3,7,14 produce
Some adenovirus types (3, 7, 14) tend to additionally produce – conjunctivitis – is called pharyngoconjunctival fever.
- This is more prevalent in school children and swimming pool children – swimming pool conjunctivitis.
what does adenoviruses type 3 and 7 produce
Pneumonia – type 3 & 7 are associated with pneumonia in adults
resembling primary atypical pneumonia.
- But type 7 causes more serious and even fatal pneumonia in
infants & young children.
what do serotypes 4,7,21 produce
iii) Acute respiratory disease (ARD) – occurs usually as outbreaks in military recruits (Serotypes - 4, 7 & 21).
what is epidemic keratoconjunctivitis
iv) Epidemic keratoconjunctivitis (EKC)
– is a serious condition in epidemic causes follicular conjunctivitis - mostly self-limiting
some time more serious – involves in the corneal epithelium may be followed by corneal opacity lasting several years.
Transmission through –
- shared towels
- ophthalmic solutions
- person – person contact
- improper sterilized ophthalmologic instruments.
what does serotype 40 41 of adenoviruses produce
Gastrointestinal tract – causes infantile gastroenteritis (40 & 41).
what are the less common diseases caused by adenoviruses
Less common diseases caused by adenoviruses
several serotypes have associated with (particularly serotypes 11 and 21) - an acute, self limited hemorrhagic cystitis – occurs in children (especially boys) – characterized by hematuria.
Recently, adenovirus infection in heart muscle – shown left ventricular dysfunction in both children & adults.
Lab. Diagnosis
Collect samples – throat
- eye
- urine & faeces.
