On January 5th 2020, the World Health Organisation published a "Disease Outbreak News" article about a disease that was later to be called COVID-19.

It states:

Based on the preliminary information from the Chinese investigation team, no evidence of significant human-to-human transmission and no health care worker infections have been reported.

They repeated this statement in a tweet on January 14th, 2020.

We now know that human-to-human transmission of the virus behind COVID-19 is common. The WHO is under political attack from President Trump. The BBC investigated the claim - they gave background, but didn't seem to reach a clear conclusion.

Was this statement true on January 5th? Was the assessment still accurate on January 14th?

  • 2
    I have made a major edit to avoid it being a political opinion. I am still concerned it treats an organisation of 7,000 poeple as a single cohesive entity. It seems far more likely that some people would have been convinced by evidence at any given date, and some people would either not be convinced or had not yet seen the evidence (including the social media team)
    – Oddthinking
    Commented Apr 19, 2020 at 12:04
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    What exactly are you questioning? The WHO statement says that no such transmissions have been reported by the Chinese investigation team at that point. This is not a statement on likelihood, that's a statement of missing reports. That the Wuhan HC stated at the same time that "the possibility of limited human-to-human transmission could not be excluded" (BBC) is not a contradiction. What exactly are you skeptic about?
    – DevSolar
    Commented Apr 19, 2020 at 14:00
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    I don't understand. The tweet makes no claims whatsoever about the likelihood of human to human transmission. All it says is that the preliminary information doesn't include evidence of such transmission happening. That, however, in no way implies that it does not happen. Only that the preliminary information doesn't show it happening. If people read that as a strong claim that no human to human transmission exists, then that's on them, the tweet itself is carefully worded to avoid making any such claims.
    – terdon
    Commented Apr 20, 2020 at 13:28
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    " preliminary information doesn't include evidence of such transmission happening." is a claim, albeit not a string one, about the likelihood of such transmission.
    – einpoklum
    Commented Apr 20, 2020 at 17:59
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    @einpoklum no, it's not a claim about the likelihood of transmission. It's a claim about the content of someone else's claim about transmission. If Bob lies, and you report what Bob said, you are not lying.
    – barbecue
    Commented Apr 21, 2020 at 1:20

2 Answers 2


The answer to this is going to opinion based to some extent. The WHO like everyone else was largely dependent on China for information at that point. Here's for example what the ECDC reported/concluded on Jan 17:

In China, 763 close contacts have been identified and monitored. Of these, 644 have completed the observation period, while 119 remain under medical observation. So far, none has tested positive for 2019-nCoV [7,10].

There are some later examples of (quite) insensitive Chinese tests see q on med SE, so Hanlon's razor probably applies here, not only to China but whomever else believed their test results.

This info had to be counterbalanced against the clusters observed, from the ECDC report:

Among the cases reported, two small family clusters were identified. In one cluster, all three members of the family had attended the specific Wuhan market before disease onset. In the other cluster, one member was the spouse of a salesman in the market.

The WHO seems to have said something similar about the family clusters being a little troublesome, although seemingly just in a press conference, according to an answer on politics SE:

According to the WHO COVID-19 Timeline's entry for January 14th:

Dr. Maria Van Kerkhove noted in a press briefing there had been limited human-to-human transmission of the coronavirus (in the 41 confirmed cases), mainly through family members, and that there was a risk of a possible wider outbreak. Dr. Kerkhove noted that human-to-human transmission would not be surprising given our experience with SARS, MERS and other respiratory pathogens.

So it was a matter of balancing the overwhelmingly negative tests reported by China with the few epidemiological findings to the contrary. As that press conference suggests, not everyone inside the WHO was equally convinced of how to weigh these somewhat contrary findings coming from China.

For comparison, here's what the US CDC was saying (Jan 17) based on the same reports:

Chinese authorities additionally report that several hundred health care workers caring for outbreak patients are being monitored and no spread of this virus from patients to health care workers has been seen. They report no sustained spread of this virus in the community, however there are indications that some limited person-to-person spread may have occurred.

So you can quibble about wording like "no significant" vs "limited" but it doesn't look like any major health authorities [outside China] could infer the magnitude of the problem at the time. Basically, the WHO, the ECDC and the US CDC were reading the same findings put out by China and coming to fairly similar conclusions in that Jan 14-17 time frame.

Very long aside below, but hopefully insightful as to what was going on in China in those crucial days:

AP news (April, 15)

China didn’t warn public of likely pandemic for 6 key days

In the six days after top Chinese officials secretly determined they likely were facing a pandemic from a new coronavirus, the city of Wuhan at the epicenter of the disease hosted a mass banquet for tens of thousands of people; millions began traveling through for Lunar New Year celebrations.

That delay from Jan. 14 to Jan. 20 was neither the first mistake made by Chinese officials at all levels in confronting the outbreak, nor the longest lag, as governments around the world have dragged their feet for weeks and even months in addressing the virus. [...]

It’s uncertain whether it was local officials who failed to report cases or national officials who failed to record them. It’s also not clear exactly what officials knew at the time in Wuhan, which only opened back up last week with restrictions after its quarantine. [...]

Without these internal reports, it took the first case outside China, in Thailand on Jan. 13, to galvanize leaders in Beijing into recognizing the possible pandemic before them. It was only then that they launched a nationwide plan to find cases — distributing CDC-sanctioned test kits, easing the criteria for confirming cases and ordering health officials to screen patients. They also instructed officials in Hubei province, where Wuhan is located, to begin temperature checks at transportation hubs and cut down on large public gatherings. And they did it all without telling the public.

The documents show that the head of China’s National Health Commission, Ma Xiaowei, laid out a grim assessment of the situation on Jan. 14 in a confidential teleconference with provincial health officials. A memo states that the teleconference was held to convey instructions on the coronavirus from President Xi Jinping, Premier Li Keqiang and Vice Premier Sun Chunlan, but does not specify what those instructions were.

“The epidemic situation is still severe and complex, the most severe challenge since SARS in 2003, and is likely to develop into a major public health event,” the memo cites Ma as saying.

The National Health Commission is the top medical agency in the country. In a faxed statement, the Commission said it had organized the teleconference because of the case reported in Thailand and the possibility of the virus spreading during New Year travel. It added that China had published information on the outbreak in an “open, transparent, responsible and timely manner,” in accordance with “important instructions” repeatedly issued by President Xi.

The documents come from an anonymous source in the medical field who did not want to be named for fear of retribution. The AP confirmed the contents with two other sources in public health familiar with the teleconference. Some of the memo’s contents also appeared in a public notice about the teleconference, stripped of key details and published in February.

Under a section titled “sober understanding of the situation,” the memo said that “clustered cases suggest that human-to-human transmission is possible.” It singled out the case in Thailand, saying that the situation had “changed significantly” because of the possible spread of the virus abroad.

“With the coming of the Spring Festival, many people will be traveling, and the risk of transmission and spread is high,” the memo continued. “All localities must prepare for and respond to a pandemic.”

In the memo, Ma demanded officials unite around Xi and made clear that political considerations and social stability were key priorities during the long lead-up to China’s two biggest political meetings of the year in March. While the documents do not spell out why Chinese leaders waited six days to make their concerns public, the meetings may be one reason.

The National Health Commission also distributed a 63-page set of instructions to provincial health officials, obtained by the AP. The instructions ordered health officials nationwide to identify suspected cases, hospitals to open fever clinics, and doctors and nurses to don protective gear. They were marked “internal” — “not to be spread on the internet,” “not to be publicly disclosed.”

In public, however, officials continued to downplay the threat, pointing to the 41 cases public at the time.

“We have reached the latest understanding that the risk of sustained human-to-human transmission is low,” Li Qun, the head of the China CDC’s emergency center, told Chinese state television on Jan. 15. That was the same day Li was appointed leader of a group preparing emergency plans for the level one response, a CDC notice shows.


“They may not have said the right thing, but they were doing the right thing,” said Ray Yip, the retired founding head of the U.S. Centers for Disease Control’s office in China. “On the 20th, they sounded the alarm for the whole country, which is not an unreasonable delay.”

If health officials raise the alarm prematurely, it can damage their credibility — “like crying wolf” —and cripple their ability to mobilize the public, said Benjamin Cowling, an epidemiologist at the University of Hong Kong.


[Earlier on, Chinese] officials obstructed medical staff who tried to report such cases. They set tight criteria for confirming cases, where patients not only had to test positive, but samples had to be sent to Beijing and sequenced. They required staff to report to supervisors before sending information higher, Chinese media reports show. And they punished doctors for warning about the disease.

As a result, no new cases were reported for almost two weeks from Jan. 5, even as officials gathered in Wuhan for Hubei province’s two biggest political meetings of the year, internal China CDC bulletins confirm.

During this period, teams of experts dispatched to Wuhan by Beijing said they failed to find clear signs of danger and human-to-human transmission. [...]

The second [Beijing] expert team, dispatched on Jan. 8, similarly failed to unearth any clear signs of human-to-human transmission. Yet during their stay, more than half a dozen doctors and nurses had already fallen ill with the virus, a retrospective China CDC study published in the New England Journal of Medicine would later show.

The teams looked for patients with severe pneumonia, missing those with milder symptoms. They also narrowed the search to those who had visited the seafood market — which was in retrospect a mistake, said Cowling, the Hong Kong epidemiologist, who flew to Beijing to review the cases in late January. [...]

“I always suspected it was human-to-human transmissible,” said Wang Guangfa, the leader of the second expert team, in a Mar. 15 post on Weibo, the Chinese social media platform. He fell ill with the virus soon after returning to Beijing on Jan. 16.

When the Thai case was reported, health authorities finally drew up an internal plan to systematically identify, isolate, test, and treat all cases of the new coronavirus nationwide.

Wuhan’s case count began to climb immediately — four on Jan. 17, then 17 the next day and 136 the day after. Across the country, dozens of cases began to surface, in some cases among patients who were infected earlier but had not yet been tested. In Zhejiang, for example, a man hospitalized on Jan. 4 was only isolated on Jan. 17 and confirmed positive on Jan. 21. Shenzhen, where Yuen had earlier found six people who tested positive, finally recorded its first confirmed case on Jan. 19.

The Wuhan Union Hospital, one of the city’s best, held an emergency meeting on Jan. 18, instructing staff to adopt stringent isolation — still before Xi’s public warning. A health expert told AP that on Jan. 19, she toured a hospital built after the SARS outbreak, where medical workers had furiously prepared an entire building with hundreds of beds for pneumonia patients.

“Everybody in the country in the infectious disease field knew something was going on,” she said, declining to be named to avoid disrupting sensitive government consultations. “They were anticipating it.”

So yeah, as the WHO (and US CDC, ECDC) was/were repeating what China had said a few days prior, the Chinese authorities were themselves waking up to the true extent of the problem and gearing up the response... while not quite revealing it in public until the 20th or so.


Note: This isn't intended as a complete answer, only a partial one (which is too extensive to place in comments).

A Washington Post article from April 19, 2020 states:

More than a dozen U.S. researchers, physicians and public health experts, many of them from the Centers for Disease Control and Prevention, were working full time at the Geneva headquarters of the World Health Organization as the novel coronavirus emerged late last year and transmitted real-time information about its discovery and spread in China to the Trump administration, according to U.S. and international officials.

A number of CDC staff members are regularly detailed to work at the WHO in Geneva as part of a rotation that has operated for years. Senior Trump-appointed health officials also consulted regularly at the highest levels with the WHO as the crisis unfolded, the officials said.

So CDC staff working with WHO did communicate (in "real time") to the White House staff information about the virus.

And an article in the March 30, 2020 issue of The New Yorker contains a story, written by an English professor from the US, relating his experience with the virus while living in China during the origin of the outbreak. He implies that the presence of the virus was well-known by mid-January, and a "lock-down" was implemented to prevent its spread between people.

What I can't show is that the details (ie, people-to-people transmission) was transmitted to the WHO, though it's clear that the fact would have been known to anyone outside of China who was following the situation there, since it was so well-known within China.

  • This sounds strange. how can they work on that virus if it hsdn't been isolated/identified yet?
    – einpoklum
    Commented Apr 20, 2020 at 19:41
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    How does this answer whether the WHO had evidence of significant human-to-human transmission of SARS-CoV-2 prior to January 14, 2020?
    – Oddthinking
    Commented Apr 20, 2020 at 20:39
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    This seems to be an unclear (to assume good faith) answer. Your evidence is basically that the US CDC and WHO knew roughly the same thing. (Something I don't disagree with.) But then claim rather vaguely in a comment that "the virus was pretty well known by mid-January". What do yo mean by that? Are you saying they could have inferred enough (in re pathogenicity) from its genetic sequence? Do you have (at least) some expert quotes to that effect? Commented Apr 20, 2020 at 21:08
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    I've read this article and it never mentions anything about human-to-human transmission at all, let alone how significant it might be.
    – barbecue
    Commented Apr 20, 2020 at 21:48
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    Hmm, OK, but the question was specifically about the WHO knowing about human-to-human transmission, not knowing about the virus. This seems more like a comment than an answer.
    – barbecue
    Commented Apr 21, 2020 at 0:34

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