 May 1999 - Vol. 4, No. 5
Picornaviruses (both enteroviruses and rhinoviruses), as well as parainfluenza virus type 3, were the most common viruses isolated during April...a certain, virologic sign that spring is here! Respiratory syncytial virus and influenza A and B viruses were isolated in small numbers, and only a few RSV and Flu A rapid EIA antigen detection tests were positive in April. Virology Question of the Month Why are we seeing parainfluenza virus type 3 at this time? The parainfluenza viruses usually exhibit rather predictable seasonality. For example, parainfluenza virus type 1 is more commonly seen in the fall, and parainfluenza virus type 3 is more commonly seen in the spring and summer, although type 3 can resurge in fall during some years. The seasonality of parainfluenza virus types 2 and 4 is less predictable. Infection with parainfluenza viruses is common during childhood, with over 90% of 2-year- olds being infected with parainfluenza virus type 3, and most 2- to 5-year-olds experiencing infection with parainfluenza viruses types 1 and 2. Parainfluenza virus type 4 is rare, but can infect infants less than 2, as well as older children. This newsletter is supported in part by an unrestricted educational grant from ZymeTx, Inc., Oklahoma City, OKCroup is most commonly associated with infection with types 1 and 2, whereas type 3 usually causes upper respiratory infections, as well as bronchiolitis, pneumonia, and even aseptic meningitis. Parainfluenza virus type 4, although rare, can cause a variety of respiratory illnesses. Severe, even life-threatening disease can occur when parainfluenza viruses infect immunocompromised hosts. The laboratory diagnosis of parainfluenza virus infection is primarily through viral culture. It usually takes 3 to 5 days to isolate and identify parainfluenza virus in respiratory secretions. The virus may also be detected in respiratory secretions by direct immuno-fluorescence assay (DFA). A rapid test, such as what is offered for RSV and influenza, is not available for parainfluenza viruses at this time. There is no specific, proven anti-viral treatment for parainfluenza virus infection and disease at this time; however, ribavirin has shown activity in cell culture systems against the virus. Research evaluating prevention by vaccine has been conducted for many years, but a suitable candidate for licensure has not yet been found. You may copy or post this newsletter. Call us with any questions or suggestions.
Gail J. Demmler, M.D., Director (832) 824-2280 phone
This newsletter is supported in part by an unrestricted educational grant from ZymeTx, Inc., Oklahoma City, OK
Modified: June-2-1999 | ||||||||||||||||||||||||||||||||||