ESR’s surveillance of hospitalisations for severe acute respiratory infection (SARI) shows that for the week ending 11 July, the overall weekly rate of SARI hospitalisations in the Auckland region has decreased compared with the previous week and rates are now below the baseline seasonal threshold.
ESR Public Health Physician, Dr Sarah Jefferies says the weekly rate of RSV-positive SARI hospitalisations remains much higher than expected seasonal activity.
“The current number of cases is more than two-fold greater than the historical average rate (2014-2019) for this time of year. The rates of RSV-positive SARI hospitalisations in infants are also continuing to increase, over 1.75 cases per 1000 per week, twice the expected rate, while the rates of RSV-positive SARI hospitalisations in children aged 1-4 have decreased in the week ending 11 July but remains high.
“We are also receiving increasing reports of outbreaks in early childcare settings across the country. The peak in national RSV illness activity is possibly still to come.
“This unusually high RSV activity is likely due to there being lower levels of protective natural immunity in New Zealand at the start of our winter season due to the very little seasonal RSV circulating in 2020 as a result of the COVID-19 response. There is also more mixing of people and opportunities for viruses to spread this year.
“RSV is typically a very common illness in New Zealand in the winter months with only a small proportion of suspected cases commonly tested. Most adults and older children with RSV will experience symptoms similar to the common cold. However, very young children and babies, as well as older adults and people with certain medical conditions, can become very sick and may require hospitalisation.”
Figure 1: Weekly rate of RSV-positive SARI hospitalisations in the Auckland region (all ages)
“The information being collected through the sentinel surveillance systems provides useful data to inform public health decisions, however we are also very cognisant that many diagnoses will be made by clinicians around the country and not through the network of laboratories, so it is difficult to provide an accurate picture of all cases in the community,” says Dr Jefferies.
RSV is very infectious and spreads easily from person to person, for example, through coughs and sneezes. People also can be infected by touching contaminated items. So good hygiene practices including catching coughs and sneezes, frequent hand washing, and wiping down toys with warm water and detergent, as described by the Ministry of Health, are important to prevent the spread of the virus.
“While RSV is common at this time of year, it’s important people follow the medical advice and guidance on the Ministry of Health webpage. This includes to stay at home and away from young children if you are sick, and call your general practice or Healthline if you are developing symptoms of concern such as shortness of breath,” says Dr Jefferies.