Authorities in New South Wales (NSW) and Queensland (QLD) are reporting a spike in the number of rotavirus cases being reported in children under five years old.
The number of people suffering from the virus, which is the most common cause of severe gastroenteritis in children and babies, is reaching levels not experienced in the last five years.
The reason for the surge is unknown, leading health officials to consider whether the structure of the virus has changed, making people more susceptible to it. Dr Vicky Sheppeard, NSW Health's director of communicable diseases, confirmed they were investigating this.
"We have sent off samples to the reference laboratories to see if there is a change in the coding of the virus that is also making people less immune to it." she said.
The current outbreak in NSW is the worst for five years with over 1300 cases recorded by NSW Health in 2017, already more than triple the 412 cases reported last year.
Children aged between 2 and 4 years old based in metropolitan Sydney are the worst affected, with Sydney Children’s Hospital reporting between 5 and 6 times more hospitalisations from the virus than in average years.
In QLD, it’s a similar story with over 1527 recorded cases so far in 2017, more than double the number of cases in previous years. Over 230 people have been hospitalised due to contracting the virus this year.
What Is Rotavirus?
Rotavirus is a highly contagious virus passed on via the faecal-oral route. It most commonly affects babies and young children up to the age of five.
In Australia, there are approximately 2 deaths every year due to rotavirus, with thousands more people requiring hospitalisation.
Symptoms of rotavirus include fever, diarrhea, vomiting and stomach cramps. It takes 1 to 3 days after becoming infected to start showing symptoms. Symptoms can last from 3 to 7 days.
The virus is passed from person to person by touching contaminated hands or faeces. It can also be passed on via objects (such as toys) and through food and drink. There have been many cases of infected food handlers passing on the virus to others by preparing food items with unwashed hands.
The problem is worsened by rotavirus being asymptomatic in many adults. This means that they may be carrying the virus but not show any symptoms, and so may not pay as much attention to important tasks like hand washing as they may have done if they actually felt sick.
Since the introduction of the rotavirus vaccine in 2007, between 70% and 90% of Australian children are vaccinated at two and four months old.
The introduction of the vaccine appears to have been a success. Prior to the vaccine, rotavirus was responsible for around 10,000 hospitalisations and 115,000 doctors visits every year. This has reduced by 70% since the vaccine was introduced.
However, the vaccine doesn’t offer full protection and wears off after a few years. The suggested mutation of the virus may also explain the recent spike in numbers.
It’s very rare to see adults suffering from the symptoms of rotavirus. Immunity to the virus increases with each infection and by the time most people have reached five years old, they no longer suffer severe symptoms.
However, the virus can still live on the hands of an asymptomatic adult. This is why thorough hand-washing is essential to prevent becoming a carrier for the infection.
For mild cases of rotavirus, plenty of fluids and rest are recommended to recover from infection. However for severe cases of infection (characterized by frequent vomiting and diarrhea), medical specialists should be contacted immediately.
After recovering from the virus, children should be kept away from school or childcare for at least 24 hours after the symptoms have resolved.
Food handlers suffering from rotavirus must stay away from the workplace for at least 48 hours after the last bout of vomiting and diarrhea.