Pathophysiology: Little is known about the route and the source of transmission of the virus. VZV is certainly transmissible through the airborne route and does not require close personal contact. The skin lesions are certainly full of infectious virus particles whilst in contrast, it is almost impossible to isolate virus from the upper respiratory tract. It is possible that aerial transmission originates from symptomless oral lesions.
Disease statistics: In the pre-vaccine era, approximately 350,000 varicella cases were estimated to occur each year in Canada. However, assessing the effect of varicella immunization programs on the incidence of varicella is difficult because varicella infections are significantly under-reported, less than 10% of the expected cases being reported through the Canadian Notifiable Disease Surveillance System (CNDSS) annually. A review of data from the Canadian Institute for Health Information for 1994 to 2000 showed that over 1,550 varicella hospitalizations occur annually for all age groups.
Treatment: Several studies indicate that antiviral medications decrease the duration of symptoms and the likelihood of postherpetic neuralgia, especially when initiated within 2 days of the onset of rash. In typical cases that involve individuals who are otherwise healthy, oral acyclovir may be prescribed. An important study by Kubeyinje (1997) suggested that the use of acyclovir in healthy young adults with zoster is not clearly justified, especially in situations of limited economic resources.
Research: Epidemiology of varicella zoster virus infection in Canada. The objective of this study was to provide a comprehensive picture of the pre-vaccine epidemiology of the varicella zoster virus (VZV) to aid in the design of immunization programs and to adequately measure the impact of vaccination. Population-based data including physician visit claims, sentinel surveillance and hospitalization data from Canada.