One second is all it takes: It’s easy to catch COVID-19

The crazy story that proves how easy it is to get infected with COVID-19

View of a doorway at hotel Washington, where journalists wait in quarantine prior to the Tokyo 2020 Olympic Games, in Tokyo, Japan, July 3, 2021. Picture taken July 3, 2021. (photo credit: REUTERS)
View of a doorway at hotel Washington, where journalists wait in quarantine prior to the Tokyo 2020 Olympic Games, in Tokyo, Japan, July 3, 2021. Picture taken July 3, 2021.
(photo credit: REUTERS)

In New Zealand, one person with the virus infected three people without coming into contact with them at all, a mystery researchers tried to crack. Genetic testing and security cameras helped them come to this interesting conclusion.

We’ve been living with this pandemic for almost two years now, so it's hard to surprise us. But sometimes, one short story proves how crazy and contagious this virus is. This case was in New Zealand which implemented  sweeping measures against the virus such as closing the skies to travel, isolation hotels, total closures across the country following a single verified case, etc.

Someone who flew in and was then isolated in a hotel for monitoring managed to infect three other passengers in the same hotel even though there was no contact between them. It seems, according to the epidemiological investigation, the infection occurred on both sides of the room corridor. The doors of the rooms were open for just a few seconds and air leaked from the sick person’s room to other rooms where people were isolated.

According to the researchers who examined this case, this is further proof of the high infection rate of the coronavirus, but also proof of the effectiveness of the vaccine, since one isolator who was vaccinated and stayed in the same room with three unvaccinated people that had been infected for several weeks wasn’t found positive for the virus even once.

What exactly happened?

All of these travelers arrived in New Zealand in July, at the height of the wave of morbidity caused by the Delta strain, which until Omicron was the most contagious strain. One person from the Philippines was found positive when he arrived and he was sent to a government-run isolation hotel.

Five people from the UAE stayed at the same place; one was positive. The five stayed in a room across the hall from the Filipino. Everyone was  forbidden to leave their rooms, and the door was opened only for PCR tests and food deliveries.  According to the hotel's policy, the doors of the various rooms weren’t to be opened at the same time. But, it did happen anyway, as revealed by Andrew Fox Lewis and colleagues from the Auckland Health Council who investigated this surprising case of infection. Researchers wrote that video from CCTV cameras showed four different times the doors of the two rooms were opened at the same time for short periods, during the period of infection of patient A. Each such simultaneous opening of doors lasted no more than a single second.

Of the five from the Emirates (one of whom was positive on arrival at the hotel), three more became infected. However, genetic flooring performed on their samples revealed that their roommate was not the source of the infection. The genetic fingerprint of the virus found in the people from the UAE actually matched that of the Filipino across the hall.

After examining all the materials and documentation researchers concluded that airborne infection which carried the virus particles from one side of the corridor to the other was the most plausible explanation.

"These findings are of global importance for the intervention and prevention of the virus and for public health," Fox Lewis and colleagues wrote in an article published in the journal Emerging Infectious Diseases.

"We checked and found that patient A didn’t leave his room at any stage while he was contagious. He was allowed to leave his room for exercise only after he was no longer contagious - from July 28 onwards (by this time patients B and C were already positive for coronavirus),” the researchers wrote. It’s possible that what happened was that patient A emitted infectious virus particles into the air space in the hallway, and the infected air penetrated the room of the Emirates travelers while their door was open for a few seconds.

It should be noted that health authorities in New Zealand also considered this type of scenario and tried to prevent it by using special fans that were supposed to pump the air in the hallway out as well as air purifiers installed in the hotel. These were probably not effective enough in the case of simultaneous door opening, though. "The ventilation system was separated from room to room, and each room had an exterior window that occupants could open independently and freely to let in fresh air," the researchers noted.

They concluded that their findings were consistent with the notion that during short periods of time in which the doors of the two rooms were opened simultaneously, virus particles carried in the air from the room of A, moved and crossed the corridor into the room of BCDEF.

Who wasn’t infected?

Only one person returning from the UAE wasn’t infected; he was vaccinated. Although he shared a room with four other infected people, PCR tests showed that the vaccinated man was never infected. Tests were done on July 14, 18, 21, 27, 29 and 31 and August 14, 16 and 23. In all of them, he was negative for coronavirus; he’s been vaccinated with two doses of the Pfizer vaccine. None of his travel companions were vaccinated.

Passing across the hall in Hong Kong

This is not the only documentation of coronavirus infection from different rooms on both sides of a corridor. Only recently, in early December 2021, researchers from Hong Kong reported a vaccinated patient infected with the Omicron strain and staying in isolation in a hotel infected someone staying across the hall, and both had been vaccinated twice.

Here, too, security cameras in the hallway showed that they didn’t leave their rooms or come into contact with each other or with others. The doors of their rooms were opened for very short periods of time to grab food trays left outside and to perform PCR tests every 3 days. Here, too, genetic tests confirmed that the virus strains in their samples were almost identical although they arrived on different days and from different countries. Epidemiological researchers in Hong Kong came to the same conclusion as those from New Zealand and it is that the transmission of virus-borne virus particles from room to room causes people to be infected with the coronavirus.