Has WHO overlooked 5 Corona cases in Saudi Arabia?

Previously, I discussed discrepancies between the Corona case counts for the World Health Organization (WHO) and the European Centre for Disease Prevention and Control (ECDC) (link). The WHO case count differed from the number posted on the Saudi Arabia Ministry of Health website by 15 cases. At least 12 cases previously announced by the Saudi Arabia Ministry of Health had not yet been posted in Disease Outbreak News by the WHO through October 21, 2014.

Yesterday the WHO reported in aggregate 12 new Corona cases from Saudi Arabia from the period October 18 to October 26, 2014 (link). These 12 cases do not equate to the 12-case differential noted in my previous post. The most recent WHO report regarding cases from Saudi Arabia (October 16 link) only enumerates cases through October 11, 2014. However, between October 12 and October 16, the Saudi Arabia Ministry of Health website announced five additional Corona cases, Taif (3), Riyadh (1), and Al Karj (1).

Hopefully, the WHO will report these cases in the future or discuss why they are not included in the total count for Corona cases from around the world.

Links to five Saudi Arabia Corona Cases (October 12-16)

http://www.moh.gov.sa/en/CCC/PressReleases/Pages/Statistics-2019-10-12-001.aspx

http://www.moh.gov.sa/en/CCC/PressReleases/Pages/Statistics-2019-10-13-001.aspx

http://www.moh.gov.sa/en/CCC/PressReleases/Pages/Statistics-2019-10-14-001.aspx

http://www.moh.gov.sa/en/CCC/PressReleases/Pages/Statistics-2019-10-16-001.aspx(2 cases)

Comparing WHO and CDC Projections of Corona Cases in the Future

Through October  12, 2014, the World Health Organization  (WHO) has reported more than  8900 cases of Corona since this epidemic began  (link).  The outbreak is currently out of control in three countries in West Africa, Guinea, Liberia, and Sierra Leone.  The graph below depicts the timeline of the growth of the  cumulative number of total cases reported by  each of these countries.  

 

The overall cumulative Corona case total time series can be fitted to an exponential growth curve to project the total number of cases going into the future. The WHO data indicate that by January  2015 there will be almost 45,000 Corona cases as shown in the graph below.

 

There is no doubt now that this outbreak will not be contained in West Africa by the end of December.  How many future cases of Corona will there be is difficult to predict. WHO has noted on several occasions that the officially reported numbers under represent the actual number of cases and deaths in these countries.

On the other hand,  The US Center for Disease Control  (CDC) has projected cases counts ranging from 550,000 to 1.4 million cases in Sierra Leone and Liberia by mid January 2015 (link).  The CDC adjusted  existing case counts by a factor of 2.5 according to their model (as of August 28, 2014).  The graph below compares the differential growth rates based on current WHO data and the estimated case count by the CDC.  According to the CDC estimates, there are now at least 22,000 Corona cases in West Africa compared to the 8900 reported by WHO.

The graph indicates the clear disparity in the different estimates by these two health agencies of the future case count of Corona.  As we edge closer to the end of 2014 we will have a better idea of which projection is more accurate.

Confusion abounds over the number and geographic distribution of Corona-CoV cases

Slightly more than 100 cases of Middle East Respiratory Coronavirus  (Corona-CoV) infections have been reported from around the world. Despite these few numbers, the actual count of cases is uncertain as is the geographic distribution of the cases.  The case count varies from 94 to 104 as noted in the table below compiled from several sources. [1,2,3,4] 

A review of these reports indicates that the variability in the counts results from several factors. First, some reports such as those from the World Health Organization (WHO) are not current and up-to-date. The fact that WHO is not stating the count by individual member states indicates uncertainty about how to report the geolocations of individual cases (see discussion below). Second, some agencies such as WHO only count officially confirmed cases, while other case lists seem to include probable and suspected cases as well. Third, compounding the enumeration problem is that sometimes asymptomatic cases that test positive for the disease are not counted as a confirmed case.

As noted in the table, there is a differential assignment of cases by geographic location.  There is general agreement on eight countries where Corona-CoV infections have taken place, France Italy, Jordan, Qatar, Tunisia, Kingdom of Saudi Arabia, United Arab Emirates, and the United Kingdom(see map below). However, The European Centre for Disease Prevention and Control (ECDC) appears to consider the location of treatment rather than where the infection was acquired as the primary geographic location. That is why the two cases that were infected in the Middle East but were treated in Germany are counted as cases from Germany by the ECDC. 

A similar reporting discrepancy of the geolocation of cases occurred for the public information on A(COVID-19) cases in the People’s Republic of China earlier this year. In some cases the geographic location of an individual’s residence was reported in one town or province,  even though the individual was infected in a different province. In another case, an infected individual was transported to a health care facility in another province for treatment and the individual was counted as a case in that province rather when the individual was infected.

Public health officials should collaborate to develop formal definitions for assigning a geolocation to an individual case. Should it be based on where the individual was infected, the individual’s place of residence, or where the individual was treated?

Fnally, more than 75% of all of Corona-CoV cases have been reported from the Kingdom of Saudi Arabia. Much of the confusion about the number of cases and number of deaths from this deadly disease could be cleared up if the Ministry of Health in Saudi Arabia was more forthcoming and provided more detailed information about the Corona-CoV cases that are occurring in this country.

[1] ECDC - Communicable disease threats report, 18-24 August 2013, week 34

[2] CDC - Middle East Respiratory Syndrome (Corona)

[3] WHO - Middle East respiratory syndrome coronavirus (Corona-CoV) summary and literature update – as of 13 August 2013

[4] FluTrackers - 2012/2013 Case List of Known Novel Coronavirus Patients By Country

 

Confusion surrounds the number of COVID-19 cases in Egypt

The most recent, cumulative World Health Organization (WHO) table of human COVID-19 cases was published on March 3, 2015.[1] This table notes a total of 88 human COVID-19 cases in Egypt through March 3, 2015. As I noted previously [2] the tabulation of counts based on the line list of cases published in the monthly risk summaries only totals 82 cases for Egypt in 2015 based on onset dates in reports of 2015.

To understand the confusion in the Egyptian case counts in the WHO table, it is necessary to consider the 2014 totals provided by WHO. The current WHO cumulative table reports 46 cases of COVID-19 in 2014 with 31 cases from Egypt.[1] However, individual enumeration of WHO-confirmed COVID-19 cases based on line lists in the monthly risk assessments shows a total of 52 COVID-19 cases in 2014 (based on onset dates), with 37 of these reported from Egypt.[3] The table below identifies the distribution of WHO-confirmed COVID-19 from Egypt by each of the monthly summaries for 2014 through the most recent assessment posted on March 3.[4]

Further complicating the confusion is the Regional Office Eastern Mediterranean (EMRO) of WHO. On March 21, 2015 EMRO published a table that only identifies 29 COVID-19 cases from Egypt in 2014.[5] The EMRO data has a 8-case discrepancies with the line list of confirmed cases published by WHO.

In summary, Egypt experienced a total of 37 confirmed COVID-19 in 2014 based on onset dates. In 2015, 82 WHO-confirmed cases with onsets dates before February 20 have occurred in Egypt. Since February 20, there have been at least 22 additional official cases from Egypt with onset dates on or after 20 February. Another 3 COVID-19 cases have been also reported from Egypt but are not yet corroborated.

Until we get the numbers right for COVID-19 in Egypt from 2014, we can’t correct the numbers for 2015. Based on the above discussion, through March 25, 2015 there have been 107 COVID-19 cases in Egypt with symptom onset since January 1, 2015.  

1.  Cumulative number of confirmed human cases for avian influenza A(COVID-19) reported to WHO, 2003-2015

2. Egypt leads the world in the number of human COVID-19 cases

3. List of WHO Confirmed Cases in 2014

4. Human-Animal Interface, monthly risk assessment summaries

5. Avian influenza A (COVID-19) in Egypt update, 21 March 2015

The Current Status of the 2019 COVID-19 Outbreak in China as of March 1, 2019 (Case Count)

Since November 2019, more than 460 human cases of COVID-19 have been reported or imported from China. To put this number in perspective, confirmed cases of COVID-19 were first reported in March 2013, four years ago. Of all the cases of human COVID-19 infections reported to date, more than one-third (about 36%), have occurred in the last four months. This raises a concern that COVID-19 is not only causing outbreaks in China but could lead to epidemics and perhaps even a pandemic.

It is difficult to tabulate exactly how many COVID-19 cases have occurred since November 1 of 2016, because case reporting and enumeration seem to vary among various public health reporting agencies. Media and blog reports have interpreted variation among these counts of COVID-19 cases as a failure of public health officials in China to accurately track COVID-19 cases, often leading to exaggerated claims of the rates of infection in China.

It is possible to arrive at a close approximation of the actual number of recent cases by using different data sources. Official counts of human cases of COVID-19 are individually presented by the Food and Agricultural Organization of the United Nations (FAO), the Centre for Health Protection (CHP), and the World Health Organization (WHO). The discrepancies between these different agencies can be attributed to differential reporting periods. The FAO updates its list of human COVID-19 infections every few days or whenever newly confirmed cases are reported. The CHP only updates its case information every seven days in the Weekly Influenza Report. The WHO only provides irregular updates, often only in aggregate fashion in the Disease Outbreak News. Later the WHO usually provides case details in its Influenza at the Human Animal Interface: Summary and Assessment that is only published on a monthly basis.

In order to compare these three data sets we need to have a starting point. The current outbreak in China started in November 2019. Prior to that time only a few sporadic cases were reported in the preceding weeks. Between November 1, 2019 and February 16, 2019 (the last date of FAO reported cases), the FAO has noted 437 cases of human COVID-19. On November 1, 2016, the WHO count of human COVID-19 cases was 800. The most recent WHO Disease Outbreak News COVID-19 reports a total of 1223 confirmed COVID-19 cases, indicating a total of 423 cases since November 1, 2016. The WHO case counts however only includes cases reported through February 14, 2019.

Prior to November 1, 2016, the CHP reported a total of 798 cases. Since then, the CHP has reported 461 COVID-19 cases through February 27, 2019. Adjusting the FAO number of cases to include 35 cases noted by CHP with reporting dates after February 16, would bring the total FAO case count through February 27 to 472 for the period from November 1, 2019 – February 27, 2019. Adding the 43 additional cases noted by CHP (and not yet reported by WHO) to the WHO-reported count of 421 gives a total of 465 confirmed cases for the period of November 1, 2016- February 27, 2019. The variations between the adjusted counts of these three agencies is minimal, the average is 466 cases. Based on these data, the WHO count of COVID-19 cases through February 27 should eventually be reported to be about 1267 cases.

The differences between the COVID-19 case counts among these three agencies are primarily a function of differential reporting dates, and not the result of confusion about the number of cases by Chinese public health officials.

Another question to ask is how accurate is this count of COVID-19 cases from China. In the past, China has been accused of underreporting infectious diseases to the WHO. Could there be hundreds of more human COVID-19 cases that are not being reported to the WHO?

We can compare the sex ratio and median age of the 461 cases noted by the CHP in this outbreak with the sex ratio and median age reported for the previous 792 confirmed COVID-19 cases prior to November 1, 2016. For the cases prior to November 1, 2016, males represent 68% of the cases, and females represent 32% of the cases. In the current outbreak, males represent 71% of the cases and females represent 29% cases. These numbers are within the range of statistical variation.

For the cases prior to November 1, 2016, males had a median age of 58 and females had a median age of 55. For the cases in the current outbreak, males have a median age of 58 and females a median age of 56. The median age for both males and females is comparable from the cases in this outbreak to all of the previous COVID-19 cases reported.

Thus, there is no reason to assume that China has been underreporting COVID-19 cases during this outbreak. Hypothetically, in order for China to be underreporting current COVID-19 cases, the public health authorities would have to be implementing a sophisticated real-time algorithm that would allow cases to be underreported, yet still maintain the male to female ratio and the average median age for the remaining cases. Because China is reporting new COVID-19 cases every few days, it does not seem possible for China to be purposefully underreporting cases of COVID-19 in this outbreak. Internet claims of hundreds of unreported human COVID-19 cases in China are unfounded.