Coronavirus disease 2019 (COVID-19)
Global health organisations have published preventive measures to reduce the chances of infection (see figure 1). Recommendations are similar to those published for other coronaviruses. The use of facemasks by healthy people is not recommended. However, people should wear a facemask when around with other people (e.g., sharing a room or vehicle) and before entering a healthcare provider’s office.

To prevent transmission, the WHO recommends the following for everyone. Wash your hands frequently and thoroughly clean your hands with an alcohol-based hand rub or wash them with soap and water. See video 2 for proper instructions. Maintain social distancing. Maintain at least 2 metre distance between yourself and anyone who is coughing or sneezing. Avoid touching eyes, nose and mouth. If you have fever, cough and difficulty breathing, seek medical care early. Make sure you, and the people around you, follow good respiratory hygiene. This means covering your mouth and nose with your bent elbow or tissue when you cough or sneeze. Then dispose of the used tissue immediately. Practice respiratory hygiene. The WHO has also updates on travel advices.

Like WHO, the CDC has recommended that individuals wash hands often with soap and water for at least 20 seconds, especially after going to the toilet or when hands are visibly dirty and after blowing one's nose, coughing, or sneezing. It is further recommended to use an alcohol-based hand sanitiser with at least 60% alcohol when soap and water are not readily available. The US Environmental Protection Agency (EPA) has published a list of disinfectants for use against SARS-CoV-2.

Figure 1. Preventive measures

Video 1. WHO: How to protect yourself against COVID-19

Video 2. What You Need to Know About Handwashing. (Source: CDC)

The WHO recommends the following procedures regarding the use of masks:
If you are healthy, you are strongly recommended to wear a mask if you are taking care of a person with suspected 2019-nCoV infection.

• Wear a mask if you are coughing or sneezing.
• Masks are effective only when used in combination with frequent hand-cleaning with alcohol-based hand rub or soap and water.
• If you wear a mask, then you must know how to use it and dispose of it properly.

How to put on, use, take off and dispose of a mask:

• Before putting on a mask, clean hands with alcohol-based hand rub or soap and water.
• Cover your mouth and nose with mask and make sure there are no gaps between your face and the mask.
• Avoid touching the mask while using it. In case you touch your mask, clean your hands with properly with soap and water or an alcohol based detergent.
• Replace the mask with a new one as soon as it is damp and do not re-use single-use masks.
• To remove the mask, you should remove it from behind without touching the front of mask. Discard the used mask immediately in a closed bin and clean hands properly with soap and water or an alcohol based detergent.

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Middle East respiratory syndrome (MERS)
No vaccine or specific treatment is currently available for MERS. As a general precaution, anyone visiting farms, markets, barns, or other places where dromedary camels and other animals are present should practice general hygiene measures, including regular hand washing with soap and water after touching animals. Especially, contact should be avoided with sick animals. The consumption of raw or undercooked animal products, including milk and meat, carries a high risk of infection from a variety of organisms that might cause disease in humans. Animal products that are processed appropriately through cooking or pasteurization are safe for consumption, but should also be handled with care to avoid cross contamination with uncooked foods. Camel meat and camel milk are nutritious products that can continue to be consumed after pasteurization, cooking, or other heat treatments.

People with chronic lung disease, diabetes, renal failure, and immunocompromised persons are considered to be at high risk of severe disease from MERS-CoV infection. These people should avoid contact with camels.

The WHO currently recommends that all individuals coming into contact with MERS suspects should in addition to standard precautions:

• Wear a medical mask
• Wear eye protection (i.e. goggles or a face shield)
• Wear a clean, non sterile, long sleeved gown; and gloves (some procedures may require sterile gloves)
• Perform hand hygiene before and after contact with the person and his or her surroundings and immediately after removal of personal protective equipment (PPE)

For procedures which carry a risk of aerosolization, such as intubation, the WHO recommends that care providers also:

• Wear a particulate respirator and, when putting on a disposable particulate respirator, always check the seal
• Wear eye protection (i.e. goggles or a face shield)
• Wear a clean, non-sterile, long-sleeved gown and gloves (some of these procedures require sterile gloves)
• Wear an impermeable apron for some procedures with expected high fluid volumes that might penetrate the gown
• Perform procedures in an adequately ventilated room; i.e. minimum of 6 to 12 air changes per hour in facilities with a mechanically ventilated room and at least 60 liters/second/patient in facilities with natural ventilation
• Limit the number of persons present in the room to the absolute minimum required for the person's care and support
• Perform hand hygiene before and after contact with the person and his or her surroundings and after PPE removal.

The duration of infectivity of MERS-CoV is not fully understood, so it is unclear how long people must be isolated, but current recommendations are for 24 hours after disappearance of symptoms. In the 2003 SARS outbreak the virus was not cultured from people after the disappearance of their symptoms.

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Severe acute respiratory syndrome (SARS)
Clinical isolation and quarantine remain the most effective means to prevent the spread of SARS as there is still no vaccine available. Other preventive measures include:

• Hand-washing
• Disinfection of surfaces for fomites
• Avoiding contact with bodily fluids
• Washing the personal items of someone with SARS in hot, soapy water (eating utensils, dishes, bedding, etc.)
• Keeping children with symptoms home from school
• Simple hygiene measures
• Isolating oneself as much as possible to minimize the chances of transmission of the virus

During the outbreak in 2003, many public health interventions were made to try to control the spread of the disease. These interventions included earlier detection of the disease, isolation of infected people, droplet and contact precautions, and the use of facemasks and isolation gowns. A screening process was also put in place at airports to monitor air travel to and from affected countries. Although no cases have been identified since 2004, the WHO and CDC arel working to make rapid response guidelines and recommendations in the event of a reappearance of the virus.