Communicable Disease Report
Communicable Disease Report 19 to 25 October 2009
Summary
This week we report two cases of hepatitis A virus infection which were both acquired in Australia. Influenza activity remains low, however outbreaks of viral gastroenteritis continue to be reported.
Contents:
- Rabies and bat lyssavirus infection
- Measles
- Hepatitis A
- Pandemic (H1N1) 2009 influenza
- Viral gastroenteritis
- Measles
Note: click on the heading of each section to see a fact sheet. Updated data are provided in the links below each section.
Rabies and Australian bat lyssavirus infection [new]
Rabies is an infection of mammals that is transmitted bite and scratch. While it occurs in many parts of the world, it does not occur in Australia. Infection with rabies can sicken and kill the affected mammal.
In some countries, mammals such as bats, dogs, cats, raccoons, skunks and monkeys can carry rabies. Rabies is more common in Africa and in Asia. Australians travelling overseas who are bitten or scratched from a wild mammal or an unvaccinated domestic mammal may be at risk of rabies. If a traveller is bitten or scratched while overseas, the wound should be washed thoroughly and they should seek urgent medical attention.
Australian Bat Lyssavirus is a virus that is closely related to rabies. Two cases of human infection with Australian Bat Lyssavirus have been recorded in Australia. Both these cases died. Like rabies, this infection can be transmitted following a bite or a scratch from an infected bat.
In Australia, both flying foxes (fruit bats) and the smaller insectivorous (or micro bats) can have the infection. Other Australian wild and domestic animals are not affected.
People who handle Australian bats are at risk of Australian Bat Lyssavirus infection. Do not approach or attempt to handle any Austalian bat unless it is part of your job, and you have been vaccinated and trained and use protective equipment. Rabies vaccination is recommended for those who are at risk from bat bites (eg. veterinarians, bat handlers and wildlife officers)
Measles [new]
One case of measles was reported in a man in his 30s who has been living in the Newcastle area for the last 5 months. His onset was 20 September, but measles was not confirmed until 5 October, by IgM and IgG sero-conversion. The case reported no recent travel, and the source of infection remains unknown - but doubtless an unrecognised case. Due to the delay in confirmation, contacts were only provided with information. Contacts were identified at a university, at two hospitals within the Newcastle area. No secondary cases have been identified to date.
There have been 12 cases of measles reported in NSW in 2009 to date compared with 39 for the same period in 2008.
Most cases of measles are seen in non-immune travellers who return with the infection from countries where measles is endemic or non-immune people who are exposed to a known case. Many people who were born since 1966 and before the mid 80s are not immune because they have not received two doses of a measles vaccine. Measles vaccine is now routinely given to infants at 12 months and 18 months and this confers long-lasting immunity.
Click here for updated data on measles.
Hepatitis A [new]
Northern Sydney Central Coast and Greater Southern Public Health Units are each investigating a case of hepatitis A infection. Unusually, neither case had recently travelled overseas. Before they developed symptoms, both cases visited Melbourne where there has been an outbreak of hepatitis A virus infection associated with eating sun dried tomatoes. [LINK: http://hnb.dhs.vic.gov.au/web/pubaff/medrel.nsf/LinkView/D8172AF758EDF26ECA25764A002574DE?OpenDocument]
Hepatitis A virus infection is one of the causes of inflammation of the liver ("hepatitis"). Symptoms include feeling unwell, aches and pains, fever, nausea, lack of appetite, abdominal discomfort, followed by dark urine, pale stools and jaundice (yellowing of the eyeballs and skin). Illness usually lasts one to three weeks (although some symptoms can last longer) and is almost always followed by complete recovery. Hepatitis A is usually transmitted when virus from an infected person is swallowed by another person through eating contaminated food, drinking contaminated water, handling nappies, linen and towels soiled with the faeces of an infectious person or after direct contact (including sexual contact) with a person in the infectious stage of the illness.
Pandemic (H1N1) 2009 influenza [update]
Influenza activity in NSW is measured by the number of people who presented to emergency departments with influenza like illness, and the number of patients who tested positive for H1N1 at a diagnostic laboratory. Influenza activity in NSW remains low after peaking in July.
The weekly number of patients presenting to emergency departments with influenza-like illness has declined to baseline levels.
Weekly counts for patients admitted to hospital following presentation to emergency departments with pneumonia or influenza-like illness increased slightly. Current activity is just above seasonal levels however the weekly counts are now well below activity in July.
Admissions from emergency departments to hospital for pneumonia or influenza-like illness peaked in mid July at around 410 admissions. Click on the link for updated influenza information.
Click on the link for updated influenza information.
Gastroenteritis outbreaks in institutions [update]
There were 17 outbreaks of gastroenteritis in institutions reported this week including 11 outbreaks in aged care facilities, 4 outbreaks in child care centres and 2 outbreaks in hospitals. All outbreaks appear to have been caused by viruses and spread from one person to another. Outbreaks of viral gastroenteritis are commonly seen in winter months.
Weekly counts of patients presenting to emergency departments with a provisional diagnosis of gastrointestinal illness are decreasing and are within seasonal range. Presentations in those aged 65 years and over are slightly higher levels than expected and Presentations in those aged 35-64 years are at slightly lower levels than expected. Visits to emergency departments in GSAHS are at slightly higher levels than expected.
Click on the link for information on preventing gastroenteritis.