Module 2: VICNISS online self guided surveillance education
To download this module and/or the associated multiple choice exercises as PDF files, click on Education Resources.)
Module Menu
Overview
This module gives you an overview of measles and current management strategies.
Objectives
After you have completed this module you should be able to:
- Identify the clinical features of measles, its period of infectivity and its mode of transmission;
- List the key criteria to consider when identifying an individual’s susceptibility to measles; and
- Identify infection control measures required for an identified or suspected case of measles.
Measles
Measles is an acute viral illness. Clinical features include:
- Prodromal fever;
- Conjunctivitis;
- Coryza (inflammation of the mucous membrane lining the nose-usually causing discharge);
- Cough; and
- Koplik’s spots on the buccal mucosa.
The characteristic
red, blotchy rash appears on the third to seventh day. It begins on the face before becoming generalised. It generally lasts 4-7 days. Persons who
have previously been immunised may present with non-classical features. Incubation period is approximately 10 days, but varies from 7-10 days from
exposure to the onset of fever. It is usually 14 days until the rash appears.
Measles is rare since the introduction of widespread immunisation, but outbreaks are still occurring, especially in school aged children. Complications can include otitis media, pneumonia and encephalitis and as a late sequel subacute sclerosing panencephalitis (SSPE). Death is rare but does occur.
Reservoir
The environment in which the Measles virus lives and multiples is humans. Measles has a short survival time (<2 hours) in air and is rapidly
inactivated by heat, light and acidic PH.
Period of Infectivity
Measles is highly infectious from the beginning of the prodromal (3-5 days before the rash appears) period for as many as 4 days after the
appearance of the rash.
Transmission
The measles virus can be spread by more than one route: Airborne by droplet spread or by direct contact with infected nasal or throat secretions.
Host Defence Mechanisms
Vaccination at 12 months produces antibody in approximately 95 percent of recipients. It is not yet clear whether vaccine induced immunity is
lost over time but the majority of evidence suggests this is uncommon. Unvaccinated children in the following groups are at particular risk from
severe measles infection:
- Children with chronic conditions such as cystic fibrosis, congenital heart or kidney disease, failure to thrive, Down’s syndrome;
- Children from the age of 1 year upwards in child care centres, family day care and playgroups;
- Children living in institutions;
- Aboriginal and Torres Strait Island children; and
- HIV positive individuals.
Infection Control Measures
A measles outbreak exists in a healthcare facility whenever one case of measles is confirmed. The diagnosis should confirm that the disease is
actually measles.
Control of Cases
When a person is known or suspected to have measles, during the infectious period.
In a hospital setting:
- He/she should be placed in a single isolation room (preferably negative pressure) with the door closed and a stop sign posted;
- He/she should wear a surgical mask if required to leave the room;
- Ideally non-immune persons (staff and visitors) should not enter the room. If it is however required a surgical mask, gloves and gown should be
worn; and
- Linen once contained within a linen bag will not pose a risk. No special cleaning procedure is required upon patient discharge.
In the Community:
- Exclusion from childcare settings, school and work is compulsory.
Note: Notification (Group A) to Human Services is required.
Control of Contacts
Contacts should be checked for documentation of measles immunisation. If susceptible, immunisation should be given within 72 hours of contact. Children aged between
6-12 months should be given a measles containing vaccine, but should be revaccinated at 12 months or 3 months after the last dose, whichever is later. It is also
acceptable to give normal immunoglobulin to children in this age group in a dose of 0.2ml/kg then to vaccinate them at 12 months (or 3 months after the administration
of immunoglobulin).
Host Measures: Immunisation
Two doses of Measles-Mumps-Rubella (MMR) are required. MMR vaccine is recommended for all children at 12 months of age and at 4 years of age, unless there is a genuine contraindication. MMR vaccine should be given to all susceptible persons who are older than 12 months of age. There are no ill effects from vaccinating those with pre-existing immunity to one or more of the three diseases.
Definition of a person who is susceptible to measles
A susceptible person to measles is someone who cannot provide acceptable presumptive evidence of immunity to measles.
A person (including healthcare workers) can be considered to have acceptable presumptive evidence of immunity if they meet one of the following criteria:
- Children aged 1-4 years who have documented evidence of having received one dose of a measles containing vaccine; or
- Persons over 4 years of age and born after 1970 (unless serosurveillance data shows otherwise) who have documented evidence of receiving two doses of measles containing vaccine; or
- Persons born before 1970 (unless serosurveillance data shows otherwise); or
- Documented evidence of immunity; or
- Documented evidence of confirmed measles.
Test your Knowledge - Exercise 1
Clicking the above link will take you to the Education Resources page where you can download a PDF version of the Exercises Questions and Answers
Case Study - Exercise 2
You are the Infection Control Consultant at a busy Victorian Hospital. You arrive for work one morning and, after checking your emails, have just made a
cup of tea when the phone rings.
(Click on telephone to answer)
Clicking the above ringing telephone link will take you to the Education Resources page where you can download a PDF version of the Exercises Questions and Answers
Further Information:
References
- National Health and Medical Research Council (NHMRC) (2000) The Australian Immunisation Handbook 7th edition Pirie Printers Canberra
- Department of Human Services (DHS) The BLUE BOOK: Guidelines for the control of infectious diseases
- Rural Infection Control Practice Group (RICPRAC) (2002) Infection Prevention and Control Manual