SEASONAL
INFECTIONS AND DISEASE SURVEILLANCE
30th
June 2004
By
Dr Sally Cockburn
We talk about winter as being the “Flu Season” but Flu is not the only virus that is seasonal and by experience health experts know that certain infections tend to happen at particular times of the year.
In winter
people spend more time inside in groups and so infections that are spread by
person to person contact (communicable diseases) can whiz through communities
with ease.
Public Health Specialists have been
collecting data on infections for years and by graphing the figures they can
predict when particular infections are likely to hit the population and so
prepare health services, like vaccine availability and staffing accordingly.
By comparing year-to-date trends health experts can identify potential problems which may indicate a higher number of infections occurring in a particular area which could mean an epidemic .
This system involves a lot of coordination and cooperation from health agencies, doctors, staff and patients around the country. Doctors are required to report cases of certain diseases to government authorities so that the public health data can be kept up to date. This data collection is aimed at identifying and reducing potential outbreaks and not at pointing the finger at individuals.
The media is very important in getting the message out to the community. Its vital that the message is right.
Two recent examples of Communicable diseases in the media are
1.
Respiratory Syncytial Virus (RSV)
infection in South Australia
RSV can be a major cause of serious respiratory infection in infants. These infections tend to peak annually in winter or spring in temperate climates. Graphs of reported data allows health specialists to observe patterns in the outbreak behaviour. This year in South Australia it was noted that while the peak is normally seen around July, the figures are already close to last years peak. The issue is whether this is just an early peak or heralding a worse than normal year. Health Authorities need to alert the public without causing undue alarm. This is not always easy to package. The messages are be aware, reduce risk of spread and seek medical advice if your child seems sicker than you are comfortable to manage. We would always prefer to see your child if you are worried even if it is only to allay your fears.
In adults and children over about 3 RSV is usually not severe and may be passed off as a “cold” but in babies it can be more serious and even result in the lower respiratory tract conditions called bronchiolitis and pneumonia and in some cases may cause respiratory failure. Spread is usually via an infected person and this is why hygiene is so important.
Recognition of severe respiratory infection in young babies is vital and parents or carers should seek advice if they are worried that their child is sicker than expected. In particular : High fever which is not responding to normal medication, severe cough, wheezing, abnormally rapid breathing, or difficulty breathing. Abnormal retractions of the muscles between the ribs, or a bluish colour of the lips or fingernails caused by lowered levels of oxygen in the blood can indicate very serious infection and immediate medical attention is required.
The incubation period for RSV is 4 to 6 days and the infection normally lasts 7 to 14 days, but some cases may last up to 3 weeks. In severe cases children who require admission to hospital with lower respiratory tract illness usually stay in for around 5 to 7 days.
There is no
vaccine available that can prevent RSV as yet, however in some infants felt to
be at immediate serious risk sometimes passive immunity might be given through
injection of pooled immunoglobulin.
There is no specific cure and since it is a virus antibiotics wont work. Treatment revolves around treating symptoms and respiratory support.
RSV is highly contagious and up to 50% of infants may be affected during an RSV epidemic. Infants in Day Care centres and particularly premature babes and those with older siblings in school are at particular risk for transmission.
RSV is a
particularly contagious virus because it can survive on table and bench surfaces
for hours, it is also easily passed from person to person. Hand washing is
a major key to preventing spread.
Older children and adults may have an RSV infection, and think its "just a cold" but they can still pass infectious RSV particles through oral and nasal fluids. People are most contagious during the first 2 to 4 days of the illness, but RSV particles may be spread for up to 2 weeks after the stuffy nose begins.
2.
Viral Gastro Enteritis in New
South Wales
A
media release in May from the NSW Department of health alerted the community to
some data which pointed towards a higher than expected number of reported cases
of Viral Gastroenteritis. The particular infection suspected is a virus called
Noro Virus and it causes fever nausea vomiting abdominal pain, and diarrhoea.
This information has appeared in the media again this week
According
to the may media release several Sydney emergency departments had recorded a 44
per cent increase of people presenting with diarrhoea that
month compared to January 2004. This represents a 30 per cent increase
over the same period (Jan to May) in recent years.
Viral gastroenteritis outbreaks can occur throughout the year but cases tend to rise during winter. There are possibly millions of cases per year in Australia. Most people get over viral gastroenteritis with simple remedies in a few days. However certain groups like the very young and very old are more at risk because of the potential for dehydration.
There is no specific cure for Viral gastroenteritis but treatment revolves around symptomatic relief, hydration and prevention of spread.
TIPS FOR REDUCTION OF SPREAD
OF
GASTRO
AND RESPIRATORY COMMUNICABLE INFECTIONS
1. Wash hands frequently and thoroughly – preferably use air driers or disposable towels.
2. Don’t use the same cloth to dry hands and clean benches
3. Cough away from people or into tissues
4. Stay home is infected – particularly health and child care workers
5. If in a high risk group (immune problems, on cortisone, premature baby) be alert for outbreaks and take precautions.
FURTHER
INFORMATION AND LOCAL CONTACTS :
Federal
Department of Health and Aging : Communicable Diseases Australia :
http://www.cda.gov.au/surveil/index.htm
National
Flu surveillance info :
http://www.cda.gov.au/surveil/ozflu/flucurr.htm
Respiratory
syncytial virus
http://www.cda.gov.au/pubs/cdi/2003/cdi2701/htm/cdi2701j.htm
New
South Wales Department of Health : Public
Health Division
http://www.health.nsw.gov.au/public-health/
Fact
sheet on viral gastro :
http://www.health.nsw.gov.au/public-health/phb/HTML2003/sepoct03html/factsheetp206.html
Consumer
information area :
http://www.health.nsw.gov.au/living/infect.html#factsheets
South
Australia
Department of Human Services : Communicable Disease Control
http://www.dhs.sa.gov.au/pehs/branches/branch-communicable.htm
Victoria
Department of Human Services :
Public
health http://www.dhs.vic.gov.au/phd/index.htm
Disease
surveillance
http://www.health.vic.gov.au/ideas/
Tasmania
Department of Health and Human Services: Communicable Diseases http://www.dhhs.tas.gov.au/publichealth/communicablediseases/index.html
Queensland
Department of Health : Communicable Diseases Unit
http://www.health.qld.gov.au/phs/cdu/
Diarrhoea
in young children
http://www.health.qld.gov.au/phs/Documents/cdu/594dmp.htm
Western
Australia Department of Health : Communicable Disease Control
http://www.population.health.wa.gov.au/Communicable/index.cfm
Northern
territory Government Health Site
http://www.nt.gov.au/ntg/health.shtml