Status:
Resolved
Health alert:
130009
Date Issued:
03 Sep 2013 (This is an update of the 23 August CHO Alert for measles)
Issued by:
Dr Rosemary Lester, Chief Health Officer, Victoria
Issued to:
Hospital Emergency Departments and General Practitioners within metropolitan Melbourne

Key messages

  • There is ongoing transmission of measles in Melbourne, with 15 cases reported over the last four weeks.
  • Community exposure sites where cases may still emerge include Burwood (up to 13 September), Reservoir (up to 5 September) and Frankston (up to 17 September)
  • Be alert for measles in patients presenting with a rash and fever at rash onset.
  • Minimise the risk of transmission within your department/practice through immediate isolation of suspected cases.
  • Notify the Communicable Disease Prevention and Control section at the Department of Health on 1300 651 160 of suspected and confirmed cases immediately.

What is the issue?

Since early August, the Department of Health has been notified of 15 confirmed cases of measles. Measles is highly infectious (airborne transmission) and further secondary cases are likely to occur.

The two known clusters have had additional confirmed cases in unimmunised household contacts, with no new exposures identified.

Cluster 1

The first case was acquired locally from an unidentified contact. The case flew on a domestic flight to Melbourne on 31 July, spent time whilst infectious at Northland on Thursday afternoon August 1 and attended an East Brunswick medical practice on Saturday morning August 3.

Further cases have now been linked to this case including a worker at Northland who may have exposed others at the same location. 

Cluster 2

The second cluster is linked to a returned traveller from Europe who was infectious from 1 to 10 August 2013 and secondary cases have now been confirmed. In addition, there has been another confirmed case linked to exposure at Tullamarine airport for this flight. Any cases linked to this exposure site should have presented by now.

Most recently, two confirmed cases (in unimmunised siblings) have been identified. Two other siblings who developed illness two and four weeks ago respectively are likely to be confirmed. The initial sibling travelled to Thailand, which is the probable source for this new cluster.

Possible Cluster 3

Most recently, two confirmed cases (in unimmunised siblings) have been identified. Two other siblings who developed illness two and four weeks ago respectively are likely to be confirmed. The initial sibling travelled to Thailand, which is the probable source for this new cluster.

Who is at risk?

Children or adults born during or since 1966 who do not have documented evidence of receiving doses of a measles-containing vaccine or documented evidence of laboratory-confirmed measles are considered to be susceptible to measles. People who are immunocompromised are also at risk. All cases are aged between 14 and 34 years of age.

Symptoms and transmission

Clinical features of measles include prodromal fever, a severe cough, conjunctivitis, and coryza. Koplik spots on the buccal mucosa may be present for three to four days prior to rash onset but not at time of rash. Individuals, especially children, are typically unwell.

The most important clinical predictors are the following features:

  • generalised maculopapular rash, usually lasting three or more days
  • fever (at least 38°C, if measured) present at the time of rash onset
  • cough or coryza or conjunctivitis.

Measles is transmitted by airborne droplets and direct contact with discharges from respiratory mucous membranes of infected persons and less commonly by articles freshly soiled with nose and throat secretions.

Measles is highly infectious and can persist in the environment for up to two hours.

The incubation period is variable and averages 10 days (range: 7 – 18 days) from exposure to the onset of fever, with an average of 14 days from exposure to the onset of rash. The infectious period of patients with measles is roughly five days before, to four days after, the appearance of the rash.  The picture below is typical of rash on the face. This is rash on day three in a young boy.

Picture courtesy of U.S. Centers for Disease Control and Prevention

Recommendations

  • Be alert for new measles cases - ensure all staff, especially triage nurses, have a high index of suspicion for patients presenting with a febrile rash.
  • Notify suspected cases immediately to the Communicable Disease Prevention and Control section via telephone on 1300 651 160.
  • Take blood for serological confirmation. IgM is generally positive if the rash has been present for three or more days and IgG can determine susceptibility. Nose and throat swabs for PCR diagnosis are best for early diagnosis (including prior to rash); please contact the Department prior to taking swabs to gain approval for these to be tested at the Victorian Infectious Diseases Reference Laboratory.
  • Minimise the risk of measles transmission within your department:
    • Avoid keeping patients with a febrile rash illness in shared waiting areas
    • Give the suspected case a single use mask and isolate them, until a measles diagnosis can be excluded.
    • Leave vacant all consultation rooms used in the assessment of patients with suspected measles for at least two hours after the consultation. 
  • Seek advice from the Communicable Disease Prevention and Control section regarding the management of susceptible hospital or clinic contacts.
  • On advice, follow up all persons who attended the Emergency Department or clinic at the same time as a case and for two hours after the visit. These people are considered to be exposed to the measles virus.
  • For advice around prevention of measles in susceptible contacts please contact the Communicable Disease Prevention and Control section at the Department of Health.
  • Check your staff vaccination records.
  • Earlier outbreaks have affected health care workers, including some who have not been involved in the direct care of measles cases and have only been in the same ward, clinic, or department as a case. All staff born during or since 1966 should have documentation of two doses of measles-containing vaccine, or laboratory-confirmed evidence of past measles infection.