Coronavirus (COVID-19)

Coronavirus disease 2019 (COVID-19) is a potentially severe acute respiratory infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The virus was identified as the cause of an outbreak of pneumonia of unknown cause in Wuhan City, Hubei Province, China, in December 2019. The clinical presentation is that of a respiratory infection with a symptom severity ranging from a mild common cold-like illness, to a severe viral pneumonia leading to acute respiratory distress syndrome that is potentially fatal.

The International Committee on Taxonomy of Viruses has confirmed SARS-CoV-2 as the name of the virus owing to the virus's genetic similarity to the SARS-CoV virus, but taking into account that there may be differences in disease spectrum and transmission. The World Health Organization has confirmed COVID-19 (a shortened version of coronavirus disease 2019) as the name of the disease that SARS-CoV-2 infection causes. Prior to this, the virus and/or disease was known by various names including novel coronavirus (2019-nCoV), 2019-nCoV, or variations on this.

Epidemiology

The World Health Organization (WHO) was informed of 44 cases of pneumonia of unknown microbial aetiology associated with Wuhan City, Hubei Province, China on 31 December 2019. Most of the patients in the outbreak reported a link to a large seafood and live animal market (Huanan South China Seafood Market).The WHO announced that a novel coronavirus had been detected in samples taken from these patients. Laboratory tests ruled out severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome (MERS)-CoV, influenza, avian influenza, and other common respiratory pathogens.Since then, the outbreak has escalated rapidly, with the WHO declaring a public health emergency of international concern on 30 January 2020. The numbers of cases and deaths have surpassed the toll from the 2002-2003 outbreak of severe acute respiratory syndrome (SARS).

Cases in China

• The National Health Commission of the People's Republic of China has reported over 75,000 confirmed cases and over 2200 deaths in China, with majority of cases in Hubei Province (as of 21 February 2020).

Cases outside of China

• At least 1200 cases have been confirmed in the following 27 countries outside of China: Australia,Belgium, Cambodia, Canada, Finland, France, Germany, Egypt, India, Iran, Italy, Japan, Lebanon, Malaysia, Nepal, the Philippines, Russia, Singapore, South Korea, Spain, Sri Lanka, Sweden,Thailand, the United Arab Emirates, the UK, the US, and Vietnam. At least 8 deaths have been reported outside of mainland China (as of 21 February 2020).

• At least 14 countries have reported cases of local transmission inside the reporting country: Australia, Egypt, France, Germany, Iran, Japan, Malaysia, Singapore, South Korea, Thailand, the United Arab Emirates, the UK, the US, and Vietnam (as of 21 February 2020). At least 634 cases have been reported on an international conveyance (a cruise ship) in Japan.

These case counts are correct at the time of publication; however, they are increasing daily, and you should consult the case count resources below for updated information if necessary:

These case counts are correct at the time of publication; however, they are increasing daily, and you should consult the case count resources below for updated information if necessary:

Early reports suggest that the infection is more likely to affect older males with underlying health conditions or comorbidities (e.g., chronic cardiovascular, cerebrovascular, endocrine, digestive, or respiratory disease).Severe, possibly fatal, complications may also be more common in these patients. The median age of

patients ranges from 49 to 59 years.Infection in children is being reported much less commonly than among adults, and all cases so far have been in family clusters or in children who have a history of close contact with an infected patient.

Primary prevention

General prevention measures

• The only way to prevent infection is to avoid exposure to the virus and people should be advised to:

• Wash hands often with soap and water or an alcohol-based hand sanitiser and avoid touching the eyes, nose, and mouth with unwashed hands.

• Avoid close contact with people (i.e., maintain a distance of at least 1 metre [3 feet]), particularly those who have a fever or are coughing or sneezing.

• Practice respiratory hygiene (i.e., cover mouth and nose when coughing or sneezing, discard tissue immediately in a closed bin, and wash hands).

• Seek medical care early if they have a fever, cough, and difficulty breathing, and share their previous travel and contact history with their healthcare provider.

• Avoid direct unprotected contact with live animals and surfaces in contact with live animals when visiting live markets in affected areas.

• Avoid the consumption of raw or undercooked animal products, and handle raw meat, milk, or animal organs with care as per usual good food safety practices.

Medical masks

• The World Health Organization (WHO) does not recommend that people wear a medical mask in community settings if they do not have respiratory symptoms as there is no evidence available on its usefulness to protect people who are not ill. However, masks may be worn in some countries according to local cultural habits. Individuals with fever and/or respiratory symptoms are advised to wear a mask, particularly in endemic areas.

• It is mandatory to wear a medical mask in public in certain areas of China, and local guidance should be consulted for more information.

Screening and quarantine

• People travelling from areas with a high risk of infection may be screened using questionnaires about their travel, contact with ill persons, symptoms of infection, and/or measurement of their temperature.Combined screening of airline passengers on exit from an affected area and on arrival elsewhere has been relatively ineffective when used for other infections such as Ebola virus infection, and has been modelled to miss up to 50% of cases of COVID-19, particularly those with no symptoms during an incubation period, which may exceed 10 days. Symptom-based screening processes have been reported to be ineffective in detecting SARS-CoV-2 infection in a small number of patients who were later found to have evidence of SARS-CoV-2 in a throat swab.

• Enforced quarantine has been used in some countries to isolate easily identifiable cohorts of people at potential risk of recent exposure (e.g., groups evacuated by aeroplane from affected areas, or groups on cruise ships with infected people on board). The psychosocial effects of enforced quarantine may have long-lasting repercussions.

Vaccine

• There is currently no vaccine available. Vaccines are in development, but it may take up to 12 months before a vaccine is available.

Screening

Management of contacts

People who may have been exposed to individuals with suspected COVID-19 (including healthcare workers) should be advised to monitor their health for 14 days from the last day of possible contact, and seek immediate medical attention if they develop any symptoms, particularly fever, respiratory symptoms such as

coughing or shortness of breath, or diarrhoea.

Some people may be put into voluntary or compulsory quarantine depending on the guidance from local health authorities.

Screening of travelers

Exit screening is advised for areas with ongoing transmission and involves checking for signs and symptoms (fever and cough) and interviewing passengers with respiratory infection symptoms leaving the affected areas in regards to potential exposure to high-risk contacts or to the presumed animal source.

Entry screening may detect exported symptomatic cases; however, it may miss patients who are incubating the disease or those who are concealing symptoms, and so it is important to also disseminate risk communication materials to raise awareness and encourage health-seeking behaviour. Several countries are actively performing entry screening according to local protocols.

Some people may be put into voluntary or compulsory quarantine depending on the guidance from local health authorities.

Infection prevention and control

Triage all patients on admission and immediately isolate all suspected and confirmed cases in an area separate from other patients. Implement appropriate infection prevention and control procedures.

Screening questionnaires may be helpful. Report all suspected and confirmed cases to your local health authorities.

The World Health Organization (WHO) recommends the following basic principles:

• Immediately isolate all suspected cases in an area that is separate from other patients

• Implement standard precautions at all times:

• Practice hand and respiratory hygiene

• Offer a medical mask to patients who can tolerate one

• Wear personal protective equipment

• Prevent needlestick and sharps injury

• Practice safe waste management, environmental cleaning, and sterilisation of patient care equipment and linen

• Implement additional contact and droplet precautions until the patient is asymptomatic:

• Place patients in adequately ventilated single rooms; when single rooms are not available, place all suspected cases together in the same ward

• Wear a medical mask, gloves, an appropriate gown, and eye/facial protection (e.g., goggles or a face shield)

• Use single-use or disposable equipment

• Consider limiting the number of healthcare workers, family members, and visitors in contact with the patient, ensuring optimal patient care and psychosocial support for the patient

• Consider placing patients in negative pressure rooms, if available

• Implement airborne precautions when performing aerosol-generating procedures

• All specimens collected for laboratory investigations should be regarded as potentially infectious.

It is important to disinfect inanimate surfaces in the surgery or hospital as patients may touch and contaminate surfaces such as door handles and desktops.

Detailed guidance on infection prevention and control procedures are available from the WHO and the Centers for Disease Control and Prevention (CDC):

Clinical presentation

The clinical presentation resembles viral pneumonia, and the severity of illness ranges from mild to severe. Most patients present with mild illness. Based on early data, approximately 20% of symptomatic patients may progress to severe illness, although this figure may change as the situation evolves.

Some patients may be minimally symptomatic or asymptomatic. Large-scale screening in non-endemic areas may pick up more of these types of patients. A milder clinical course has been reported in cases identified outside of China, with most patients being healthy adults.

Based on an early analysis of case series, the most common symptoms are:

• Fever

• Cough

• Dyspnoea

• Myalgia

• Fatigue.

Less common symptoms include:

• Anorexia

• Sputum production

• Sore throat

• Confusion

• Dizziness

• Headache

• Rhinorrhoea

• Chest pain

• Haemoptysis

• Diarrhoea

• Nausea/vomiting

• Abdominal pain.

Approximately 90% of patients present with more than one symptom, and 15% of patients present with fever, cough, and dyspnoea.It appears that fewer patients have prominent upper respiratory tract or gastrointestinal symptoms compared with SARS, MERS, or influenza.Patients may present with nausea or diarrhoea 1 to 2 days prior to onset of fever and breathing difficulties. Most children present with mild symptoms, without fever or pneumonia. However, they may have signs of pneumonia on chest imaging despite having minimal or no symptoms. Retrospective reviews of pregnant women with COVID-19 found that the clinical characteristics in pregnant women were similar to those reported for nonpregnant adults.A retrospective case series of 62 patients in Zhejiang province found that the clinical features were less severe than those of the primary infected patients from Wuhan City, indicating that second-generation infection may result in milder infection. This phenomenon was also reported with MERS.

Perform a physical examination. Patients may be febrile (with or without chills/rigors) and have obvious cough and/or difficulty breathing. Auscultation of the chest may reveal inspiratory crackles, rales, and/or bronchial breathing in patients with pneumonia or respiratory distress. Patients with respiratory distress may have tachycardia, tachypnoea, or cyanosis accompanying hypoxia.

Initial investigations

Order the following investigations in all patients with severe illness:

• Pulse oximetry

• ABG (as indicated to detect hypercarbia or acidosis)

• FBC

• Comprehensive metabolic panel

• Coagulation screen

• Inflammatory markers (serum procalcitonin and C-reactive protein)

• Serum troponin

• Serum lactate dehydrogenase

• Serum creatine kinase.

The most common laboratory abnormalities in patients hospitalised with pneumonia include leukopenia (9% to 25%), lymphopenia (35% to 63%), leukocytosis (24% to 30%), and elevated liver transaminases (28% to 37%). Other abnormalities include neutrophilia, thrombocytopenia, decreased haemoglobin,decreased albumin, and renal impairment.

Pulse oximetry may reveal low oxygen saturation (SpO₂ <90%).

Coronavirus: A Timeline