IRELAND’S HEALTH WATCHDOG has advised NPHET on the “higher risk” settings and activities that allow for the novel coronavirus to spread.

The Health Information and Quality Authority (Hiqa) said that certain activities and settings may need more public health measures as they are “conducive to superspreading”.

These high risk settings or activities include: health and social care settings, meat and food processing plants, cruise ships, prisons, shopping malls, religious settings, bars, nightclubs and restaurants, gyms, offices, weddings and large shared accommodation.

Hiqa said this is not a definitive list. It also identified the risk in households, and said that there is “a clear rationale” for self-isolation guidelines within households.

According to an analysis by Hiqa, the main factors found to contribute to transmission risk include:

• indoor environments,
• crowds, and
• prolonged and intense contact with others.

Other important factors may include:

• the level of ventilation,
• speaking volume,
• insufficient use of face coverings,
• the viral load of the index case.

Activities involving dining, drinking, exercising, singing or shouting, prolonged face-to-face conversation, especially in-indoor crowded environments, were associated with an increased risk of transmission in several studies, Hiqa said.

Hiqa said that households play “an important role” in the transmission of coronavirus. Based on international literature, it said, the estimated ‘secondary attack rate’ in household settings is 18%, compared with <1% in healthcare settings.

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In work settings, additional factors found to be related to the spread of Covid include: working despite symptoms (‘presenteeism’); a lack of access to hand-washing facilities; and an inadequate or inappropriate use of personal protective equipment (PPE).

For schools, Hiqa says that because they are “supervised, controlled” environments, they are assumed to be of less risk than incidents like house parties, which are “unsupervised, uncontrolled” environments.

The report notes:

Although schools, may potentially be viewed as high risk settings (due to high density, close proximity for prolonged durations, indoor setting etc.), it was noted that this is not reflected in the Irish data with relatively few clusters (2% of all reported clusters), consistently low test positivity rates and limited evidence of transmission occurring in the school setting.

“This highlights that transmission risks within school populations can be effectively mitigated with the implementation of proper protective measures.”

You can read Hiqa’s advice to NPHET, sent on 12 November and published today, here.