14 June 2017
The 2017 influenza season has started. Every year during winter months, May to August, South Africa experiences an increase in influenza circulation. During this time the number of individuals who become sick, seek medical care, get admitted to hospital or who die due to respiratory illness increases. The influenza season is considered to have started when the detection rate of specimens from the influenza-like illness (ILI) programme, Viral Watch, tested at the NICD has risen above 10% and is sustained for ≥2 weeks. While there have been low levels of influenza circulation since week 18 (week ending 7 May 2017), the number of specimens testing positive for influenza has increased. According to the data from Viral Watch programme, this year the detection rate rose to 25% in week 21 (week ending 28 May 2017), and to 32% in week 22 (week ending 4 June). To date all influenza positive samples for this season have been influenza A(H3N2).
Influenza vaccination, which provides protection against at least three strains of influenza each season, remains the most effective measure to prevent illness and possibly fatal outcomes. Protecting those who are at increased risk of severe influenza outcomes plays an important role in management of respiratory illnesses. Individuals at risk of influenza and severe disease include among others the pregnant women, and those vulnerable due to pre-existing illnesses or risk factors. Vaccines should be given sufficiently early to provide protection for the influenza season, though it is never too late to vaccinate. A protective antibody response takes about 2 weeks to develop. The 2017 influenza vaccine has been available in South Africa since the middle of April and it can be accessed at local clinics and private providers (pharmacies and private practitioners). Clinicians are encouraged to vaccinate individuals in the groups that are targeted for influenza vaccination. Influenza NICD recommendations for diagnosis, prevention, management and public health response, can be accessed at: http://www.nicd.ac.za/wp- content/uploads/2017/03/Influenza-guidelines-final_24_05_2017.pdf