Update on 2019-nCoV: part 9 – ‘silent’ transmission

A rude awakening this morning: “Study claiming new coronavirus can be transmitted by people without symptoms was flawed” was reported in Science. This is the patient described by German colleagues in NEJM and by Jon in the previous blog post.

The story in short: An index patient (a woman from Shanghai) was visiting Germany for business, and managed to transmit the coronavirus to two patients, who subsequently transmitted the virus to two other colleagues, before symptoms arose (in the index patient). The story was reported by hospital physicians from Munich and a virologist from the Charité hospital in Berlin (where the famous Robert Koch once worked).

In Science: “The Robert Koch Institute (RKI), the German government’s public health agency, has written a letter to NEJM to set the record straight, even though it was not involved in the paper.”

The researchers in Munich didn’t actually speak to the woman before they published the paper. “Afterward, however, RKI and the Health and Food Safety Authority of the state of Bavaria did talk to the Shanghai patient on the phone, and it turned out she did have symptoms while in Germany. According to people familiar with the call, she felt tired, suffered from muscle pain, and took paracetamol, a fever-lowering medication.”

When reading this I recalled two dreams I had this night.

Somewhere – in a not-mentioned country – physicians were very excited as the first patient with disease X had fallen in their lap. “Let’s first send this to NEJM and then contact our public health officials, otherwise they run away with it.” The day after – at the other site of the country – the NEJM fell on the floor in the oval office of the head of public health – responsible for the nations’ faith. He/she contacted the index and found out that she – in retrospect and after 20 times repeating the same question – admitted that “yes, she felt tired, had some muscle pain and took a paracetamol”. “That’s it”, he/she shouted, “this is the perfect call”, “READ THE TRANSCRIPT!” and called Science.

The other dream: Somewhere – in a not-mentioned country – physicians were very excited as the first patient with disease X had fallen in their lap, and they immediately contacted the head of public health – responsible for the nations’ faith. “Let’s first send this to NEJM and then contact the index. Might give us 2 citations in NEJM.” The day after the NEJM fell on the floor in the oval office of the head of public health and he/she contacted the index and found out that she – in retrospect and after 20 times repeating the same question – admitted that “yes, she felt tired, had some muscle pain and took a paracetamol”. “That’s it”, he/she shouted, “this is the perfect call”, “READ THE TRANSCRIPT!” and called Science.

Then my alarm went off, and I couldn’t dream of other, more realistic scenarios.

The big question now is whether our view on the transmission dynamics of this outbreak should change with this new information. The point of silent transmission, i.e. before symptoms occur, is that it will be more difficult to identify infectious persons and isolate them in time to interrupt transmission. The symptoms reported in retrospect (when knowing of being indeed infected, susceptible to recall bias!) were “tiredness and muscle pain”. Cough and fever are not mentioned. If this is what it is, then this woman might still have been identified of being at risk for 2019_nCoV infection in Germany, simply because she came from China. Yet, in Wuhan this would probably not be recognized as a risk, necessitating isolation. And the same would hold if sustained transmission occurs in other countries.

So, this information sheds new light, and addresses the definition of being asymptomatic. If symptomatic would be defined as “symptoms that allow someone to be recognized as infected and to be isolated in time to prevent transmission”, I think, this subject would be considered asymptomatic.

The letter from RKI has not yet been published. The Science reporting is based on someone who was in the room during the phone call (sweet irony).

Disclaimer: if the letter describes a feverish Chinese woman coughing continuously, I immediately change some of my views.

Update on 2019_nCoV outbreak part 7

We live in fascinating times. Within a week R_0 has be become a fashionable topic to discuss at cocktail receptions, science has transitioned from old-fashioned hidden peer review to open review on preprint servers and China is doing the largest experiment in infection control ever. And since tonight we have a public health emergency of international concern (PHEIC).

I’m very impressed by the actions in China, so far. It looks as if they very rapidly (within a month) recognized a cluster among patients with severe pneumonia in which no pathogen was detected (which happens in about 50% of these patients). Then, within a month they identified the cause of these infections, sequenced it and found the receptor for the virus, and immediately shared all information.

They also must have realized around that time that they were dealing with something very transmissible, which was subsequently confirmed by the many R_0 estimates. I think most agree that R_0 is somewhere between 2 and 3, but what does that mean for infection control?

R_0 is determined in the very early phase of the epidemic, when all subjects are susceptible to infection and when preventive measures have not been started. In that phase the virus is transmitted in a certain network, in this case a city of 10 Million, in which many contacts occur that could lead to successful transmission. When the outbreak is recognized, many mechanisms start that reduce transmission. In hospitals protective measures are taken and outside hospitals people start changing their behaviour. For instance, they avoid public transport and mass gatherings and stay at home. From then on it is better to name R an effective R value, which is of course less than R_0. Infection control aims to bring the effective R value below 1, and keep it there. The latter is not to be underestimated: if the original behaviour is resumed at a time that the virus is still circulating, the epidemic may rapidly speed up again. As may happen if the virus escapes to another – unprepared – network.

How can we see whether R declines? Just look at the epidemic curve (from which R is derived). As long as the number of newly infected subjects per day increases, R is >1. So, we want to reach the downhill slope of the epidemic curve, as fast as possible.

How to do that? Every epidemic dies out if the number of susceptibles declines. That is when a large part of the population has become immune, either through vaccination, surviving the infection (with immunity), or protective therapy (not really immune, but similar effect). The proportion of the population needed in this category is around 60-70% with this R_0, which is unlikely to happen soon for this virus. This leaves classical measures to reduce transmission with at least 60-70%.

China has the laudable ambition to do this. For that they have quarantined millions, which is a daunting task. Imagine Ursula van der Leyen (chair of the European commission) quaratining London, Paris, Amsterdam and Madrid.

Within the fence almost all transmission must be stopped. How long will this take? Well, if all transmission (100%) is prevented as of tomorrow, new infections will occur for at least a week, due to the incubation period. If interruption is less effective, say 70%, it will take (much) longer. The effectiveness to stop transmission outside hospitals requires isolation of infectious persons during their infectious period, which might start before being symptomatic. So, it may take some time before the outbreak is controlled sufficiently to open the fences without risks of the epidemic starting all over again. Question is how long they can keep the gates closed.

So, let’s carefully follow the epidemic curves, and hope that they are accurate and not compromised by reduced case notification due to shortness in testing capacity or collapses of hospital systems, which may give a false-positive reassurance. If China succeeds in controlling this outbreak, their efforts could be placed next to the Chinese Wall, as another Wonder of the World.

Update on 2019_nCoV, part 5

All quiet at the 2019_nCoV outbreak front, today (so far), it seems. As the world is now informed about the R_0 concept, we can start thinking how to best provide medical care to patients. The evidence base is empty and needs to be filled, preferably with unbiased estimates from randomized studies. Yet, if we had to define research questions now, and then start looking for partners and then draft a protocol, find funding and wait for IRB approval, the first patient-in might coincide with the last patient affected by the virus. So, for pandemic research you better be PREPARED.

The Platform for European Preparedness Against (Re-)emerging Epidemics (PREPARE) is an ”EU funded network for harmonized large-scale clinical research studies on infectious diseases (IDs), prepared to rapidly respond to any severe ID outbreak, providing real-time evidence for clinical management of patients and for informing public health responses.” The trick for better preparedness is to have ongoing large-scale studies in many different EU regions, that can capture a pandemic whenever it starts.

For this we started almost 6 years ago with what is now called “A Randomized, Embedded, Multifactorial, Adaptive Platform trial for Community-Acquired Pneumonia (REMAP-CAP).” This is a perpetual European adaptive RCT evaluating the effectiveness of several interventions (antibiotics, corticosteroids) in improving outcome in adults admitted to ICU with severe CAP, see and here.

The study design allows addition of study domains, such as for instance diagnostic testing or new treatments, embedded in the existing study protocol. Only a “simple” amendment is required as IRBs already approved the possibility of such adaptations, in case of a pandemic.

REMAP-CAP is enrolling patients in 52 centres in 13 countries in Europe, Australia/New Zeeland and North-America and more ICUs are ready to start. The study team is discussing – on a daily basis – what interventions to add. Corticosteroids and macrolide use for immunomodulation are already included.

Any studies in China? Yes, 2 protocols posted. “A randomized, open-label, blank-controlled trial for the efficacy and safety of lopinavir-ritonavir and interferon-alpha 2b in hospitalization patients with novel coronavirus infection”, see. The comparator is standard care and the target is 160 patients. The other is “a prospective comparative study for Xue-Bi-Jing injection in the treatment of pneumonia cause by novel coronavirus infection”, see. Xue-Bi-Jing is Chinese herbal medication, which will be compared to standard of care, and here the target is 200 patients per study arm. Rumor has it that recruitment has already been completed.

Any news on R_0 today? Not much. A new publication was embraced as good news, as it showed a dramatic reduction of R_0 in time. Indeed, it started with 8 on December 29th and then rapidly declined to a steady 2.5-3 from Januari 2nd till 18th……2019_nCoV.

A hand hygiene cracker from the Christmas BMJ

The annual Christmas BMJ is always good for a laugh. This year, one of the featured articles introduces the idea of using the tune of Frère Jacques to help memorise the WHO’s six-step hand hygiene technique.

And here’s the song in action:

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Persistence and transmission of Candida auris on and from gloves

Schermafbeelding 2019-05-02 om 10.17.46

Interesting results from Jabeen et al. that many of us might have missed, as they are published in a mycology journal and not in an infection control journal.  Persistence of Candida spp. on latex and nitrile gloves was highest for C. auris and C. parapsilosis.  Interestingly, persistence on nitril gloves was generally less than on latex gloves. Transmission of Candida spp. from gloves (latex, nitril not tested)  to urinary catheter surface was most effective for C. auris and C. albicans.

To be frank, the chosen methods and set-up of the experiments leave quite some room for improvement, but the basic idea of the experiment and the message it conveys are – while not new – of importance: Glove use can be an important factor in the spread of all microorganisms, and in this case, especially C. auris.

Previously it has been shown that glove-use may negatively effect hand hygiene behavior. After years of focusing our attention on hand hygiene compliance and hand-rub technique, this publication is an important reminder, to not forget about adequate glove-use.

Jabeen K, Mal PB, Tharwani A,Hashmi M, Farooqi J. Persistence of Candida auris on latex and nitrile gloves with transmission to sterile urinary catheters.  Medical Mycology, 2019, 0, 1–5 doi: 10.1093/mmy/myz033 Advance Access Publication Date: 0 2019

Are we over-complicating effective hand hygiene technique?

The WHO method for hand hygiene is very well embedded as the ‘gold standard’ for hand hygiene technique. But is it feasible to perform every time in the busy clinical environment? A new study in Clinical Infectious Diseases seems to suggest that a shorter, simpler hand hygiene method be just as effective and more feasible in the real world.

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Working while sick

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Compared with the general population, healthcare workers (HCWs) have an increased risk of being exposed to respiratory pathogens including flu, causing a potential threat for their own health and their patients’ safety.  At present, the problem of HCW vaccination seems to get the main attention when dealing with influenza prevention, whereas the problem of HCWswho work while feeling sick, seems to be far less addressed.  That is, until recently when Chow et al. studied hospital-acquired respiratory viral infections, sick leave policy, and a need for culture change.

The ISAC Infection Control Study group had already piloted a survey on the topic and wishes to poll your thoughts with the present survey.

While there is nothing to earn, except of the good feeling of having helped someone, we kindly ask you to take the questionnaire (takes 4-5 minutes) and send it to others, including friends or family not in healthcare, as we are especially interested in possible differences.

Link for the survey: https://www.surveymonkey.com/r/ISAC_Influenza

Thanks for helping and of course results will be back on this blog.

Must we screen for resistant bacteria?

This is a cry for help. In 2 weeks time I have a pro-con debate on the statement “screening for highly-resistant microorganisms is a must”. I face 2 problems: the organizers gave me the “PRO” position and my opponent is professor Andreas Voss.

We will be watched by a Dutch audience, so the bacteria involved are MRSA, VRE, anything resistant to carbapenems and ESBL-producing Gram-negatives, and I (and hopefully Andreas too) interpreted the question as “screening at the time of hospital admission”.

I am desperately seeking high-level scientific evidence supporting my allocated point. 

My question to the knowledgeable reflectionsipc readership is: What do you consider the single most convincing piece of evidence underpinning my case.

As in all good practice I will provide feedback (if I survive the battle).

Mapping C. dfficile hospital acquisition: short-stay diagnostic areas are important!

Recent genomic studies have concluded that hospital-acquired acquisition of C. difficile is rare, suggesting that acquisition of C. difficile outside of hospitals followed by hospital-onset disease is the most common explanation for C. difficile infection. These studies hinge on an assumption that in-hospital patient contact occurs due to shared or recent stay on the same hospital ward. A short publication in JAMA Internal Medicine eloquently challenges this assumption, suggesting that hospital contact that we would usually assume to be casual and not a risk for acquisition of hospital pathogens (e.g. short-stay diagnostic areas such as ultrasound and endoscopy) can be an important source of acquisition.

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Exposed: Dutch and London clinical microbiologists

Six weeks ago I blogged on the exposure of Dutch clinical microbiologists by Marcel Levi, former boss of the Academic Medical Center in Amsterdam and now leading 5 academic centers in London. Apart from describing his new “totally resistance-free” work situation, he criticized  the microbiologists in both countries for “not attempting to change the money-wasting and empty-brain practice of microbiological diagnostics”. Unfortunately, Marcel Levi is not just “another person” with an opinion. So, here are four suggestions to change his opinion, before all microbiologists have been sacked. Continue reading