Can microscopic screening be used to determine the suitability of sputum for culture of Haemophilus species?

Sputum specimens with less than 25 squamous epithelial cells per low-power field were also examined microscopically for the presence of alveolar macrophages and Haemophilus-like organisms and cultured for Haemophilus species. The isolation of Haemophilus species was considered to be clinically significant in 11 of 13 (84.6%) specimens containing greater than or equal to 2+ alveolar macrophages (at least 1 alveolar macrophage/high-power field) and predominant Haemophilus-like organisms (greater than or equal to 12 Haemophilus-like organisms/oil immersion field); in 12 of 27 (44.4%) specimens with greater than 2+ alveolar macrophages and few, if any, Haemophilus-like organisms; and in only 1 of 20 (5%) specimens with few, if any, alveolar macrophages and Haemophilus-like organisms. It was concluded that only sputum specimens with either greater than or equal to 2+ alveolar macrophages or predominant Haemophilus-like organisms or both should be candidates for culture of Haemophilus species.