I travel a fair bit. Enough to have priority status to skip lines, get upgrades and free drinks in lounges. It sounds glamorous, but travel for work takes its toll. The perks you earn from all the travel basically balance out the hours of being stuck at airports due to delayed flights and nights away from home. Priority is status. It means you’re special. It means you’re treated differently or regarded to as being more important. For example, when boarding planes, the passengers are organized into zones. Zone 1 are the really special people who get to board first, Zone 2 are pretty special and by the time you get to Zone 4 or 5…well, you’re not so special.
The same can be said about diseases. There are the really special ones, the pretty special ones and the run of the mill ones that we’re not too concerned with. At the beginning of February, Disease Experts reviewed the numerous known diseases and identified those that based on the potential to cause a public health emergency and the fact there are no drugs or vaccines to cure and/or mitigate transition, urgently need our focus. The “Zone 1” diseases identified were: Crimean-Congo haemorrhagic fever (CCHF), Ebola virus disease and Marburg virus disease, Lassa fever, Middle East respiratory syndrome coronavirus (MERS-CoV) and Severe Acute Respiratory Syndrome (SARS), Nipah and henipaviral diseases, Rift Valley fever (RVF), Zika and Disease X.
CCHF, Ebola, Marburg and Lassa are all haemorrhagic fevers that while limited to areas where animals that carry them live are of concern, not only because of transmission from person to person, but also because of the potential use in bioterrorism. In relation to MERS-CoV and SARS, I will admit I have a bit of a soft spot for as it was during the 2003 SARS Outbreak that hit Toronto that I began my career in infection prevention. The most interesting disease of this group for me is Disease X. Disease X does not exist. It represents the knowledge that at any time a serious international epidemic could be caused by a currently unknown pathogen. I suppose back in 2003, SARS would have been considered Disease X. We did not know what we were dealing with. We simply knew that we were dealing with something that caused severe respiratory distress, was killing people and was showing up in cities around the globe.
There are of course additional diseases of interest. These would be the Zone 2 and Zone 3 diseases. We need to mindful and not forget about them. We need to ensure research is on-going to understand their attributes, develop better diagnostic tools and of course develop ways to treat these diseases and/or vaccines to prevent the transmission.
The long and the short is that while the current priority diseases listed in WHO’s Blueprint priority diseases are viruses, any type of pathogen can land on this list. The experts also discussed the importance and value of a One Health approach as many of our priority list diseases are zoonotic in nature. While we need to develop measures to protect human health, we cannot forget or underestimate the importance of considering animal health measures. These measures can help prevent and control animal diseases to minimize spill-over to humans and of course, protect our food supplies.