Spanjaard L, van den Hof S, de Melker H E, Vermeer-de Bondt P E, van der Ende A, Rijkers G T
Academisch Medisch Centrum/Universiteit van Amsterdam, Nederlands Referentielaboratorium voor Bacteriële Meningitis, L-1-Z, Postbus 22.660, 1100 DD Amsterdam.
Ned Tijdschr Geneeskd. 2005 Dec 3;149(49):2738-42.
To describe the increase of invasive Haemophilus influenzae type b (Hib) infections in The Netherlands before and after the introduction of Hib vaccination in 1993, and to hypothesise about possible explanations.
Descriptive.
Data on the prevalence of invasive Hib infections, such as meningitis and epiglottitis, during 1990-2004 were obtained from The Netherlands Reference Laboratory for Bacterial Meningitis, which collects Hib isolates from spinal fluid and blood from across the country.
The incidence of invasive Hib infections decreased substantially for a few years after 1993. The total number of isolates was at a minimum in 1999 (n = 12) and increased to 49 in 2004. The annual number of patients with vaccine failure was 5 or less during 1995-2001, but was between 10 and 15 from 2002 onwards. A definite explanation for the increase in the incidence of invasive Hib infections cannot be given. Improbable causes are a surveillance artefact, an impaired response to the vaccine due to vaccination-scheme changes or interaction with other vaccines, or selection of Hib variants that are less sensitive to the vaccine-induced immunity. It most likely involves secondary vaccine failure: Hib carriership is decreased by mass vaccination, whereupon natural boosting occurs less frequently later in life. Subsequently, immunity decreases and susceptibility to invasive infection increases. Careful surveillance of invasive Hib infections in The Netherlands remains important.
描述1993年荷兰引入b型流感嗜血杆菌（Hib）疫苗接种前后侵袭性Hib感染的增加情况，并对可能的原因进行假设。
描述性研究。
1990 - 2004年期间侵袭性Hib感染（如脑膜炎和会厌炎）的患病率数据来自荷兰细菌性脑膜炎参考实验室，该实验室收集来自全国各地脑脊液和血液中的Hib分离株。
1993年后的几年里，侵袭性Hib感染的发病率大幅下降。分离株总数在1999年降至最低（n = 12），2004年增至49。1995 - 2001年期间每年疫苗接种失败的患者人数为5人或更少，但从2002年起在10至15人之间。侵袭性Hib感染发病率增加的确切原因尚无法给出。不太可能的原因是监测假象、由于疫苗接种方案改变或与其他疫苗相互作用导致对疫苗的反应受损，或选择了对疫苗诱导免疫不太敏感的Hib变体。最有可能涉及继发性疫苗接种失败：大规模接种疫苗降低了Hib携带率，因此在生命后期自然增强免疫的情况较少发生。随后，免疫力下降，侵袭性感染的易感性增加。在荷兰对侵袭性Hib感染进行仔细监测仍然很重要。
