Measles Research and Development
Population based sero-epidemiological studies have often used convenience samples of residual sera held in diagnostic or reference laboratories.
Following the national Measles Control Campaign in 1998, similar estimates of age-specific immunity to a number of vaccine preventable diseases, including measles, were obtained in 1999 by a large convenience sample conducted by the NCIRS and a 3-stage random cluster sample conducted by VIDRL.
Laboratory-based surveillance of population immunity, together with outbreak investigations, have now provided evidence of residual measles susceptibility in young adults who, as infants, did not receive the vaccine when it first became available.
The young adult group represents a potential focus of transmission and infection with imported measles virus strains. Evidence from Victoria prompted the Commonwealth Department of Health and Ageing to implement an immunisation campaign aimed at young adults in 2000.
Vaccination of health-care workers
The importance of the protection of health-care workers from measles infection has been promoted through studies performed at VIDRL.
click here for reference (ref. 22)
Vaccination of health care workers is an important issue because these workers are often young adults who remain susceptible to measles infection because of failure to receive vaccine during infancy or early childhood.
The potential of health care workers to transmit infection to sick patients is high and has been observed in many hospital settings.
click here for reference (ref. 58)
Dried blood specimens for measles diagnosis and surveillance
As measles becomes rare within a country or region, it is important to obtain laboratory confirmation of all suspected cases.
In resource poor countries, the collection, transport and storage of appropriate clinical specimens may be problematic, since collection of venous blood requires trained staff and transport and storage of serum needs to be timely and temperature controlled.
As part of an ongoing research program at VIDRL, methods for testing blood dried onto filter paper have been developed.
This technology represents an important advance in the performance of laboratory testing and surveillance in countries with limited laboratory infrastructure
click here for reference
VIDRL's molecular epidemiological studies of measles have made an important contribution to measles control in Australia.
The sequential replacement of circulating viral genotypes at progressively shortening intervals by imported strains strongly suggest the interruption of endogenous measles transmission in Australia.
Molecular analysis of viruses from serologically-proven measles cases has facilitated their linkage to, or separation from contemporaneous cases and clusters.
This greatly assists epidemiological investigations to track chains of transmission and, on several occasions has facilitated the correct assignment of individual cases to outbreak clusters where epidemiological studies were inconclusive.
Molecular surveillance performed at VIDRL has enabled the description of several new measles genotypes. Indeed, 3 of the 22 currently recognised measles virus genotypes were first identified at VIDRL.
(For references see Chibo 2000, 2002 & 2003 in the Publications section)