Percentage of asymptomatic cases identified in weekly Covid figures doubled since January-CSO

Data published by the CSO in March that showed one in four people testing positive for Covid-19 were asymptomatic. 
Percentage of asymptomatic cases identified in weekly Covid figures doubled since January-CSO

Walk-in Covid testing centres have been set up to try and identify more asymptomatic cases.

Asymptomatic cases identified as a percentage of the weekly testing data has more than doubled since the year began, according to the latest Central Statics Office (CSO) records. 

On the week ending January 15, the percentage of asymptomatic cases confirmed stood at 15% and rose over 12 weeks until April 2 when it stood at 30%. 

This weekly rate of increase means that on January 15, of the 18,815 cases identified, 2,822 of them have been asymptomatic cases. 

Testing data of Covid cases confirmed since the start of January 2021. Picture: CSO
Testing data of Covid cases confirmed since the start of January 2021. Picture: CSO

In comparison, on April 2, three months later, of the 3,010 cases confirmed, 903 of them have been asymptomatic cases. 

According to the HSE:  "An asymptomatic case is a person who tests positive for SARS-CoV-2 and never develops symptoms of Covid-19."

Identified cases per week have dropped since then as lockdown restrictions tackled the third wave of the coronavirus infection. 

The latest data comes as public health teams attempt to identify the largest cause of community infection in the country. 

Data published by the CSO in March that showed one in four people testing positive for Covid-19 were asymptomatic. 

These increased testing results do coincide with the introduction of walk-in HSE testing centres for communities in counties with persistent rates of infection. 

On March 24, the HSE set up five walk-in testing centres for areas of high incidence rates of the virus, four in Dublin and one in Tullamore, Co Offaly. 

In Limerick, Public Health Mid-West and HSE Mid-West Community Healthcare have set up a walk-in testing centre today at St Joseph’s Health Campus, Mulgrave Street and will operate for six days.

The testing centres are open for those who do not have Covid-19 symptoms and for people who are concerned that they may have been at risk of infection in the past two weeks.

Covid outbreaks and employment

Meanwhile, in the last four weeks, of the 14,173 cases identified, public health teams have traced 4,930 of them back to outbreaks.  

The under-24 age cohort made up 41% of all cases linked to an outbreak over this period and there were 1,798 cases, or 36%, linked to an outbreak in private houses.  

Also, 122, 2% cases were in nursing homes, 280, 6% were in a hospital or a community hospital/long-stay unit and 216 or 4% were in residential institutions.

In terms of the workplace, 585 cases, or 12% were linked to an outbreak in the last four weeks.

For Covid-19 cases by employment sector, the wholesale and retail trade reported the highest number of confirmed cases followed by industry. 

Agriculture, forestry, and fishing reported the lowest amount of cases. 

Infection rates across the country

Across the country, there has been a national decline in Covid-19 cases as Level 5 lockdown restrictions take effect. 

However, there have been important variances in certain counties for a percentage change in weekly cases. 

A county by county breakdown of confirmed Covid-19 cases. Picture: CSO
A county by county breakdown of confirmed Covid-19 cases. Picture: CSO

For example, the CSO graph for the period March 26 to April 2, shows how although the number of new cases has fallen nationally by 21%, this diverges across counties from a 107% increase in Monaghan to a 62% decrease in Kilkenny. 

Other notable decreases include Donegal at 57%, Clare at 56% and 42% in Tipperary. 

Age of confirmed cases

The weekly number of confirmed cases in the age cohort 80 years and over has been suppressed since the start of the year as the vaccination rollout takes effect.

An age breakdown of weekly confirmed cases. Picture: CSO
An age breakdown of weekly confirmed cases. Picture: CSO

Similarly in the same nine-week period, the number of confirmed cases in the 25-44 age cohort declined. 

The age category 25-44 continued to represent the highest number of confirmed cases across the same period. 

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