Virus Diseases

Wednesday, October 1, 2014

Australia's response to Ebola virus disease in West Africa: is too little enough?

Written by Dr. Katherine E. Arden and Dr. Ian M. Mackay

The outbreak of Ebola virus disease (EVD) began in December 2013 in Guinea. It spread to Sierra Leone, Liberia, Nigeria and Senegal. The last two countries on that list were able to contain EVD because they had functioning healthcare systems with doctors and nurses, protective equipment and hospitals that work. The United States of America (US) had its first imported cases arrive 30th September. To some extent, these final three countries could “see it coming”. None of these preparations were in place or possible in Guinea, Sierra Leone or Liberia. They are hosting the largest EVD outbreak in recorded history.

Help wanted.

On August 8th, this epidemic was labelled by the World Health Organization (WHO) as a Public Health Emergency of International Concern (PHEIC). The time for help to arrive and be effective is now. Before 70% of the predicted hundreds of thousands of cases to become infected by this variant of Zaire ebolavirus die. Money is required, and Australia has now donated eight million dollars. Three weeks ago a one billion dollar cost was forecast; a ten-fold increase in a month.[6] But what is really needed urgently are people. People to create beds through the building of treatment facilities, people to staff those facilities to provide the best supportive care possible under the circumstances, people to be trained to safely care for the sick and dying and to trains others, people to track cases, people to help educate family members in how to care for a sick loved one, people to help the psychologically traumatised try and deal with the loss of their children, their parents, siblings, cousins and friends. People are what’s needed. The United Nations (UN), which includes Australia, unanimously adopted Resolution 2177(2014) on the 18th of September within which it provided some instructions to member states. One of those is:

“8. Urges Member States, as well as bilateral partners and multilateral organizations, including the AU, ECOWAS, and European Union, to mobilize and provide immediately technical expertise and additional medical capacity, including for rapid diagnosis and training of health workers at the national and international level, to the affected countries, and those providing assistance to the affected countries, and to continue to exchange expertise, lessons learned and best practices, as well as to maximize synergies to respond effectively and immediately to the Ebola outbreak, to provide essential resources, supplies and coordinated assistance to the affected countries and implementing partners and calls on all relevant actors to cooperate closely with the Secretary-General on response assistance efforts;”

Australian Prime Minster Tony Abbott noted to the UN that “We were one of the first countries to arrive with help in Japan after the 2011 earthquake; and in the Philippines after the 2013 typhoon.”[5] Why haven’t we arrived in West Africa yet?

Australian Foreign Minister Julie Bishop said on 29th of September, that Australia has not been specifically asked by the WHO to provide healthcare professionals to help.[2] But we a member state of the UN and the WHO is the United Nations’ public health arm. In that article the Minister was quoted as saying that we were unable to repatriate infected Australians safely, with this being an integral reason behind our limited response to the Resolution.

Lightbulb Moment.

Until the Foreign Minister’s comment, the importance of the US concept of building a smaller, healthcare worker-specific treatment facility in West Africa was perhaps lost on the two of us. Such an elitist construction looked bad to the people of the region and, without sufficient background, to others outside it. However, if such a facility reduces or removes the need to spend tens to hundreds of thousands of dollars per person [3] to send them home for treatment, then it seems like a brilliant plan. That money could be better spent, and the added healthcare should help attract more international healthcare workers to the region. In fact, why doesn’t Australia assemble the components and airlift a similar facility, flat-packed, to one of the regions in need of our help? This could be done in a jiffy with Australian military precision. Once built, this facility may well remove the need to repatriate any Australian healthcare professional who may get infected. This may be a better and faster solution than us trying to use British or US facilities or doing a deal with them to evacuate our people.

A good global citizen.

Prime Minister Abbott noted “That is what you’d expect from a country such as Australia which always wants to be the best global citizen”.[4] We are currently not being the best global citizens that we could be.

Let’s not hide behind excuses. Do we want our national character to be stingy and afraid or strong, generous and willing to give a fair go to those in need? We pride ourselves on our innovative character. We can use this to find a way around problems, real or perceived, in answering the UN’s call for help. Help we are able to provide.

It would be difficult, heartbreaking, hard work. We know that Aussies are more than capable of doing that. In fact, the more people on the ground, helping, the easier the burden would be. There may be some problems, and it would be naive to expect otherwise. That is why the UN has called for help. If there were no risk, and everything was simple and easy, this situation would not exist in the first place. Should a healthcare worker fall ill, there is a high chance they would die. A tragedy for their family, friends and workmates. And let’s be real, there are more risks to healthcare workers than just Ebola virus disease in these countries. There are scared and sometimes violent villagers, as well as plenty of other diseases like malaria to contend with.

The lucky country.

Australians have the wealth, the innovation, the ability, the equipment and the skills in our excellent health care workers, engineers, keepers of the peace and logistical organisers. We have the willing volunteers.

How much of our global village has to burn down before we do more than buy a bucket? Why must we focus on security threats, economic impact, terrorism and political stability when it is the humanitarian aspects that should our priority? Yes, this seems to be the only way to communicate with politicians. But is the way forward for us as a nation that something has to be become a direct threat to us and our lucky country way of life before we lend a hand? Is that who we want to be? Can we not expect a more human perspective from our leaders and ourselves? We think we can.

References

Tuesday, September 30, 2014

The United States of America is the 6th country to host a 2014 West African Ebola virus variant..

v2 01102014 5:51pm AEST

First thing...

CALM DOWN!

This is the first case of Ebola virus infection to arrive in the United States that was not deliberately flown in. Its not the first viral haemorrhagic fever case though (1 case of Marburg virus disease and at least 4 Lassa virus infections and the Reston ebolavirus outbreak among imported animals[3,5]), and none of the earlier infections resulted in secondary transmission among humans; no-one else got infected from by the case.[4]

Countries that have hosted people infected
with the Ebola virus variant causing the
& 2014 West African Ebola virus
disease epidemic.
Click on image to enlarge.

The male is in critical condition.
When he flew from Liberia to the United States (finally arriving in Dallas,Texas). The man was not showing signs of disease when leaving Liberia or on the plane or immediately after arriving.[6]

This means that the man was not infectious - he could not spread it to fellow travellers or airport workers - because it is well known that disease in another does not develop due to virus being shed before disease is obvious in the infected person.

Briefly[1,2]:

19th: Departed Liberia, checked and found to be symptom-free
20th: Arrived in Dallas, US (connecting flights?)
24th: Started to develop symptoms
26th: Initially sought care
28th: Admitted to hospital in Texas.
30th: Texas public health laboratory found Ebola virus this morning of 30th Sept. CDC received samples, tested and confirmed as Ebola virus disease
Patient is ill and is under intensive care

US family and community contacts (a "handful") are known or being traced and will be under observation/monitoring for 21-days (~21-Oct) for fever. Will any become positive for Ebola virus? Perhaps. I look to Port Harcourt (Nigeria) for some comfort. There were around 60 "high risk" contacts of there and they did not all become ill.

So now we have evidence that supports all those talking heads (me included) who noted that it was possible for sporadic cases of EVD to be imported into countries outside of those in West Africa (Guinea, Liberia, Sierra Leone, Nigeria, Senegal).

Soon, I very much believe, we will also have evidence that in richer countries with functioning healthcare systems, a good knowledge of what is needed to contain virus infections spread by all possible routes, stocks of the necessary personal protective equipment needed to protect healthcare workers from nosocomial infections and the training to use those stocks...to support that even when such cases arrive, they do not result in outbreaks.

References...

Monday, September 29, 2014

The numbers are underestimates...

Ebola virus numbers.

Sorry but D'uh - yes the numbers during the Ebola virus disease (EVD) outbreak happening since December in Guinea then progressing to Sierra Leone, Liberia, Nigeria and Senegal....are an underestimate.

Of course they are!

How could they possibly not be?

Have you not watched a single documentary or news video detailing how heartbreakingly difficult it is to visit and help the people of West Africa, to characterize and gather those case numbers, to take, transport and test samples?

The suspect cases are an underestimate.
The probable cases are an under-estimate.
The fatal cases are an under-estimate.

The only thing that is spot on is the laboratory confirmation numbers, because they are what they were when someone wrote them down having had some semblance of control over the steps to acquire them.

But let's put that underestimation into context.

"The tip of the iceberg"
Image originally provided by Gregory Haertl, WHO.
Click to enlarge

Influenza case numbers each year are also an under-estimate.

In fact, some of those, the subtyping numbers, are deliberately so because it's too expensive and wasteful to subtype every single laboratory confirmed case - so a sample of cases are tested and that is assumed to reflect the subtype distribution for that region during that period.

But seasonal influenza case numbers as a whole are a huge underestimate. Influenza does not drive everyone to a general practitioner nor to a hospital. Some infections with influenza virus don't even produce noticeable symptoms at all. They are still infections. They just don't get counted. So influenza A virus, possibly the most tracked of any respiratory virus, is underestimates. And that's okay.

Well, measles too, in the respiratory virus department.

The latest big bad is the species D enterovirus 68 (EV-D68). But the paltry few detections of it (identified by genotyping) that have reported across the United States are likely a monstrous underestimate. In fact we have very little idea of a normal denominator for EV-D68 detections so it's hard to even know if 2014 is seeing all that big a change in its spread and distribution. Usually the enteroviruses (includes rhinoviruses) cause common cold-like illnesses and only get sought out in the great detail from a research point of view.

Middle East respiratory syndrome coronavirus (MERS-CoV) cases or the emerging influenza A(H7N9) virus cases are all underestimated as well.

The population of your state or country is an underestimate too you know?

This is because we cannot capture every single case of infection, or person, at once.

So the next time you are about to say "the WHO numbers are an underestimate" as if that is a revelation or an unexpectedly horrible thing you can also lay at their doorstep - please just don't. It's not smart, new or unusual.

You might as well say the world is round; underestimation of infection numbers is just that well established a fact. It's just by how much, and frankly that doesn't even matter too much because the trends can usually be easily seen, or quickly extrapolated.

Perhaps you did not know all that before. But if you have read to here, you do now.

The control gap...

v2 300914

I have a theory.

This theory is meant only to apply to disease outbreak/epidemic/pandemic situations, and then only to those which include fatal cases.

This theory of mine has only emerged since I've been plotting Ebola virus cases numbers from the West African epidemic. I precede the explanation with the caveat that there is very probably already a well developed, well-known actual epidemiology term to describe this theory. But I'm not a trained epidemiologist and this is just a blog, so please forgive me my ignorance.

The theory goes that when a gap grows between the number of new cases being reported and the number of deaths or laboratory confirmations in that population, despite the outbreak having been going for a while, this represents an indication that control of the situation is slipping, or has been lost.

Mind the gap.

This "control gap" - my term, so don't expect to find it anywhere official or that knows of that which it speaks - can also appear when looking at suspected or probable cases of disease X, and the number of those that have been confirmed by a laboratory test.

Other explanations for the control gap may exist of course; testing may be scaled back deliberately, reporting of deaths may have been deliberately throttled for some political reason. So it may not reflect being "out of control" as much as someone else being "in control".

Probably still more variations that I have not thought of at all.

Ebola virus disease (EVD) in Liberia.

In the graphics below I've used the accumulation of World Health Organization data for Liberia, up to 23-Sept.

First up - the fold increase in total case numbers (suspect+probable+laboratory confirmed) compared to the fold-increase in the distance between that total and the total number of laboratory confirmed cases alone. This distance, or the "control gap|lab", has widened over time. It has widened because total cases have climbed more steeply than the number given a laboratory confirmed diagnosis of EVD.

For whatever reason(s), laboratory confirmations are not keeping pace with the total case numbers, and they seemed to start slipping at the end of July.

I suspect a principal reason - and I'm not on the ground of course, so this is all speculation and second-hand knowledge - is that laboratory capacity is overwhelmed.

Other reasons include that samples might not always be collected or that many recent clinically defined EVD cases are actually due to something clinically similar to EVD, but not an Ebola virus infection. If it were this last one though, the total numbers would be readjusted downwards as new diagnoses were made...if the laboratory has time to make those of course...so I doubt it as a major role.

The control gap|lab
A.) Ebola virus disease case graph for Liberia showing the accumulation of total (suspect+probable+laboratory confirmed) cases (pink line; left y-axis) and deaths (blue line; left y-axis), the laboratory confirmations (green line; left y-axis) and the proportion of fatal cases (right y-axis) at each reporting date (x-axis). The size of the gap between laboratory confirmed cases and total cases is indicated for a range of reporting dates, using a vertical green drop-line.

B.) The drop-lines have been copied and aligned and the amount they have grown has been measured using a scale bar so that the fold-increase can be compared to the first reporting date used, 8-July. The fold-increase value is written at the top of each drop-line. Along the bottom (enclosed within a grey box) are the case numbers at each reporting date examined and the fold-increase (in bold) compared to the 8-July baseline.

Next up -the fold increase in total case numbers (suspect+probable+laboratory confirmed) compared to the fold-increase in the distance between that total and the total number of deaths. The control gap|deaths comparison finds that the deaths and the total cases don't diverge as much as total cases and lab confirmations do.

The control gap|deaths
A.) Ebola virus disease case graph for Liberia showing the accumulation of total (suspect+probable+laboratory confirmed) cases (pink line; left y-axis) and deaths (blue line; left y-axis), the laboratory confirmations (green line; left y-axis) and the proportion of fatal cases (right y-axis) at each reporting date (x-axis). The size of the gap between laboratory confirmed cases and deaths is indicated for a range of reporting dates, using a vertical blue drop-line.

B.) The drop-lines have been copied and aligned and the amount they have grown has been measured using a scale bar so that the fold-increase can be compared to the first reporting date used, 8-July. The fold-increase value is written at the top of each drop-line. Along the bottom (enclosed within a grey box) are the number of deaths at each reporting date examined and the fold-increase (in bold) compared to the 8-July baseline.

So with that visualization under our belt, there is another, less laborious way to look at this, by graphing the numbers, rather than the gaps.

What we see when we plot the fold-change values against report date is that total cases lost control as we suspected, but deaths are less obviously out of control. From 9-Sept onwards the gap has widened a little more consistently. Before that though the deaths did not dramatically drift away from the rate at which new cases were being added.

I'll graph Sierra Leone, Guinea and Nigeria in the next day or two. Nigeria should serve as an example of how this looks for a country in which EVD is definitely in control.

Graphing the control gaps

Friday, September 26, 2014

MERS-CoV data request: A response from the Ministry of Health

Four days after I posted a blog requesting missing data on retrospective Middle East respiratory syndrome coronavirus (MERS-CoV) detections and deaths, I received a response.

Dr Anees Sindi, Deputy Commander of the Command and Control Centrer, Ministry of Health, Saudi Arabia replied. With his permission, I have reproduced his reply below.

______________

Sent: Tuesday, 23 September 2014 6:36 PM
To: Ian M Mackay
Subject: Re: your request for missing data on retrospective MERS-CoV detections

Dear Dr. Mackay,

I’m writing in response to your blog posting entitled “A request for missing data on retrospective MERS-CoV detections.”

Thank you for acknowledging the steps that the Ministry of Health’s Command & Control Center has taken to ensure members of the public -- including researchers around the world -- have access to real-time information about MERS-CoV cases in the Kingdom of Saudi Arabia.

These daily postings are a small step on our journey toward full transparency. We want scientists to have access to the data they need to produce meaningful publications that advance our understanding of this disease for the benefit of mankind.

With that in mind, I am happy to inform you that the Ministry of Health is in the process of preparing additional data for public release. I will follow up with you once we have a confirmed release date.

Collaboration with the international research community is a key pillar of our work. In addition to sponsoring more than 30 research projects focused on MERS-CoV, the Ministry of Health has opened its doors to academics and experts from the World Health Organization and U.S. Centers for Disease Control & Prevention. MOH shares more data with the WHO than is required under the International Health Regulations, and we stand ready to support other scientists with an interest in better understanding coronavirus.

Thank you again for your interest in our work.

Best Regards,

Dr. Anees A. Sindi
Deputy Commander

Command and Control Center, Ministry of Health

Saudi Arabia

______________

This is fantastic news and I am very excited to hear that we may soon be able to complete the data picture for MERS-CoV.

I am most grateful to Dr Sindi, the Minister and the Ministry for taking my request seriously and for replying to it so quickly.

With these data in hand, many of us will be able to build better epidemiological picture of the timing, spread and impact of MERS-CoV over the past 2 years as well as more specifically quantify MERS among fatal cases.

These data do not answer all the questions we have of course, but they definitely answer some, and for that I'm thankful.

This social media thing does seem to have some impact.

Sunday, September 21, 2014

Ebola virus, HCWs infections and personal protective equipment..

Co-authored by Dr Katherine Arden.

No one could offer anything but our deepest and most heartfelt thanks and a feeling of pride in the selfless, essential and humanitarian work being done by healthcare workers (HCWs), both local and international, in West Africa.

But they have paid a high price for this work, as they always do in emerging disease outbreaks.

WHO Ebola virus disease
numbers up to
14-Sept-2014

Of the >5,300 people reported as infected by the West African variant of Zaire ebolavirus (EBOV) to date, around 315 have been HCWs. Both numbers are very likely an underestimate. Half of the HCW cases have died. I don't know just how many HCWs there are in Guinea, Liberia and Sierra Leone who are dealing with the EBOV outbreak. I do know that these deaths are as horrible as each of the losses among non-HCWs, and are also worrying for those trying to recruit the many more HCWs needed to expand care of ill patients.

This week a commentary article on the Centre for Infectious Disease Research and Policy (CIDRAP) website delves into this issue by suggesting an improvement to HCW respiratory protection.[1]

Two quick things first:

The World Health Organization (WHO) defines human transmission of Ebola virus as being by direct contact (between mucous membranes or a break in the skin and the blood and other body fluids of an infected individual via physical contact or by wet material being propelling onto mucous membranes or skin breaks) and by indirect contact via contaminated surfaces.[3,4]
When dealing with patients, the WHO recommends wearing gloves, a disposable impermeable gown to cover exposed skin, a waterproof apron over any gown that is not impermeable or when undertaking strenuous activity, facial protection to prevent splashes to the nose, mouth and eyes including a medical mask + eye protection (visor or goggles) or a face shield and medical mask.[3]

The CIDRAP article's authors claimed a belief that there is scientific and epidemiologic evidence that Ebola virus has the potential to be transmitted via infectious particles. Unfortunately they don't make a convincing argument to support their belief-nor could they, since no data currently exist to for any claim that an Ebola virus is transmitted between humans by an airborne route. So we're left with a commentary based on those beliefs, and some speculation.

Some collaborators and I wrote about Ebola virus not being an airborne virus based on what we know and what's been done to answer this question before.[2] I'll first add that if it were an airborne virus, we would likely be seeing many, many more cases-"Compared to this Ebola outbreak, the H1N1 swine flu had already spread to an estimated 10,000 times as many people in its first 10 months" noted United Kingdom virologist Ben Neuman.[13] H1N1 being an influenza A virus; a real airborne virus. In our post, we noted that big wet droplets (part of an "aerosol"-a messy term that may not be well understood by the public...or some scientists...that includes big wet droplets and small rapidly drying droplets) can be propelled at a mucous membrane or fall to the ground to contaminate surfaces.

A schematic of the makeup of an "aerosol".
From [2]

Big wet propelled droplets can contain infectious Ebola virus and are included in the established risk messaging. Hence the need for droplet precautions.

We also know that from every human aerosol, after the heavy larger droplets fall to the ground or impact on a surface, the remaining lighter droplets very quickly dry to form droplet nuclei (these can be gelatinous, gooey, or water-free). It's these droplet nuclei that can linger for hours or more in the air. We know that droplet nuclei can be made to contain infectious Ebola virus under lab conditions[8] thus droplet nuclei produced by an infected human may contain Ebola virus. We can't say with certainty that they do or do not. However, as far as we have been able to tell, infection of humans and resultant disease from inhaling lingering droplet nuclei, has not occurred. And when an airborne route was investigated using infected and uninfected non-human primates housed nearby but without direct contact, no infection via an airborne route was found to have taken place.[9]

When putting one's faith in the belief that a different piece of PPE will prevent or significantly reduce HCW infections, one has to wonder if that will empower a false sense of security among HCWs in the field where the infections are happening. Most of the studies looking at aerosol of Ebola virus do so in temperature and humidity-controlled laboratories with lots of lab grown virus.

And relying on one added component raises a few questions for me:

Could the faith in this one extra precaution threaten the very important, meticulous care required when donning, using, and removing contaminated PPE-of any sort?
What role does a lack of the basics, like soap and clean water [10], play in HCW infections?
Could an additional extra safety measure really have a major effect on reducing the known risks involved with treating Ebola virus disease (EVD) patients, such as the long hours, tiredness, the constant and pervasive tension of imminent exposure, the oppressive heat, delirious and sometimes violent patients and the ease with which one can self-inoculate?[6]
Does the extra safety measure even have a role in reducing risk associated with HCWs who are unknowingly infected while not wearing PPE?[7]

How much do the things listed above, mostly unrelated to having a hi-tech battery-powered breathing apparatus on your hip, contribute to the tally of HCW infections?

Glaringly, the authors overlooked mentioning that early on, many HCWs may have had few or no masks at all and few other essential barriers such as those listed by WHO above, to protect against direct contact. They also did not mention the lack of HCW training in the use of any of that equipment if available, and did not highlight the lack of experience HCWs had dealing with EVD patients. These HCWs had (and may well still have) direct contact with very ill EVD cases, and got infected. What fraction of HCW infections resulted from absent or incomplete PPE and training versus the HCWs that they believe became ill while wearing full droplet precaution PPE?

MSF designed suit of PPE.
Graphic tweeted by the
Washington Post.[5]

Others have also made note of the disparities between the imagery of a biosafety level 4 (BSL4) laboratory researcher working in a negatively pressurized, airlocked laboratory within a tethered, airtight suit (probably unnecessarily high precautions [13]) versus highly biocontained single patients being shipped home on dedicated planes (kept somewhat contamination-free using isolators) to rich nations for specialized support and treatment versus Médecins Sans Frontières (MSF) workers who use respirators (specialized face masks that fit more snugly and contain more layers to better filter what is breathed in) instead of surgical masks versus the WHO recommendations of standard precautions which include a surgical mask. Notably, the WHO recommendations vary according to the type of risk one is exposed too [see pg 96-7 96 of the 113 pg PDF at [3]).[10] There clearly is a range of thinking and messages here. But equally, there are a lot of different applications to cover, and no way for every need to be specifically catered for by one guideline. If everyone could agree on such a thing anyway.

I share the concern of many over the deaths of HCWs in West Africa. They may still be unnecessarily exposed to virus due to the lack of enough PPE. They may not have enough training to understand how easy it is to become infected. They may not be given the message that during an EVD outbreak as monstrous and different as this one, many heavily populated areas have been included for the first time resulting in very real risks of infection occurring outside the hospital setting, not just inside it. There are also real risks of infection in supposedly EVD-free hospital settings like maternity wards.[11] There are many, many non-airborne related risks for HCWs.

We freely admit that we are not trained in the use of PPE for treating Ebola patients; just for working with actual respiratory and blood borne viruses in PC2 & PC3 laboratory settings, respectively. Still, some may find this post irrelevant.

Deeply concerned about bloggers with no PPE research track rec, no clinical or infection control expertise making recommendations about PPE.
— Raina MacIntyre (@RainaMacIntyre) September 16, 2014

By all means stop and read that disclaimer on the right about this blog not providing medical advice. You come here of your own free will and this blog is not part of any Organization's reference list when they write PPE guidelines...because it's a blog.

But for what it's worth, I would follow the MSF lead if working in the battlefield of a 100+ bed treatment facility. In an ideal world with unlimited and readily available resources, a more roomy and breezy head covering that allows patients to see your face and which can be worn for longer periods would be useful. You can see an image, provided by 3M, of this battery-powered air-purifying respirator (PAPR) accompanying the CIDRAP post.

However....first and foremost, and well before we get to this level of hair-splitting based on speculation and belief and no evidence of an airborne virus-I'd be wanting to make sure there was a minimum level of disposable PPE actually available for use by every HCW and the appropriate education about how to use it and about all the risks for acquiring EBOV infection.

Reasons for HCW infections are many and varied. As much as we may believe or wish it were so, no single act or change will circumvent these risks nor these infections.

References..

Friday, September 19, 2014

MERS risk reduction and signs of illness to watch for during hajj and umrah...

I love a good infographic and this one ticks a lot of boxes for getting a clear message out about the Middle East respiratory syndrome (MERS) disease and how to avoid catching and spreading the MERS-coronavirus (MERS-CoV).

Thanks World Health Organization.

World Health Organization poster describing risk of infection
and how to identify when you might have MERS.

Of course, I'd be happier if the poster specifically suggested putting more distance between people and potentially infected camels, rather than just avoiding "close contact".

Granted, close contact can include spending time in the close, but not physically connected, "personal space" of a camel. But "close contact" is, in my opinion, one of those infectious disease terms that needs to be made more simple and clear. Like "aerosol" and "airborne", "close contact" gets a little lost when translated to the people who are at actual risk from infection.