MoH Warns Influenza B Can Be Serious Health
21 June 2005
Ministry of Health warns Influenza B can be serious health risk to children and young people
A CURRENTLY-circulating strain of influenza has not been common in New Zealand since 1987 and means children and young people can be at particular risk of serious illness, the Ministry of Health says.
"Influenza B is reaching epidemic rates in children and young people in the North Island, with high rates of absenteeism in some schools. We now know that In the last six weeks three young people became ill with influenza B and have died from complications from the virus," Ministry spokesman Dr Pat Tuohy said.
"We are currently asking all hospitals to tell us whether they are treating children and young people with the same sorts of illnesses."
The Ministry last week advised parents and clinicians to be vigilant and warned that the current rate of influenza in New Zealand communities was higher than at the same time last year, with tests confirming influenza B viruses were dominant.
Dr Tuohy, Chief Advisor Child and Youth Health, said today that information since then had confirmed that the three deaths in young people involved complications from influenza B.
"In New Zealand we have not seen large numbers of people infected with this type of influenza (Hong Kong B) since 1987, although a few people had it in 2002. What that means is that most people born since 1987 will not have natural immunity and are hence more likely to be susceptible,'' he said.
"There are two strains of influenza B circulating at present - Hong Kong and Shanghai. The three young people who died had the Hong Kong strain."
"We have to remember that as many as 600 children and young people die each year in New Zealand and up to 10 per cent of these are from infectious diseases. However we are sufficiently concerned by these three influenza-related deaths to repeat our messages of last week and ask parents and health professionals to be extra vigilant."
"All parents, caregivers and clinicians need to be aware that the impact of Influenza B on children and adolescents can be much more severe than has previously been recognised, and to care for any young person with influenza-like symptoms with this in mind."
Dr Tuohy said it was only now being recognised internationally that Influenza B could lead to serious illness and death from a secondary infection in children.
"It now seems likely that around the world influenza B has been implicated in more deaths in children and young people than the records show. Although the cause of death may have been recorded as bacterial pneumonia or some other infection in fact it was the Influenza B which made them vulnerable to that infection."
Dr Tuohy said the Ministry of Health was advising all health professionals of the particular risks influenza B poses to children and young people. It was recommending to family doctors that if they suspected a child or young person could have influenza B they should assess them and refer them to specialist care if they had any concerns about possible complications. Hospital doctors are also being informed.
"For parents it's really important that that we keep a close eye on children sick with flu-like symptoms. If children are unwell they should be kept at home from school with a parent or responsible guardian.''
The Ministry also advises that sick children should be kept warm, given paracetamol (NOT aspirin) for fever and plenty of fluids. If the child is not getting better, or gets better and then develops another fever, or is having breathing difficulties, the child should be taken to a GP.
If parents have already taken their child to a doctor and had a diagnosis of influenza, but they are concerned about their child or the child gets sicker, then parents are advised to take the child back to the doctor, as they may have developed another infection.
Dr Tuohy said the annual influenza immunisation is the best form of defence against influenza, and he strongly urged people to get immunised, particularly those who are most vulnerable and in the at-risk groups . These people are at higher risk of developing complications from an influenza infection.
Of the two influenza B strains in circulation B Shanghai is included in this year's vaccine. B Hong Kong is not in this year's vaccine but was included in last year's vaccine.
Flu vaccine is recommended and subsidised for children with certain chronic health conditions such as cystic fibrosis, congenital heart disease or who are being treated for cancer.
NOTE: Dr Tuohy is available for interview until 5.30pm.
Questions and Answers
What is influenza?
Influenza is a serious illness that in New Zealand usually causes epidemics every year during the winter months. The illness usually comes on suddenly with a fever, sore throat, dry cough, aches and pains and headaches. People feel very unwell and some children, elderly and chronically ill people can develop pneumonia and other problems. They may need hospital care.
The main types of the influenza virus are A and B. There are different influenza B viruses circulating in New Zealand. They are: Influenza B Shanghai, which is in this year's influenza vaccine, and the B Hong Kong virus, which isn't. The original B Hong Kong virus was last in circulation widely in New Zealand in 1987, which means many younger people have not been exposed to the virus and do not have protection.
In general, influenza B causes less severe diseases compared with influenza A. However, it is being recognised internationally that influenza B may lead to serious illness and death from a secondary infection.
What about the strain of Influenza B that is causing illness in the community at the moment?
Tests have confirmed that this particular strain has not been common in New Zealand. The original strain was last widely seen in 1987. There have been isolates of this strain in 2002 and one isolate each in 2003 and 2004. This means many children and young people will not have been exposed to the virus and are particularly vulnerable.
Because B Hong Kong was in last year's vaccine, people who were immunised in 2004 may have some residual protection. B Hong Kong is not in this year's vaccine. This year's vaccine contains B Shanghai, which is circulating as part of the current epidemic.
Is the influenza B outbreak in the community regarded as an epidemic? Yes. For an illness to reach epidemic proportions, there needs to be at least 200 cases/100,000 people.
How many cases have been reported?
Influenza infection is not a notifiable disease, so it is not possible to count all the cases. However, reports from Medical Officers of Health in Auckland and Wellington indicate hundreds of children have been affected. The Ministry also gets information from the influenza sentinel surveillance system. See the weekly reports about consultation rates and viruses isolated from swabs on the ESR website
How many children or young people have died from this Influenza B virus? There have been three confirmed cases in different areas of the North Island in the past six weeks.
What has the Ministry of Health done since the outbreak?
The Ministry has had advice from and discussions with Medical Officers of Health, who are working in local communities where influenza is occurring.
We have also had discussions with primary care leaders, HealthLine and PlunketLine and have sent advice to General Practitioners, practice nurses, District Health Boards, Emergency Departments, paediatricians, hospital paediatric departments and adult medical departments.
In addition, we have sought advice from the Centers for Disease Control and Prevention (CDC) in the United States. How long is this epidemic expected to last?
There is no real way to predict this, but the peak influenza season is usually from May to September.
What should parents or caregivers do if their child becomes sick? It's important to keep a close eye on children sick with flu-like symptoms. If children are unwell they should be kept at home from school with a parent or responsible guardian.
The Ministry also advises that sick children should be kept warm, given paracetamol (not aspirin) for fever and plenty of fluids. If the child is not getting better, gets better and then develops another fever, or is having breathing difficulties, the child should be taken to a GP. If possible, parents should ring their medical centre before going in, so staff can take steps to minimise the spread to others.
If parents have already taken their child to a doctor and had a diagnosis of influenza, but they are concerned about their child or the child gets sicker, then parents are advised to take the child back to the doctor, as they may have developed a secondary infection.
How can people tell the difference between a cold and influenza? Influenza makes people feel unwell suddenly and is much more serious than a common cold. Influenza illness may last for up to 10 days. Most people suffer from a high fever and may require bed rest. Some may also have shivering attacks, muscular pains, headaches, a dry cough, possible vomiting and complications like pneumonia can follow.
A cold, however, has much less severe symptoms and generally lasts only 2-4 days. High fever is less common and shivering attacks and severe headaches are rare. Muscular pains and vomiting are infrequent and the cough will be less severe. There is no vaccine available.
What is the influenza infection control advice in the home and to schools?
The key measures to limit the spread of influenza or other highly infectious viruses are: Cover coughs with a tissue and not hands. Wash hands ? after going to the toilet, and before eating and preparing food. Schools should ensure that good hand-washing and drying facilities are available. Keep children away from school if they are unwell with flu-like symptoms or have diarrhoea or vomiting.
Why does the Ministry of Health recommend that people have an influenza vaccination?
Influenza immunisation is the best protection against influenza. Influenza infection in people with ongoing medical conditions, even if their condition is well controlled, may lead to more serious illness and death.
Who is eligible for free influenza immunisation?
Those people with chronic health conditions are more at risk of complications from influenza and that is why the vaccination is provided free to these groups. This includes those 65 years and over, and those adults and children with certain chronic conditions including:
heart disease stroke ongoing respiratory (chest) diseases like chronic bronchitis or asthma (but only those requiring regular preventative medication) diabetes ongoing renal (kidney) disease most cancers other conditions affecting the immune system such as HIV/AIDS, rheumatoid arthritis and organ transplants.
Where can eligible people get a free vaccination?
Free vaccinations are available from your local General Practitioner although a practice nurse may be the one who actually administers the injection to you. The vaccine is injected into your upper arm.
How safe is the vaccine?
The immunisation will not give you influenza because the vaccine contains disrupted virus. Most people have no reaction to the injection. Occasionally the place where the injection was given is red or sore. Some people may feel unwell for a day or two. These are normal responses to the immunisation.
What influenza strains are in this year's vaccine?
The three influenza strains in this year's vaccine are:
A/New Caledonia/1999 (H1N1), and
Who decides which viral strains go into the vaccine?
The World Health Organization made influenza vaccine composition recommendations for 2005 for New Zealand, Australia and South Africa.
For more information on the vaccine composition discussions, go to the Influenza in New Zealand 2004 annual report on the ESR website:
Will people get influenza from the vaccination?
No. Influenza vaccine cannot give you the 'flu as it contains fragments of disrupted virus.
Summary of 2004 influenza statistics
Influenza activity in New Zealand peaked late last year, at the end of September, a month later than the peak in 2003 and 2002. It is estimated that influenza-like illness affected more than 35,000 New Zealanders during the season, compared with more than 46,000 people in 2003.
For more information on 2005 influenza activity, go to the ESR website:
How are the statistics collected?
There are two parts to the influenza surveillance systems in New Zealand - sentinel general practice (GP) surveillance and laboratory-based (mainly hospital) virological surveillance.
General Practice Surveillance
The sentinel GP surveillance system started in 1991 as part of the WHO Global programme for influenza surveillance. It is operated nationally by ESR and locally by influenza surveillance co-ordinators in the public health services.
In 2004, national influenza GP surveillance was carried out from May to October. Local surveillance co-ordinators recruited General Practices within their region to participate on a voluntary basis. GPs recorded the number of consultations for influenza-like illness each week and the age group of each of these suspected cases.
Each practice was also asked to collect throat or nose swabs from patients seen with an influenza like illness each week. The swabs were sent to a regional virus diagnostic laboratory and/or ESR for strain identification.
Laboratory-based surveillance (year round)
In addition to positive identification of the influenza virus from GP surveillance, year round virological surveillance of influenza (and other viruses) is carried out by the four regional virus diagnostic laboratories at Auckland, Waikato, Christchurch and Dunedin hospitals, and by ESR. ESR acts as New Zealand's designated WHO National Influenza Centre.
Each week the regional virus diagnostic laboratories report all viral identifications including influenza largely from hospital in-patients and outpatients, to ESR, where the data is collated and reported nationally.
For more information www.moh.govt.nz/influenzab