Superspreader: 25 People On A Single Flight Test Positive For Covid-19

Indian airline Vistara was banned from flying to Hong Kong for two weeks earlier this month after bringing in passengers who tested positive for Covid-19 on two separate flights.

While four passengers initially tested positive on April 4th’s Delhi – Hong Kong flight, 25 people on that flight have now tested positive.

Everyone on the flight would have presented a negative test to board. 5 people tested positive 12 days after the flight. This doesn’t mean that the virus was spread on the plane. India is experiencing its greatest surge in cases since the start of the pandemic – it’s not surprising that passengers on a flight out of India would be carrying the virus. And predeparture testing doesn’t guarantee someone doesn’t have the virus in small enough amounts so as not to show up at the time the test occurred.

While HEPA air filtration and downward air flow reduce the risk of transmission on a plane, making it one of the safer indoor environments, that safety is often only limited to actual travel time. United Airlines, for instance, is rare among airlines in running the auxiliary power unit on the ground during board and deplaning to take advantage of fresh air circulation and filtration. The boarding and deplaning process is otherwise a risk factor, along with time spent in the airport (at security, at the gate, and even on the jetway).

Just because passengers were seated near each other who tested positive doesn’t mean the transmission occurred on the aircraft – people seated near each other are often part of the same party (a family who may have spread it from one infected person to another) and even people seated nearby who aren’t traveling together may be queued together for boarding.

Flights like this are relatively rare but do happen, and seems consistent with how Covid-19 spreads more generally. Most people infected with the virus don’t spread it at all, even inside the home (where transmission risk is greatest, on average). Instead a small percentage of cases are responsible for superspreader events.

There have been other flights identified with clusters of passengers infected but this remains fairly uncommon and flights into places like Hong Kong, New Zealand and Australia are extensively tested. That’s good news overall.

My view throughout the pandemic is that I would rather have been flying on a plane than eating indoors at a restaurant over similar periods of time. `And of course much of the risk of travel comes from things people might do at their destination. (Skipping travel to visit a few relatives in favor of holding a large gathering at home isn’t good risk-management.) But incidents like this Vistara flight in which so many clustered cases are associated with a flight points to the importance of vaccination.

(HT: @tedfrank)

About Gary Leff

Gary Leff is one of the foremost experts in the field of miles, points, and frequent business travel - a topic he has covered since 2002. Co-founder of frequent flyer community, emcee of the Freddie Awards, and named one of the "World's Top Travel Experts" by Conde' Nast Traveler (2010-Present) Gary has been a guest on most major news media, profiled in several top print publications, and published broadly on the topic of consumer loyalty. More About Gary »

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  1. Your story is (crazily) already out of date – same person on Twitter said an hour ago that it’s up to 47 people on the flight. 188 seats, not sure how full the flight was.

  2. @Gary, thanks for reaffirming the need for vaccination.

    I have some anti-vax friends who won’t get vaxxed ‘cuz they are ‘healthy, great immune system, won’t get sick’. Alright, that much might be true. BUT that won’t stop transmission, folks!

    Then in the next breath they are pissing and moaning about not being allowed to travel because they aren’t vaxxed!

  3. People wake up there are 7 university doctors that are suing the cdc because the cdc said it sent COVID samples to the university’s to be worked with and when the university tested it for its work it was nothing but influenza and the cdc can’t send a verified sample for work to be done
    There is no “COVID” just the flu virus that is very strong

  4. I have had the flu vaccine but will not get the deadly cocktail of the COVID still in test not FDA approved, rat poison mix of COVID shot
    I am not going to be a genie pig!!
    You can and I will watch the side affects!!!

  5. Think of an airplane as a pressure cooker. If one person is infected most likely many will become infected and nearly all exposed to the virus. An airplane is very small air volume per person much more than in restaurant dinning. I’m not saying go to a restaurant I’m say don’t believe the myth that flying is not a risk due to HEPA filters. We don’t test in the US as Asia does so we have no idea how much Covid spread is from flying. Perhaps that South African and UK variant came over on a boat?

  6. @carolyn
    The majority of people who contract Covid unvaccinated usually live a long life. Many get sick for years and a much smaller % (3 million to date) dies.
    The majority of people Covid vaccinated live longer lives. Few get sick and a handful have died.
    You do not have to believe in science or math or facts. Maybe you will be a lucky one.

  7. @Carolyn Smith is not only ignorant but also illiterate (no Carolyn, that has nothing to do with your parents’ marital state at the time you were born.)

    Too bad you don’t wanna be a “genie pig.” Then you could grant yourself 3 wishes and get rid of all the people who live their lives based on knowledge and reason.

  8. @ Carolyn — Clearly you have no idea what you are talking about. We’re about a year past the COVID-is-fake nonsense. In case you also missed the following news items: Donald Trump isn’t President and COVID vaccines work.

  9. Vaccines should be required for air travel if only to prevent total morons from coming onboard.

  10. @Carolyn – Even Donald Trump got vaccinated, shortly before leaving office. Though in typical Trumpian fashion, he didn’t broadcast the news because he’s more concerned about himself and his image than the health of his followers or the public in general.

  11. It took 5 comments for the Trump comments. He still lives rent free in your head. Give it up already

  12. @Carolyn, @Paul and @Gene

    To add to Gene’s and Paul’s points, even Donald and Melanie Trump got vaccinated in January. So Carolyn, your likely hero must have a “rat poison mix” running through his system…maybe that is why he is losing weight

  13. So much for “it is very unlikely for a person to get Covid on an airplane”! Believe whatever you want, but the only way to stop Covid is thru vaccinations. These anti-vaxers are going to make Covid worse. With more infections comes the greater chances of mutations. Vaccinating is the best way to stop new variants/mutations from occurring. Get over your whack job excuses and GET VACCINNATED!

  14. Why does the CDC not ground all airline flights? They did for cruise ships even though they would only allow vaccinated pax.

    Let’s face it, we will not get to herd immunity as we will never get to the 75 (or whatever) percent vaccinated. Even now, with about 40%, there are hardly any waits for the vaccine appointments in many places – showing the demand has decreased. Two months ago it was difficult to get a vaccine shot.
    And as US (Biden) will not create a secure vaccine passport, there is no way to control who can go anywhere. COVID restrictions may continue for years.

  15. Gary, let’s talk about the title.

    First word is “superspreader”.

    Then within a couple of sentences you fully back off with “5 people tested positive 12 days after the flight. This doesn’t mean that the virus was spread on the plane.”

    You write your own headlines so you can’t blame “the editor”.

    Gary you regularly call out airlines for “improving” their loyalty program when in fact it’s a devaluation.

    Gary, you expect airlines to be intellectually honest with their customers.

    Is it too much for your readers to ask that if you?

  16. Carolyn, I think you meant guinea not genie. Altho, I could use a genie about now, then poof the Covid menace or hoax is gone, as well as this new fake of an administration.

  17. Thank you Gary for continuing to post and take abuse from others. As a doc I don’t always agree 100% with what you say medically, but I do appreciate your attempts to inform us as fellow travelers. We are all beyond done with this virus. Let’s all aim for civility and kindness as we stumble across the finish line in the next year

  18. Again all the more reason why only fully vaccinated people should be allowed on planes. This airline has now brought in at least 50 covid positive people among two flights this month alone. Hong Kong is suspending all flights connecting it with India until May 3rd. They have also suspended air travel connecting them with Pakistan and the Philippines during the same time period.

  19. I have a Doctor of Pharmacy degree- pharmaceutically speaking I recommend the free Covid vaccine and so do many people at the CDC who are scientifically multi degreed.

  20. I m no genie pig… but with a fake test available for 50 rupees, one would be stupid to get a real one.

  21. The Modi government in India is very dishonest with how bad the COVID-19 situation is in India and instead it tries to present a face of strength to mask the government’s incompetence from top to bottom. And the Modi government supporters include a lot of Trump sympathizers, so it’s probably unreasonable to expect honesty/decency and competence when it comes to its supporters flying around.

  22. Carolyn – you’re an illiterate idiot.

    Leff – you’re still not qualified to comment on this stuff.

  23. Gary, why do your posts attract so many stone cold imbeciles? Now we’ve got @joanie adams who, after half-a-million deaths just in the U.S., is still calling covid a hoax. Anyone who continues to believe that fantasy has an IQ lower than her shoe size. And to call the new administration fake?! Time for her family to put her into a home for the mentally unbalanced! Unlike the former guy, who really was fake with his hiding the facts about Covid, then saying injecting bleach would be an effective cure, this administration has managed to get at least one dose of the vaccine into nearly 50% of the country in fewer than 100 days, has passed an economic package that rivals the New Deal, and which has gotten cash into the hands of everyday Americans, and is at an all time high approval rating over any other administration in the last 20 years.

  24. No wonder. People in India kept thinking we’ve escaped the worst. Too many Maskless Morons. My own apartment complex has 65 cases.

  25. Do these guys actually every go back and read their comments at any point after writing them?

    Snarky, snide, and condescending.

    So many people who make comments on this site are apparently so unhappy with themselves or their lives that they only comment to denigrate others, well, except when they”re congratulating other nasty people for having as odious an attitude as themselves. I am so glad I don’t have to live with any of them in real life….and I feel sorry for their spouses unless of course they’re just as base and mean as these patronizing commenters.

    Although I’ve been following it for several years, this is my first post on this site, and I’m only commenting now because the tone has gotten so over the top these past few months….

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