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.

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To the Saudi Arabian Ministry of Health: A request for missing data on retrospective MERS-CoV detections

From: Ian M Mackay

To: The Office of the Minister of Health, Kingdom of Saudi Arabia

I write to humbly ask for your help on a matter of infectious disease communication. I ask that you please consider completing the already near-complete public data picture for all retrospectively confirmed cases of Middle East respiratory syndrome coronavirus (MERS-CoV) that have occurred on your soil. I ask that this be publicly released for analysis, and suitably acceptable citation, by all. The Ministry of Health has already made a number of advances in tracking and communicating new cases of MERS-CoV, addressing criticisms along the way. But there remain some small but epidemiolgically important gaps in an otherwise complete set of data that could be easily closed.

Today, the 19th of September, I make note of the Command and Control Center announcement of the discovery of 19 MERS-CoV cases, identified after retrospective analysis of cases.[1] This adds to the 113 MERS-CoV detections announced 3rd June 2014.[2] I also note the reference to removal of a duplicate case and two false positive cases. In addition to these items, there have been many identified deaths that cannot be linked to publicly announced cases because key date data are no longer published along with the time of death announcements, as they once were (see example [3]).

So I ask if it is possible for you to publish a minimum set of deidentified details from cases that have not been fully described by the World Health Organization Disease Outbreak News reports. I suggest an open access spreadsheet on the CCC website.  I do not ask that any compromising or identifying data be included nor do I believe there is a need for identification of hospital or treatment facility. I would be happy to help identify these cases if that could be of use. 

These data include:

• Age
• Sex
• Date when symptoms began
• Date of hospital admission
• Date when a fatal case was first reported (allowing a link to be made)
• City where case likely acquired

The Command and Control Center website and its updates on contemporary MERS cases have evolved into an essential global asset for many international researchers and for the global public, each of whom are still trying to understand this emerging virus. What I suggest here would add even more reach and value to your efforts to keep us all informed. 

As the custodian of over 90% of MERS case data, the world wholly relies upon your transparency, good will, expertise and willingness to openly share it. I believe a complete set of MERS-CoV data have great potential to engage more researchers from around the globe. These links may help identify new and interesting patterns that could be of use to Saudi Arabia and other Middle East and African nations trying to improve control of MERS-CoV now and in the future.

Thank you for reading this.

Yours sincerely,

Ian M. Mackay, Ph.D.
Virologist
Science communicator
ian.mackay.im (at) gmail.com

NB. A response was received and is posted here [4]

1. http://www.moh.gov.sa/en/CCC/PressReleases/Pages/Statistics-2014-09-18-002.aspx
2. http://www.moh.gov.sa/en/CCC/PressReleases/Pages/mediastatement-2014-06-03-001.aspx
3. http://www.moh.gov.sa/en/CCC/PressReleases/Pages/mediastatement-2014-05-24-001.aspx
4. http://newsmedicalnet.blogspot.com.au/2014/09/mers-cov-data-request-response-from.html

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Updating a model of a modern Ebola epidemic...

Professor David Fisman, University of Toronto, Canada published one of the excellent recent models designed to estimate where Ebola virus disease case numbers might be heading.[1] He has updated his model using the latest World Health Organization EVD data that includes up to 13-Sept.

This morning I awoke to find the fruits of his labour generously presented to the world via Twitter.

I'm constantly impressed by how much info can and is being provided for everyone to share, discuss and  constructively mull over. This is just the latest fantastic effort.


Prof Fisman's (@DavidFisman) model has provided a very close estimate when compared to the real figures on which it is, of course, based (Figure 1.). His estimates have not changed with the latest data. He calculates an overall R0 of 1.75, and 'd' (a value that can indicate the level of control; when d is zero, you have uncontrolled exponential growth) is at 0.0078. The d values for different countries in the outbreak, differ.

Figure 1. Showing that the model (black line) fits extremely well
to actual reported case numbers (red bars) to date

The projected end date is November 2016 with a final size of approximately 480,000 cases. (Figure 2) This is just based on current numbers and without knowing what interventions are coming not how successful they will be. Prof Fisman says his model currently predicts an epidemic peak in June-2015 at which time there could be 227,000 cases. By Jan-2015, projected case counts reach 28,450.

Figure 2. Extending the model into 2017.
Red curve (right y-axis): incidence by 15-day generation.
Blue curve (left y-axis): cumulative cases.

Keeping in mind that these numbers do not include deaths. The proportion of fatal cases (PFC) requires some further mathematical wizardry in order to account for the time between when cases present to a treatment facility, and when they die. 

Figure 3. Ebola virus disease cumulative curve for Nigeria.
The proportion of fatal cases is markedly lower than for
 the more overwhelmed countries. This does
not appear to be an artefact as most cases have
been laboratory confirmed.

It's not a simple division of deaths and total cases at the same time point (these are the crude percentages I report on VDU and which the WHO report-this reporting may change in the future). 

The addition of that calculation spikes the PFC to >80% at times (see the post by @maiamajumder post on HealthMap), but seems to vary to lower figures depending on country and population for example, in Nigeria (Figure 3). But whatever way you look at it, many people will die from Ebola virus infection, as well as all the other diseases and medical care needs that going with sufficient attention.

References..

1. Early Epidemic Dynamics of the West African 2014 Ebola Outbreak: Estimates Derived with a Simple Two-Parameter Model
   http://currents.plos.org/outbreaks/article/obk-14-0036-early-epidemic-dynamics-of-the-west-african-2014-ebola-outbreak-estimates-derived-with-a-simple-two-parameter-model/

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Happy 2nd birthday Middle East respiratory syndrome coronavirus (MERS-CoV)...

Its been 2-years since Prof. Ali Mohamed Zaki sent his email to ProMED notifying them of a novel coronavirus. That email was published 20-Sept 2012.[1] 

A year ago we had 138 cases and 58 deaths. Today we have 856 cases with perhaps 306 fatal (36%).

I won't rehash what I said a year ago - I invite you to check that out over at the 1st birthday post.[2]

Suffice to say the past year has been, to my mind anyway, mostly about:

• Camels
• High level job "shuffling"
• Controversial parallel publications
• Very problematic infection prevention and control issues.

The latter leading to the relatively huge number of MERS-CoV detections and deaths in Saudi Arabia and to some exported detections and cases. The one constant over both years has been that the MERS-CoV is a pitiful spreader among humans. MERS-CoV is nonetheless a virus that is very capable of inducing fatal outcomes, especially among older males with underlying diseases.

Has MERS-CoV gone away? No. Of course it hasn't. MERS has, mostly. That's the disease, not the virus. For now anyway MERS cases are sporadic, although still geographically widespread. 

MERS cases fell to zero cases per week for a number of weeks this year following containment of the Jeddah-2014 outbreak. Nonetheless, this is a virus of camels that seems to  spread, rarely, to humans and when in us, it has not been in any rush to mutate into the pandemic SARS-like threat many once worried about. 

Camels are where this virus likely remains. And there have been no signs that that has in any way changed. The latest information suggests camels have been harbouring MERS-CoV for at least 30-years.[3] This, as with a great deal of the research to date, is knowledge gained mostly thanks to the efforts of international research teams and their funding

So Happy 2nd Birthday you opportunistic, spiky little killer. I'm once again wishing Dr Zaki well and congratulating him on co-parenting the birth of this novel coronavirus. This year I also wish Prof. Ziad Memish well and congratulate him on seeing the infant virus through to toddler age.

Oh, and 2-years on, I still see no sign that the contentious patenting issues were any sort of hindrance to diagnostics or actual research. Just sayin'.

References...

1. http://www.promedmail.org/direct.php?id=20120920.1302733
2. Happy 1st birthday Middle East respiratory syndrome coronavirus (MERS-CoV)http://newsmedicalnet.blogspot.com.au/2013/09/happy-1st-birthday-middle-east.html
3. MERS Coronavirus Neutralizing Antibodies in Camels, Eastern Africa, 1983�1997
   http://wwwnc.cdc.gov/eid/article/20/12/14-1026_article

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The proportion of fatal cases (PFC)...

This is excerpted and altered a little, from a more influenza A(H7N9) virus slanted article to be found here. But I think it deserves its own page.

In July 2013 I coined a term on VDU to avoid the use of the term Case Fatality Ratio/Rate/Risk (CFR). 

My term was the Proportion of Fatal Cases (PFC). I use the term on VDU and have published it an article.[1] I have no expectations that anyone else will use it although I notice it made an appearance in a HeathMap story[2] by Maia Majumder.

The PFC is a percentage calculated as the currently known number of fatalities divided by the number of total lab-confirmed cases including fatalities, regardless of whether surviving cases are inpatients (hospitalized) or outpatients.

The PFC is just a number - it's not meant to imply that every case that ever happened is included - it never could. It does not account for those cases who will die later on, either directly or indirectly, as a result of their infection but who may be alive at the time of calculation. 

The PFC is a snapshot to be used before an outbreak is done and dusted. It is meant as a guide to what is happening right now using the data we can get our hands on. Sometimes that means lots of data and sometimes they are very limited or just plain behind closed doors.

The CFR makes use of the number of recovered cases in its denominator.[3] So it's important to know survivor numbers. As suggested above, this requires that all the people who will recover from their infection, have recovered (and been discharged) from their infection. 

Using the CFR early in an emerging virus/disease outbreak, when what usually brings in outbreak to our attention is death, is great for selling papers, but not helpful realistic in a bigger picture sense. 

The CFR is most useful at the end of an epidemic/pandemic, but not so much when data-in-hand is poor during the early days of many outbreak. 

Of course, some will take a PFC and multiply it by the world's population as an estimate of how many are going to die if the virus reaches pandemic levels. That's not helpful or accurate. Just accept it as that snapshot of what's happening now.

References...

1. J. P. Dudley and I. M. Mackay. Age-Specific and Sex-Specific Morbidity and Mortality from Avian Influenza A(H7N9). J. Clin. Virol. 2013. Nov;58(3):568-70. ePub Sept.
   http://www.ncbi.nlm.nih.gov/pubmed/24091087
2. http://www.healthmap.org/site/diseasedaily/article/estimating-fatality-2014-west-african-ebola-outbreak-91014
3. http://en.wikipedia.org/wiki/Case_fatality_rate

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