The 2019_CoV outbreak remains as interesting as the House of Cards once was (until it was bypassed by reality). After the gold rush for R_0, last week was devoted to the question on silent transmission; yes or no. Tuesdays’ story had an unexpected follow-up today, but the true clifhanger is a new study published yesterday.
So, first there was a bunch of Germans (Group 1) that reported, in NEJM, transmission that had occurred before symptoms started in a Chinese business woman visiting Germany. Than another bunch of Germans (Group 2) questioned the asymptomatic status of the woman, after they had traced her and spoken to her, and contacted Science, see. Today Group 1 published additional information of their interview with the Chinese woman, to definitely prove that she was asymptomatic while in Germany. READ THE TRANSCRIPT of yet another perfect call. And now we wait for Group 2?
More interesting are the results published yesterday (by Group 1), see. Actually not published, but shared through a press release, that’s even faster than on a preprint server. The story is that they “monitored virus shedding in patients currently under treatment in Munich… During these studies it was found in several patients that infectious virus could be isolated from pharyngeal swabs in cell culture. These patients had symptoms of common cold rather than viral pneumonia. Concomintantly, both laboratories found signs of viral replication not only in the lung, but also in the pharynx and gut.” And then they conclude: “Taken together, this suggests that persons who have mild or early symptoms of common cold (sore throat, signs of sinusitis, feeling unwell without fever) may be able to transmit 2019-nCoV to other persons.”
In the meantime, the virus keeps on spreading in China: the number of new confirmed cases per day keeps on rising, although there seems to be some flattening in the last 3 days (3241, 3952, 3722). We also see new cases in other countries, mostly still linked to sources in China, but also with evidence of local transmission. The good news is that these bushfires seem to be contained.
But do we see all there is? Before Wuhan was closed from the outside world and with ongoing virus transmission, many planes flew from there to other destinations. There is detailed information on the number of persons going from there and to what countries. Each of these passengers could have been infected and symptoms may have become apparent in other countries. The paper published yesterday analysed the relationship between numbers of patients flying to a destination and the number of 2019_CoV infected patients detected in these places. There is a correlation and a lower and upper confidence line. If you (as a country) are above the upper confidence line you might have bad luck by getting – by chance – more infected persons, or you did a very good job in detecting infections. The same holds for the opposite scenario: if you are below the lower line you were just lucky, or…. you’re just not doing such a good job in detecting infected persons.
The three countries below the lower confidence line are Cambodia, Indonesia and Thailand. The authors state: “We recommend that outbreak surveillance and control capacity should be rapidly strengthened in those locations … to ensure cases are detected if occurring and avoid emergence of self-sustained transmission.” So let’s see what happens.
The 2019_CoV outbreak remains very interesting until it is bypassed by reality.