One of the most unusual symptoms of Coronavirus (COVID19) infection is the loss of a sense of smell and taste. I learned about this yesterday from a friend in Italy who I’ve been so worried about. She finally confessed that she likely had it two-three weeks ago and is normalising.
Symptoms included profound fatigue, fevers, and cough. Her most peculiar symptoms, however, were a profound loss of smell and taste. She sanitised her flat, but did not smell the bleach. She watched garlic browning on the stove, but could not smell it.
Nor could she taste these strongly scented vegetables like garlic or fennel. Fortunately, all of her symptoms are resolving. She is one of the lucky ones.
My friend also noted that, anecdotally, physicians have commented that a significant proportion of patients are presenting similarly. No studies have been done because these physicians are overwhelmed.
According to the Lancet, 9% of all infections in Italy are among medical personnel; in the hardest-hit region of Lombardy, 20% of providers were infected. They are struggling to stay alive, with a shortage of staff, ventilators, and personal protective equipment (masks, gloves, gowns). The European Union has failed to provide support.
China has stepped up, sending tons of medical equipment, masks, and even physicians to help. While this is critically important now, it is likely not entirely altruistic.
Some say Europe is being wooed by Chinese President Xi Jinping, who reportedly said he hoped to establish a “health silk road” as part of China’s global One belt, One Road Initiative.
While the Italians have not been able to systematically study the loss or alteration of smell (anosmia) or taste (dysgeusia), German virologist Hendrik Streek has been busily at work.
During an early cluster of cases in Germany, linked to auto supplier Webasto, Streek’s team had the opportunity to take daily samples from the infected workers isolated in a hospital, as well as interview them to learn about the progression of symptoms.
In an excellent interview, Streek described how his team went from house to house and to every infected person in the district of Heinsberg. They took many samples from the environment and interviewed a number of families.”Two thirds, described a loss of smell and taste lasting several days.”
As with my friend, it is difficult for sick people to remember the exact time course of their illness. Streek’s sense was that the smell abnormality occurred a bit later in infection.
These same findings were also seen by Massimo Galli, Professor of Infectious Diseases at the University of Milan, though he has been too busy to quantify the finding. He also noted that these peculiar symptoms were also noted later in the course of infection so won’t be of value as a clue to early diagnosis.
Having practised infectious disease for forty years now, the only other infection I’ve seen with a loss of smell was Herpes simplex encephalitis, so I was intrigued by this unusual symptom.
It’s not entirely clear what is causing these symptoms. Some viruses destroy the cells or cell receptors in your nose. Others infect the brain via the olfactory sensory nerves. Most disturbingly, this ability to infect the brain is thought to explain some of the cases of respiratory failure in COVID-19 infections.
It’s easy to test for loss of smell with a variety of household items, citrus, soap or cleaning supplies. You can test taste with sweet, salty, sour, or bitter items.
There was also a report from Iran of patients with loss of smell and also of vision per Dr. Ebrahim Razmpa, Deputy Chairman of Iran’s Rhinology Association.
Two prominent people also reported the odd symptom this week. Arielle Charnas, who has the blog Something Navy, noted loss of smell and taste. On Day 4 of her illness, Frozen 2 star Rachel Matthews, who provided the voice for Honeymaren reported, “Randomly lost my sense of smell and taste.”
Loss of smell and taste is a relatively newly reported symptom of coronavirus infection. We still don’t know how often it occurs nor why this has been reported more in some areas than others. Infectious diseases has never been a boring speciality. I wish it were now.