Abstract：
A serogroup W (MenW) outbreak in Chile prompted a meningococcal vaccination campaign using tetravalent meningococcal-conjugate vaccines (MCV-ACWY) in children since 2012, followed by its introduction into the National Immunization Program (NIP) in toddlers from 2014. Direct protection was observed, but no indirect effects in other age-groups were evidenced. The aim of this study was to describe invasive meningococcal disease (IMD) cases in Chile between 2009 and 2019, and its trend after the introduction of MCV-ACWYs.
IMD cases, cumulative incidence per 100,000 inhabitants, CFR, and vaccination uptake were described. Data were obtained from the Public Health Institute and NIP.
Overall-IMD cases increased in 2009-2014 period, followed by a decline in 2015-2019, focused in infants, children <5 years and people ≥60 years. Serogroup B (MenB) and MenW alternate its predominance. Median overall incidence was 0.6/100,000, increasing from 0.6/100,000 in 2009 to 0.8/100,000 in 2014, later decreasing to 0.4/100,000 in 2019. Median incidences for MenB, serogroup C (MenC) and Y (MenY) were 0.25/100,000, <0.01/100,000 and <0.01/100,000, respectively. Median MenW incidence was 0.53/100,000, increasing from 0.01/100,000 in 2009 to 0.56/100,000 in 2014, followed by a constant decline to 0.12 in 2019. Infants, children <5 years and adults ≥60 years were affected the most, with median incidences of 9.7, 0.9 and 0.93, decreasing to 1.3, 0.1 and 0.1/100,000 in 2019, respectively. Median overall-CFR was 19%, 7.5% for MenB and 24.5% for MenW. Median MCV-ACWY uptake was 93% CONCLUSION: Overall-IMD, MenW cases and incidence declined since 2015 after the MCV-ACWY introduction, while MenB, MenC and MenY have been stable. MenW incidence declined in all age groups, including non-immunized infants and people >60 years. Further analysis and a longer period of observation are needed to have a more robust conclusion about this epidemiological trend. By 2019, CFR remains high.
IMD cases, cumulative incidence per 100,000 inhabitants, CFR, and vaccination uptake were described. Data were obtained from the Public Health Institute and NIP.
Overall-IMD cases increased in 2009-2014 period, followed by a decline in 2015-2019, focused in infants, children <5 years and people ≥60 years. Serogroup B (MenB) and MenW alternate its predominance. Median overall incidence was 0.6/100,000, increasing from 0.6/100,000 in 2009 to 0.8/100,000 in 2014, later decreasing to 0.4/100,000 in 2019. Median incidences for MenB, serogroup C (MenC) and Y (MenY) were 0.25/100,000, <0.01/100,000 and <0.01/100,000, respectively. Median MenW incidence was 0.53/100,000, increasing from 0.01/100,000 in 2009 to 0.56/100,000 in 2014, followed by a constant decline to 0.12 in 2019. Infants, children <5 years and adults ≥60 years were affected the most, with median incidences of 9.7, 0.9 and 0.93, decreasing to 1.3, 0.1 and 0.1/100,000 in 2019, respectively. Median overall-CFR was 19%, 7.5% for MenB and 24.5% for MenW. Median MCV-ACWY uptake was 93% CONCLUSION: Overall-IMD, MenW cases and incidence declined since 2015 after the MCV-ACWY introduction, while MenB, MenC and MenY have been stable. MenW incidence declined in all age groups, including non-immunized infants and people >60 years. Further analysis and a longer period of observation are needed to have a more robust conclusion about this epidemiological trend. By 2019, CFR remains high.
摘要：
智利的W（MenW）血清型爆发促使自2012年以来在儿童中使用四价脑膜炎球菌结合疫苗（MCV-ACWY）进行脑膜炎球菌疫苗接种运动，随后从2014年开始在幼儿中引入国家免疫计划（NIP）。观察到直接保护，但未发现其他年龄组的间接影响.这项研究的目的是描述2009年至2019年智利的侵袭性脑膜炎球菌病（IMD）病例，以及引入MCV-ACWYs后的趋势。
IMD病例，每10万居民的累计发病率，CFR,和疫苗接种的吸收进行了描述。数据来自公共卫生研究所和NIP。
2009-2014年期间，IMD病例总体有所增加，其次是2015-2019年的下降，主要集中在婴儿，儿童<5岁，人≥60岁。血清群B（MenB）和MenW交替占主导地位。总体发病率中位数为0.6/100,000，从2009年的0.6/100,000增加到2014年的0.8/100,000，后来在2019年下降到0.4/100,000。MenB的中间发生率，血清群C（MenC）和Y（MenY）分别为0.25/100,000，<0.01/100,000和<0.01/100,000。MenW发病率中位数为0.53/100,000，从2009年的0.01/100,000上升至2014年的0.56/100,000，随后在2019年持续下降至0.12。婴儿,<5岁的儿童和≥60岁的成年人受影响最大，发病率中位数为9.7、0.9和0.93，2019年分别降至1.3、0.1和0.1/10万。整体CFR中位数为19%，MenB为7.5％，MenW为24.5％。MCV-ACWY摄取中位数为93%结论：总体IMD，自2015年MCV-ACWY引入后，MenW病例和发病率有所下降，而MenB,MenC和MenY一直稳定。所有年龄组的MenW发病率均下降，包括未免疫的婴儿和60岁以上的人。需要进一步的分析和更长时间的观察才能对这种流行病学趋势得出更有力的结论。到2019年，CFR仍然很高。
IMD病例，每10万居民的累计发病率，CFR,和疫苗接种的吸收进行了描述。数据来自公共卫生研究所和NIP。
2009-2014年期间，IMD病例总体有所增加，其次是2015-2019年的下降，主要集中在婴儿，儿童<5岁，人≥60岁。血清群B（MenB）和MenW交替占主导地位。总体发病率中位数为0.6/100,000，从2009年的0.6/100,000增加到2014年的0.8/100,000，后来在2019年下降到0.4/100,000。MenB的中间发生率，血清群C（MenC）和Y（MenY）分别为0.25/100,000，<0.01/100,000和<0.01/100,000。MenW发病率中位数为0.53/100,000，从2009年的0.01/100,000上升至2014年的0.56/100,000，随后在2019年持续下降至0.12。婴儿,<5岁的儿童和≥60岁的成年人受影响最大，发病率中位数为9.7、0.9和0.93，2019年分别降至1.3、0.1和0.1/10万。整体CFR中位数为19%，MenB为7.5％，MenW为24.5％。MCV-ACWY摄取中位数为93%结论：总体IMD，自2015年MCV-ACWY引入后，MenW病例和发病率有所下降，而MenB,MenC和MenY一直稳定。所有年龄组的MenW发病率均下降，包括未免疫的婴儿和60岁以上的人。需要进一步的分析和更长时间的观察才能对这种流行病学趋势得出更有力的结论。到2019年，CFR仍然很高。
