Risk factors for Haemophilus influenzae and pneumococcal respiratory tract colonization in CVID

To the Editor: Disease-specific studies focused on infection risk in common variable immune deficiencies (CVIDs) are needed to define strategies for controlling respiratory infections predominantly due to bacteria such as Streptococcus pneumoniae and Haemophilus influenzae.1 Little information is available on the rate of airway bacterial carriage and its consequence in hypogammaglobulinemias. Despite IgG replacement, recurrent respiratory infections are common in CVID, possibly leading to chronic lung damage2 and poor quality of life.3 Thus, patients are often prescribed antibiotics and/or long-term antimicrobial prophylactic regimens. Several regimens are used including rotation or periodically changing antibiotics.4 However, antibiotics influence antimicrobial resistance among airway microbiota. In a recent meta-analysis on patients with chronic lung diseases, 30% of S pneumoniae showed resistance to macrolides.5