What is hemophagocytic syndrome a disease? What is the incidence? Although hemophagocytic syndrome was named in 1952, it is only in the last decade or so that we really know it. Currently, there is no accurate epidemiological data on the incidence of hemophagocytic syndrome internationally. Some foreign experts have made statistics and believe that the incidence of hemophagocytic syndrome in newborns is 1 in 50,000; however, epidemiological surveys on the incidence in adults vary greatly, with some believing it to be 2 in 100,000 and others believing it to be 5 in a million. Although there are no accurate incidence data, it is clear that hemophagocytic syndrome must not be a rare disease, as there are many patients who are misdiagnosed and this disease is not uncommon. What are the types of hemophagocytic syndromes? Currently, according to international guidelines, phagocytic syndromes are roughly divided into two main categories: the first is primary phagocytic syndrome; the second is secondary or acquired phagocytic syndrome.