Long Covid now has an official definition from the World Health Organization

This week, tThe World Health Organization has published diagnostic criteria for long covid, a confusing disease that has affected covid-19 survivors. Among other things, the WHO notes that patients can experience symptoms months after their initial infection and that these symptoms can be severe enough to impact their daily functioning.

Long covid is the label that was adopted and popularized by its patients at the start of the pandemic. Much of the early research into its characteristics was carried out by or heavily involved in these patient communities. But it remains a lot of questions over long covid, including how often it actually happens and the underlying mechanisms behind the many symptoms associated with it.

A necessity in studying any medical problem is to have a clear description of it, which can be widely adopted by physicians, patients and other concerned parties. Wednesday, WHO published a clinical case definition for long covid, which they officially call “post-covid-19 condition”.

The short, sweet version defines long covid as something that occurs in people with a history of probable or confirmed SARS CoV-2 infection, usually three months after the onset of their original case. Symptoms include, but are not limited to, fatigue, shortness of breath, and cognitive dysfunction, often referred to as brain fog. Symptoms may be persistent from acute infection or appear later, and their severity may vary over time, but they should last for at least two months before a formal diagnosis is made. It is important to note that there should also not be an alternate explanation that could better match a patient’s condition.

To arrive at these criteria, WHO conducted what is known as a Delphi Consensus, which calls for bringing together contributions from relevant experts and other stakeholders on a topic. This included surveys of WHO staff, outside experts, patients and patient researchers. All in all, they reached to people in 44 countries across six regions of the world covered by WHO.

Also this month, the United States Centers for Disease Control and Prevention officially added a formal diagnostic code for the long covid, or “post-covid-19 condition,” to the latest edition of the International Classification of Diseases, ICD-10. CIM codes are used by physicians, hospitals, and insurance companies for diagnostic and billing purposes, the latter of which are likely to be crucial for patients requiring long-term care and rehabilitation. The Biden administration has promised that long covid patients will be considered disabled if their symptoms are severe enough to severely restrict their life.

WHO has called on countries, researchers and others around the world to adopt their criteria as a global standard moving forward. But they recognize that this can change over time as we learn more about the long covid.

“Covid-19 will remain a challenge for the foreseeable future. Many pending answers regarding covid-19 and its sequelae remain, with new questions constantly being asked, ”wrote the authors of the full report outlining the new definition. “This definition of the post-covid-19 state will help advance both advocacy and research, but will likely change as new evidence emerges and our understanding of the consequences of covid-19 continues to evolve. “