Increase in Influenza and Acute Respiratory Infections in Singapore

26 Jan 2011

1.   Influenza and acute respiratory infections (ARI) have risen in Singapore in the past few weeks. Singapore typically experiences an increase in influenza activity in the January to February period. World-wide, countries in the temperate regions of the Northern Hemisphere have also reported increases in influenza activity as expected during their winter season.

Local situation
2.   The number of patients seeking treatment in polyclinics for ARI increased by 13% from 18,377 in E-week 2 (9 – 15 Jan 2011) to 20,702 in E-week 3 (16 – 22 Jan 2011). It remained above the epidemic threshold.

3.   The proportion of influenza-like-illness (ILI) among ARI polyclinic attendances has however remained low at 1 - 2% (in comparison, this proportion was 15 - 20% during the height of the pandemic in 2009). The number of Emergency Department (ED) attendances for ARI and the number of ED admissions for pneumonia also showed upward trends in the last few weeks.

4.   These increases in attendances for ARI have been accompanied by a corresponding increase in the influenza positivity rate among patients with ILI in the community. The prevalence of influenza among ILI samples has risen to 52% (preliminary) during the past four weeks from about 40% in December 2010. Influenza A (H1N1-2009) was the predominant strain, comprising 76% of the influenza virus isolates in December 2010, while influenza A (H3N2) and influenza B each constituted 12%. Preliminary data showed that influenza A (H1N1-2009) remained as the predominant strain in January 2011.

Public advisory – need for vigilance and vaccination
5.    While most people with influenza recover with rest and symptomatic treatment, influenza can result in pneumonia requiring hospitalisation or even death, especially in vulnerable groups such as very young children, the elderly and patients with chronic illnesses (see Annex for the full list). These groups of people should get themselves vaccinated every year It is also important for the public to practise good personal hygiene (e.g. by washing hands frequently), be socially responsible when unwell (e.g. by not going to school or work), and to lead a healthy lifestyle which helps to build up one’s immunity and protects one against infection.
 
ANNEX
Recommendations for influenza vaccination
It is recommended that the following groups receive the influenza vaccine:

• Persons aged 65 years and older;
  

• Children aged 6 months to 5 years;
  

• Residents of nursing homes and other chronic care facilities;
  

• Adults and children who have chronic disorders of the lungs or heart, including asthma;
  

• Adults and children who have required regular medical follow-up or hospitalization during the preceding year because of chronic metabolic disease (including diabetes mellitus), kidney or blood disorders, or lowered immunity caused by medications or by HIV;
  

• Household contacts of the above (those at risk of transmitting the flu virus);
  

• Household contacts and out-of-home caregivers of children aged 0 to 23 months, in particular for children aged 0 – 5 months as influenza vaccines have not been approved for use among children aged < 6 months;
  

• Children and teenagers aged 6 months to 18 years who are receiving long term aspirin therapy;
  

• Women who are in the second or third trimester of pregnancy; and
  

• Healthcare workers and allied health personnel.