Meanwhile, there’s been no evidence of perinatal transmission; the virus has not been detected in amniotic fluid, cord blood, neonatal throat swabs, or breast milk. Maternal morbidity appears to be similar to uninfected women. “The data around pregnancy are reassuring,” said John Brooks, MD, chief medical officers for HIV/AIDS prevention at the Centers for Disease Control and Prevention, Atlanta, who has been involved with CDC’s containment efforts.
There’s no data yet for immunocompromised people, but for people with HIV, he said, “we think the risk of severe illness would be greater” with lower CD4 counts and unsuppressed viral loads. “People living with HIV should take precautions against this new virus,” including having at least a 30-day supply of HIV medications; keeping up flu and pneumonia vaccinations; and having a care plan if quarantined. Setting up telemedicine might be a good idea.
The usual incubation period for COVID-19 is 4-6 days but can be longer. Recovery time is about 2 weeks in mild cases and 3-6 weeks in more severe cases. People who die do so within 2 months of symptom onset.
The most common symptoms among hospitalized patients in China are fever, dry cough, fatigue, and headache. Truly asymptomatic cases are not common; most go on to develop symptoms. There have been reports of diarrhea before other symptoms by a day or two, but it’s probably a red herring. The virus has been isolated from stool, but there is no evidence of fecal-oral transmission, Dr. Wu said.
Eighty percent of COVID-19 cases are mild or moderate and most patients recover spontaneously, especially middle aged and younger people. There is no meaningful difference in distribution between the sexes.
There are limited pediatric data perhaps due to underreporting, “but we know [children] experience milder illness than adults,” the CDC’s Dr. Brooks said.
He pegged the latest case fatality estimate at 0.5% to 3.5%, which is considerably higher than seasonal flu, but might well drop as more mild cases are detected and added to the denominator, he said.
For now, death rates top 5% in adults over 60 years old and climb further with increasing age, approaching 16% in people 80 years or older. Patients with hypertension, diabetes, cardiovascular disease, and chronic respiratory illness are at increased risk. The ultimate cause of death is acute respiratory distress syndrome, said Ralph Baric, PhD, a coronavirus expert and epidemiology professor at the University of North Carolina, Chapel Hill, who also presented at the meeting.
Several drug and vaccine candidates are under study for the infection. An intriguing possibility is that angiotensin converting enzyme (ACE) inhibitors might help. Hypertension is a known risk factor for severe infection; the virus makes use of ACE receptor pathways to infect airway epithelial cells; and there have been reports of ACE inhibitors having effect against the virus that caused severe acute respiratory syndrome (SARS), another coronavirus outbreak in 2003.
“I think it’s a very good idea to go back and re-explore use of these drugs,” Dr. Baric said.
The presenters didn’t have any relevant disclosures.
