Ken Wu

A 2-year-old girl presents to the paediatric emergency department with a 3-day history of fever and cough. Parents also say that she is eating and drinking less than usual. She has no significant medical history. As you are taking the history, you eyeball the patient, who looks coryzal but generally well. To say this is a common scenario for paediatricians, especially in the winter months, is an understatement – this is our bread and butter work. Except it is February 2020, and this family recently returned from China where there is an outbreak of Coronavirus Disease 2019 (COVID-19).

Paediatricians are all too familiar with viral upper respiratory tract infections. The main viral culprits we are used to seeing are respiratory syncytial viruses (RSV) and influenza viruses. These are so common that some emergency departments have started using point-of-care rapid diagnostic tests for RSV and flu to help with patient management and cohorting admissions.

Coronaviruses are another group of viruses that can cause upper respiratory tract infections in children. One study in Norway found that they account for 9% of all children with respiratory tract infections. The virus itself is an enveloped, positive sense, single-stranded RNA virus, with a distinct morphological appearance on microscopy giving its name – “corona” is Latin for “garland” or “wreath”. Coronaviruses can affect a wide range of species, from mammals such as pigs and bats to birds such as chickens. Seven serotypes of coronaviruses can affect humans; four are common and cause a mild cold-like disease and three are rare and can cause severe respiratory infections.

Occasionally, a virus can “jump” from one species to another, resulting in a new type of disease and infection. This was the case in the Severe Acute Respiratory Syndrome (SARS) outbreak in 2002, caused by the SARS-CoV coronavirus which originated from bats and was subsequently transmitted to Masket Palm Civet cats as an intermediate host before arriving in humans, and the Middle East respiratory syndrome (MERS) outbreak in 2012, caused by the MERS-CoV coronavirus which also originated from and was subsequently transmitted to camels as an intermediate host before arriving in humans.

The COVID-19 outbreak started in the city of Wuhan in China in December 2019. This virus itself is similar to the SARS virus on genomic analysis,

hence it was officially given the name of SARS-CoV-2. The exact origins of the virus is unknown as of February 2020, as is the mechanism of how it ended up in humans. With any new outbreak, there are lots of unknowns, rumours, new information, and general panic both from the patients and from healthcare workers. As a clinician and paediatrician seeing patients on the front line, there are a few key points to bear in mind and keep a track of new developments. Below is a list of these, and how they relate to COVID-19 from published case reports.

How does it affect patients?

1. How do patients present? These are predominantly non-specific, namely fever, cough, fatigue. Some patients can also be asymptomatic.
2. What are their investigations like? Initial blood tests showed raised inflammatory markers (CRP) and lymphopenia. Radiology: chest x-ray showed pneumonia, mostly bilateral. CT chest findings also showed ground-glass opacities and evidence of pneumonia.
3. How long does it take between being infected to having symptoms? This is commonly known as the incubation period (i.e. the time from infection to onset of illness) – latest data shows a mean of 5.2 days, but can range anywhere from 2 days to over 2 weeks.
4. What is the progression of the disease? Latest data shows 26% of hospitalized patients were admitted to intensive care. Clinically these patients are likely to develop Acute Respiratory Distress Syndrome (ARDS).
5. What causes patients to die? Patients who have died from COVID-19 are generally older with medical co-morbidities. These patients tend to develop multi-organ failure and some have ARDS. Mortality rate is difficult to estimate but currently it is estimated at 2%.
6. How do we treat? There are no proven treatments. Patients are generally treated empirically for bacterial and viral pneumonia with antibiotics and oseltamivir.

What do healthcare professionals need to know?

In disease outbreaks, the WHO and your country’s public health organisations will give detailed guidance, which is frequently updated sometimes on a daily basis, on the following:

1. Case definition – what criteria qualifies as a case of a particular disease.
2. Who should be screened?
3. What diagnostic testing should be done and which types of specimens to collect?
4. Where should you send specimens?
5. What infection prevention and control measures should you take?
6. How and where to report a confirmed case?

What do researchers want to know?

1. R₀ (or transmission rate or basic reproduction number) – this is the average expected number of cases, in an otherwise uninfected population, stemming from one infected case over the course of an infectious period. As a general guide, if >1, it is likely to keep spreading; if <1, it is likely to fizzle out. Current estimated R₀ for COVID-19 is 2.2.
2. Where did it come from? This is commonly known as the index case or patient zero – the first documented case to describe the disease. This is currently unconfirmed but the earliest case reported is from early December 2019 in Wuhan.
3. How is it transmitted? Currently unknown, but likely to be droplet spread.
4. Who transmits it and when? Both symptomatic and asymptomatic people can be infectious. Their infectious period is currently unknown.
5. How does it affect special populations i.e. children, pregnant women? There have been very few reports of paediatric cases of COVID-19. They mainly come from family clusters. Much like the SARS outbreak, children have similar but milder symptoms compared to adults with the infection. The reason behind why children have a milder course of disease is still unknown.

The framework outlined above will act as a guide to help you navigate the multitude of information in an outbreak that comes from the inevitable media frenzy. The important thing is to know where to find trusted and accurate information, both for you and your colleagues and to inform your patients. For the COVID-19 outbreak, organisations, including the WHO, NEJM, The Lancet, The BMJ, JAMA have set up dedicated websites to provide up-to-date and accurate information as it becomes available.

Ken Wu is a UK Paediatric trainee, and currently a fellow at the New England Journal of Medicine.

Disclaimer: as with any outbreak, information about COVID-19 is constantly changing. Here at Paediatric FOAMed we aim to provide up-to-date information about COVID-19 as it becomes available. This article was last updated on 19th February 2020.