Barenkamp S J, Granoff D M, Munson R S
J Infect Dis. 1981 Sep;144(3):210-7. doi: 10.1093/infdis/144.3.210.
Isolates of Haemophilus influenzae type b with a distinctive outer-membrane protein subtype, designated 1H, were responsible for 11 of 13 cases of invasive infection in children attending six day-care centers with secondary cases of disease, in comparison to three of 14 cases in children attending 10 centers with single cases and two centers with unrelated cases. The other 11 cases were caused by type b isolates of six different subtypes. The secondary attack rate in contacts younger than four years of age exposed to disease due to isolates of the 1H subtype was 16 per 1,000, compared with 1.6 per 1,000 after exposure to disease caused by subtypes other than 1H (P less than 0.008). Carriage rates were increased in day-care-center contacts exposed to patients with disease, and most of the carriers were colonized by isolates with subtypes homologous to those responsible for the respective index cases. Both 1H and non-1H strains were capable of colonizing contacts, but 1H strains may be more pathogenic than other subtypes.
在六个有二代病例的日托中心就诊的儿童中，13例侵袭性感染病例中有11例是由具有独特外膜蛋白亚型（称为1H）的b型流感嗜血杆菌分离株引起的；相比之下，在10个仅有单个病例的中心和2个无关联病例的中心就诊的儿童中，14例病例中有3例是由该分离株引起的。其他11例病例由六种不同亚型的b型分离株引起。接触1H亚型分离株所致疾病的4岁以下接触者的二代发病率为每1000人中有16例，而接触1H以外亚型所致疾病后的二代发病率为每1000人中有1.6例（P<0.008）。日托中心接触患病患者的带菌率增加，大多数携带者被与各自索引病例相同亚型的分离株定植。1H菌株和非1H菌株都能够定植于接触者，但1H菌株可能比其他亚型更具致病性。
