Immune deficiency: changing spectrum of pathogens

Abstract

Current UK national standards recommend routine bacteriology surveillance in severe antibody-deficient patients, but less guidance exists on virology screening and viral infections in these patients. In this retrospective audit, we assessed the proportion of positive virology or bacteriology respiratory and stool samples from patients with severe, partial or no immune deficiency during a 2-year period. Medical notes were reviewed to identify symptomatic viral infections and to describe the course of persistent viral infections. During the 2-year period, 31 of 78 (39·7%) severe immune-deficient patients tested had a positive virology result and 89 of 160 (55.6%) had a positive bacteriology result. The most commonly detected pathogens were rhinovirus (12 patients), norovirus (6), Haemophilus influenzae (24), Pseudomonas spp. (22) and Staphylococcus aureus (21). Ninety-seven per cent of positive viral detection samples were from patients who were symptomatic. Low serum immunoglobulin IgA levels were more prevalent in patients with a positive virology sample compared to the total cohort (P = 0·0078). Three patients had persistent norovirus infection with sequential positive isolates for 9, 30 and 16 months. Virology screening of symptomatic antibody-deficient patients may be useful as a guide to anti-microbial treatment. A proportion of these patients may experience persistent viral infections with significant morbidity.

Keywords: IgA; antibody deficiency; infection; norovirus; viral.

Figure 1

C-reactive protein (CRP) and serum immunoglobulin levels at the time of positive virology result. CRP levels at the time of positive virology result are shown in (a). Serum immunoglobulin IgG, IgA and IgM (b) at the time of each positive virology result are shown. Dotted lines indicate reference ranges.

Figure 2

Three common variable immune deficiency (CVID) patients with persistent viral infections. Serum immunoglobulin IgG, IgA, IgM and the time–course of diarrhoeal symptoms and treatments are shown for patient 1 (a), patient 2 (b) and patient 3 (c). Positive norovirus samples (filled diamonds), negative norovirus samples (open diamonds), positive rhinovirus samples (filled circles), negative rhinovirus samples (open circles), positive rotavirus antigen (plus signs), positive respiratory syncytial virus (RSV) samples (crosses) and negative RSV samples (dots) are shown. Light grey bars indicate intermittent symptoms.