High Rates of Community and Hospital Acquired Infections in Patients with Cellular Immunodeficiencies.

PURPOSE: Patients with primary immunodeficiency diseases (PID) are perceived to be at high risk for acquiring as well as developing complications from infections. There is little data describing the infection type and frequency these patients may acquire in the community or during hospital admissions. Data is critically needed in order to inform best practices on how to protect these vulnerable patients.
METHODS: This is a retrospective study which included PID patients who were discharged from Children's National Health System (CNHS) from January 1, 2011, through August 31, 2017, and were assigned a discharge diagnosis code indicating PID. Hospitalizations that occurred in the study period were reviewed to extract information on the type of infections upon admission and during hospitalization. The rate of hospital acquired infections (HAIs) was calculated by the number of HAIs divided by the total number of days between date of admission and date of discharge or receiving the first bone marrow transplant, whichever the one came first. The rates were then compared to the HAI rate among oncology patients receiving treatment at CNHS during the same study period.
RESULTS: During this study period, 33 PID patients were admitted 80 times for a total of 1855 patient days. Of these 80 admissions, 31 were due to an infection. Ten of the 31 admissions with severe combined immunodeficiency disease (SCID) were infection related, 4/4 in ectodermal dysplasia with immunodeficiency due to gain of function mutation (IkappaBalpha) patients, 8/10 in Wiskott-Aldrich patients, 1/2 in STAT3 mutation patients, 1/1 in Hyper IGM patient, 1/5 in severe chronic active EBV (SCAEBV) patients, 1/1 NK defect, 2/21 in primary hemophagocytic lymphohistiocytosis patients, 3/4 chronic granulomatous disease, and 0/1 congenital neutropenia. HAI occurred in 11 out of 80 admissions (13.75%). Patients with SCID had the highest HAI rate of 13.09 per 1000 patient days, followed by SCAEBV (11.10), IkappaBalpha (6.58), and Wiskott-Aldrich (4.91). Comparing to oncology patients in which the HAI rate was 0.92 per 1000 patient days. SCID patients had 11.7 (95% confidence interval 3.7-29; p < 0.001) and T cell defects excluding SCID had 4.8 (95% CI 1.0-14.8; p = 0.03) times greater risk of acquiring an infection during a hospitalization.
CONCLUSIONS: Patients with severe T cell defects such as SCID are at greater risk for infections in the community and in hospital settings. Additional infection prevention measures are likely needed when caring for these patients in a clinic or as an inpatient. Further studies are urgently needed to determine the most appropriate measures for these patients.