Measures to limit Covid-19 spread
Here are some of the individual measures to protect against infection with SARS-CoV-2, that have been consistently recommended by WHO and others.
- Cough hygiene
A cough should be caught in a single use tissue, or the crook of the elbow. The tissue should be immediately disposed of and hand hygiene performed. Coughing into bare hands means they can become heavily contaminated; unless immediate and thorough hand hygiene is performed, they can become a vehicle for transmission. Cough hygiene can reduce, but not totally eliminate, droplets being released by a cough or sneeze.
- Avoiding face touching:
Avoiding face touching is a self-protective measure. The risk is that contaminated hands can contact mucosal surfaces and cause an infection. The extent of its role in transmission of infection has not been thoroughly investigated. People have been observed to touch their face 23 times per hour and more in times of stress and in some social groups.
- Physical distancing
Physical distancing is a series of measures which include minimising social contact of large groups of people in crowded spaces. It may also involve minimising physical contact through actions like hand shaking and kissing as a greeting, depending on social norms, which are culturally specific. Physical distancing can protect both the individual and others around them.
Self isolation is a more extreme form of social distancing, it has been recommended for high-risk contacts and for those with mild symptoms who do not require medical care. The isolation of asymptomatic high-risk contacts is rational if there is strong evidence of pre or asymptomatic infection. However mass isolation may have major social and economic effects so the risks and benefits should be balanced, and may be tailored according to risk, or consequences of, infection.
- Hand hygiene
Frequent hand hygiene with either soap and water, or alcohol-based hand rub. Key moments are after using the toilet, coughing or sneezing, before preparing food or eating, after touching communal surfaces such as door handles and before touching your face. Hand hygiene should be thorough, to decontaminate all areas of the hands.
- Face masks
The value of wearing these outside health care settings is controversial but it is one of the most visible features of the response in many areas. The evidence for the protective effect of asymptomatic individuals wearing masks is weak and facemasks may change face touching behaviour if they become uncomfortable and need adjusting. There is evidence that wearing a mask reduces the droplet spray if individuals cough or sneeze. Physical distancing and cough hygiene are other measures that can be instituted to control the effect of droplet spread.
Other advice (less consistently seen) includes:
- Avoiding wet/live meat markets
This is only relevant in areas where these exist. Many early cases were associated with the Huanan seafood market for this outbreak but it is not clear that this is where zoonotic transmission (spread from animals to humans) occurred. Without evidence of multiple events where zoonotic transmission of SARS-CoV-2 has occurred in wet/live meat markets, this measure won’t affect the course of this outbreak, but it could reduce the risk of a similar future emergence.
Active monitoring of health after travel to areas with transmission.
- Avoiding close contact with anyone who is sick
This is the other side of self-isolation but will be harder to adhere to for people with caring responsibilities.
- Not spreading rumours
- Regular household surface disinfection
- Avoiding spitting in public
In some cultures public spitting is much less socially acceptable in general so a specific injunction isn’t required.
Source : London School of Hygiene & Tropical Medicine 2020