Development and evaluation of low-volume tests to detect and characterize antibodies to SARS-CoV-2.

Low-volume antibody assays can be used to track SARS-CoV-2 infection rates in settings where active testing for virus is limited and remote sampling is optimal. We developed 12 ELISAs detecting total or antibody isotypes to SARS-CoV-2 nucleocapsid, spike protein or its receptor binding domain (RBD), 3 anti-RBD isotype specific luciferase immunoprecipitation system (LIPS) assays and a novel Spike-RBD bridging LIPS total-antibody assay. We utilized pre-pandemic (n=984) and confirmed/suspected recent COVID-19 sera taken pre-vaccination rollout in 2020 (n=269). Assays measuring total antibody discriminated best between pre-pandemic and COVID-19 sera and were selected for diagnostic evaluation. In the blind evaluation, two of these assays (Spike Pan ELISA and Spike-RBD Bridging LIPS assay) demonstrated >97% specificity and >92% sensitivity for samples from COVID-19 patients taken >21 days post symptom onset or PCR test. These assays offered better sensitivity for the detection of COVID-19 cases than a commercial assay which requires 100-fold larger serum volumes. This study demonstrates that low-volume in-house antibody assays can provide good diagnostic performance, and highlights the importance of using well-characterized samples and controls for all stages of assay development and evaluation. These cost-effective assays may be particularly useful for seroprevalence studies in low and middle-income countries.

Contacts and behaviours of university students during the COVID-19 pandemic at the start of the 2020/2021 academic year.

University students have unique living, learning and social arrangements which may have implications for infectious disease transmission. To address this data gap, we created CONQUEST (COroNavirus QUESTionnaire), a longitudinal online survey of contacts, behaviour, and COVID-19 symptoms for University of Bristol (UoB) staff/students. Here, we analyse results from 740 students providing 1261 unique records from the start of the 2020/2021 academic year (14/09/2020-01/11/2020), where COVID-19 outbreaks led to the self-isolation of all students in some halls of residences. Although most students reported lower daily contacts than in pre-COVID-19 studies, there was heterogeneity, with some reporting many (median = 2, mean = 6.1, standard deviation = 15.0; 8% had ≥ 20 contacts). Around 40% of students' contacts were with individuals external to the university, indicating potential for transmission to non-students/staff. Only 61% of those reporting cardinal symptoms in the past week self-isolated, although 99% with a positive COVID-19 test during the 2 weeks before survey completion had self-isolated within the last week. Some students who self-isolated had many contacts (mean = 4.3, standard deviation = 10.6). Our results provide context to the COVID-19 outbreaks seen in universities and are available for modelling future outbreaks and informing policy.

Attitudes of Pregnant Women and Healthcare Professionals Toward Clinical Trials and Routine Implementation of Antenatal Vaccination Against Respiratory Syncytial Virus: A Multicenter Questionnaire Study.

INTRODUCTION: Respiratory syncytial virus (RSV) is a common cause of infant hospitalization and mortality. With multiple vaccines in development, we aimed to determine: (1) the awareness of RSV among pregnant women and healthcare professionals (HCPs), and (2) attitudes toward clinical trials and routine implementation of antenatal RSV vaccination. METHODS: Separate questionnaires for pregnant women and HCPs were distributed within 4 hospitals in South England (July 2017-January 2018). RESULTS: Responses from 314 pregnant women and 204 HCPs (18% obstetricians, 75% midwives, 7% unknown) were analyzed. Most pregnant women (88%) and midwives (66%) had no/very little awareness of RSV, unlike obstetricians (14%). Among pregnant women, 29% and 75% would likely accept RSV vaccination as part of a trial, or if routinely recommended, respectively. Younger women (16-24 years), those of 21-30 weeks' gestation, and with experience of RSV were significantly more likely to participate in trials [odds ratio (OR): 1.42 (1.72-9.86); OR: 2.29 (1.22-4.31); OR: 9.07 (1.62-50.86), respectively]. White-British women and those of 21-30 weeks' gestation were more likely to accept routinely recommended vaccination [OR: 2.16 (1.07-4.13); OR: 2.10 (1.07-4.13)]. Obstetricians were more likely than midwives to support clinical trials [92% vs. 68%, OR: 2.50 (1.01-6.16)] and routine RSV vaccination [89% vs. 79%, OR: 4.08 (1.53-9.81)], as were those with prior knowledge of RSV, and who deemed it serious. CONCLUSIONS: RSV awareness is low among pregnant women and midwives. Education will be required to support successful implementation of routine antenatal vaccination. Research is needed to understand reasons for vaccine hesitancy among pregnant women and HCPs, particularly midwives.

Determinants of Influenza and Pertussis Vaccination Uptake in Pregnancy: A Multicenter Questionnaire Study of Pregnant Women and Healthcare Professionals.

INTRODUCTION: Uptake rates of antenatal vaccination remain suboptimal. Our aims were to determine (1) the acceptability of routine vaccination among pregnant women, (2) the confidence of maternity healthcare professionals (HCPs) discussing vaccination and (3) HCP opinion regarding the optimum healthcare site for vaccine administration. METHODS: Separate questionnaires for pregnant women and HCPs were distributed within 4 national health service (NHS) trusts in South England (July 2017 to January 2018). RESULTS: Responses from 314 pregnant women and 204 HCPs (18% obstetricians, 75% midwives, 7% unidentified) were analyzed. Previous/intended uptake of influenza and pertussis vaccination was 78% and 92%, respectively. The commonest reason for declining vaccination was feared side effects for their child. White British women (79%) were significantly more accepting of influenza [85% vs. 61%; odds ratio (OR) 3.25; 95% confidence interval [CI], 1.67-6.32] and pertussis vaccination (96% vs. 83%; OR 4.83; 95% CI: 1.77-13.19) compared with nonwhite British women. Among HCPs, 25% were slightly or not at all confident discussing vaccination. Obstetricians felt significantly more confident discussing pertussis vaccination than midwives (68% vs. 55% were very/moderately confident; OR 2.05; 95% CI: 1.02-4.12). Among HCPs, 53%, 25% and 16% thought vaccines should be administered in primary care (general practice), community midwifery and in hospital, respectively. CONCLUSION: Misconceptions exist regarding safety/efficacy of antenatal vaccination, and framing information towards the child's safety may increase uptake. Education of HCPs is essential, and vaccine promotion should be incorporated into routine antenatal care, with an emphasis on women from ethnic minorities. Administration of vaccines in primary care presents logistical barriers; however, support for alternative sites appears low among HCPs.

Think about the 'C' (in custard and crackers).

CASE HISTORY: A 9-year-old girl with autistic spectrum disorder (ASD) was admitted for a flare-up of chronic recurrent multi-osteomyelitis (CRMO). She complained of leg pain over 3 months, was unable to weight-bear and had a petechial rash for 10 days. She had bleeding gums and a long history of only eating custard and crackers.CRMO was diagnosed at age 3. She'd had shoulder, knee, and ankle involvement, two courses of pamidronate (2011 and 2015) and was currently taking simple analgesia.On examination, she was afebrile, with a widespread petechial rash, most pronounced over her ankles/shins. Her knees and ankles were tender; her ankles had small medial effusions. INVESTIGATIONS: Mild hypochromic anaemia, normal platelets, white cell countand coagulation. CRP 16. Figures 1 and 2 show her knee radiograph and MRI, respectively.edpract;103/6/304/F1F1F1Figure 1edpract;103/6/304/F2F2F2Figure 2 QUESTION 1: Give four differential diagnoses of petechial rash, bleeding gums and leg pain in an afebrile child? QUESTION 2: Name three behaviours associated with ASD with health consequences. Answers to the questions are on page 02 ANSWERS TO THE QUESTIONS ON PAGE 02.

Influenza and humidity--Why a bit more damp may be good for you!

Influenza viruses cause much winter-time morbidity and death in temperate regions. We still do not understand why 'flu is more common in winter. Since the 1960s, investigators have studied the role of relative humidity and temperature on viral survival, transmission and infection rates but results have demonstrated only inconclusive trends. Over the past few years however, a series of exciting studies have instead focussed on absolute humidity and demonstrated highly significant correlations with viral survival and transmission rates in both laboratory and epidemiological models. Here we review the evidence for a causal association between absolute humidity and 'flu transmission and outline how this could lead to a new approach to curbing this and perhaps other viral epidemics in the winter months.

Streptococcus pneumoniae carriage prevalence in Nepal: evaluation of a method for delayed transport of samples from remote regions and implications for vaccine implementation.

BACKGROUND: Pneumococcal disease is a significant cause of morbidity and mortality in young children in Nepal, and currently available pneumococcal conjugate vaccines offer moderate coverage of invasive disease isolates. METHODS: A prevalence study of children aged 1.5 to 24 months in urban and rural Nepal was conducted. In the urban group, nasopharyngeal swabs (NPS) were transported using silica desiccant packages (SDP) with delayed processing (2 weeks), or skim-milk-tryptone-glucose-glycerin (STGG) with immediate processing (within 8 hours). Pneumococcal nasopharyngeal carriage prevalence, serogroup/type distribution and isolate genotypes (as defined by multilocus sequence typing) were determined. RESULTS: 1101 children were enrolled into the study: 574 in the urban group and 527 in the rural group. Overall carriage prevalence based on culture from specimens transported and stored in STGG was 58.7% (337/574), compared to 40.9% (235/574) in SDP. There was concordance of detection of pneumococcus in 67% of samples. Using the SDP method, pneumococcal carriage prevalence was higher in the rural population (69.2%; 364/526) compared to the urban population (40.9%; 235/574). Serogroup/type distribution varied with geographical location. Over half of the genotypes identified in both the urban and rural pneumococcal populations were novel. CONCLUSION: The combination of delayed culture and transport using SDP underestimates the prevalence of pneumococcal carriage; however, in remote areas, this method could still provide a useful estimate of carriage prevalence and serogroup/type distribution. Vaccine impact is unpredictable in a setting with novel genotypes and limited serotype coverage as described here. Consequently, continued surveillance of pneumococcal isolates from carriage and disease in Nepali children following the planned introduction of pneumococcal conjugate vaccines introduction will be essential.

Evaluation of haemophilus influenzae type b vaccine for routine immunization in Nepali infants.

BACKGROUND: Haemophilus influenzae type b (Hib) carriage and disease studies in Nepali children suggest a significant burden of infection. Hib conjugate vaccines (HibCV) do not have uniform immunogenicity between populations. We determined the immunogenicity of HibCV in Nepali infants, before its introduction into the routine immunization schedule. METHODS: Ninety infants recruited at Patan Hospital, Kathmandu, received 3 doses of the HibCV with routine immunizations (diphtheria, tetanus, whole cell pertussis-hepatitis B vaccine + oral polio vaccine) at 6, 10 and 14 weeks of age, and a HibCV booster at 52 weeks. Anti-polyribosylribitol phosphate (PRP) concentrations were measured at 18, 52 and 56 weeks, and the antibody persistence at 52 weeks was compared with antibody values in unimmunized controls (n = 30). RESULTS: After 3 doses of primary immunizations, at 18 weeks of age (n = 74), all infants had anti-PRP concentrations above the accepted thresholds for short- and long-term protection (0.15 and 1.0 µg/mL, respectively). At 1 year of age, before administration of the booster of HibCV, the anti-PRP geometric mean antibody concentration was 2.76 µg/mL (confidence interval: 1.88-4.07) in sera from the immunized children compared with 0.11 µg/mL (95% confidence interval: 0.08-0.17) in the nonimmunized control group (n = 30). Twenty-seven percent (20/74) of participants, however, had anti-PRP concentrations <1.0 µg/mL. Four weeks after the booster dose of HibCV, 98.5% of infants had anti-PRP concentrations above 1.0 µg/mL. CONCLUSION: Immunization with HibCV given as part of the Expanded Program on Immunization schedule in Nepal elicits robust antibody responses. Though the antibody wanes during the first year of life, most 1-year-old infants remain protected and respond robustly to a booster dose of the vaccine.