Genomic Analysis of Lassa Virus during an Increase in Cases in Nigeria in 2018.

During 2018, an unusual increase in Lassa fever cases occurred in Nigeria, raising concern among national and international public health agencies. We analyzed 220 Lassa virus genomes from infected patients, including 129 from the 2017-2018 transmission season, to understand the viral populations underpinning the increase. A total of 14 initial genomes from 2018 samples were generated at Redeemer's University in Nigeria, and the findings were shared with the Nigerian Center for Disease Control in real time. We found that the increase in cases was not attributable to a particular Lassa virus strain or sustained by human-to-human transmission. Instead, the data were consistent with ongoing cross-species transmission from local rodent populations. Phylogenetic analysis also revealed extensive viral diversity that was structured according to geography, with major rivers appearing to act as barriers to migration of the rodent reservoir.

The resurgence of yellow fever outbreaks in Nigeria: a 2-year review 2017-2019.

BACKGROUND: Yellow fever outbreaks are documented to have a considerable impact not only on the individuals but on the health system with significant economic implications. Efforts to eliminate yellow fever outbreaks globally through the EYE strategy remains important following outbreaks in Africa, Nigeria included. The outbreaks reported in Nigeria, since 2017 and the response efforts provide an opportunity to document and guide interventions for improving future outbreaks in Nigeria and other countries in Africa. METHODS: We reviewed the available yellow fever surveillance and vaccination response data between September 2017 and September 2019 across the 36 states across Nigeria. We described the epidemiology of the difference outbreaks and the periods for all interventions. We also documented the emergency vaccination responses as well as preventive mass vaccinations implemented towards improving population immunity and limiting epidemic potentials in Nigeria. RESULTS: A total of 7894 suspected cases with 287 laboratory-confirmed cases were reported in Nigeria between September 2017 and September 2019 with a mean age of 19 years and a case fatality of 2.7% amongst all reported cases. Outbreaks were confirmed in 55 LGAs with most of the outbreaks across four major epicentres in Kwara/Kogi, Edo, Ebonyi and Bauchi states. In response to these outbreaks, eight reactive vaccination campaigns, supported through ICG applications, were implemented. The duration for responding to the outbreaks ranged from 15 to 132 days (average 68 days) and a total of 45,648,243 persons aged < 45 years vaccinated through reactive and preventive mass campaigns between September 2017 and September 2019. CONCLUSIONS: Nigeria experienced intermediate outbreaks of yellow fever between September 2017 and 2019 with vaccination responses conducted to control these outbreaks. However, there are delays in the timeliness of responses and more efforts required in improving reporting, response times and preparedness to further prevent morbidity and mortality from the yellow fever disease outbreaks. These efforts, including improving routine yellow fever coverage, contribute towards improving population immunity and other activities related to achieving the goals of the EYE strategy.

Prevalence of Antibodies to Crimean-Congo Hemorrhagic Fever Virus in Ruminants, Nigeria, 2015.

Crimean-Congo hemorrhagic fever virus (CCHFV) is a highly transmissible human pathogen. Infection is often misdiagnosed, in part because of poor availability of data in disease-endemic areas. We sampled 150 apparently healthy ruminants throughout Nigeria for virus seropositivity and detected virus-specific IgG in cattle (24%) and goats (2%), highlighting the need for further investigations.

Ebola Virus Epidemiology and Evolution in Nigeria.

Containment limited the 2014 Nigerian Ebola virus (EBOV) disease outbreak to 20 reported cases and 8 fatalities. We present here clinical data and contact information for at least 19 case patients, and full-length EBOV genome sequences for 12 of the 20. The detailed contact data permits nearly complete reconstruction of the transmission tree for the outbreak. The EBOV genomic data are consistent with that tree. It confirms that there was a single source for the Nigerian infections, shows that the Nigerian EBOV lineage nests within a lineage previously seen in Liberia but is genetically distinct from it, and supports the conclusion that transmission from Nigeria to elsewhere did not occur.

Toward a Common Secure Future: Four Global Commissions in the Wake of Ebola.

Lawrence Gostin and colleagues offer a set of priorities for global health preparedness and response for future infectious disease threats.

Will Africa's future epidemic ride on forgotten lessons from the Ebola epidemic?

The Ebola virus disease (EVD) outbreak in the three West Africa countries of Guinea, Liberia, and Sierra Leone, was declared by the World Health Organization (WHO) as a public health event of international concern in August 2014. The disease, which has caused more than 10,000 deaths from over 25,000 cases, has thrived on a failed disease control system, national denial, and a poor and fragile healthcare delivery system. The slow and initially uncoordinated national and global response turned the outbreak into an unprecedented humanitarian disaster. Prevention and control of future outbreaks depend on improving and upgrading disease surveillance into a responsive component of a reliable and efficient health care delivery system. Appropriate capacity building with a conducive operating environment, which has been lacking in the past few decades, will be key to the health system strengthening.

Progress toward laboratory containment of poliovirus after polio eradication.

BACKGROUND: The first steps (phase 1) toward laboratory containment of poliovirus after eradication are a national survey of biomedical facilities and a global inventory of such facilities retaining wild poliovirus (WPV) infectious and potentially infectious materials. METHODS: We reviewed published reports on national laboratory surveys and inventories of WPV materials from each of the 3 polio-free World Health Organization (WHO) regions (the European Region, completed in 2006; the Western Pacific Region, completed in 2008; and the Region of the Americas, completed in 2010), as well as reports on progress in polio-free countries of the remaining 3 regions (the African Region, the Eastern Mediterranean Region, and the WHO South-East Asia Region). RESULTS: Containment phase 1 activities are complete in 154 of 194 WHO Member States (79%), including all countries and areas of the polio-free regions and most polio-free countries in the remaining 3 regions. A reported 227 209 biomedical facilities were surveyed, with 532 facilities in 45 countries identified as retaining WPV-associated infectious or potentially infectious materials. CONCLUSIONS: Completion of containment phase 1 global activities is achievable within the time frame set by the Polio Eradication and Endgame Strategic Plan 2013-2018.

Multiple independent emergences of type 2 vaccine-derived polioviruses during a large outbreak in northern Nigeria.

Since 2005, a large poliomyelitis outbreak associated with type 2 circulating vaccine-derived poliovirus (cVDPV2) has occurred in northern Nigeria, where immunization coverage with trivalent oral poliovirus vaccine (tOPV) has been low. Phylogenetic analysis of P1/capsid region sequences of isolates from each of the 403 cases reported in 2005 to 2011 resolved the outbreak into 23 independent type 2 vaccine-derived poliovirus (VDPV2) emergences, at least 7 of which established circulating lineage groups. Virus from one emergence (lineage group 2005-8; 361 isolates) was estimated to have circulated for over 6 years. The population of the major cVDPV2 lineage group expanded rapidly in early 2009, fell sharply after two tOPV rounds in mid-2009, and gradually expanded again through 2011. The two major determinants of attenuation of the Sabin 2 oral poliovirus vaccine strain (A481 in the 5'-untranslated region [5'-UTR] and VP1-Ile143) had been replaced in all VDPV2 isolates; most A481 5'-UTR replacements occurred by recombination with other enteroviruses. cVDPV2 isolates representing different lineage groups had biological properties indistinguishable from those of wild polioviruses, including efficient growth in neuron-derived HEK293 cells, the capacity to cause paralytic disease in both humans and PVR-Tg21 transgenic mice, loss of the temperature-sensitive phenotype, and the capacity for sustained person-to-person transmission. We estimate from the poliomyelitis case count and the paralytic case-to-infection ratio for type 2 wild poliovirus infections that ∼700,000 cVDPV2 infections have occurred during the outbreak. The detection of multiple concurrent cVDPV2 outbreaks in northern Nigeria highlights the risks of cVDPV emergence accompanying tOPV use at low rates of coverage in developing countries.

Dynamics of Mpox infection in Nigeria: a systematic review and meta-analysis.

The seasonal outbreaks of Mpox continue in most parts of West and Central Africa. In the past year, Nigeria had the highest number of reported cases. Here, we used the PRISMA guidelines to carry out a systematic review and meta-analysis of available evidence on Mpox in Nigeria to assess the prevalence, transmission pattern, diagnostic approach, and other associated factors useful for mitigating the transmission of the disease. All relevant observational studies in PubMed/MEDLINE, Embase, AJOL, Web of Science, Scopus and Google Scholar on Mpox in Nigeria were assessed within the last fifty years (1972 to 2022). In all, 92 relevant articles were retrieved, out of which 23 were included in the final qualitative analysis. Notably, most of the cases of Mpox in Nigeria were from the southern part of the country. Our findings showed a progressive spread from the southern to the northern region of the country. We identified the following factors as important in the transmission of Mpox in Nigeria; poverty, lack of basic healthcare facilities, and risk of exposure through unsafe sexual practices. Our findings reiterate the need to strengthen and expand existing efforts as well as establish robust multi-sectoral collaboration to understand the dynamics of Mpox Nigeria.

Domestic Animals as Potential Reservoirs of Zoonotic Viral Diseases.

Zoonoses are diseases and infections naturally transmitted between humans and vertebrate animals. Over the years, zoonoses have become increasingly significant threats to global health. They form the dominant group of diseases among the emerging infectious diseases (EID) and currently account for 73% of EID. Approximately 25% of zoonoses originate in domestic animals. The etiological agents of zoonoses include different pathogens, with viruses accounting for approximately 30% of all zoonotic infections. Zoonotic diseases can be transmitted directly or indirectly, by contact, via aerosols, through a vector, or vertically in utero. Zoonotic diseases are found in every continent except Antarctica. Numerous factors associated with the pathogen, human activities, and the environment play significant roles in the transmission and emergence of zoonotic diseases. Effective response and control of zoonotic diseases call for multiple-sector involvement and collaboration according to the One Health concept.

Ecological correlates and predictors of Lassa fever incidence in Ondo State, Nigeria 2017-2021: an emerging urban trend.

Lassa fever (LF) is prevalent in many West African countries, including Nigeria. Efforts to combat LF have primarily focused on rural areas where interactions between rodents and humans are common. However, recent studies indicate a shift in its occurrence from rural to urban areas. We analysed secondary data of reported LF outbreaks from 2017 to 2021 in Ondo State, Nigeria to identify the distribution pattern, ecological variations, and other determinants of disease spread from the ward level using nearest neighbour statistics and regression analysis. Data utilised include LF incidence, ecological variables involving population, nighttime light intensity, vegetation, temperature, market presence, road length, and building area coverage. ArcGIS Pro 3.0 software was employed for spatial analysis. Results revealed spatio-temporal clustering of LF incidents between 2017 and 2021, with an increasing trend followed by a decline in 2021. All wards in Owo Local Government Area were identified as LF hotspots. The ecological variables exhibited significant correlations with the number of LF cases in the wards, except for maximum temperature. Notably, these variables varied significantly between wards with confirmed LF and those without. Therefore, it is important to prioritise strategies for mitigating LF outbreaks in urban areas of Nigeria and other LF-endemic countries.

Monkeypox: The consequences of neglecting a disease, anywhere.

A disease anywhere can spread everywhere, if neglected.

SARS CoV-2 Seroprevalence in Selected States of High and Low Disease Burden in Nigeria.

Importance: The global impact of COVID-19 has led to an increased need to continuously assess disease surveillance tools. The utility of SARS-CoV-2 serologic tools in determining immunity levels across different age groups and locations in helping to quickly assess the burden of COVID-19 with significant health policy implications is unknown. Objective: To determine the prevalence of SARS-CoV-2 antibodies with respect to the age group and sex of participants. Design, Setting, and Participants: A cross-sectional survey of 4904 individuals across 12 states with high and low COVID-19 disease burden in Nigeria was carried out between June 29 and August 21, 2021. Main Outcomes and Measures: Enzyme-linked immunosorbent assay was used for the detection of specific SARS-CoV-2 immunoglobulin G and immunoglobulin M antibodies, such as the nucleocapsid protein-NCP and spike protein S1. Interviewer-administered questionnaires provided information on participants' history of disease and associated risk factors. Results: A total of 4904 individuals participated in the study (3033 were female [61.8%]; mean [SD] age, 26.7 [6.51] years). A high seroprevalence of SARS-CoV-2 (78.9%) was obtained. Seropositivity was consistent across the states surveyed, ranging from 69.8% in Lagos to 87.7% in Borno. There was no association between sex and seropositivity (female, 2414 [79.6%]; male, 1456 [77.8%]; P = .61); however, an association was noted between age and seropositivity, with the peak prevalence observed in participants aged 15 to 19 years (616 [83.6%]; P = .001). Similarly, loss of appetite (751 [82.3%]; P = .04) and smell (309 [84.4%]; P = .01) were associated with seropositivity. Conclusions and Relevance: In this cross-sectional study, a high SARS-CoV-2 seroprevalence was obtained among the study population during the low level of vaccination at the time of the survey. Thus, there is a need for both an efficacy and antibody neutralization test study to ascertain the efficacy of the antibody detected and the potential for herd immunity in Nigeria.

Ebola virus disease: current vaccine solutions.

Ebola Virus Disease (EVD) is an emerging zoonotic disease with intermittent outbreaks in Central and West African countries. The unpredictable high case fatality rate has made it a disease of public health concern. Different vaccine platforms have shown prophylactic protection in human and non-human primates, with the progress towards a licensed vaccine greatly accelerated in response to the devastating outbreak of EVD in West Africa from 2013-2016. Currently, two vaccines: Ervebo (rVSV-ZEBOV) and a two-dose combination of Zabdeno (Ad26.ZEBOV) and Mvabea (MVA-BN-Filo) have been licensed and in use. The licensing of an Ebola vaccine for use is challenging for several reasons, including the sporadic and limited nature of EVD outbreaks and the enormous resources needed to bring a vaccine to licensure. While vaccine solutions remain important in reducing the fatality of EVD, other strategic interventions are necessary for the prevention and control of EVD.

Lessons from the elimination of poliomyelitis in Africa.

In August 2020, Africa was declared free of poliomyelitis (polio), bringing to fruition a goal that took more than 30 years to achieve. This Perspective chronicles global, continental, national and community actions taken by diverse stakeholders that finally led to the elimination of transmission of wild poliovirus in Africa. The cascade of events started with the development of polio vaccines and the realization that polio, much like smallpox, could be eradicated. After a 1988 pledge by the World Health Assembly to eradicate polio globally, concerted and deliberate efforts were made in Africa to achieve this goal. This included the use of evidence-based approaches for the harmonization and standardization of public health strategies, using a network of polio laboratories and emergency operation centres and actively pursuing underserved populations. Innovative solutions to counter challenges such as conflict and vaccine hesitancy may be of use in future public health interventions.

52 Years of Lassa Fever Outbreaks in Nigeria, 1969-2020: An Epidemiologic Analysis of the Temporal and Spatial Trends.

The year 2020 made 52 years since the first report of Lassa fever (LF) outbreaks from Nigeria, but what progress has been made in its control? We sought to answer this through an epidemiologic analysis of the temporal and spatial trends of the outbreaks from 1969 to 2020. The analysis showed an overall strengthening of the outbreaks, hallmarked by the change from irregular to regular annual and from limited local to nationwide outbreaks, while there was a sharp contrast between the upward trend in case numbers and downward trend in case fatality. Pending the availability of effective vaccines, greater effort is required to reverse the upward trend in case numbers and sustain the downward trend in case fatality. We discuss the factors associated with the observed trends as well as the prerequisites for further improvements.

Pandemic diseases preparedness and response in the age of COVID-19-a symposium report.

For years, experts have warned that a global pandemic was only a matter of time. Indeed, over the past two decades, several outbreaks and pandemics, from SARS to Ebola, have tested our ability to respond to a disease threat and provided the opportunity to refine our preparedness systems. However, when a novel coronavirus with human-to-human transmissibility emerged in China in 2019, many of these systems were found lacking. From international disputes over data and resources to individual disagreements over the effectiveness of facemasks, the COVID-19 pandemic has revealed several vulnerabilities. As of early November 2020, the WHO has confirmed over 46 million cases and 1.2 million deaths worldwide. While the world will likely be reeling from the effects of COVID-19 for months, and perhaps years, to come, one key question must be asked, How can we do better next time? This report summarizes views of experts from around the world on how lessons from past pandemics have shaped our current disease preparedness and response efforts, and how the COVID-19 pandemic may offer an opportunity to reinvent public health and healthcare systems to be more robust the next time a major challenge appears.