54 research outputs found

    Population Impact and Effectiveness of Monovalent Rotavirus Vaccination in Urban Malawian Children 3 Years After Vaccine Introduction: Ecological and Case-Control Analyses.

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    BACKGROUND: Rotavirus vaccines have been introduced in many low-income African countries including Malawi in 2012. Despite early evidence of vaccine impact, determining persistence of protection beyond infancy, the utility of the vaccine against specific rotavirus genotypes, and effectiveness in vulnerable subgroups is important. METHODS: We compared rotavirus prevalence in diarrheal stool and hospitalization incidence before and following rotavirus vaccine introduction in Malawi. Using case-control analysis, we derived vaccine effectiveness (VE) in the second year of life and for human immunodeficiency virus (HIV)-exposed and stunted children. RESULTS: Rotavirus prevalence declined concurrent with increasing vaccine coverage, and in 2015 was 24% compared with prevaccine mean baseline in 1997-2011 of 32%. Since vaccine introduction, population rotavirus hospitalization incidence declined in infants by 54.2% (95% confidence interval [CI], 32.8-68.8), but did not fall in older children. Comparing 241 rotavirus cases with 692 test-negative controls, VE was 70.6% (95% CI, 33.6%-87.0%) and 31.7% (95% CI, -140.6% to 80.6%) in the first and second year of life, respectively, whereas mean age of rotavirus cases increased from 9.3 to 11.8 months. Despite higher VE against G1P[8] than against other genotypes, no resurgence of nonvaccine genotypes has occurred. VE did not differ significantly by nutritional status (78.1% [95% CI, 5.6%-94.9%] in 257 well-nourished and 27.8% [95% CI, -99.5% to 73.9%] in 205 stunted children;P= .12), or by HIV exposure (60.5% [95% CI, 13.3%-82.0%] in 745 HIV-unexposed and 42.2% [95% CI, -106.9% to 83.8%] in 174 exposed children;P= .91). CONCLUSIONS: Rotavirus vaccination in Malawi has resulted in reductions in disease burden in infants <12 months, but not in older children. Despite differences in genotype-specific VE, no genotype has emerged to suggest vaccine escape. VE was not demonstrably affected by HIV exposure or stunting

    Plasma Rotavirus-specific IgA and Risk of Rotavirus Vaccine Failure in Infants in Malawi

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    BackgroundRotavirus vaccine efficacy is reduced in low-income populations, but efforts to improve vaccine performance are limited by lack of clear correlates of protection. Although plasma rotavirus (RV)-specific immunoglobulin A (IgA) appears strongly associated with protection against rotavirus gastroenteritis in high-income countries, weaker association has been observed in low-income countries. We tested the hypothesis that lower RV-specific IgA is associated with rotavirus vaccine failure in Malawian infants.MethodsIn a case-control study, we recruited infants presenting with severe rotavirus gastroenteritis following monovalent oral rotavirus vaccination (RV1 vaccine failures). Conditional logistic regression was used to determine the odds of rotavirus seronegativity (RV-specific IgA ResultsIn 116 age-matched pairs, infants with RV1 vaccine failure were more likely to be RV-specific IgA seronegative than controls: odds ratio, 3.1 (95% confidence interval [CI], 1.6-5.9), P=.001. In 60 infants with convalescent serology, 42/45 (93%; 95% CI. 81-98) infants seronegative at baseline became seropositive. Median rise in RV-specific IgA concentration following acute infection was 112.8 (interquartile range, 19.1-380.6)-fold.ConclusionsIn this vaccinated population with high residual burden of rotavirus disease, RV1 vaccine failure was associated with lower RV-specific IgA, providing further evidence of RV-specific IgA as a marker of protection. Robust convalescent RV-specific IgA response in vaccine failures suggests differences in wild-type and vaccine-induced immunity, which informs future vaccine development

    Nonsecretor Histo-blood Group Antigen Phenotype Is Associated With Reduced Risk of Clinical Rotavirus Vaccine Failure in Malawian Infants

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    Background Histo–blood group antigen (HBGA) Lewis/secretor phenotypes predict genotype-specific susceptibility to rotavirus gastroenteritis (RVGE). We tested the hypothesis that nonsecretor/Lewis-negative phenotype leads to reduced vaccine take and lower clinical protection following vaccination with G1P[8] rotavirus vaccine (RV1) in Malawian infants Methods A cohort study recruited infants receiving RV1 at age 6 and 10 weeks. HBGA phenotype was determined by salivary enzyme-linked immunosorbent assay (ELISA). RV1 vaccine virus shedding was detected by quantitative real-time polymerase chain reaction (qRT-PCR) in stool collected on alternate days for 10 days post-immunization. Plasma rotavirus–specific immunoglobulin A was determined by ELISA pre- and post-immunization. In a case-control study, HBGA phenotype distribution was compared between RV1-vaccinated infants with RVGE and 1:1 age-matched community controls. Rotavirus genotype was determined by RT-PCR. Results In 202 cohort participants, neither overall vaccine virus fecal shedding nor seroconversion differed by HBGA phenotype. In 238 case-control infants, nonsecretor phenotype was less common in infants with clinical vaccine failure (odds ratio [OR], 0.39; 95% confidence interval [CI], 0.20–0.75). Nonsecretor phenotype was less common in infants with P[8] RVGE (OR, 0.12; 95% CI, 0.03–0.50) and P[4] RVGE (OR, 0.17; 95% CI, 0.04–0.75). Lewis-negative phenotype was more common in infants with P[6] RVGE (OR, 3.2; 95% CI, 1.4–7.2). Conclusions Nonsecretor phenotype was associated with reduced risk of rotavirus vaccine failure. There was no significant association between HBGA phenotype and vaccine take. These data refute the hypothesis that high prevalence of nonsecretor/Lewis-negative phenotypes contributes to lower rotavirus vaccine effectiveness in Malawi

    Population impact and effectiveness of monovalent rotavirus vaccination in urban Malawian children 3 years after vaccine introduction: ecological and case-control analyses

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    Background. Rotavirus vaccines have been introduced in many low-income African countries including Malawi in 2012. Despite early evidence of vaccine impact, determining persistence of protection beyond infancy, the utility of the vaccine against specific rotavirus genotypes, and effectiveness in vulnerable subgroups is important. Methods. We compared rotavirus prevalence in diarrheal stool and hospitalization incidence before and following rotavirus vaccine introduction in Malawi. Using case-control analysis, we derived vaccine effectiveness (VE) in the second year of life and for human immunodeficiency virus (HIV)–exposed and stunted children. Results. Rotavirus prevalence declined concurrent with increasing vaccine coverage, and in 2015 was 24% compared with prevaccine mean baseline in 1997–2011 of 32%. Since vaccine introduction, population rotavirus hospitalization incidence declined in infants by 54.2% (95% confidence interval [CI], 32.8–68.8), but did not fall in older children. Comparing 241 rotavirus cases with 692 test-negative controls, VE was 70.6% (95% CI, 33.6%–87.0%) and 31.7% (95% CI, −140.6% to 80.6%) in the first and second year of life, respectively, whereas mean age of rotavirus cases increased from 9.3 to 11.8 months. Despite higher VE against G1P[8] than against other genotypes, no resurgence of nonvaccine genotypes has occurred. VE did not differ significantly by nutritional status (78.1% [95% CI, 5.6%–94.9%] in 257 well-nourished and 27.8% [95% CI, −99.5% to 73.9%] in 205 stunted children; P = .12), or by HIV exposure (60.5% [95% CI, 13.3%–82.0%] in 745 HIV-unexposed and 42.2% [95% CI, −106.9% to 83.8%] in 174 exposed children; P = .91). Conclusions. Rotavirus vaccination in Malawi has resulted in reductions in disease burden in infants &lt;12 months, but not in older children. Despite differences in genotype-specific VE, no genotype has emerged to suggest vaccine escape. VE was not demonstrably affected by HIV exposure or stunting

    Confirmed SARS-CoV-2 infection in Scottish neonates 2020-2022:a national, population-based cohort study

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    Objectives: To examine neonates in Scotland aged 0–27 days with SARS-CoV-2 infection confirmed by viral testing; the risk of confirmed neonatal infection by maternal and infant characteristics; and hospital admissions associated with confirmed neonatal infections. Design: Population-based cohort study. Setting and population: All live births in Scotland, 1 March 2020–31 January 2022. Results: There were 141 neonates with confirmed SARS-CoV-2 infection over the study period, giving an overall infection rate of 153 per 100 000 live births (141/92 009, 0.15%). Among infants born to women with confirmed infection around the time of birth, the confirmed neonatal infection rate was 1812 per 100 000 live births (15/828, 1.8%). Two-thirds (92/141, 65.2%) of neonates with confirmed infection had an associated admission to neonatal or (more commonly) paediatric care. Six of these babies (6/92, 6.5%) were admitted to neonatal and/or paediatric intensive care; however, none of these six had COVID-19 recorded as their main diagnosis. There were no neonatal deaths among babies with confirmed infection. Implications and relevance: Confirmed neonatal SARS-CoV-2 infection was uncommon over the first 23 months of the pandemic in Scotland. Secular trends in the neonatal confirmed infection rate broadly followed those seen in the general population, although at a lower level. Maternal confirmed infection at birth was associated with an increased risk of neonatal confirmed infection. Two-thirds of neonates with confirmed infection had an associated admission to hospital, with resulting implications for the baby, family and services, although their outcomes were generally good. Ascertainment of confirmed infection depends on the extent of testing, and this is likely to have varied over time and between groups: the extent of unconfirmed infection is inevitably unknown

    Studying the Long-term Impact of COVID-19 in Kids (SLICK). Healthcare use and costs in children and young people following community-acquired SARS-CoV-2 infection:protocol for an observational study using linked primary and secondary routinely collected healthcare data from England, Scotland and Wales

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    IntroductionSARS-CoV-2 infection rarely causes hospitalisation in children and young people (CYP), but mild or asymptomatic infections are common. Persistent symptoms following infection have been reported in CYP but subsequent healthcare use is unclear. We aim to describe healthcare use in CYP following community-acquired SARS-CoV-2 infection and identify those at risk of ongoing healthcare needs.Methods and analysisWe will use anonymised individual-level, population-scale national data linking demographics, comorbidities, primary and secondary care use and mortality between 1 January 2019 and 1 May 2022. SARS-CoV-2 test data will be linked from 1 January 2020 to 1 May 2022. Analyses will use Trusted Research Environments: OpenSAFELY in England, Secure Anonymised Information Linkage (SAIL) Databank in Wales and Early Pandemic Evaluation and Enhanced Surveillance of COVID-19 in Scotland (EAVE-II). CYP aged ≥4 and &lt;18 years who underwent SARS-CoV-2 reverse transcription PCR (RT-PCR) testing between 1 January 2020 and 1 May 2021 and those untested CYP will be examined.The primary outcome measure is cumulative healthcare cost over 12 months following SARS-CoV-2 testing, stratified into primary or secondary care, and physical or mental healthcare. We will estimate the burden of healthcare use attributable to SARS-CoV-2 infections in the 12 months after testing using a matched cohort study of RT-PCR positive, negative or untested CYP matched on testing date, with adjustment for confounders. We will identify factors associated with higher healthcare needs in the 12 months following SARS-CoV-2 infection using an unmatched cohort of RT-PCR positive CYP. Multivariable logistic regression and machine learning approaches will identify risk factors for high healthcare use and characterise patterns of healthcare use post infection.Ethics and disseminationThis study was approved by the South-Central Oxford C Health Research Authority Ethics Committee (13/SC/0149). Findings will be preprinted and published in peer-reviewed journals. Analysis code and code lists will be available through public GitHub repositories and OpenCodelists with meta-data via HDR-UK Innovation Gateway

    Clinical characteristics of children and young people admitted to hospital with covid-19 in United Kingdom: prospective multicentre observational cohort study.

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    OBJECTIVE: To characterise the clinical features of children and young people admitted to hospital with laboratory confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in the UK and explore factors associated with admission to critical care, mortality, and development of multisystem inflammatory syndrome in children and adolescents temporarily related to coronavirus disease 2019 (covid-19) (MIS-C). DESIGN: Prospective observational cohort study with rapid data gathering and near real time analysis. SETTING: 260 hospitals in England, Wales, and Scotland between 17 January and 3 July 2020, with a minimum follow-up time of two weeks (to 17 July 2020). PARTICIPANTS: 651 children and young people aged less than 19 years admitted to 138 hospitals and enrolled into the International Severe Acute Respiratory and emergency Infections Consortium (ISARIC) WHO Clinical Characterisation Protocol UK study with laboratory confirmed SARS-CoV-2. MAIN OUTCOME MEASURES: Admission to critical care (high dependency or intensive care), in-hospital mortality, or meeting the WHO preliminary case definition for MIS-C. RESULTS: Median age was 4.6 (interquartile range 0.3-13.7) years, 35% (225/651) were under 12 months old, and 56% (367/650) were male. 57% (330/576) were white, 12% (67/576) South Asian, and 10% (56/576) black. 42% (276/651) had at least one recorded comorbidity. A systemic mucocutaneous-enteric cluster of symptoms was identified, which encompassed the symptoms for the WHO MIS-C criteria. 18% (116/632) of children were admitted to critical care. On multivariable analysis, this was associated with age under 1 month (odds ratio 3.21, 95% confidence interval 1.36 to 7.66; P=0.008), age 10-14 years (3.23, 1.55 to 6.99; P=0.002), and black ethnicity (2.82, 1.41 to 5.57; P=0.003). Six (1%) of 627 patients died in hospital, all of whom had profound comorbidity. 11% (52/456) met the WHO MIS-C criteria, with the first patient developing symptoms in mid-March. Children meeting MIS-C criteria were older (median age 10.7 (8.3-14.1) v 1.6 (0.2-12.9) years; P<0.001) and more likely to be of non-white ethnicity (64% (29/45) v 42% (148/355); P=0.004). Children with MIS-C were five times more likely to be admitted to critical care (73% (38/52) v 15% (62/404); P<0.001). In addition to the WHO criteria, children with MIS-C were more likely to present with fatigue (51% (24/47) v 28% (86/302); P=0.004), headache (34% (16/47) v 10% (26/263); P<0.001), myalgia (34% (15/44) v 8% (21/270); P<0.001), sore throat (30% (14/47) v (12% (34/284); P=0.003), and lymphadenopathy (20% (9/46) v 3% (10/318); P<0.001) and to have a platelet count of less than 150 × 109/L (32% (16/50) v 11% (38/348); P<0.001) than children who did not have MIS-C. No deaths occurred in the MIS-C group. CONCLUSIONS: Children and young people have less severe acute covid-19 than adults. A systemic mucocutaneous-enteric symptom cluster was also identified in acute cases that shares features with MIS-C. This study provides additional evidence for refining the WHO MIS-C preliminary case definition. Children meeting the MIS-C criteria have different demographic and clinical features depending on whether they have acute SARS-CoV-2 infection (polymerase chain reaction positive) or are post-acute (antibody positive). STUDY REGISTRATION: ISRCTN66726260

    Duration and Density of Fecal Rotavirus Shedding in Vaccinated Malawian Children With Rotavirus Gastroenteritis.

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    Quantifying rotavirus shedding among vaccinated individuals will aid understanding of vaccine indirect effects. Serial stool samples were collected from 196 children who presented with rotavirus gastroenteritis to health facilities in Blantyre, Malawi, and were tested for rotavirus using a VP6 semi-quantitative, real-time polymerase chain reaction. The median duration of fecal shedding was 28 days (95% CI, 19-28). The median copy numbers for peak shedding were 1.99 × 107 (interquartile range, 3.39 × 106 to 6.37 × 107). The fecal viral load was positively associated with disease severity and negatively associated with serum anti-rotavirus immunoglobin A. High and persistent rotavirus shedding among vaccinated children with breakthrough disease may contribute to ongoing transmission in this setting

    Improving care pathways for children with severe illness through implementation of the ASPIRE mHealth primary ETAT package in Malawi

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    Providing emergency care in low resource settings relies on delivery by lower cadres of health workers (LCHW). We describe the development, implementation and mixed methods evaluation of a mobile health (mHealth) triage algorithm based on the WHO Emergency, Triage, Assessment, and Treatment (ETAT) for primary-level care. We conducted an observational study design of implementation research. Key stakeholders were engaged throughout implementation. Clinicians and LCHW at eight primary health centres in Blantyre district were trained to use an mHealth algorithm for triage. An mHealth patient surveillance system monitored patients from presentation through referral to tertiary and final outcome. A total of 209,174 children were recorded by ETAT between April 2017 and September 2018, and 155,931 had both recorded mHealth and clinician triage outcome data. Concordance between mHealth triage by lower cadres of HCW and clinician assessment was 81·6% (95% CI [81·4, 81·8]) over all outcomes (kappa: 0·535 (95% CI [0·530, 0·539]). Concordance for mHealth emergency triage was 0.31 with kappa 0.42. The most common mHealth recorded emergency sign was breathing difficulty (74·1% 95% CI [70·1, 77·9]) and priority sign was raised temperature (76·2% (95% CI [75·9, 76·6]). A total of 1,644 referrals out of 3,004 (54·7%) successfully reached the tertiary site. Both providers and carers expressed high levels of satisfaction with the mHealth ETAT pathway. An mHealth triage algorithm can be used by LCHWs with moderate concordance with clinician triage. Implementation of ETAT through an mHealth algorithm documented successful referrals from primary to tertiary, but half of referred patients did not reach the tertiary site. Potential harms of such systems, such as cases requiring referral being missed during triage, require further evaluation. The ASPIRE mHealth primary ETAT approach can be used to prioritise acute illness and support future resource planning within both district and national health system

    Infrequent Transmission of Monovalent Human Rotavirus Vaccine Virus to Household Contacts of Vaccinated Infants in Malawi

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    Horizontal transmission of rotavirus vaccine virus may contribute to indirect effects of rotavirus vaccine, but data are lacking from low-income countries. Serial stool samples were obtained from Malawian infants who received 2 doses of monovalent human rotavirus vaccine (RV1) (days 4, 6, 8, and 10 after vaccination) and from their household contacts (8-10 days after vaccine). RV1 vaccine virus in stool was detected using semiquantitative real-time reverse-transcription polymerase chain reaction. RV1 fecal shedding was detected in 41 of 60 vaccinated infants (68%) and in 2 of 147 household contacts (1.4%). Horizontal transmission of vaccine virus within households is unlikely to make a major contribution to RV1 indirect effects in Malawi
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