Epidemiology of Influenza A virus infection in patients with acute or chronic leukemia

Abstract

Influenza infection is a significant cause of morbidity and mortality in immunocompromised hosts, but its importance in adult cancer patients is largely undescribed. We therefore conducted a prospective study of the incidence and clinical features of influenza infection in patients with acute or chronic leukemia. The cohort, which consisted of all adult leukemia patients undergoing remission-induction chemotherapy during the 1991-1992 influenza epidemic, was followed prospectively for development of signs and symptoms of acute infection of the upper or lower respiratory tract. Of these 294 patients, 111 received chemotherapy as inpatients and 183 as outpatients. Throat swabs and nasal washes for viral culture were obtained from all symptomatic patients, who were then followed until all signs and symptoms resolved. Symptoms of respiratory tract infection developed in 37 leukemia patients (13%). Among these, influenza (A/Beijing/ H3N2) caused 3 (21%) of the 14 infections that developed during hospitalization but only 1 (4%) of the 23 that developed in the community (P = 0.14). Influenza patients presented with fever, rhinorrhea, nasal congestion, headache, and myalgia; those with other infections presented with signs and symptoms of lower respiratory tract infection (productive cough, rales, or rhonchi). Development of pneumonia was common in influenza patients, 1 of whom died from secondary fungal and gram-negative pneumonia. Influenza A virus infections accounted for a substantial portion of acute respiratory infections among adult leukemia patients during a community epidemic. Most infections appeared to be nosocomial and the most likely sources were visitors or hospital personnel. Immunization of household contacts and hospital staff may reduce the risk of influenza infection and its pulmonary complications in leukemia patients.

A Prospective Study of the Factors Shaping Antibody Responses to the AS03-Adjuvanted Influenza A/H1N1 Vaccine in Cancer Outpatients

“…Whether or not influenza vaccination should be systematically offered to cancer patients remains controversial, mainly because the quality of immune responses elicited by seasonal influenza vaccines is difficult to interpret as a result of previous immunizations, previous infections, and patient heterogeneity [2,8,[23][24][25][26]. Because the majority of adults are unlikely to have been exposed to or immunized against the new H1N1 strain of influenza, we postulated that the influenza A/H1N1 pandemic observed in 2009 provided a unique opportunity to unravel this controversy.…”

Differences in clinical outcomes after 2009 influenza A/H1N1 and seasonal influenza among hematopoietic cell transplant recipients

“…Previous studies of seasonal influenza in HCT recipients have consistently demonstrated a higher rate of progression to LRD and need for mechanical ventilatory support, 6 prolonged viral shedding, 23 and a higher mortality 3,[24][25][26] in HCT recipients than in the general population. Although rates of infection and hospitalization after 2009 influenza H1N1 are remarkably different by age group from rates reported in previous years, 27 clinical disease in the general population after infection with 2009 H1N1 and seasonal influenza have been shown to be remarkably similar with regard to overall disease severity and rates of complications.…”

How I treat influenza in patients with hematologic malignancies

“…A few small series have documented seasonal influenza outbreaks among such patients, demonstrating the susceptibility of immunocompromised populations. [11][12][13][14] These limited reports suggest that cancer patients are at a high risk for acquisition of influenza in both the community and health care settings.…”