Random Analytica

This week (ending 26 January 2014) the Avian Influenza A(H7N9) has been busy. According to CIDRAP at least 45-cases have been reported during the past seven days alone, topping the busiest weeks of the disease in its first wave (approximately April 2013). As of today 245-cases of H7N9 have been reported with an unofficial fatality count of 57 (a Case Fatality Rate of 23.3%).

As someone who has practiced Workforce Planning for a decade or more I am always interested in what people do. One item I have noticed over the past ten months of amateur epidemiology is that health researchers are also interested in what you do, especially where your work (or lack thereof) puts you at risk or directly in harms-way of disease or death.

Here are some more H7N9 charts looking first at employment then an age chart concentrating on Zhejiang Province which hit 100-cases as of today.

The first chart looks only at the Job Title announced via a medical facility, Chinese media or via an online journal or study (the latter being my preferred). Over the past ten-months I have been able to populate my Job Title data in 179 out of 245 cases (or 73.1% of all H7N9 cases). The two predominant employment types are either a Farmer (30.7%) or Retired (28.5%). Potentially this proves the theory that exposure to live birds either in a farm setting or purchasing birds from live markets (as many retirees are understood to do) might increase your chances of catching H7N9. After Live Poultry Trade (5.0%) the breakdowns become less than 2.8% shared amongst 35 further job titles. Couple of interesting points:

• The average age of farmers infected by H7N9 is 61.0 whereas the current average age of victims is 55.7;
• Foreign workers (or even tourists) only make up three (1.7%) of the cases. One businessman from Taiwan, one foreign driver and one Indonesian maid based out of Hong Kong;
• There were five unemployed people confirmed in the first wave up to mid-April. The last person confirmed as unemployed was case number #101 with onset 16 April 2013. Does that mean that the unemployed are not catching the disease anymore OR that those without employment are part of the 26.9% of cases without a notifiable job title?
• There has been only one confirmed medical staff employment type to have caught H7N9 and to have subsequently died. The case of Dr. Zhang Xiaodong, a 31-year-old surgeon from Shanghai has raised alarms but reflects 0.6% of known job titles and 0.4% of all H7N9 cases to date. When you compare this against MERS-CoV, especially in Saudi Arabia which has seen multiple cases and deaths amongst its healthcare practitioners you can only but commend the Chinese authorities and medical fraternity;
• Not trying to stir up trouble but I noted that the Japanese Journal of Infectious Diseases refers to Chinese Farmers as ‘Peasants’ (see page 558 Laboratory Diagnosis and Epidemiology of Avian Influenza A (H7N9) Virus Infection in Humans in Nanchang City, China).

The second chart looks at employment by Job Family (see appended note for methodology). In this we see that the largest groups are represented by Non-Participatory (38.0% comprising retirees, children and the unemployed) closely followed by Farming, Fishing & Forestry (31.8%). After those two groups Food Preparation & Serving (9.5% including food sales, catering, market vendor, chef/cook & live poultry trade) and Production, Factory & Food Processing (factory worker, butcher, poultry abattoir, sheet metal worker and stone processor) equate to 82.7% of all cases. As per my comment in the previous chart this aligns reasonably well with the theory that the disease is spread through the contact with poultry.

Note 1: Often Workforce Planners will use a layered methodology of employment groups with job title as the most granular level up to Job Families. The purpose of this is to split the job titles into logical and practical segments to allow deeper workforce analysis to occur. A job family is a grouping of similar jobs at the highest level that usually consists of several job functions. In Australia I would use the Australian and New Zealand Standard Classification of Occupations or ANZSCO but given I have a choice I’ve opted to use the much more logical Bureau of Labor Statistics Occupation Employment Statistics.

Note 2: I created two groups outside of the BLS methodology. The first was ‘Non-Participatory’ to align with those people unemployed or no longer participating in the labour market. The second was ‘Other’ which reflects job titles such as ‘Worker’, ‘Company Employee’ or ‘Staff’.

As Ian M. Mackay pointed out in his latest Virology Down Under update Zhejiang H7N9 cases hit 100 today. Last chart is a look at the age pyramid for Zhejiang. A quick comparison shows that of male onsets is slightly lower than the total average (61% for Zhejiang, 70.2% overall) although the average age of 57.5 is slightly higher than the 55.7 H7N9 average. This is reflected in the age pyramid with has no Zhejiang cases in the lowest four cohorts and 59% of cases between the ages of 50 – 74. For a comparison against the first 226-cases see: Random Analytics: H7N9 Age Pyramid and Average Age (to 22 Jan 2014).

As always, stay safe, stay healthy and make good choices.