COVID-19 research briefing 25/03/20

Researchers from across BHP are collaborating to analyse and summarise the latest COVID-19 literature to help inform clinical colleagues.

Research update – 25th March 2020

Incubation period:
Face with thermometer

95% of patients see initial symptoms 4-6 days after infection

Face with medical mask

97.5% display all symptoms between 7-14 days


Of those hospitalised, this occurred 6-12 days after infection.

Spiral calendar pad

The evidence strongly supports the 14 day quarantine.

After patients report symptoms, the presence of CoV-2 antibodies was spotted:

      • Around day 5: IgA and IgM
      • Around day 14: IgG
Clinical characteristics:

89% of adult hospitalised patients (but only 3.5% of child hospitalised patients) present with lymphopenia (low white blood cell count). The lower the white blood cell count, the more severe the infection. Most ICU deaths have occurred in those with the lowest count.

Of the hospitalised paediatric coronavirus patients that have been reported:

      • 40% had tachycardia (increase heart rate)
      • 41% had pneumonia
      • 100% had pre-existing medical conditions

Unsurprisingly, more than 95% of patients present with dyspnoea (difficult/laboured breathing) and around 70% with a persistent cough. Other symptoms include headache, vomiting and digestive problems but data are limited.

Viral biology:

COVID-19 infects cells through the ACE2 receptor and can be blocked in vitro with camostat meylate. It also  infects neuronal cells, transmitting via the synape, and brain cells in both mice and humans contained the virus. Mice infected nasally with COVID-19 developed cardio-respiratory circuit dysfunction.

Therapy update:

NO antiviral treatment has yet been effective in humans.

      • Lopinavir/ritonavir – no change in mortality, improvement or viral load.
      • Chloroquine – negative in mice.
      • Hydroxychloroquine – data are limited.

See also the 20th March update.