Seroprevalence of poliovirus antibodies in Nigeria: refining strategies to sustain the eradication effort

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.

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

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.

Factors associated with viral suppression among adults living with HIV on antiretroviral therapy in Nigeria: Analysis of a population-based survey, 2018

OBJECTIVE

Viral load suppression (VLS) is critical in reducing morbidity and mortality associated with HIV as well as minimizing the likelihood of HIV transmission to uninfected persons. The objective of this study was to identify factors associated with VLS among people living with HIV (PLWH) on antiretroviral (ARV) therapy to inform HIV programme strategies in Nigeria.

METHODS

Adult participants, aged 15-64 years, from the 2018 Nigeria HIV/AIDS Indicator and Impact Survey (NAIIS), who self-reported to be a PLWH or had detectable ARVs, were analysed to examine factors associated with VLS defined as HIV RNA <1000 copies/mL. NAIIS measured HIV prevalence, viral load, ARV and hepatitis B in PLWH. Logistic regression models were used and reported weighted prevalence.

RESULTS

Of 1322 participants, 949 (68.25%) were women and 1287 (96.82%) had detectable ARVs. The median age was 39.31 [interquartile range (IQR): 31.47-47.63] years. Prevalence of VLS was 80.88%. Compared with participants with detectable ARVs, those with undetectable ARVs in their blood specimens had lower odds of VLS [adjusted odds ratio (aOR) = 0.24, 95% confidence interval (CI): 0.08-0.64). Coinfection with hepatitis B and nonnucleoside reverse transcriptase inhibitor metabolites were also associated with lower odds of VLS. Older people (45-54 vs 15-24 years) had increased odds of VLS (aOR = 2.81, 95% CI: 1.14-6.90).

CONCLUSION

Young people and those with undetectable ARVs had lower odds of virological suppression. Targeted interventions focusing on young people and adherence to medication are needed to achieve the UNAIDS 95-95-95 goals for HIV epidemic control.

Assessing the effect of electronic health information exchange on the completeness and validity of data for measuring viral load testing turnaround time in Nigeria

INTRODUCTION

Implementation of health information exchange has been shown to result in several benefits which includes the improvement in the completeness and timeliness of data for public health program monitoring and surveillance.

OBJECTIVE

The objective of this study was to assess the effect of implementing an electronic health information exchange (HIE) on the quality of data available to measure HIV viral load testing turnaround time (TAT) in Nigeria.

METHODS

We measured viral load data validity and completeness before the implementation of electronic health information exchange, and 6 months after implementation. Records of specimens collected at 30 healthcare facilities and tested in 3 Polymerase Chain Reaction (PCR) labs were analyzed. We define data completeness as the percentage of non-missing values and measured this value by specimens and by data elements in the dataset for calculating TAT. To examine data validity, we classified TAT segments with negative values and date fields that were not in International Organization for Standardization(ISO) standard date format as invalid. Validity was measured by specimens and by each TAT segment. Pearson's chi square was used to assess for improvements in validity and completeness post implementation of HIE.

RESULTS

15,226 records of specimens were analyzed at baseline and 18,022 records of specimens analyzed at endline. Data completeness for all specimens recorded increased significantly from 47% before HIE implementation to 67% six months after implementation (p < 0.01). Data validity also increased from 90% before implementation to 91% after implementation (p < 0.01) CONCLUSION: Our study demonstrated evidence of significant improvement in the quality of data available to measure viral load turnaround time with the implementation of HIE.

Accelerating HIV epidemic control in Benue state, Nigeria, 2019-2021: the APIN program experience

Introduction

As at 2019, Nigeria was ranked the fourth highest HIV burden in the world. There is varied geographical HIV prevalence in Nigeria. The progress made is inequitable across geographical locations and sub-populations (18). Benue state has the second highest HIV prevalence in Nigeria. In 2018, about 35,623 people living with HIV (PLHIV) were yet to commence antiretroviral treatment (ART) in the state, accounting for an estimated ART coverage gap of 11% out of the combined gap of 320,921 in the country. To close this gap, the Benue ART surge (BAS) was implemented. The aim of this study was to describe the BAS strategic approaches and demonstrate progress in expanding ART access for PLHIV in Benue State, Nigeria.

Methods

BAS was implemented in 252 health facilities from May 2019 to September 2021. Data were collected and reported using an Excel-based dashboard and electronic medical records. The trend of HIV case identification, ART initiation, viral load suppression rate, and rate of interruption in treatment during the BAS period was then described and analyzed.

Results

Out of 893,462 clients reached, 6.7% (n = 60,297) were diagnosed with HIV and 99.8% (n = 60,236) were initiated on ART. HIV case identification per month increased by 467% from 650 at baseline to a peak of 3685 in August 2020, and then declined by 35% to 2380 in September 2021. All new HIV-infected patients (100%) were linked to ART. Viral load testing coverage and viral load suppression rate increased from 30% (43,185/126,004) and 84% (n = 36,165/43,185) at baseline to 95% (n = 193,890/204,095) and 96% (185,785/193,890), respectively.

Conclusion

Implementation of the BAS improved access to comprehensive HIV services in Benue State. The increase in HIV case identification and ART initiation significantly reduced the HIV treatment gap in the state. To fast track the attainment of UNAIDS 95-95-95 goals, lessons learnt from the BAS should be adapted and scaled up in the national HIV program in Nigeria.

Low-level viraemia among people living with HIV in Nigeria: a retrospective longitudinal cohort study

BACKGROUND

HIV transmission can occur with a viral load of at least 200 copies per mL of blood and low-level viraemia can lead to virological failure; the threshold level at which risk for virological failure is conferred is uncertain. To better understand low-level viraemia prevalence and outcomes, we analysed retrospective longitudinal data from a large cohort of people living with HIV on antiretroviral therapy (ART) in Nigeria.

METHODS

In this retrospective cohort study using previously collected longitudinal patient data, we estimated rates of virological suppression (≤50 copies per mL), low-level viraemia (51-999 copies per mL), virological non-suppression (≥1000 copies per mL), and virological failure (≥2 consecutive virological non-suppression results) among people living with HIV aged 18 years and older who initiated and received at least 24 weeks of ART at 1005 facilities in 18 Nigerian states. We analysed risk for low-level viraemia, virological non-suppression, and virological failure using log-binomial regression and mixed-effects logistic regression.

FINDINGS

At first viral load for 402 668 patients during 2016-21, low-level viraemia was present in 64 480 (16·0%) individuals and virological non-suppression occurred in 46 051 (11·4%) individuals. Patients with low-level viraemia had increased risk of virological failure (adjusted relative risk 2·20, 95% CI 1·98-2·43; p<0·0001). Compared with patients with virological suppression, patients with low-level viraemia, even at 51-199 copies per mL, had increased odds of low-level viraemia and virological non-suppression at next viral load; patients on optimised ART (ie, integrase strand transfer inhibitors) had lower odds than those on non-integrase strand transfer inhibitors for the same low-level viraemia range (eg, viral load ≥1000 copies per mL following viral load 400-999 copies per mL, integrase strand transfer inhibitor: odds ratio 1·96, 95% CI 1·79-2·13; p<0·0001; non-integrase strand transfer inhibitor: 3·21, 2·90-3·55; p<0·0001).

INTERPRETATION

Patients with low-level viraemia had increased risk of virological non-suppression and failure. Programmes should revise monitoring benchmarks and targets from less than 1000 copies per mL to less than 50 copies per mL to strengthen clinical outcomes and track progress to epidemic control.

FUNDING

None.

Performance of SARS-CoV-2 Antigens in a Multiplex Bead Assay for Integrated Serological Surveillance of Neglected Tropical and Other Diseases

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.

Seroprevalence of SARS-CoV-2 in four states of Nigeria in October 2020: A population-based household survey

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.

Expanding access to HIV services during the COVID-19 pandemic-Nigeria, 2020

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.

Lessons From Rapid Field Implementation of an HIV Population-Based Survey in Nigeria, 2018

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.

Development and implementation challenges of a quality assured HIV infant diagnosis program in Nigeria using dried blood spots and DNA polymerase chain reaction

Nigeria has one of the highest HIV burdens as well as mother-to-infant transmission rates in the world. A pilot program using polymerase chain reaction (PCR)-based testing of dried blood spot (DBS) specimens was implemented to enable early identification of HIV-infected infants and timely referral and linkage to care. From February 2007 to October 2008, whole blood was collected by finger prick to prepare DBS from infants <18 months presenting in six public mother-and-child health facilities in Lagos, Nigeria. The DBS were tested using the Roche Amplicor HIV-1 DNA Test, v1.5. To monitor laboratory testing quality, all of the PCR-positive and 10% of the PCR-negative DBS were retested by the same method at another reference laboratory. Three hundred and sixty-five randomly selected infants were screened using HIV rapid tests (RT) according to the national algorithm and RT-negative and PCR-positive specimens were also tested using Genscreen enzyme-linked immunosorbent assay (EIA) (Bio-Rad, France). The turnaround time (TAT) from sample collection, testing, and dispatching of results from each health facility was monitored. A total of 1,273 infants with a median age of 12.6 weeks (1 day to 71.6 weeks) participated in the program and 280 (22.0%) were PCR positive. HIV transmission levels varied greatly in the different health facilities ranging from 7.1% to 38.4%. Infants aged 48 to 72 weeks had the highest level of PCR positivity (41.1%). All PCR-positive specimens were confirmed by retesting. The mean turnaround time from DBS collection to returning of the laboratory result to the health facilities was 25 days. Three infants were found to be HIV antibody negative by rapid tests but were positive by both PCR and the fourth generation EIA. The DBS-based PCR program accurately identified all of the HIV-infected infants. However, many programmatic challenges related to the laboratory and TAT were identified.

An analysis and report of custodial deaths in Nebraska, USA

All medico-legal cases from the Lancaster County Coroner's Office in Lincoln, Nebraska USA, between 1991 and 1996, were reviewed for deaths which occurred in custody. The leading causes of death, in ranked order include: natural 45.1% (23/51), suicide 33.3% (17/51), homicide 11.8% (6/51), accident 7.8% (4/51), and undetermined 2% (1/51). Each cause of death was explored using the following variables: cause of death, age, sex, and race of the decedents. The findings of this investigation are compared with previous studies in other geographic regions of the country. Many similarities and differences in the frequencies of the modes of death are discussed. In addition, six unusual case studies including one accidental death, one homicide, and four suicides are presented and may serve as a reference for pathologists, forensic physicians and other forensic scientists confronted with aberrant cases.

Regulation of uveal sympathetic neurotransmission by peroxides

PURPOSE

To investigate the effect of naturally occurring and synthetic peroxides on norepinephrine release from isolated iris-ciliary bodies of several mammalian species.

METHODS

Hemiirides (bovine) and iris-ciliary bodies (human, rabbit, and rat) were incubated in Krebs solution containing [3H]-norepinephrine ([3H]NE) for 60 minutes. After incubation, tissues were set up for studies of [3H]NE release using the superfusion method. Release of [3H]NE was elicited through electrical field stimulation.

RESULTS

In bovine irides, hydrogen peroxide (H2O2), cumene hydroperoxide (cuOOH), and tert-butyl hydroperoxide (buOOH) caused a concentration-dependent potentiation of field-stimulated [3H]NE release with the following rank order of potency: cuOOH > H2O2 > buOOH. Furthermore, the free radical scavenger, melatonin (2 mM), prevented the enhancement of evoked [3H]NE overflow elicited by H2O2 and cuOOH. At equimolar concentrations, H2O2 (1 mM) increased stimulated [3H]NE release from rabbit, human (mean age, 29.7; range, 15 to 48 years), and Fischer 344 rat (4 months old) iris-ciliary bodies by 98%, 50%, and 40%, respectively. However, H2O2 (1 mM) caused a 9% increase in evoked [3H]NE release in tissue from aged Fischer 344 rats (30 months old) and a 5% decrease in neurotransmitter release in tissue from old human donors (mean age, 72.3 years; range, 69 to 74 years).

CONCLUSIONS

Peroxides such as H2O2 can potentiate sympathetic neurotransmission in the anterior uvea of several mammalian species. In bovine irides, H2O2-induced enhancement of neurotransmitter release can be mimicked by synthetic peroxides and may involve the generation of reactive oxygen species.