Ultrasound is very useful for looking at soft tissue parts of the body such as the kidneys and bladder. Soft tissues do not show up well on x-ray. Your baby or child may have a renal ultrasound to: 1  find out if there are any blockages in the urinary tract (kidney, ureter, bladder and urethra).
Astrovirus is a type of virus that was first discovered in 1975 using electron microscopes following an outbreak of diarrhoea in humans.stroviruses are associated with 5â9% of cases of gastroenteritis in young children. The occurrence of astrovirus infection varies depending on the season. In temperate climates infection is highest during winter months. This is in contrast to tropical regions where prevalence is highest during the rainy season.
Retrovirus. Retroviruses are enveloped viruses that belong to the viral family Retroviridae. A retrovirus is an RNA virus that is duplicated in a host cell using the reverse transcriptase enzyme to produce DNA from its RNA genome. On infection, the single-stranded RNA viral genome and the enzyme enters the host cell.he viral genome is released into the host cell, from which a copy of DNA is made by the help of the enzyme reverse transcriptase. The cDNA is integrated into the host chromosome. The virus remains unexpressed until the host's immune system is stimulated.