Last data update: Nov 04, 2024. (Total: 48056 publications since 2009)
Records 1-30 (of 49 Records) |
Query Trace: Greby S[original query] |
---|
Seroprevalence and risk factors for toxoplasma gondii infection in women of reproductive age in Nigeria in 2018
Blackburn D , Mba N , Nwachukwu W , Zhou H , Hill A , Abbott A , Parameswaran N , Awala S , Greby S , Alagi M , Iriemenam NC , Okoye MI , Swaminathan M , Priest JW , Martin D , Straily A , Ihekweazu C . Am J Trop Med Hyg 2024 Congenital transmission of Toxoplasma gondii can occur when a woman becomes infected for the first time during or just before pregnancy. Toxoplasma gondii in the fetus can lead to miscarriage, stillbirth, ocular or neurological abnormalities at birth, or progressive visual, hearing, motor, and cognitive deficiencies. The national seroprevalence of T. gondii infection in Nigeria was previously unknown. The 2018 Nigeria HIV/AIDS Indicator and Impact Survey collected demographic, socioeconomic, and HIV-related data and stored blood specimens with consent for future analysis for other pathogens of public health importance. We evaluated toxoplasmosis seropositivity and risk factors in a sample of 44,269 women of reproductive age (WRA) between 15 and 44 years. The national T. gondii seroprevalence among WRA was 26.8% (95% CI: 25.8-27.7%). We found that WRA from all 36 states and the Federal Capital Territory had T. gondii exposure. Seroprevalence was higher in 25- to 44-year-olds than in 15- to 24-year-olds. A similar proportion of pregnant and nonpregnant women were seropositive. Increased odds of seropositivity were associated with unimproved toilet facilities and drinking water sources, being in a higher wealth quintile, and primary and secondary education compared with no education. Decreased odds of seropositivity were associated with living in an urban area and owning livestock. This study provides the first-ever national seroprevalence estimate for WRA in Nigeria. Although information on known risk factors for toxoplasmosis (e.g., consumption of undercooked meat, cat ownership) was not collected, future studies could further investigate potential risk factors to inform the development of effective toxoplasmosis prevention measures. |
Seroprevalence of poliovirus antibodies in Nigeria: refining strategies to sustain the eradication effort
Bolu O , Adamu U , Franka R , Umeokonkwo CD , An Q , Greby S , McDonald S , Mainou B , Mba N , Agala N , Archer WR , Braka F , Etapelong SG , Gashu TS , Siddique AR , Asekun A , Okoye M , Iriemenam N , Wiesen E , Swaminathan M , Ihekweazu C , Shuaib F . Pan Afr Med J 2023 45 2 INTRODUCTION: in 2016, a switch from trivalent oral poliovirus vaccine (OPV) (containing serotypes 1,2,3) to bivalent OPV (types 1,3) was implemented globally. We assessed the seroprevalence of poliovirus antibody levels in selected Nigerian states, before and after the switch, documented poliovirus type2 outbreak responses conducted and ascertained factors associated with immunity gaps based on seroprevalence rates. METHODS: we conducted a secondary analysis of stored serum samples from the 2018 Nigeria National HIV/AIDS Indicator and Impact Survey. Serum from 1,185 children aged 0-119 months residing in one southern and four northern states were tested for serotype-specific PV neutralizing antibodies; seropositivity was a reciprocal titer ≥8. We conducted regression analysis to determine sociodemographic risk factors associated with low seroprevalence using SAS 9.4. RESULTS: children aged 24-119 months (pre-switch cohort) had seroprevalence against PV1, PV2, and PV3, of 97.3% (95% CI:96.4-98.2), 93.8% (95% CI:92.2-95.5), and 91.3% (95% CI:89.2-93.4), while children aged <24 months (post-switch) had seroprevalence of 86.0% (95% CI:81.2-90.8), 55.6% (95% CI: 47.7-63.4), and 77.2% (95% CI:71.0-83.4) respectively. Regression analysis showed age <24 months was associated with lower seroprevalence against all PV serotypes, (p<0.0001); females had lower seroprevalence against PV1 (p=0.0184) and PV2 (p=0.0354); northern states lower seroprevalence against PV1 (p=0.0039), while well-water source lower seroprevalence against PV3 (p=0.0288). CONCLUSION: this study showed high seroprevalence rates against PV 1, 2, and 3 in pre-switch children (aged 24-119 months). However, post-switch children (<24 months) had low immunity against PV2 despite outbreak responses. Strategies to increase routine immunization coverage and high-quality polio campaigns can increase immunity against polio virus. |
Schistosomiasis seroprevalence among children aged 0-14 years in Nigeria, 2018
Straily A , Tamunonengiyeofori I , Wiegand RE , Iriemenam NC , Okoye MI , Dawurung AB , Ugboaja NB , Tongha M , Parameswaran N , Greby SM , Alagi M , Akpan NM , Nwachukwu WE , Mba N , Martin DL , Secor WE , Swaminathan M , Adetifa I , Ihekweazu C . Am J Trop Med Hyg 2023 110 (1) 90-97 The first nationally representative, population-based study of schistosomiasis seroprevalence in Nigeria was conducted using blood samples and risk-factor data collected during the 2018 Nigeria HIV/AIDS Indicator and Impact Survey (NAIIS). Schistosomiasis seroprevalence was estimated by analyzing samples for reactivity to schistosome soluble egg antigen (SEA) in a multiplex bead assay; NAIIS survey data were assessed to identify potential risk factors for seropositivity. The SEA antibody data were available for 31,459 children aged 0 to 14 years. Overall seroprevalence was 17.2% (95% CI: 16.3-18.1%). Seropositive children were identified in every age group, including children < 5 years, and seroprevalence increased with increasing age (P < 0.0001). Several factors were associated with increased odds of seropositivity, including being a boy (odds ratio [OR] = 1.34, 95% CI: 1.24-1.45), living in a rural area (OR = 2.2, 95% CI: 1.9-2.5), and animal ownership (OR = 1.67, 95% CI: 1.52-1.85). Access to improved sanitation and drinking water sources were associated with decreased odds of seropositivity (OR = 0.52, 95% CI: 0.47-0.58 and OR = 0.53, 95% CI: 0.47-0.60, respectively) regardless of whether the child lived in a rural (sanitation: adjusted odds ratio [aOR] = 0.7, 95% CI: 0.6-0.8; drinking water: aOR = 0.7, 95% CI: 0.6-0.8) or urban area (sanitation: aOR = 0.6, 95% CI: 0.5-0.7; drinking water: aOR = 0.5, 95% CI: 0.4-0.6), highlighting the importance of these factors for schistosomiasis prevention and control. These results identified additional risk populations (children < 5 years) and a new risk factor (animal ownership) and could be used to monitor the impact of control programs. |
Dynamics of IgG antibody response against Plasmodium antigens among Nigerian infants and young children
Leonard CM , Uhomoibhi P , Abubakar A , Ogunniyi A , Mba N , Greby SM , Okoye MI , Iriemenam NC , Ihekweazu C , Steinhardt L , Rogier E . Front Immunol 2023 14 1208822 BACKGROUND: Plasmodium falciparum malaria is a leading cause of child mortality in Nigeria. Neonates are born with maternal antibodies from placental transfer which may protect against malaria infection in the first months of life. The IgG dynamics of the transition from passively transferred antimalarial antibodies to actively acquired IgG from natural exposure have not been well elucidated. METHODS: Blood samples collected during a 2018 Nigeria nationwide HIV/AIDS household survey were available for 9,443 children under 5 years of age, with a subset of infants under 2 months of age having maternal samples available (n=41). Samples were assayed for the P. falciparum HRP2 antigen and anti-malarial IgG antibodies. LOESS regression examined the dynamics in IgG response in the first 5 years of life. Correlation with maternal IgG levels was assessed for mother/child pairs. RESULTS: Consistent decreases were observed in median IgG levels against all Plasmodium spp. antigen targets for the first months of life. At a population level, P. falciparum apical membrane antigen-1 (AMA1) and merozoite surface protein-1 19kD (PfMSP1) IgG decreased during the first 12 months of life before reaching a nadir, whereas IgGs to other targets only declined for the first 4 months of life. Seropositivity showed a similar decline with the lowest seropositivity against AMA1 and PfMSP1 at 10-12 months, though remaining above 50% during the first 2 years of life in higher transmission areas. No protective association was observed between IgG positivity and P. falciparum infection in infants. Maternal antibody levels showed a strong positive correlation with infant antibody levels for all P. falciparum antigens from birth to 2 months of age, but this correlation was lost by 6 months of age. DISCUSSION: Maternally transferred anti-malarial IgG antibodies rapidly decline during the first 6 months of life, with variations among specific antigens and malaria transmission intensity. From 3-23 months of age, there was a wide range in IgG levels for the blood-stage antigens indicating high individual variation in antibody production as children are infected with malaria. Non-falciparum species-specific antigens showed similar patterns in waning immunity and correlation with paired mother's IgG levels compared to P. falciparum antigens. |
Treponemal antibody seroprevalence using a multiplex bead assay from samples collected during the 2018 Nigeria HIV/AIDS indicator and impact survey: Searching for yaws in Nigeria
Guagliardo SAJ , Parameswaran N , Agala N , Abubakar A , Cooley G , Ye T , Kamb M , Mba N , William N , Greby S , Iriemenam N , Alagi M , Okoye M , Martin D . Am J Trop Med Hyg 2023 108 (5) 977-980 Yaws is a chronic, relapsing disease of skin, bone, and cartilage caused by Treponema pallidum subsp. pertenue. Yaws was last reported in Nigeria in 1996, although neighboring countries have recently reported cases. We investigated serological evidence for yaws among children aged 0-14 years in Nigeria by measuring antibodies to the treponemal antigens rp17 and TmpA in blood specimens from a 2018 nationally representative HIV survey using a multiplex bead assay. The presence of antibodies to both antigens ("double positive") likely reflects current or recent treponemal infection. Overall, 1.9% (610/31,549) of children had anti-TmpA antibodies, 1.5% (476/31,549) had anti-rp17 antibodies, and 0.1% (39/31,549) were double positive. Among households, 0.5% (84/18,021) had a double-positive child, with a clustering of double-positive children. Although numbers are low, identification of antibodies to both TmpA and rp17 may warrant investigation, including more granular epidemiologic and clinical data, to assess the potential for continuing yaws transmission in Nigerian children. |
Prevalence of influenza-specific vaccination hesitancy among adults in the United States, 2018
Srivastav A , Lu PJ , Amaya A , Dever JA , Stanley M , Franks JL , Scanlon PJ , Fisher AM , Greby SM , Nguyen KH , Black CL . Vaccine 2023 41 (15) 2572-2581 BACKGROUND: The role of vaccine hesitancy on influenza vaccination is not clearly understood. Low influenza vaccination coverage in U.S. adults suggests that a multitude of factors may be responsible for under-vaccination or non-vaccination including vaccine hesitancy. Understanding the role of influenza vaccination hesitancy is important for targeted messaging and intervention to increase influenza vaccine confidence and uptake. The objective of this study was to quantify the prevalence of adult influenza vaccination hesitancy (IVH) and examine association of IVH beliefs with sociodemographic factors and early-season influenza vaccination. METHODS: A four-question validated IVH module was included in the 2018 National Internet Flu Survey. Weighted proportions and multivariable logistic regression models were used to identify correlates of IVH beliefs. RESULTS: Overall, 36.9% of adults were hesitant to receive an influenza vaccination; 18.6% expressed concerns about vaccination side effects; 14.8% personally knew someone with serious side effects; and 35.6% reported that their healthcare provider was not the most trusted source of information about influenza vaccinations. Influenza vaccination ranged from 15.3 to 45.2 percentage points lower among adults self-reporting any of the four IVH beliefs. Being female, age 18-49 years, non-Hispanic Black, having high school or lower education, being employed, and not having primary care medical home were associated with hesitancy. CONCLUSIONS: Among the four IVH beliefs studied, being hesitant to receiving influenza vaccination followed by mistrust of healthcare providers were identified as the most influential hesitancy beliefs. Two in five adults in the United States were hesitant to receive an influenza vaccination, and hesitancy was negatively associated with vaccination. This information may assist with targeted interventions, personalized to the individual, to reduce hesitancy and thus improve influenza vaccination acceptance. |
Non-falciparum malaria infection and IgG seroprevalence among children under 15 years in Nigeria, 2018
Herman C , Leonard CM , Uhomoibhi P , Maire M , Moss D , Inyang U , Abubakar A , Ogunniyi A , Mba N , Greby SM , Okoye MI , Iriemenam NC , Maikore I , Steinhardt L , Rogier E . Nat Commun 2023 14 (1) 1360 Plasmodium falciparum (Pf) is the dominant malaria parasite in Nigeria though P. vivax (Pv), P. ovale (Po), and P. malariae (Pm) are also endemic. Blood samples (n = 31,234) were collected from children aged 0-14 years during a 2018 nationwide HIV survey and assayed for Plasmodium antigenemia, Plasmodium DNA, and IgG against Plasmodium MSP1-19 antigens. Of all children, 6.6% were estimated to have Pm infection and 1.4% Po infection with no Pv infections detected. The highest household wealth quintile was strongly protective against infection with Pm (aOR: 0.11, 95% CI: 0.05-0.22) or Po (aOR= 0.01, 0.00-0.10). Overall Pm seroprevalence was 34.2% (95% CI: 33.3-35.2) with lower estimates for Po (12.1%, 11.6-12.5) and Pv (6.3%, 6.0-6.7). Pm seropositivity was detected throughout the country with several local government areas showing >50% seroprevalence. Serological and DNA indicators show widespread exposure of Nigerian children to Pm with lower rates to Po and Pv. |
Effect of Nigeria Presidential Task Force on COVID-19 pandemic, Nigeria
Bolu O , Mustapha B , Ihekweazu C , Muhammad M , Hassan A , Abdulwahab A , Asekun AA , Nsirim R , Okechukwu E , Attah I , Swaminathan M , Greby S , Adebiyi A , Alex-Okoh M , Okwor T , Ilori E , Mba N , Mutah J , Akujobi J , Battah N , Haggai W , Okatubo G , Okigbo A , Castle E , Abubakar I , Akataobi C , Adekunle O , Aliyu SH . Emerg Infect Dis 2022 28 (13) S168-s176 Nigeria had a confirmed case of COVID-19 on February 28, 2020. On March 17, 2020, the Nigerian Government inaugurated the Presidential Task Force (PTF) on COVID-19 to coordinate the country's multisectoral intergovernmental response. The PTF developed the National COVID-19 Multisectoral Pandemic Response Plan as the blueprint for implementing the response plans. The PTF provided funding, coordination, and governance for the public health response and executed resource mobilization and social welfare support, establishing the framework for containment measures and economic reopening. Despite the challenges of a weak healthcare infrastructure, staff shortages, logistic issues, commodity shortages, currency devaluation, and varying state government cooperation, high-level multisectoral PTF coordination contributed to minimizing the effects of the pandemic through early implementation of mitigation efforts, supported by a strong collaborative partnership with bilateral, multilateral, and private-sector organizations. We describe the lessons learned from the PTF COVID-19 for future multisectoral public health response. |
Plasmodium falciparum infection prevalence among children aged 6-59months from independent DHS and HIV surveys: Nigeria, 2018
Oviedo A , Abubakar A , Uhomoibhi P , Maire M , Inyang U , Audu B , Iriemenam NC , Ogunniyi A , Ssekitooleko J , Kalambo JA , Greby SM , Mba N , Swaminathan M , Ihekweazu C , Okoye MI , Rogier E , Steinhardt LC . Sci Rep 2023 13 (1) 1998 Prevalence estimates are critical for malaria programming efforts but generating these from non-malaria surveys is not standard practice. Malaria prevalence estimates for 6-59-month-old Nigerian children were compared between two national household surveys performed simultaneously in 2018: a Demographic and Health Survey (DHS) and the Nigeria HIV/AIDS Indicator and Impact Survey (NAIIS). DHS tested via microscopy (n = 8298) and HRP2-based rapid diagnostic test (RDT, n = 11,351), and NAIIS collected dried blood spots (DBS) which were later tested for histidine-rich protein 2 (HRP2) antigen (n = 8029). National Plasmodium falciparum prevalence was 22.6% (95% CI 21.2- 24.1%) via microscopy and 36.2% (34.6- 37.8%) via RDT according to DHS, and HRP2 antigenemia was 38.3% (36.7-39.9%) by NAIIS DBS. Between the two surveys, significant rank-order correlation occurred for state-level malaria prevalence for RDT (Rho = 0.80, p < 0.001) and microscopy (Rho = 0.75, p < 0.001) versus HRP2. RDT versus HRP2 positivity showed 24 states (64.9%) with overlapping 95% confidence intervals from the two independent surveys. P. falciparum prevalence estimates among 6-59-month-olds in Nigeria were highly concordant from two simultaneous, independently conducted household surveys, regardless of malaria test utilized. This provides evidence for the value of post-hoc laboratory HRP2 detection to leverage non-malaria surveys with similar sampling designs to obtain accurate P. falciparum estimates. |
Comparison of one single-antigen assay and three multi-antigen SARS-CoV-2 IgG assays in Nigeria
Iriemenam NC , Ige FA , Greby SM , Okunoye OO , Uwandu M , Aniedobe M , Nwaiwu SO , Mba N , Okoli M , William NE , Ehoche A , Mpamugo A , Mitchell A , Stafford KA , Thomas AN , Olaleye T , Akinmulero OO , Agala NP , Abubakar AG , Owens A , Gwyn SE , Rogier E , Udhayakumar V , Steinhardt LC , Martin DL , Okoye MI , Audu R . J Clin Virol Plus 2023 3 (1) 100139 OBJECTIVES: Determining an accurate estimate of SARS-CoV-2 seroprevalence has been challenging in African countries where malaria and other pathogens are endemic. We compared the performance of one single-antigen assay and three multi-antigen SARS-CoV-2 IgG assays in a Nigerian population endemic for malaria. METHODS: De-identified plasma specimens from SARS-CoV-2 RT-PCR positive, dried blood spot (DBS) SARS-CoV-2 RT-PCR positive, and pre-pandemic negatives were used to evaluate the performance of the four SARS-CoV-2 assays (Tetracore, SARS2MBA, RightSign, xMAP). RESULTS: Results showed higher sensitivity with the multi-antigen (81% (Tetracore), 96% (SARS2MBA), 85% (xMAP)) versus the single-antigen (RightSign (64%)) SARS-CoV-2 assay. The overall specificities were 98% (Tetracore), 100% (SARS2MBA and RightSign), and 99% (xMAP). When stratified based on <15 days to ≥15 days post-RT-PCR confirmation, the sensitivities increased from 75% to 88.2% for Tetracore; from 93% to 100% for the SARS2MBA; from 58% to 73% for RightSign; and from 83% to 88% for xMAP. With DBS, there was no positive increase after 15-28 days for the three assays (Tetracore, SARS2MBA, and xMAP). CONCLUSION: Multi-antigen assays performed well in Nigeria, even with samples with known malaria reactivity, and might provide more accurate measures of COVID-19 seroprevalence and vaccine efficacy. |
Seroprevalence of SARS-CoV-2 in four states of Nigeria in October 2020: a population-based household survey
Audu RA , Stafford KA , Steinhardt L , Musa ZA , Iriemenam N , Ilori E , Blanco N , Mitchell A , Hamada Y , Moloney M , Iwara E , Abimiku A , Ige FA , William NE , Igumbor E , Ochu C , Omoare AA , Okunoye O , Greby SM , Rangaka MX , Copas A , Dalhatu I , Abubakar I , McCracken S , Alagi M , Mba N , Anthony A , Okoye M , Okoi C , Ezechi OC , Salako BL , Ihekweazu C . PLoS Glob Public Health 2022 2 (6) e0000363 The observed epidemiology of SARS-CoV-2 in sub-Saharan Africa has varied greatly from that in Europe and the United States, with much lower reported incidence. Population-based studies are needed to estimate true cumulative incidence of SARS-CoV-2 to inform public health interventions. This study estimated SARS-CoV-2 seroprevalence in four selected states in Nigeria in October 2020. We implemented a two-stage cluster sample household survey in four Nigerian states (Enugu, Gombe, Lagos, and Nasarawa) to estimate age-stratified prevalence of SARS-CoV-2 antibodies. All individuals in sampled households were eligible for interview, blood draw, and nasal/oropharyngeal swab collection. We additionally tested participants for current/recent malaria infection. Seroprevalence estimates were calculated accounting for the complex survey design. Across all four states, 10,629 (96.5%) of 11,015 interviewed individuals provided blood samples. The seroprevalence of SARS-CoV- 2 antibodies was 25.2% (95% CI 21.8-28.6) in Enugu State, 9.3% (95% CI 7.0-11.5) in Gombe State, 23.3% (95% CI 20.5-26.4) in Lagos State, and 18.0% (95% CI 14.4-21.6) in Nasarawa State. Prevalence of current/recent malaria infection ranged from 2.8% in Lagos to 45.8% in Gombe and was not significantly related to SARS-CoV-2 seroprevalence. The prevalence of active SARS-CoV-2 infection in the four states during the survey period was 0.2% (95% CI 0.1-0.4). Approximately eight months after the first reported COVID-19 case in Nigeria, seroprevalence indicated infection levels 194 times higher than the 24,198 officially reported COVID-19 cases across the four states; however, most of the population remained susceptible to COVID-19 in October 2020. |
Evaluation of accuracy and performance of self-reported HIV and antiretroviral therapy status in the Nigeria AIDS Indicator and Impact Survey (2018)
Jahun I , Ehoche A , Bamidele M , Yakubu A , Bronson M , Dalhatu I , Greby S , Agbakwuru C , Baffa I , Iwara E , Alagi M , Asaolu O , Mukhtar A , Ikpeazu A , Nzelu C , Tapdiyel J , Bassey O , Abimiku A , Patel H , Parekh B , Aliyu S , Aliyu G , Charurat M , Swaminathan M . PLoS One 2022 17 (8) e0273748 BACKGROUND: Data on awareness of HIV status among people living with HIV (PLHIV) are critical to estimating progress toward epidemic control. To ascertain the accuracy of self-reported HIV status and antiretroviral drug (ARV) use in the Nigeria HIV/AIDS Indicator and Impact Survey (NAIIS), we compared self-reported HIV status with HIV rapid diagnostic test (RDT) results and self-reported ARV use with detectable blood ARV levels. METHODS: On the basis of responses and test results, participants were categorized by HIV status and ARV use. Self-reported HIV status and ARV use performance characteristics were determined by estimating sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Proportions and other analyses were weighted to account for complex survey design. RESULTS: During NAIIS, 186,405 participants consented for interview out of which 58,646 reported knowing their HIV status. Of the 959 (weighted, 1.5%) who self-reported being HIV-positive, 849 (92.1%) tested HIV positive and 64 (7.9%) tested HIV negative via RDT and polymerase chain reaction test for discordant positive results. Of the 849 who tested HIV positive, 743 (89.8%) reported using ARV and 72 (10.2%) reported not using ARV. Of 57,687 who self-reported being HIV negative, 686 (1.2%) tested HIV positive via RDT, with ARV biomarkers detected among 195 (25.1%). ARV was detected among 94.5% of those who self-reported using ARV and among 42.0% of those who self-reported not using ARV. Overall, self-reported HIV status had sensitivity of 52.7% (95% confidence interval [CI]: 49.4%-56.0%) with specificity of 99.9% (95% CI: 99.8%-99.9%). Self-reported ARV use had sensitivity of 95.2% (95% CI: 93.6%-96.7%) and specificity of 54.5% (95% CI: 48.8%-70.7%). CONCLUSIONS: Self-reported HIV status and ARV use screening tests were found to be low-validity measures during NAIIS. Laboratory tests to confirm self-reported information may be necessary to determine accurate HIV and clinical status for HIV studies in Nigeria. |
Performance of SARS-CoV-2 Antigens in a Multiplex Bead Assay for Integrated Serological Surveillance of Neglected Tropical and Other Diseases.
Gwyn S , Abubakar A , Akinmulero O , Bergeron E , Blessing UN , Chaitram J , Coughlin MM , Dawurung AB , Dickson FN , Esiekpe M , Evbuomwan E , Greby SM , Iriemenam NC , Kainulainen MH , Naanpoen TA , Napoloen L , Odoh I , Okoye M , Olaleye T , Schuh AJ , Owen SM , Samuel A , Martin DL . Am J Trop Med Hyg 2022 107 (2) 260-7 Serosurveillance can provide estimates of population-level exposure to infectious pathogens and has been used extensively during the COVID-19 pandemic. Simultaneous, serological testing for multiple pathogens can be done using bead-based immunoassays to add value to disease-specific serosurveys. We conducted a validation of four SARS-CoV-2 antigens-full-length spike protein, two receptor binding domain proteins, and the nucleocapsid protein-on our existing multiplex bead assay (MBA) for enteric diseases, malaria, and vaccine preventable diseases. After determining the optimal conditions for coupling the antigens to microsphere beads, the sensitivity and specificity of the assay were determined on two instruments (Luminex-200 and MAGPIX) when testing singly (monoplex) versus combined (multiplex). Sensitivity was assessed using plasma from 87 real-time reverse transcription polymerase chain reaction (rRT-PCR) positive persons collected in March-May of 2020 and ranged from 94.3% to 96.6% for the different testing conditions. Specificity was assessed using 98 plasma specimens collected prior to December 2019 and plasma from 19 rRT-PCR negative persons and ranged from 97.4% to 100%. The positive percent agreement was 93.8% to 97.9% using 48 specimens collected > 21 days post-symptom onset, while the negative percent agreement was ≥ 99% for all antigens. Test performance was similar using monoplex or multiplex testing. Integrating SARS-CoV-2 serology with other diseases of public health interest could add significant value to public health programs that have suffered severe programmatic setbacks during the COVID-19 pandemic. |
Mapping HIV prevalence in Nigeria using small area estimates to develop a targeted HIV intervention strategy
O'Brien-Carelli C , Steuben K , Stafford KA , Aliogo R , Alagi M , Johanns CK , Ibrahim J , Shiraishi R , Ehoche A , Greby S , Dirlikov E , Ibrahim D , Bronson M , Aliyu G , Aliyu S , Dwyer-Lindgren L , Swaminathan M , Duber HC , Charurat M . PLoS One 2022 17 (6) e0268892 OBJECTIVE: Although geographically specific data can help target HIV prevention and treatment strategies, Nigeria relies on national- and state-level estimates for policymaking and intervention planning. We calculated sub-state estimates along the HIV continuum of care in Nigeria. DESIGN: Using data from the Nigeria HIV/AIDS Indicator and Impact Survey (NAIIS) (July-December 2018), we conducted a geospatial analysis estimating three key programmatic indicators: prevalence of HIV infection among adults (aged 15-64 years); antiretroviral therapy (ART) coverage among adults living with HIV; and viral load suppression (VLS) rate among adults living with HIV. METHODS: We used an ensemble modeling method called stacked generalization to analyze available covariates and a geostatistical model to incorporate the output from stacking as well as spatial autocorrelation in the modeled outcomes. Separate models were fitted for each indicator. Finally, we produced raster estimates of each indicator on an approximately 5×5-km grid and estimates at the sub-state/local government area (LGA) and state level. RESULTS: Estimates for all three indicators varied both within and between states. While state-level HIV prevalence ranged from 0.3% (95% uncertainty interval [UI]: 0.3%-0.5%]) to 4.3% (95% UI: 3.7%-4.9%), LGA prevalence ranged from 0.2% (95% UI: 0.1%-0.5%) to 8.5% (95% UI: 5.8%-12.2%). Although the range in ART coverage did not substantially differ at state level (25.6%-76.9%) and LGA level (21.9%-81.9%), the mean absolute difference in ART coverage between LGAs within states was 16.7 percentage points (range, 3.5-38.5 percentage points). States with large differences in ART coverage between LGAs also showed large differences in VLS-regardless of level of effective treatment coverage-indicating that state-level geographic targeting may be insufficient to address coverage gaps. CONCLUSION: Geospatial analysis across the HIV continuum of care can effectively highlight sub-state variation and identify areas that require further attention in order to achieve epidemic control. By generating local estimates, governments, donors, and other implementing partners will be better positioned to conduct targeted interventions and prioritize resource distribution. |
Validation of xMAP SARS-CoV-2 Multi-Antigen IgG assay in Nigeria.
Iriemenam NC , Ige FA , Greby SM , Mpamugo A , Abubakar AG , Dawurung AB , Esiekpe MK , Thomas AN , Okoli MU , Awala SS , Ugboaja BN , Achugbu CC , Odoh I , Nwatu FD , Olaleye T , Akayi L , Akinmulero OO , Dattijo J , Onokevbagbe E , Okunoye O , Mba N , Agala NP , Uwandu M , Aniedobe M , Stafford KA , Abimiku A , Hamada Y , Swaminathan M , Okoye MI , Steinhardt LC , Audu R . PLoS One 2022 17 (4) e0266184 OBJECTIVE: There is a need for reliable serological assays to determine accurate estimates of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence. Most single target antigen assays have shown some limitations in Africa. To assess the performance of a multi-antigen assay, we evaluated a commercially available SARS-CoV-2 Multi-Antigen IgG assay for human coronavirus disease 2019 (COVID-19) in Nigeria. METHODS: Validation of the xMAP SARS-CoV-2 Multi-Antigen IgG assay was carried out using well-characterized SARS-CoV-2 reverse transcription polymerase chain reactive positive (97) and pre-COVID-19 pandemic (86) plasma panels. Cross-reactivity was assessed using pre-COVID-19 pandemic plasma specimens (213) from the 2018 Nigeria HIV/AIDS Indicator and Impact Survey (NAIIS). RESULTS: The overall sensitivity of the xMAP SARS-CoV-2 Multi-Antigen IgG assay was 75.3% [95% CI: 65.8%- 82.8%] and specificity was 99.0% [95% CI: 96.8%- 99.7%]. The sensitivity estimate increased to 83.3% [95% CI: 70.4%- 91.3%] for specimens >14 days post-confirmation of diagnosis. However, using the NAIIS pre-pandemic specimens, the false positivity rate was 1.4% (3/213). CONCLUSIONS: Our results showed overall lower sensitivity and a comparable specificity with the manufacturer's validation. There appears to be less cross-reactivity with NAIIS pre-pandemic COVID-19 specimens using the xMAP SARS-CoV-2 Multi-Antigen IgG assay. In-country SARS-CoV-2 serology assay validation can help guide the best choice of assays in Africa. |
Parental vaccine hesitancy and association with childhood diphtheria, tetanus toxoid, and acellular pertussis; measles, mumps, and rubella; rotavirus; and combined 7-series vaccination
Nguyen KH , Srivastav A , Lindley MC , Fisher A , Kim D , Greby SM , Lee J , Singleton JA . Am J Prev Med 2022 62 (3) 367-376 INTRODUCTION: Parental vaccine hesitancy can be a barrier to routine childhood immunization and contribute to greater risk for vaccine-preventable diseases. This study examines the impact of parental vaccine hesitancy on childhood vaccination rates. METHODS: This study assessed the association of parental vaccine hesitancy on child vaccination coverage with ≥4 doses of diphtheria, tetanus toxoid, and acellular pertussis vaccine; ≥1 dose of measles, mumps, and rubella vaccine; up-to-date rotavirus vaccine; and combined 7-vaccine series coverage for a sample of children aged 19-35 months using data from the 2018 and 2019 National Immunization Survey-Child (N=7,645). Adjusted differences in multivariable analyses of vaccination coverage were estimated among vaccine hesitant and nonhesitant parents and population attributable risk fraction of hesitancy on undervaccination, defined as not being up to date for each vaccine. RESULTS: Almost a quarter of parents reported being vaccine hesitant, with the highest proportion of vaccine hesitancy among parents of children who are non-Hispanic Black (37.0%) or Hispanic (30.1%), mothers with a high school education or less (31.9%), and households living below the poverty level (35.6%). Childhood vaccination coverage for all vaccines was lower for children of hesitant than nonhesitant parents, and the population attributable fraction of hesitancy on undervaccination ranged from 15% to 25%, with the highest percentage for ≥1 dose of measles, mumps, and rubella vaccine. CONCLUSIONS: Parental vaccine hesitancy may contribute up to 25% of undervaccination among children aged 19-35 months. Implementation of strategies to address parental vaccine hesitancy is needed to improve vaccination coverage for children and minimize their risk of vaccine-preventable diseases. |
Validation of Commercial SARS-CoV-2 Immunoassays in a Nigerian Population.
Ige F , Hamada Y , Steinhardt L , Iriemenam NC , Uwandu M , Greby SM , Aniedobe M , Salako BL , Rangaka MX , Abubakar I , Audu R . Microbiol Spectr 2021 9 (2) e0068021 Validated assays are essential for reliable serosurveys; however, most SARS-CoV-2 immunoassays have been validated using specimens from China, Europe, or U.S. populations. We evaluated the performance of five commercial SARS-CoV-2 immunoassays to inform their use in serosurveys in Nigeria. Four semiquantitative enzyme-linked immunosorbent assays (ELISAs) (Euroimmun anti-SARS-CoV-2 nucleocapsid protein [NCP] immunoglobulin G [IgG], Euroimmun spike SARS-CoV-2 IgG, Mologic Omega COVID-19 IgG, Bio-Rad Platelia SARS-CoV-2 Total Ab) and one chemiluminescent microparticle immunoassay (Abbott Architect SARS-CoV-2 IgG) were evaluated. We estimated the analytical performance characteristics using plasma from 100 SARS-CoV-2 PCR-positive patients from varied time points post-PCR confirmation and 100 prepandemic samples (50 HIV positive and 50 hepatitis B positive). The Bio-Rad assay failed the manufacturer-specified validation steps. The Euroimmun NCP, Euroimmun spike, and Mologic assays had sensitivities of 73.7%, 74.4%, and 76.9%, respectively, on samples taken 15 to 58 days after PCR confirmation and specificities of 97%, 100%, and 83.8%, respectively. The Abbott assay had 71.3% sensitivity and 100% specificity on the same panel. Parallel or serial algorithms combining two tests did not substantially improve the sensitivity or specificity. Our results showed lower sensitivity and, for one immunoassay, lower specificity compared to the manufacturers' results and other reported validations. Seroprevalence estimates using these assays might need to be interpreted with caution in Nigeria and similar settings. These findings highlight the importance of in-country validations of SARS-CoV-2 serological assays prior to use to ensure that accurate results are available for public health decision-making to control the COVID-19 pandemic in Africa. IMPORTANCE This study used positive and negative sample panels from Nigeria to test the performance of several commercially available SARS-CoV-2 serological assays. Using these prepandemic and SARS-CoV-2-positive samples, we found much lower levels of sensitivity in four commercially available assays than most assay manufacturer reports and independent evaluations. The use of these assays with suboptimal sensitivity and specificity in Nigeria or countries with population exposure to similar endemic pathogens could lead to a biased estimate of the seroprevalence, over- or underestimating the true disease prevalence, and limit efforts to stop the spread of SARS-CoV-2. It is important to conduct in-country validations of serological SARS-CoV-2 assays prior to their widespread use, especially in countries with limited representation in published assay validations. |
Expanding access to HIV services during the COVID-19 pandemic-Nigeria, 2020.
Boyd AT , Jahun I , Dirlikov E , Greby S , Odafe S , Abdulkadir A , Odeyemi O , Dalhatu I , Ogbanufe O , Abutu A , Asaolu O , Bamidele M , Onyenuobi C , Efuntoye T , Fagbamigbe JO , Ene U , Fagbemi A , Tingir N , Meribe C , Ayo A , Bassey O , Nnadozie O , Boyd MA , Onotu D , Gwamna J , Okoye M , Abrams W , Alagi M , Oladipo A , Williams-Sherlock M , Bachanas P , Chun H , Carpenter D , Miller DA , Ijeoma U , Nwaohiri A , Dakum P , Mensah CO , Aliyu A , Oyeledun B , Okonkwo P , Oko JO , Ikpeazu A , Aliyu G , Ellerbrock T , Swaminathan M . AIDS Res Ther 2021 18 (1) 62 BACKGROUND: To accelerate progress toward the UNAIDS 90-90-90 targets, US Centers for Disease Control and Prevention Nigeria country office (CDC Nigeria) initiated an Antiretroviral Treatment (ART) Surge in 2019 to identify and link 340,000 people living with HIV/AIDS (PLHIV) to ART. Coronavirus disease 2019 (COVID-19) threatened to interrupt ART Surge progress following the detection of the first case in Nigeria in February 2020. To overcome this disruption, CDC Nigeria designed and implemented adapted ART Surge strategies during February-September 2020. METHODS: Adapted ART Surge strategies focused on continuing expansion of HIV services while mitigating COVID-19 transmission. Key strategies included an intensified focus on community-based, rather than facility-based, HIV case-finding; immediate initiation of newly-diagnosed PLHIV on 3-month ART starter packs (first ART dispense of 3 months of ART); expansion of ART distribution through community refill sites; and broadened access to multi-month dispensing (MMD) (3-6 months ART) among PLHIV established in care. State-level weekly data reporting through an Excel-based dashboard and individual PLHIV-level data from the Nigeria National Data Repository facilitated program monitoring. RESULTS: During February-September 2020, the reported number of PLHIV initiating ART per month increased from 11,407 to 25,560, with the proportion found in the community increasing from 59 to 75%. The percentage of newly-identified PLHIV initiating ART with a 3-month ART starter pack increased from 60 to 98%. The percentage of on-time ART refill pick-ups increased from 89 to 100%. The percentage of PLHIV established in care receiving at least 3-month MMD increased from 77 to 93%. Among PLHIV initiating ART, 6-month retention increased from 74 to 92%. CONCLUSIONS: A rapid and flexible HIV program response, focused on reducing facility-based interactions while ensuring delivery of lifesaving ART, was critical in overcoming COVID-19-related service disruptions to expand access to HIV services in Nigeria during the first eight months of the pandemic. High retention on ART among PLHIV initiating treatment indicates immediate MMD in this population may be a sustainable practice. HIV program infrastructure can be leveraged and adapted to respond to the COVID-19 pandemic. |
Optimizing community linkage to care and antiretroviral therapy Initiation: Lessons from the Nigeria HIV/AIDS Indicator and Impact Survey (NAIIS) and their adaptation in Nigeria ART Surge
Jahun I , Said I , El-Imam I , Ehoche A , Dalhatu I , Yakubu A , Greby S , Bronson M , Brown K , Bamidele M , Boyd AT , Bachanas P , Dirlikov E , Agbakwuru C , Abutu A , Williams-Sherlock M , Onotu D , Odafe S , Williams DB , Bassey O , Ogbanufe O , Onyenuobi C , Adeola A , Meribe C , Efuntoye T , Fagbamigbe OJ , Fagbemi A , Ene U , Nguhemen T , Mgbakor I , Alagi M , Asaolu O , Oladipo A , Amafah J , Nzelu C , Dakum P , Mensah C , Aliyu A , Okonkwo P , Oyeledun B , Oko J , Ikpeazu A , Gambo A , Charurat M , Ellerbrock T , Aliyu S , Swaminathan M . PLoS One 2021 16 (9) e0257476 BACKGROUND: Ineffective linkage to care (LTC) is a known challenge for community HIV testing. To overcome this challenge, a robust linkage to care strategy was adopted by the 2018 Nigeria HIV/AIDS Indicator and Impact Survey (NAIIS). The NAIIS linkage to care strategy was further adapted to improve Nigeria's programmatic efforts to achieve the 1st 90 as part of the Nigeria Antiretroviral Therapy (ART) Surge initiative, which also included targeted community testing. In this paper we provide an overview of the NAIIS LTC strategy and describe the impact of this strategy on both the NAIIS and the Surge initiatives. METHODS: The NAIIS collaborated with community-based organizations (CBOs) and deployed mobile health (mHealth) technology with real-time dashboards to manage and optimize community LTC for people living with HIV (PLHIV) diagnosed during the survey. In NAIIS, CBOs' role was to facilitate linkage of identified PLHIV in community to facility of their choice. For the ART Surge, we modified the NAIIS LTC strategy by empowering both CBOs and mobile community teams as responsible for not only active LTC but also for community testing, ART initiation, and retention in care. RESULTS: Of the 2,739 PLHIV 15 years and above identified in NAIIS, 1,975 (72.1%) were either unaware of their HIV-positive status (N = 1890) or were aware of their HIV-positive status but not receiving treatment (N = 85). Of these, 1,342 (67.9%) were linked to care, of which 952 (70.9%) were initiated on ART. Among 1,890 newly diagnosed PLHIV, 1,278 (67.6%) were linked to care, 33.7% self-linked and 66.3% were linked by CBOs. Among 85 known PLHIV not on treatment, 64 (75.3%) were linked; 32.8% self-linked and 67.2% were linked by a CBO. In the ART Surge, LTC and treatment initiation rates were 98% and 100%, respectively. Three-month retention for monthly treatment initiation cohorts improved from 76% to 90% over 6 months. CONCLUSIONS: Active LTC strategies by local CBOs and mobile community teams improved LTC and ART initiation in the ART Surge initiative. The use of mHealth technology resulted in timely and accurate documentation of results in NAIIS. By deploying mHealth in addition to active LTC, CBOs and mobile community teams could effectively scale up ART with real-time documentation of client-level outcomes. |
Fit for purpose in action: Design, implementation, and evaluation of the National Internet Flu Survey
Dever JA , Amaya A , Srivastav A , Lu PJ , Roycroft J , Stanley M , Stringer MC , Bostwick MG , Greby SM , Santibanez TA , Williams WW . J Surv Stat Methodol 2021 9 (3) 449-476 Researchers strive to design and implement high-quality surveys to maximize the utility of the data collected. The definitions of quality and usefulness, however, vary from survey to survey and depend on the analytic needs. Survey teams must evaluate the trade-offs of various decisions, such as when results are needed and their required level of precision, in addition to practical constraints like budget, before finalizing the design. Characteristics within the concept of fit for purpose (FfP) can provide the framework for considering the trade-offs. Furthermore, this tool can enable an evaluation of quality for the resulting estimates. Implementation of a FfP framework in this context, however, is not straightforward. In this article, we provide the reader with a glimpse of a FfP framework in action for obtaining estimates on early season influenza vaccination coverage estimates and on knowledge, attitudes, behaviors, and barriers related to influenza and influenza prevention among civilian noninstitutionalized adults aged 18 years and older in the United States. The result is the National Internet Flu Survey (NIFS), an annual, two-week internet survey sponsored by the US Centers for Disease Control and Prevention. In addition to critical design decisions, we use the established NIFS FfP framework to discuss the quality of the NIFS in meeting the intended objectives. We highlight aspects that work well and other survey traits requiring further evaluation. Differences found in comparing the NIFS to the National Flu Survey, the National Health Interview Survey, and Behavioral Risk Factor Surveillance System are discussed via their respective FfP characteristics. The findings presented here highlight the importance of the FfP framework for designing surveys, defining data quality, and providing a set a metrics used to advertise the intended use of the survey data and results. © 2019 The Author(s). Published by Oxford University Press on behalf of the American Association for Public Opinion Research. All rights reserved. |
Considerations for quality assurance of multiplex malaria antigen detection assays with large sample sets
Alvarado R , van den Hoogen LL , Iriemenam NC , Akinmulero OO , Thomas AN , Tamunonengiyeofori I , Erasogie E , Chimaoge AC , Dawurung AB , Esiekpe MK , Okoli MU , Mba N , Ogunniyi A , Abimiku A , Maire M , Bassey OO , Okoye M , Swaminathan M , Greby SM , Ndodo N , Ihekweazu C , Abubakar A , Steinhardt L , Rogier E . Sci Rep 2021 11 (1) 13248 Multiplex assays for malaria antigen detection can gather data from large sample sets, but considerations for the consistency and quality assurance (QA) of mass testing lack evaluation. We present a QA framework for a study occurring November 2019 to March 2020 involving 504 assay plates detecting four Plasmodium antigens: pan-Plasmodium aldolase and lactate dehydrogenase (LDH), histidine-rich protein 2 (HRP2), P. vivax LDH (PvLDH). Controls on each plate included buffer blank, antigen negative blood, and 4-point positive dilution curve. The blank and negative blood provided consistently low signal for all targets except for pAldolase, which showed variability. Positive curve signals decreased throughout the 5-month study duration but retained a coefficient of variation (CV) of < 5%, with the exception of HRP2 in month 5 (CV of 11%). Regression fittings for inter-plate control signals provided mean and standard deviations (SDs), and of 504 assay plates, 6 (1.2%) violated the acceptable deviation limits and were repeated. For the 40,272 human blood samples assayed in this study, of 161,088 potential data points (each sample × 4 antigens), 160,641 (99.7%) successfully passed quality checks. The QA framework presented here can be utilized to ensure quality of laboratory antigen detection for large sample sets. |
Lessons From Rapid Field Implementation of an HIV Population-Based Survey in Nigeria, 2018
Jahun I , Greby SM , Adesina T , Agbakwuru C , Dalhatu I , Yakubu A , Jelpe T , Okoye M , Ikpe S , Ehoche A , Abimiku A , Aliyu G , Charurat M , Greenwell G , Bronson M , Patel H , McCracken S , Voetsch AC , Parekh B , Swaminathan M , Adewole I , Aliyu S . J Acquir Immune Defic Syndr 2021 87 S36-s42 BACKGROUND: The need for accurate HIV annual program planning data motivated the compressed timeline for the 2018 Nigerian HIV/AIDS Indicator and Impact Survey (NAIIS). The survey team used stakeholder cooperation and responsive design, using survey process and paradata to refine survey implementation, to quickly collect high-quality data. We describe processes that led to generation of data for program and funding decisions, ensuring HIV services were funded in 2019. SETTING: Nigeria is the most populous country in Africa, with approximately 195 million people in 36 states and the Federal Capital Territory. Challenges include multiple security threats, poor infrastructure, seasonal rains, and varied health system capacity. METHODS: Stakeholders worked together to plan and implement NAIIS. Methods from other population-based HIV impact assessments were modified to meet challenges and the compressed timeline. Data collection was conducted in 6 webs. Responsive design included reviewing survey monitoring paradata and laboratory performance. Costs required to correct data errors, for example, staff time and transportation, were tracked. RESULTS: NAIIS data collection was completed in 23 weeks, ahead of the originally scheduled 24 weeks. Responsive design identified and resolved approximately 68,000 interview errors, affecting approximately 62,000 households, saving about US$4.4 million in costs. Biweekly field laboratory test quality control improved from 50% to 100% throughout NAIIS. CONCLUSIONS: Cooperation across stakeholders and responsive design ensured timely release of NAIIS results and informed planning for HIV epidemic control in Nigeria. Based on NAIIS results, funds were provided to place an additional 500,000 HIV-positive Nigerians on antiretroviral therapy by the end of 2020, pushing Nigeria toward epidemic control. |
Cross-reactivity of two SARS-CoV-2 serological assays in a malaria-endemic setting.
Steinhardt LC , Ige F , Iriemenam NC , Greby SM , Hamada Y , Uwandu M , Aniedobe M , Stafford KA , Abimiku A , Mba N , Agala N , Okunoye O , Mpamugo A , Swaminathan M , Onokevbagbe E , Olaleye T , Odoh I , Marston BJ , Okoye M , Abubakar I , Rangaka MX , Rogier E , Audu R . J Clin Microbiol 2021 59 (7) e0051421 Background: Accurate SARS-CoV-2 serological assays are critical for COVID-19 serosurveillance. However, previous studies have indicated possible cross-reactivity of these assays, including in malaria-endemic areas.Methods: We tested 213 well-characterized pre-pandemic samples from Nigeria using two SARS-CoV-2 serological assays: Abbott Architect IgG and Euroimmun NCP IgG assay, both targeting SARS-CoV-2 nucleocapsid protein. To assess antibody binding strength, an avidity assay was performed on these samples and on plasma from SARS-CoV-2 PCR-positive persons.Results: Thirteen (6.1%) of 212 samples run on the Abbott assay and 38 (17.8%) of 213 run on the Euroimmun assay were positive. Anti-Plasmodium IgG levels were significantly higher among false-positives for both Abbott and Euroimmun; no association was found with active P. falciparum infection. An avidity assay using various concentratIons of urea wash in the Euroimmun assay reduced loosely-bound IgG: of 37 positive/borderline pre-pandemic samples, 46%, 86%, 89%, and 97% became negative using 2M, 4M, 5M, and 8M urea washes, respectively. The wash slightly reduced avidity of antibodies from SARS-CoV-2 patients within 28 days of PCR confirmation; thereafter avidity increased for all urea concentrations except 8M.Conclusions: This validation found moderate to substantial cross-reactivity on two SARS-CoV-2 serological assays using samples from a malaria-endemic setting. A simple urea wash appeared to alleviate issues of cross-reactivity. |
Parental vaccine hesitancy and its association with adolescent HPV vaccination
Nguyen KH , Santibanez TA , Stokley S , Lindley MC , Fisher A , Kim D , Greby S , Srivastav A , Singleton J . Vaccine 2021 39 (17) 2416-2423 Despite the Advisory Committee on Immunization Practices’ (ACIP) recommendations for routine vaccination of adolescents, vaccination coverage remains low for many adolescent vaccines, particularly the human papillomavirus (HPV) vaccine [1]. In 2018, 68.1% of adolescents aged 13–17 years had received ≥ 1 dose of HPV vaccine, and only 51.1% were up to date with the HPV vaccine series, well below the Healthy People 2020 target of 80% [2,3]. More efforts are needed to understand barriers to vaccination and improve coverage for all recommended vaccines in this population. |
Parental vaccine hesitancy and childhood influenza vaccination
Santibanez TA , Nguyen KH , Greby SM , Fisher A , Scanlon P , Bhatt A , Srivastav A , Singleton JA . Pediatrics 2020 146 (6) OBJECTIVES: To quantify the prevalence of parental vaccine hesitancy (VH) in the United States and examine the association of VH with sociodemographics and childhood influenza vaccination coverage. METHODS: A 6-question VH module was included in the 2018 and 2019 National Immunization Survey-Flu, a telephone survey of households with children age 6 months to 17 years. RESULTS: The percentage of children having a parent reporting they were "hesitant about childhood shots" was 25.8% in 2018 and 19.5% in 2019. The prevalence of concern about the number of vaccines a child gets at one time impacting the decision to get their child vaccinated was 22.8% in 2018 and 19.1% in 2019; the prevalence of concern about serious, long-term side effects impacting the parent's decision to get their child vaccinated was 27.3% in 2018 and 21.7% in 2019. Only small differences in VH by sociodemographic variables were found, except for an 11.9 percentage point higher prevalence of "hesitant about childhood shots" and 9.9 percentage point higher prevalence of concerns about serious, long-term side effects among parents of Black compared with white children. In both seasons studied, children of parents reporting they were "hesitant about childhood shots" had 26 percentage points lower influenza vaccination coverage compared with children of parents not reporting hesitancy. CONCLUSIONS: One in 5 children in the United States have a parent who is vaccine hesitant, and hesitancy is negatively associated with childhood influenza vaccination. Monitoring VH could help inform immunization programs as they develop and target methods to increase vaccine confidence and vaccination coverage. |
Workplace interventions and vaccination-related attitudes associated with influenza vaccination coverage among healthcare personnel working in long-term care facilities, 2015-2016 influenza season
Yue X , Black C , Ball S , Donahue S , de Perio MA , Laney AS , Greby S . J Am Med Dir Assoc 2019 20 (6) 718-724 OBJECTIVES: Influenza vaccination of healthcare personnel working in long-term care (LTC) facilities can reduce influenza-related morbidity and mortality among healthcare personnel and among resident populations who are at increased risk for complications from influenza and who may respond poorly to vaccination. The objective of this study was to investigate workplace interventions and healthcare personnel vaccination-related attitudes associated with higher influenza vaccination coverage among healthcare personnel working in LTC facilities. SETTING AND PARTICIPANTS: Data were obtained from an online survey of healthcare personnel conducted in April 2016 among a nonprobability sample of 2258 healthcare personnel recruited from 2 preexisting national opt-in Internet panels. Respondents were asked about influenza vaccination status, workplace vaccination policies and interventions, and their attitudes toward vaccination. Analyses were restricted to the 332 healthcare personnel who worked in nursing homes, assisted living facilities, or other LTC facilities. MEASURES: Logistic regression models were used to assess the independent associations between each workplace intervention and higher influenza vaccination coverage compared with referent levels, controlling for occupation, age, and race/ethnicity. Prevalence ratios were calculated under the assumption of simple random sampling. RESULTS: Approximately 77% of healthcare personnel working in LTC facilities reported receiving influenza vaccination in the 20152016 influenza season. Influenza vaccination was independently associated with an employer vaccination requirement (prevalence ratio (PR) [95% confidence interval] = 1.28 [1.11, 1.47]), being offered free onsite vaccination (PR = 1.20 [1.04, 1.39]), and employers publicizing vaccination coverage level to employees (PR = 1.24 [1.09, 1.41]). Vaccination was most highly associated with a combination of 3 or more workplace interventions. Most healthcare personnel working in LTC facilities reported positive attitudes toward the safety and effectiveness of influenza vaccination. CONCLUSIONS/IMPLICATIONS: Implementing employer vaccination interventions in LTC facilities, including employer vaccination requirements and free on-site influenza vaccination that is actively promoted, could increase influenza vaccination among healthcare personnel. |
Agreement with employer influenza vaccination requirements among US healthcare personnel during the 2016-2017 season
de Perio MA , Yue X , Laney AS , Greby SM , Black CL . Infect Control Hosp Epidemiol 2018 39 (8) 1-3 To the Editor: | | Annual vaccination of HCP is a high priority for reducing influenza-associated morbidity in healthcare settings.1 Although the percentage of HCP nationwide who reported receiving influenza vaccination was 78.6% in the 2016–17 season, coverage remains incomplete, placing HCP and patients at risk of influenza.1,2 Employer influenza vaccination requirements are associated with higher coverage rates, and, though controversial, mandatory influenza vaccination is supported by multiple healthcare professional societies.3,4 We explored agreement with employer influenza vaccination requirements among HCP nationwide. |
Implementing a multisite clinical trial in the midst of an Ebola outbreak: Lessons learned from the Sierra Leone Trial to Introduce a Vaccine against Ebola
Carter RJ , Idriss A , Widdowson MA , Samai M , Schrag SJ , Legardy-Williams JK , Estivariz CF , Callis A , Carr W , Webber W , Fischer ME , Hadler S , Sahr F , Thompson M , Greby SM , Edem-Hotah J , Momoh RM , McDonald W , Gee JM , Kallon AF , Spencer-Walters D , Bresee JS , Cohn A , Hersey S , Gibson L , Schuchat A , Seward JF . J Infect Dis 2018 217 S16-s23 The Sierra Leone Trial to Introduce a Vaccine against Ebola (STRIVE), a phase 2/3 trial of investigational rVSVG-ZEBOV-GP vaccine, was conducted during an unprecedented Ebola epidemic. More than 8600 eligible healthcare and frontline response workers were individually randomized to immediate (within 7 days) or deferred (within 18-24 weeks) vaccination and followed for 6 months after vaccination for serious adverse events and Ebola virus infection. Key challenges included limited infrastructure to support trial activities, unreliable electricity, and staff with limited clinical trial experience. Study staff made substantial infrastructure investments, including renovation of enrollment sites, laboratories, and government cold chain facilities, and imported equipment to store and transport vaccine at </=-60oC. STRIVE built capacity by providing didactic and practical research training to >350 staff, which was reinforced with daily review and feedback meetings. The operational challenges of safety follow-up were addressed by issuing mobile telephones to participants, making home visits, and establishing a nurse triage hotline. Before the Ebola outbreak, Sierra Leone had limited infrastructure and staff to conduct clinical trials. Without interfering with the outbreak response, STRIVE responded to an urgent need and helped build this capacity. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov [NCT02378753] and Pan African Clinical Trials Registry [PACTR201502001037220]. |
It's About Time: Examining the Effect of Interviewer-Quoted Survey Completion Time Estimates on Survey Efficiency
Ward CD , Welch B , Conley A , Smith PJ , Greby S . Surv Pract 2017 10 (2) Declining response rates may introduce bias into survey results and increase costs. Two national surveys, the National Immunization Survey (NIS) and the NIS-Teen, were used to study the impact of survey length, as stated by the interviewer, and inclusion of a topic of interest to respondents on response rates. The two studies included comparisons of the standard survey instruments to revised, condensed instruments. The NIS study also included variations of the standard survey with sections considered of interest for parental respondents, the Parental Concerns Module (PCM), which contained questions about parents' thoughts and beliefs about vaccinations. The outcomes of interest were differences in the response rates and resulting survey costs in each of the study conditions. The shortened instruments resulted in higher response rates compared to both the standard instruments and the instruments including the PCM and reduced the overall time needed to complete an interview. Based on these results, the NIS and NIS-Teen questionnaires were both shortened. |
Influenza vaccination coverage among health care personnel - United States, 2016-17 influenza season
Black CL , Yue X , Ball SW , Fink R , de Perio MA , Laney AS , Williams WW , Lindley MC , Graitcer SB , Lu PJ , Devlin R , Greby SM . MMWR Morb Mortal Wkly Rep 2017 66 (38) 1009-1015 The Advisory Committee on Immunization Practices (ACIP) recommends that all health care personnel (HCP) receive an annual influenza vaccination to reduce influenza-related morbidity and mortality among HCP and their patients and to reduce absenteeism among HCP (1-4). To estimate influenza vaccination coverage among HCP in the United States during the 2016-17 influenza season, CDC conducted an opt-in Internet panel survey of 2,438 HCP. Overall, 78.6% of survey respondents reported receiving vaccination during the 2016-17 season, similar to reported coverage in the previous three influenza seasons (5). Vaccination coverage continued to be higher among HCP working in hospitals (92.3%) and lower among HCP working in ambulatory (76.1%) and long-term care (LTC) (68.0%) settings. As in previous seasons, coverage was highest among HCP who were required by their employer to be vaccinated (96.7%) and lowest among HCP working in settings where vaccination was not required, promoted, or offered on-site (45.8%). Implementing workplace strategies found to improve vaccination coverage among HCP, including vaccination requirements or active promotion of on-site vaccinations at no cost, can help ensure that HCP and patients are protected against influenza (6). |
- Page last reviewed:Feb 1, 2024
- Page last updated:Nov 04, 2024
- Content source:
- Powered by CDC PHGKB Infrastructure