61 research outputs found
Patient and Provider Perspectives on How Trust Influences Maternal Vaccine Acceptance Among Pregnant Women in Kenya
Background Pregnant women and newborns are at high risk for infectious diseases. Altered immunity status during pregnancy and challenges fully vaccinating newborns contribute to this medical reality. Maternal immunization is a strategy to protect pregnant women and their newborns. This study aimed to find out how patient-provider relationships affect maternal vaccine uptake, particularly in the context of a lower middle- income country where limited research in this area exists. Methods We conducted semi-structured, in-depth narrative interviews of both providers and pregnant women from four sites in Kenya: Siaya, Nairobi, Mombasa, and Marsabit. Interviews were conducted in either English or one of the local regional languages. Results We found that patient trust in health care providers (HCPs) is integral to vaccine acceptance among pregnant women in Kenya. The HCP-patient relationship is a fiduciary one, whereby the patients’ trusts is primarily rooted in the provider’s social position as a person who is highly educated in matters of health. Furthermore, patient health education and provider attitudes are crucial for reinstating and fostering that trust, especially in cases where trust was impeded by rumors, community myths and misperceptions, and religious and cultural factors. Conclusion Patient trust in providers is a strong facilitator contributing to vaccine acceptance among pregnant women in Kenya. To maintain and increase immunization trust, providers have a critical role in cultivating a positive environment that allows for favorable interactions and patient health education. This includes educating providers on maternal immunizations and enhancing knowledge of effective risk communication tactics in clinical encounters
Implications of gestational age at antenatal care attendance on the successful implementation of a maternal respiratory syncytial virus (RSV) vaccine program in coastal Kenya
Background: Maternal immunisation to boost respiratory syncytial virus (RSV) specific antibodies in pregnant women is a strategy to enhance infant protection. The timing of maternal vaccination during pregnancy may be critical for its effectiveness. However, Kenya has no documented published data on gestational age distribution of pregnant women attending antenatal care (ANC), or the proportion of women attending ANC during the proposed window period for vaccination, to inform appropriate timing for delivery or estimate potential uptake of this vaccine. Methods: A cross-sectional survey was conducted within the Kilifi Health and Demographic Surveillance System (KHDSS), coastal Kenya. A simple random sample of 1000 women who had registered pregnant in 2017 to 2018 and with a birth outcome by the time of data collection was taken. The selected women were followed at their homes, and individually written informed consent was obtained. Records of their antenatal attendance during pregnancy were abstracted from their ANC booklet. The proportion of all pregnant women from KHDSS (55%) who attended for one or more ANC in 2018 was used to estimate vaccine coverage. Results: Of the 1000 women selected, 935 were traced with 607/935 (64.9%) available for interview, among whom 470/607 (77.4%) had antenatal care booklets. The median maternal age during pregnancy was 28.6 years. The median (interquartile range) gestational age in weeks at the first to fifth ANC attendance was 26 (21–28), 29 (26–32), 32 (28–34), 34 (32–36) and 36 (34–38), respectively. The proportion of women attending for ANC during a gestational age window for vaccination of 28–32 weeks (recommended), 26–33 weeks and 24–36 weeks was 76.6% (360/470), 84.5% (397/470) and 96.2% (452/470), respectively. Estimated vaccine coverage was 42.1, 46.5 and 52.9% within the narrow, wide and wider gestational age windows, respectively. Conclusions: In a random sample of pregnant women from Kilifi HDSS, Coastal Kenya with card-confirmed ANC clinic attendance, 76.6% would be reached for maternal RSV vaccination within the gestational age window of 28–32 weeks. Widening the vaccination window (26–33 weeks) or (24–36 weeks) would not dramatically increase vaccine coverage and would require consideration of antibody kinetics data that could affect vaccine efficacy
Elevated anti-Zta IgG levels and EBV viral load are associated with site of tumor presentation in endemic Burkitt's lymphoma patients: a case control study
<p>Abstract</p> <p>Background</p> <p>Endemic Burkitt's lymphoma (BL) is an extranodal tumor appearing predominantly in the jaw in younger children while abdominal tumors predominate with increasing age. Previous studies have identified elevated levels of antibodies to <it>Plasmodium falciparum </it>schizont extracts and Epstein-Barr virus (EBV) viral capsid antigens (VCA) in endemic BL relative to malaria exposed controls. However, these studies have neither determined if there were any differences based on the site of clinical presentation of the tumor nor examined a broader panel of EBV and <it>P. falciparum </it>antigens.</p> <p>Methods</p> <p>We used a suspension bead Luminex assay to measure the IgG levels against EBV antigens, VCA, EAd, EBNA-1 and Zta as well as <it>P. falciparum </it>MSP-1, LSA-1, and AMA-1 antigens in children with BL (n = 32) and in population-based age-and sex-matched controls (n = 25) from a malaria endemic region in Western Kenya with high incidence of BL. EBV viral load in plasma was determined by quantitative PCR.</p> <p>Results</p> <p>Relative to healthy controls, BL patients had significantly increased anti-Zta (<it>p </it>= 0.0017) and VCA IgG levels (<it>p </it>< 0.0001) and plasma EBV viral loads (<it>p </it>< 0.0001). In contrast, comparable IgG levels to all <it>P. falciparum </it>antigens tested were observed in BL patients compared to controls. Interestingly, when we grouped BL patients into those presenting with abdominal tumors or with jaw tumors, we observed significantly higher levels of anti-Zta IgG levels (<it>p </it>< 0.0065) and plasma EBV viral loads (<it>p </it>< 0.033) in patients with abdominal tumors compared to patients with jaw tumors.</p> <p>Conclusion</p> <p>Elevated antibodies to Zta and elevated plasma EBV viral load could be relevant biomarkers for BL and could also be used to confirm BL presenting in the abdominal region.</p
Rhinovirus dynamics across different social structures
Rhinoviruses (RV), common human respiratory viruses, exhibit significant antigenic diversity, yet their dynamics across distinct social structures remain poorly understood. Our study delves into RV dynamics within Kenya by analysing VP4/2 sequences across four different social structures: households, a public primary school, outpatient clinics in the Kilifi Health and Demographics Surveillance System (HDSS), and countrywide hospital admissions and outpatients. The study revealed the greatest diversity of RV infections at the countrywide level (114 types), followed by the Kilifi HDSS (78 types), the school (47 types), and households (40 types), cumulatively representing >90% of all known RV types. Notably, RV diversity correlated directly with the size of the population under observation, and several RV type variants occasionally fuelled RV infection waves. Our findings highlight the critical role of social structures in shaping RV dynamics, information that can be leveraged to enhance public health strategies. Future research should incorporate whole-genome analysis to understand fine-scale evolution across various social structures
Efficiency of transplacental transfer of respiratory syncytial virus (RSV) specific antibodies among pregnant women in Kenya
Background: Maternal immunisation to boost respiratory syncytial virus (RSV) antibodies in pregnant women, is a strategy being considered to enhance infant protection from severe RSV associated disease. However, little is known about the efficiency of transplacental transfer of RSV-specific antibodies in a setting with a high burden of malaria and HIV, to guide the implementation of such a vaccination program.
Methods: Using a plaque reduction neutralization assay, we screened 400 pairs of cord and maternal serum specimens from pregnant women for RSV-specific antibodies. Participants were pregnant women of two surveillance cohorts: 200 participants from a hospital cohort in Kilifi, Coastal Kenya and 200 participants from a surveillance cohort in Siaya, Western Kenya. Transplacental transfer efficiency was determined by the cord to maternal titre ratio (CMTR). Logistic regression was used to determine independent predictors of impaired transplacental transfer of RSV-specific antibodies.
Results: A total of 800 samples were screened from the 400 participants. At enrollment the median age was 25 years (Interquartile range (IQR): 21-31). Overall, transplacental transfer was efficient and did not differ between Kilifi and Siaya cohort (1.02 vs. 1.02; p=0.946) but was significantly reduced among HIV-infected mothers compared to HIV-uninfected mothers (mean CMTR: 0.98 vs 1.03; p=0.015). Prematurity <33 weeks gestation (Odds ratio [OR]: 0.23, 95% confidence interval [CI] 0.06–0.85; p=0.028), low birth weight <2.5 kgs (OR: 0.25, 95% CI: 0.07–0.94; p=0.041) and HIV infection (OR: 0.47, 95% CI:0.23-0.98; p=0.045) reduced efficiency of transplacental transfer among these women.
Conclusions: Transplacental transfer of RSV-specific antibodies among pregnant women in Kenya is efficient. A consideration to integrate other preventive interventions with maternal RSV vaccination targeting infants born premature (<33 weeks gestation), with low birth weight <2.5 kgs, or HIV-infected mothers is likely to improve vaccine outcomes in this setting
Provider perspectives on demand creation for maternal vaccines in Kenya [version 1; referees: 2 approved]
Background. Expansion of maternal immunization, which offers some of the most effective protection against morbidity and mortality in pregnant women and neonates, requires broad acceptance by healthcare providers and their patients. We aimed to describe issues surrounding acceptance and demand creation for maternal vaccines in Kenya from a provider perspective. Methods. Nurses and clinical officers were recruited for semi-structured interviews covering resources for vaccine delivery, patient education, knowledge and attitudes surrounding maternal vaccines, and opportunities for demand creation for new vaccines. Interviews were conducted in English and Swahili, transcribed verbatim from audio recordings, and analyzed using codes developed from interview guide questions and emergent themes. Results. Providers expressed favorable attitudes about currently available maternal immunizations and introduction of additional vaccines, viewing themselves as primarily responsible for vaccine promotion and patient education. The importance of educational resources for both patients and providers to maintain high levels of maternal immunization coverage was a common theme. Most identified barriers to vaccine acceptance and delivery were cultural and systematic in nature. Suggestions for improvement included improved patient and provider education, including material resources, and community engagement through religious and cultural leaders. Conclusions. The distribution of standardized, evidence-based print materials for patient education may reduce provider overwork and facilitate in-clinic efforts to inform women about maternal vaccines. Continuing education for providers should address communication surrounding current vaccines and those under consideration for introduction into routine schedules. Engagement of religious and community leaders, as well as male decision-makers in the household, will enhance future acceptance of maternal vaccines
Respiratory syncytial virus seasonality in three epidemiological zones of Kenya
Understanding respiratory syncytial virus (RSV) circulation patterns is necessary to guide the timing of limited‐duration interventions such as vaccines. We describe RSV circulation over multiple seasons in three distinct counties of Kenya during 2006‐2018. Kilifi and Siaya counties each had consistent but distinct RSV seasonality, lasting on average 18‐22 weeks. Based on data from available years, RSV did not have a clear pattern of circulation in Nairobi. This information can help guide the timing of vaccines and immunoprophylaxis products that are under development
Evaluation of case definitions to detect respiratory syncytial virus infection in hospitalized children below 5 years in Rural Western Kenya, 2009–2013
Malaria infection and severe disease risks in Africa
The relationship between community prevalence of Plasmodium falciparum and the burden of severe, life-threatening disease remains poorly defined. To examine the three most common severe malaria phenotypes from catchment populations across East Africa, we assembled a dataset of 6506 hospital admissions for malaria in children aged 3 months to 9 years from 2006 to 2020. Admissions were paired with data from community parasite infection surveys. A Bayesian procedure was used to calibrate uncertainties in exposure (parasite prevalence) and outcomes (severe malaria phenotypes). Each 25% increase in prevalence conferred a doubling of severe malaria admission rates. Severe malaria remains a burden predominantly among young children (3 to 59 months) across a wide range of community prevalence typical of East Africa. This study offers a quantitative framework for linking malaria parasite prevalence and severe disease outcomes in children
Malaria hospitalisation in East Africa: age, phenotype and transmission intensity.
BACKGROUND: Understanding the age patterns of disease is necessary to target interventions to maximise cost-effective impact. New malaria chemoprevention and vaccine initiatives target young children attending routine immunisation services. Here we explore the relationships between age and severity of malaria hospitalisation versus malaria transmission intensity. METHODS: Clinical data from 21 surveillance hospitals in East Africa were reviewed. Malaria admissions aged 1 month to 14 years from discrete administrative areas since 2006 were identified. Each site-time period was matched to a model estimated community-based age-corrected parasite prevalence to provide predictions of prevalence in childhood (PfPR2-10). Admission with all-cause malaria, severe malaria anaemia (SMA), respiratory distress (RD) and cerebral malaria (CM) were analysed as means and predicted probabilities from Bayesian generalised mixed models. RESULTS: 52,684 malaria admissions aged 1 month to 14 years were described at 21 hospitals from 49 site-time locations where PfPR2-10 varied from < 1 to 48.7%. Twelve site-time periods were described as low transmission (PfPR2-10 < 5%), five low-moderate transmission (PfPR2-10 5-9%), 20 moderate transmission (PfPR2-10 10-29%) and 12 high transmission (PfPR2-10 ≥ 30%). The majority of malaria admissions were below 5 years of age (69-85%) and rare among children aged 10-14 years (0.7-5.4%) across all transmission settings. The mean age of all-cause malaria hospitalisation was 49.5 months (95% CI 45.1, 55.4) under low transmission compared with 34.1 months (95% CI 30.4, 38.3) at high transmission, with similar trends for each severe malaria phenotype. CM presented among older children at a mean of 48.7 months compared with 39.0 months and 33.7 months for SMA and RD, respectively. In moderate and high transmission settings, 34% and 42% of the children were aged between 2 and 23 months and so within the age range targeted by chemoprevention or vaccines. CONCLUSIONS: Targeting chemoprevention or vaccination programmes to areas where community-based parasite prevalence is ≥10% is likely to match the age ranges covered by interventions (e.g. intermittent presumptive treatment in infancy to children aged 2-23 months and current vaccine age eligibility and duration of efficacy) and the age ranges of highest disease burden
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