Discussion
On 11 March 2020, the World Health Organization declared the spread of the novel coronavirus SARS-CoV-2, causing COVID-19, a global pandemic (2–4) . Common symptoms of COVID-19 are a cough, fever, muscle pain and fatigue, with later onset of shortness of breath and eventual acute respiratory distress syndrome (ARDS) in some (5–7) . The typical symptoms and radiological findings of ground glass opacity and reticular changes (crazy paving) have recently been described in a case study published in the Journal of the Norwegian Medical Association (8) .
However, some patients with COVID-19 present with other symptoms. Over the past two weeks, our acute admissions unit has seen an additional five patients with similar symptoms, where COVID-19 has been confirmed by real-time PCR. The main complaint of all of these patients was abdominal pain, with some also having lower abdominal pain. In addition, they reported loss of appetite, nausea and vomiting. Some also had diarrhoea, but none had new symptoms from the respiratory tract. All underwent a CT examination of their abdomen, as part of the assessment of their abdominal pain, where the images showed typical findings for COVID-19 in the lungs (Figure 2).
Figure 2 CT image of patient (not actual case study) with acute abdomen as an early symptom. The image shows the lower part of the thorax and shows patchy, bilateral characteristic ground glass opacity with peripheral distribution. The patient gave consent for the image to be published.
Studies have increasingly reported symptoms from the gastrointestinal tract in COVID-19 patients (6, 7, 9) . In a large study of 1099 patients with COVID-19, 5 % had nausea and 3.8 % vomiting. The study also found that 8.9 % never developed viral pneumonia (7) . In a recently published study of 204 patients with confirmed COVID-19, it was reported that about half of the patients had symptoms of loss of appetite, diarrhoea, vomiting and abdominal pain. It was found that the period of time from onset of symptoms to hospitalisation was longer for patients with gastrointestinal symptoms than for patients with respiratory tract symptoms, and that those with gastrointestinal symptoms had a poorer prognosis (10) .
In other infections caused by phylogenetically similar coronaviruses, such as Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS), it has been reported that 20–25 % of patients initially experienced symptoms from the gastrointestinal tract (11) -(13) .
Basal pneumonia with pleural effusion may explain pain and discomfort in the upper abdomen. However, it is less likely that basal pneumonia will cause lower abdominal pain and symptoms such as nausea, vomiting and diarrhoea. Other mechanisms must therefore be suspected. Similar to SARS-CoV, SARS-CoV-2 has been shown to have proteins that readily bind to the cell receptor angiotensin-converting enzyme 2 (ACE2) (3) . There are many ACE2 receptors on type 2 alveolar cells in the lungs, and the lungs are therefore particularly at risk. Cells in other organs have also been shown to have ACE2 receptors. The virus can therefore invade, multiply and cause infection in several organ systems. A high proportion of ACE2 receptors has been seen in the heart, ileum, oesophagus, kidneys and bladder. In one study, epithelial cells in the ileum were reported to have a very high proportion of ACE2 receptors (30 %, versus 1 % in the lungs) (14) .
Our experiences with the COVID-19 pandemic to date have led us to change the procedures in the radiology and surgery departments. Droplet precautions are used for all patients with unexplained upper abdominal pain, as well as all patients with abdominal pain (irrespective of location) and concomitant fever, until test results of COVID-19 are available. Since the typical COVID-19 findings are not necessarily located on the bases of the lungs, a CT thorax is also performed at the same time as the abdominal CT. This does not entail extra time in the CT machine. We also believe that since many patients with acute abdomen often end up getting a CT scan as part of their investigative procedures, consideration should be given to primarily doing a CT scan of the thorax, abdomen and pelvis, instead of an ultrasound examination of the abdomen and a conventional thoracic x-ray, during the current epidemic.
Early suspicion of COVID-19 is crucial for early diagnosis and reducing the risk transmission. At the time our patient was admitted, procedures had already been established for early assessment of the risk of infection in all patients arriving at our acute admission unit (pre-triage). This assessment includes questions on travel history and close contact with people with confirmed COVID-19. Enhanced droplet and contact precautions are used for a large proportion of patients. Our patient was pre-triaged in accordance with the procedures at the time, but enhanced droplet precautions were not established.
Our experience indicates that unexplained abdominal pain should be considered as a criterion in the pre-triage procedure. This will potentially reduce the risk of transmission to other patients and hospital staff. However, the experiences with COVID-19 are at an early stage, and ongoing assessments must be made of the most appropriate patient management procedures.