An Unexpected Burden
A recent study from the Data and Demographics Committee of the World Federation of Hemophilia found that the prevalence of hemophilia is 3 times more prevalent than previously believed. While the prevalence of hemophilia (both types A and B) was previously thought to be 400,000, this meta-analysis of national registries of Australia, Canada, France, Italy, New Zealand, and the United Kingdom demonstrated a prevalence of 1.1 million. The study calculated life expectancy disadvantages as 30% for hemophilia A, 37% for severe hemophilia A, 24% for hemophilia B, and 27% for severe hemophilia B. Some limitations of the study include insufficient details to adjust for comorbid conditions and ethnicity, and the lack of information from middle and low income countries.
Hemophilia is largely diagnosed through laboratory testing, including factor activity assays and genetic studies. These specialized types of analysis can be challenging to maintain on low and middle-income countries. If available, the testing may be provided at central locations in country. I was privileged to assist in the diagnosis of hemophilia while volunteering at a hospital in Port-au-Prince, Haiti. The patient was a young boy with easy bruising and recurrent hematoma formation around his knee. On this visit, we had just finished validating prothrombin time (PT) and activated partial thromboplastin (aPTT) time assays in the hospital laboratory, and so we were able to identify a deficiency in coagulation. However, we were unable to locate a laboratory in the country that could perform factor activity assays. We arranged to have samples sent to a laboratory in Miami, Florida, USA, for testing. The patient samples as well as control samples from a healthy volunteer were carried to the laboratory in Miami by a volunteer returning to the States.
If the worldwide burden of hemophilia is significantly higher than we thought, it is even more important to keep that in mind when establishing a differential diagnosis. In order to better understand the true prevalence of hemophilia, more information from middle and low income countries is needed. For both diagnosis and research, expanding the availability of factor testing in low and middle income countries is necessary. One way to expand the availability might be to establish networks to reference labs, similar to how the case in Haiti was handled.