Infections in E-beta thalassemia

Infection is a major complication and the leading cause of death in thalassemia, especially E-beta thalassemia. The spectrum of infections in E-beta thalassemia include mild and severe infections, therapy-related infections such as Yersinia enterocolitica infection associated with desferrioxamine (DFO) therapy, and transfusion-transmitted disease, as well as unique infections such as with pythiosis. Prospective studies in Thailand indicate that patients with E-beta thalassemia had more frequent episodes of both mild and severe infections. The former included upper respiratory tract infection, acute gastroenteritis, cutaneous abscess, and gingivitis. Severe infections occurred more commonly in patients with splenectomy and included septicemia, pneumonia, biliary tract infection, salmonellosis, and urinary tract infection. Responsible organisms were Escherichia coli (26%), Klebsiella pneumoniae (23%), Salmonella (15%), and Streptococcus pneumoniae (13%). Other organisms included Pseudomonas, Staphylococci, Burkholderia pseudomallei (melioidosis), and Aeromonas. Patients undergoing DFO therapy are at risk for Y. enterocolitica infection which may be localized to mesenteric nodes and tonsils or occur as a generalized form such as septicemia. Recently, we have seen a unique infection so-called vascular pythiosis. Patients usually presented with clinical features of vascular occlusion of lower limbs from ascending arteritis and thrombosis. The causative organism, Pythium insidiosum, is fungus-like, in the kingdom Stramenopila, and in the class Oomycetes. The mortality rate is high and the only effective treatment has been early amputation or possibly immunotherapy. The predisposing factors of infections in thalassemia include splenectomy, iron overload, anemia, and granulocyte dysfunctions. General management of infections in thalassemia consist of prevention, i.e., immunization with pneumococcal and hepatitis vaccines, oral penicillins especially in patients with splenectomy, removal of predisposing factors such as gallstones, iron overload, and appropriate antibiotics.