Comparison of static and dynamic models of maternal immunization to prevent infant pertussis in Brazil

BackgroundThis paper compares cost-effectiveness results from two models of maternal immunization to prevent pertussis in infants in Brazil, one static, one dynamic, to explore when static models are adequate for public health decisions and when the extra effort required by dynamic models is worthwhile.MethodsWe defined two scenarios to explore key differences between static and dynamic models, herd immunity and time horizon. Scenario 1 evaluates the incremental cost/DALY of maternal acellular pertussis (aP) immunization as routine infant vaccination coverage ranges from low/moderate up to, and above, the threshold at which herd immunity begins to eliminate pertussis. Scenario 2 compares cost-effectiveness estimates over the models’ different time horizons. Maternal vaccine prices of $9.55/dose (base case) and $1/dose were evaluated.ResultsThe dynamic model shows that maternal immunization could be cost-saving as well as life-saving at low levels of infant vaccination coverage. When infant coverage reaches the threshold range (90–95%), it is expensive: the dynamic model estimates that maternal immunization costs $2 million/DALY at infant coverage > 95% and maternal vaccine price of $9.55/dose; at $1/dose, cost/DALY is $200,000. By contrast, the static model estimates costs/DALY only modestly higher at high than at low infant coverage. When the models’ estimates over their different time horizons are compared at infant coverage < 90–95%, their projections fall in the same range.ConclusionsStatic models may serve to explore an intervention’s cost-effectiveness against infectious disease: the direction and principal drivers of change were the same in both models. When, however, an intervention too small to have significant herd immunity effects itself, such as maternal aP immunization, takes place against a background of vaccination in the rest of the population, a dynamic model is crucial to accurate estimates of cost-effectiveness. This finding is particularly important in the context of widely varying routine infant vaccination rates globally.Clinical Trial registryClinical Trial registry name and registration number: Not applicable.     

Cost-effectiveness of strategies for preventing paediatric lower respiratory infections associated with respiratory syncytial virus in eight Chinese cities

BackgroundNew monoclonal antibodies (mAbs) and vaccines against RSV with promising efficacy and protection duration are expected to be available in the near future. We evaluated the cost-effectiveness of the administration of maternal immunisation (MI), infant mAb (IA) and paediatric immunisation (PI) as well as their combinations in eight Chinese cities.MethodsWe used a static model to estimate the impact of these preventive interventions on reducing the burden of RSV-ALRI in twelve monthly birth cohorts from a societal perspective. In addition to year-round administration, we also considered seasonal administration of MI and IA (i.e., administered only to children born in selected months). The primary outcome was threshold strategy cost (TSC), defined as the maximum costs per child for a strategy to be cost-effective.ResultsWith a willingness-to-pay threshold of one national GDP per capita per QALY gained for all the cities, TSC of year-round strategies was: (i) US$2.4 (95% CI: 1.9-3.4) to US$14.7 (11.6-21.4) for MI; (ii) US$19.9 (16.9-25.9) to US$144.2 (124.6-184.7) for IA; (iii) US$28.7 (22.0-42.0) to US$201.0 (156.5-298.6) for PI; (iv) US$31.1 (24.0-45.5) to US$220.7 (172.0-327.3) for maternal plus paediatric immunisation (MPI); and (v) US$41.3 (32.6-58.9) to US$306.2 (244.1-441.3) for infant mAb plus paediatric immunisation (AP). In all cities, the top ten seasonal strategies (ranked by TSC) protected infants from 5 or fewer monthly birth cohorts.ConclusionsAdministration of these interventions could be cost-effective if they are suitably priced. Suitably-timed seasonal administration could be more cost-effective than their year-round counterpart. Our results can inform the optimal strategy once these preventive interventions are commercially available.     

改良新产程模式管理硬膜外麻醉无痛分娩产程对母婴结局的影响

目的探讨应用改良新产程模式管理硬膜外麻醉无痛分娩产程对母婴结局的影响。方法选取2018年1月-2020年2月在长春市妇产医院自愿行硬膜外麻醉无痛分娩的单胎初产足月妊娠产妇220例为研究对象,随机分为观察组和对照组,每组各110例。观察组产妇应用改良新产程模式管理无痛分娩,对照组产妇应用新产程模式管理产程无痛分娩。观察两种产程管理模式管理产程对母婴结局影响。结果观察组产妇潜伏期、加速期及第二产程时间均较对照组明显缩短,差异均有统计学意义(均P<0.01)。两组产妇剖宫产率和产后出血率比较,差异无统计学意义(P>0.05)。观察组产妇阴道助产率明显低于对照组,差异有统计学意义(P<0.05)。观察组产妇产后出血量明显少于对照组,差异有统计学意义(P<0.05)。观察组新生儿脐动脉血pH值<7.2比例低于对照组,差异有统计学意义(P<0.05)。结论采用改良新产程模式管理的硬膜外麻醉无痛分娩产妇产程时限明显缩短,阴道助产率降低,产后出血量明显减少,新生儿脐动脉血pH值<7.2比例明显降低,因此改良新产程模式管理产程,可有效保证母婴安全。     

Impact of maternal and pre-existing antibodies on immunogenicity of inactivated rotavirus vaccines

Rotavirus (RV) is a major pathogen causing severe diarrhea in infants and children aged less than 5 years. Vaccination is an economically feasible and effective strategy to prevent rotavirus infections. However, immune efficacy of live vaccines could be interfered by maternal antibodies and pre-existing antibodies of children. To develop an inactivated rotavirus vaccine (IRV), we had previously isolated a wild-type human rotavirus strain ZTR-68-A (G1P[8]) from the fecal samples of infants having severe diarrhea in a region endemic for the presence of this pathogen. In our present study, we assessed whether the presence of maternal and pre-existing antibodies in newborn BALB/c mice affected the immunogenicity of IRV administered to these animals. Our results indicate that maternal antibodies, generated from either vaccine immunization or rotavirus infection, showed partial influence with the immune responses generated by two doses of IRV vaccination. Increasing the number of immunizations can significantly improve the titer of serum neutralizing antibody and a seroconversion rate of up to 100%. In newborn mice, single-virus infection did not elicit detectable levels of serum neutralizing antibodies. After an IRV vaccination, the immune responses of these mice remained unaffected, with no significant differences in titers compared with those of control-group mice. In summary, choosing a suitable immunization dose and dosing frequency is essential for the immune effectiveness of IRV. The results of this study will provide animal experimental support for the IRV clinical research in future.     

Factors influencing birth weight in newborns of diabetic and non-diabetic women a population based study

Maternal diabetes is known to be related to an increase in birth weight of the offspring. However, the mechanism of the association is not entirely clear. In addition, the contribution of the demographic, obstetric and metabolic factors to birth weight in diabetic mothers is not well defined. All the diabetic women (68 requiring insulin-treatment and 403 on diet alone) and a random sample of 1 in 12 of all non-diabetic women (893 women) who delivered in one regional hospital between March 1987 and June 1988 inclusive, were included in the study. Tests for gestational diabetes are routinely performed in our pregnant women population, thus, the study is a population based one. The mean birth weight of infants of diabetic mothers adjusted for gestational age was higher than in those of non-diabetic mothers. However, no relationship was found between maternal glycosylated hemoglobin measured at delivery and the infants birth weight. Furthermore, at each week of gestation, infants born to diabetic mothers were heavier than the infants of non-diabetic mothers (for weeks 37 to 40, p < 0.05), while no differences were found in glycosylated hemoglobin levels between the two groups at any time. In a multivariate model we showed that after controlling for gestational age, the only factors which independently and significantly affected birth weight in our population were diabetes, ethnic origin, and the parity of the mother. Our findings support the possibility that substances which induce hyperinsulinemia, other than glucose, may be related to the higher birth weight of infants of diabetic mothers.     

重庆市孕产妇死亡监测工作调查分析

本文对重庆市１９８６～１９９７年孕产妇死亡变化规律进行了初步分析,对监测工作中存在的主要问题提出以下建议：加大质控力度、降低漏报;提高社区保健服务能力,尤其是加强基层保健医师的培训;社区保健人员应加强与计生部门的合作,以利于计划怀孕妇女的发现与管理。     

获取母血中纯化胎儿有核红细胞行产前基因分析

目的　探讨获取母血中纯化胎儿细胞的有效方法。方法　对 6 0名孕龄 7～ 40周、年龄 2 1～ 30岁的孕妇外周血进行不连续密度梯度离心 ,将分离后的细胞进行制片 ,显微镜下行显微操作分离胎儿有核红细胞 ,进行 Y染色体特异性DYZ1基因的聚合酶链反应 (PCR)。结果　 (1)早孕期母血中胎儿 NRBC检出率为 2 0 % ,中孕期母血中胎儿 NRBC检出率为 71.4% ,晚孕期母血中胎儿 NRBC检出率为 6 .6 5 % ,三者之间有显著性差异 (P <0 .0 5 ) ;(2 )用显微操作技术获得的胎儿细胞数量已满足 PCR扩增所需的模板量 ,对胎儿性别进行预测 ,男胎符合率为 11/ 13(84.6 % ) ,性别符合率为 2 6 / 2 8(92 .9% )。结论　不连续密度梯度离心合并显微操作技术对于无创性早期产前基因诊断意义重大。     

Maternal colonization and early-onset neonatal bacterial sepsis in the Gambia,West Africa: a genomic analysis of vertical transmission

ObjectivesTo define bacterial aetiology of neonatal sepsis and estimate the prevalence of neonatal infection from maternal genital tract bacterial carriage among mother-newborn pairs.MethodsWe carried out a cross-sectional study of newborns with clinical sepsis admitted to three hospitals in the Gambia neonatal wards. Neonatal blood cultures and maternal genital swabs were obtained at recruitment. We used whole-genome sequencing to explore vertical transmission for neonates with microbiologically confirmed bloodstream infection by comparing phenotypically-matched paired neonatal blood cultures and maternal genital tract bacterial isolates.ResultsWe enrolled 203 maternal-newborn pairs. Two-thirds (67%; 137/203) of neonates presented with early-onset sepsis (days 0–6 after birth) of which 26% (36/137) were because of a clinically-significant bacterial pathogen. Blood culture isolates from newborns with early-onset sepsis because of Staphylococcus aureus (n = 5), Klebsiella pneumonia (n = 2), and Enterococcus faecalis (n = 1), phenotypically matched their maternal genital tract isolates. Pairwise single-nucleotide variants comparisons showed differences of 12 to 52 single-nucleotide variants only between maternal and newborn S. aureus isolates, presumably representing vertical transmission with a transmission rate of 14% (5/36).ConclusionsWe found a low prevalence of vertical transmission of maternal genital tract colonization in maternal-newborn pairs for early-onset neonatal sepsis in the West African context. Identifying infection acquisition pathways among newborns is essential to prioritize preventive interventions, which could be targeted at the mother or infection control in the hospital environment, depending on the major pathways of transmission.     

Epidemiology of chronic suppurative otitis media and deafness in a rural area and developing an intervention strategy

Of 613 children evaluated in a village in Haryana 94 (15.3%) were observed to have chronic suppurative otitis media (CSOM). Fifty eight (61.7%) children had hearing impairment. CSOM contributed to 71.6% of the hearing impaired (58/81). On analysis of association of CSOM with literacy and socio-economic status of mothers, and age, sex, and upper respiratory tract infections (URI) in children positive correlation was observed only with URIs (P<0.001). Literacy and socio-economic status of the mothers did not correlate significantly with knowledge about treatment seeking, and ear cleaning practices, probably due to the narrow range of incomes and literacy levels. An intervention program consisting of play, demonstrations, health charts and slogans, and aural cleaning and antibiotic drops was introduced.