SEROPROTECTION RATE OF HAEMOPHILUS INFLUENZAE TYPE B CONJUGATE VACCINE AND ASSOCIATED CLINICAL OUTCOMES AMONG NIGERIAN CHILDREN AGED 6 TO 23 MONTHS.

Introduction: Haemophilus influenzae type b (Hib) causes invasive infections almost exclusively in under- fives with those aged 6-23 months being the most vulnerable. In Nigeria, it is estimated to cause nearly 400,000 annual infections and another 30,000 under-five mortality attributable to pneumonia and meningitis alone. The Hib Conjugate Vaccine (HCV) is in widespread use to combat these devastating infections. Data on its impact in Nigeria is grossly scanty. This study evaluated the seroprotection rates (SPR) of HCV and associated clinical outcomes among children aged 6-23 months in Obi L.G.A. of Nasarawa State, Nigeria. Methods: A cross-sectional study of 267 children aged 6-23 months who had completed three doses of HCV. They were enrolled via a two-staged household-level cluster sampling. Relevant sociodemographic and clinical data were obtained using structured questionnaires and serum samples collected were analysed serologically for antipolyribosylribitol phosphate (anti-PRP) antibodies using ELISA. Results: The overall SPRs against invasive Hib disease and Hib nasopharyngeal colonization were 74.2% and 26.2%, respectively. The overall geometric mean titre (GMT) of anti-PRP was 1.85 µg/mL (95%CI: 1.60-2.14) and across age groups, GMTs were >1 µg/mL-the threshold for long-term protection against invasive Hib disease. Rates/duration of healthcare admissions and average episodes of probable Hib disease syndromes were lower in seroprotected but not statistically different from non-seroprotected children. Conclusion: The demonstrated anti-PRP titres and Seroprotection Rates infer a very good HCV efficacy in Nigerian children. The lack of significant difference in clinical outcomes may be attributable to nonspecificity.

FACTORS INFLUENCING ANTI-POLYRIBOSYLRIBITOL PHOSPHATE TITRES IN YOUNG NIGERIAN CHILDREN PRIMED WITH DTWP-HEPB-HIB VACCINE.

Introduction: Recent research suggests that variation in vaccine-induced immune responses is influenced by genetic, nutritional, environmental, and vaccine-related factors, with significant vaccine design and programmatic policy implications. Haemophilus influenzae type b (Hib) Conjugate Vaccine (HCV) stimulates the production of antiPolyribosylribitol phosphate (anti-PRP) antibodies, which confer long-term protection against invasive Hib disease and nasopharyngeal colonization by Hib at titre levels ≥1µg/mL and ≥5µg/mL respectively. This study investigated the influence of these factors on the protective anti-PRP levels in children aged 6-23 months in Obi L.G.A. of Nasarawa State, Nigeria. Methods: The study was a cross-sectional, two-stage household-level cluster survey involving 267 children who had completed the E.P.I. schedule of HCV-containing DTwP-HepB-Hib. Validated questionnaires were used for enrolment and relevant clinical and laboratory evaluations including anti-PRP, ABO/Rhesus antigens, and Haemoglobin genotype assays were conducted. Regression analyses were performed using Stata to explore the correlation between sociodemographic/vaccine-related factors, nutritional status, genotype, ABO/Rhesus antigens, and protective anti-PRP titres. Results: Bivariate analysis showed that age, breastfeeding practice, household size/under-five number, nutritional, socioeconomic, Measles/Yellow fever vaccination, and Rhesus statuses were significantly associated with anti-PRP titre. However, multivariate analysis revealed that age between 6-11 months (AOR=3.12,95%CI=1.15-8.50), households with less than three under-fives (AOR=2.33,95%CI=1.14-4.78), middle socioeconomic class (AOR=3.15,95%CI=1.42-6.98), wasting (AOR=2.27,95%CI=1.23-4.22) and Measles/Yellow fever vaccination (AOR=2.90,95%CI=1.38-6.07) were significantly correlated with protective anti-PRP titres. Conclusion: Results indicate that the family and socioeconomic milieu influence anti-PRP titre, and Measles/Yellow fever vaccines may have a beneficial non-specific effect on HCV-induced seroprotection in Nigerian children.

Clinical profile and Predictors of Outcomes of Hospitalized Patients with Laboratory-Confirmed Severe Acute Respiratory Syndrome Coronavirus 2 in Nigeria: A Retrospective Analysis of 13 High Burden States in Nigeria.

Background: The majority of global COVID deaths have occurred in developed countries. Not much is known about the clinical outcomes for the patients admitted with COVID in Nigeria. We thus described the clinical characteristics, outcomes, and predictors of outcomes of hospitalized Nigerian COVID-19 patients. Methodology: We performed multilevel and mixed effects regression, Kaplan-Meir survival, and Cox proportionate hazards analyses to evaluate factors associated with death in patients admitted for COVID-19 in 13 high-burden states of Nigeria between 25th February 2020 and 30th August 2021. Results: Of the 3462 patients (median age, 40 years (interquartile range 28 years 54 years), 2,990(60.6%) were male and, 213(6.15%) of them died while on admission. Male sex (adjusted odds ratio [aOR], 1.78 [95% confidence interval {CI}, 1.23-2.56]), age group 45-65 years (OR, 3.93 [95% CI, 1.29-12.02]), age group 66-75 years (aOR, 5.37 [95% CI, 1.68-17.14]), age group > 75 years (aOR, 6.81 [95% CI, 2.04-22.82]), chronic cardiac disease (aOR, 3.07 [95% CI, 1.20-7.86]), being diabetic (aOR, 2.16 [95% CI, 1.41-3.31]), and having chronic kidney disease (OR, 11.01 [95% CI, 2.74-44.24]),were strongly associated with increased odds of death. Having concurrent malaria (aOR, 0.45 [95% CI, 0.16-1.28]), use of Azithromycin for treatment (aOR, 0.33 [95% CI, 0.19-0.54]), and use of Chloroquine/Hydroxychloroquine for treatment (aOR, 0.07 [95% CI, 0.03-0.14]) were significantly associated with decreased odds of death. Conclusions: The cumulative probability of death of male patients, diabetics, hypertensives, and patients with CKD was higher than that of female patients and those without those comorbidities while concurrent malaria and use of chloroquine/hydroxychloroquine in the treatment regimen were associated with a decreased risk of dying in patients treated in our isolation centers.

Tertiary prevention and treatment of rheumatic heart disease: a National Heart, Lung, and Blood Institute working group summary.

Although entirely preventable, rheumatic heart disease (RHD), a disease of poverty and social disadvantage resulting in high morbidity and mortality, remains an ever-present burden in low-income and middle-income countries (LMICs) and rural, remote, marginalised and disenfranchised populations within high-income countries. In late 2021, the National Heart, Lung, and Blood Institute convened a workshop to explore the current state of science, to identify basic science and clinical research priorities to support RHD eradication efforts worldwide. This was done through the inclusion of multidisciplinary global experts, including cardiovascular and non-cardiovascular specialists as well as health policy and health economics experts, many of whom also represented or closely worked with patient-family organisations and local governments. This report summarises findings from one of the four working groups, the Tertiary Prevention Working Group, that was charged with assessing the management of late complications of RHD, including surgical interventions for patients with RHD. Due to the high prevalence of RHD in LMICs, particular emphasis was made on gaining a better understanding of needs in the field from the perspectives of the patient, community, provider, health system and policy-maker. We outline priorities to support the development, and implementation of accessible, affordable and sustainable interventions in low-resource settings to manage RHD and related complications. These priorities and other interventions need to be adapted to and driven by local contexts and integrated into health systems to best meet the needs of local communities.

Research opportunities for the primary prevention and management of acute rheumatic fever and rheumatic heart disease: a National Heart, Lung, and Blood Institute workshop report.

Primary prevention of acute rheumatic fever (ARF) and rheumatic heart disease (RHD) encompasses the timely diagnosis and adequate treatment of the superficial group A Streptococcus (GAS) infections pharyngitis and impetigo. GAS is the only known inciting agent in the pathophysiology of the disease. However, sufficient evidence indicates that the uptake and delivery of primary prevention approaches in RHD-endemic regions are significantly suboptimal. This report presents expert deliberations on priority research and implementation opportunities for primary prevention of ARF/RHD that were developed as part of a workshop convened by the US National Heart, Lung, and Blood Institute in November 2021. The opportunities identified by the Primary Prevention Working Group encompass epidemiological, laboratory, clinical, implementation and dissemination research domains and are anchored on five pillars including: (A) to gain a better understanding of superficial GAS infection epidemiology to guide programmes and policies; (B) to improve diagnosis of superficial GAS infections in RHD endemic settings; (C) to develop scalable and sustainable models for delivery of primary prevention; (D) to understand potential downstream effects of the scale-up of primary prevention and (E) to develop and conduct economic evaluations of primary prevention strategies in RHD endemic settings. In view of the multisectoral stakeholders in primary prevention strategies, we emphasise the need for community co-design and government engagement, especially in the implementation and dissemination research arena. We present these opportunities as a reference point for research organisations and sponsors who aim to contribute to the increasing momentum towards the global control and prevention of RHD.

COVID-19 Subclinical Infection and Immunity: A Review.

The aetiologic agent of COVID-19 is a novel coronavirus, SARS-CoV-2. Like other coronaviruses, it generally induces enteric and respiratory diseases in animals and humans. COVID-19 may be subclinical, and symptomatic, ranging from mild-to-severe disease. The spectrum of presentation is the result of several factors ranging from the inoculum size, inherent host susceptibility, possible cross-reacting circulating antibodies. Subclinical viral infections are associated with widespread community transmission and in some cases like Polio, herd immunity. An understanding of the biology and immune behavior in subclinical coronavirus disease 2019 (COVID-19) might be useful in the quest for vaccine development as well as the current control efforts against the COVID-19 pandemic. We carried out a narrative review of the available literature on the biology, etiopathogenesis, clinical manifestation of SARS-CoV-2 viral infection, focusing on our current understanding of the disease mechanisms and its clinical manifestation, and the host immune response to the infection. We also highlighted some of the research gaps regarding subclinical infection in COVID-19 and its potential application for vaccine development and other preventive efforts toward containing the current COVID-19 pandemic.

Head Circumference of Babies at Birth in Nigeria.

BACKGROUND AND OBJECTIVES: Measuring head circumference (HC) of newborns is an important tool for evaluating intra-uterine brain development. HC reference charts currently in use in Nigeria are not representative of the local population. We thus present locally derived HC reference data for Nigerian infants at birth. SUBJECTS AND METHODS: We reviewed birth records of all infants at the Jos University Teaching Hospital (JUTH) over a 10 year period from January 2006. JUTH is a tertiary care center offering obstetric services to a large population of women in Jos and its environs. All births with gestational age between 28 and 42 weeks were included in the study. STATA version 14 was used to calculate gestational age associated HC percentile measurements. RESULTS: We included 18 282 babies to generate the reference values. The mean HC value was 34.4 ± 2.1 cm (M = 34.6 ± 2.16 cm, F = 34.1 ± 2.02 cm, p < 0.001). Our HC reference values significantly differ from the USA and INTERGROWTH-21 charts currently in use in our country. Mean HC was higher in male infants compared with female infants. This difference was uniformly so across all gestational age groups. CONCLUSIONS: The use of our locally derived HC reference values could be more appropriate in defining normal head growth in Nigerian infant populations thereby improving newborn care.