EPIDEMIOLOGY OF INFLUENZA-A VIRUS-INFECTION IN PATIENTS WITH ACUTE ORCHRONIC LEUKEMIA

Influenza infection is a significant cause of morbidity and mortality in immunocompromised hosts? but its importance in adult cancer patient s is largely undescribed, We therefore conducted a prospective study o f the incidence and clinical features of influenza infection in patien ts with acute or chronic leukemia, The cohort, which consisted of all adult leukemia patients undergoing remission-induction chemotherapy du ring the 1991-1992 influenza epidemic, was followed prospectively for development of signs and symptoms of acute infection of the upper or l ower respiratory tract, Of these 294 patients, 111 received chemothera py as inpatients and 183 as outpatients. Throat swabs and nasal washes for viral culture were obtained from all symptomatic patients, who we re then followed until all signs and symptoms resolved. Symptoms of re spiratory tract infection developed in 37 leukemia patients (13%), Amo ng these, influenza (A/Beijing/H3N2) caused 3 (21%) of the 14 infectio ns that developed during hospitalization but only 1 (4%) of the 23 tha t developed in the community (P=0.14). Influenza patients presented wi th fever, rhinorrhea, nasal congestion, headache, and myalgia; those w ith other infections presented with signs and symptoms of lower respir atory tract infection (productive cough, rales, or rhonchi), Developme nt of pneumonia was common in influenza patients, 1 of whom died from a secondary fungal and gram-negative pneumonia, Influenza A virus infe ctions accounted for a substantial portion of acute respiratory infect ions among adult leukemia patients during a community epidemic. Most i nfections appeared to be nosocomial and the most likely sources were v isitors or hospital personnel, Immunization of household contacts and hospital staff may reduce the risk of influenza infection and its pulm onary complications in leukemia patients.