Outbreaks In Nigeria Research Articles

Environmental Vibrio cholerae Strains Harboring Cholera Toxin and Vibrio Pathogenicity Island 1, Nigeria, 2008-2015.

Analysis of clinical and environmental Vibrio cholerae O1 strains obtained during 2008-2015 in Nigeria showed that lineages Afr9 and Afr12 carrying cholera toxin and Vibrio pathogenicity island 1 can be isolated from water. Our findings raise concerns about the role of the environment in maintenance and emergence of cholera outbreaks in Nigeria.

Non-typhoidal Salmonella in Nigeria: do outcomes of ‘multisectoral’ surveillance, treatment and control justify the intervention costs?

ABSTRACT Non-typhoidal salmonellosis (NTS) is significant and an economic burden in Nigeria. To determine whether investment in NTS control is economically justifiable, Outbreak Costing Tool (OCT) was used to estimate the robust funding of public and animal health systems for epidemio-surveillance and control of multisectoral NTS outbreaks in Nigeria. Health, production, and economic data were collected and used to populate the tool for evaluation. The multisectoral NTS burden for the year 2020 in Nigeria was US$ 930,887,379.00. Approximately 4,835 technical officers, and 3,700 non-technical staff (n = 8,535) were needed with an investment of >2.2 million work hours. The investment cost for NTS control was US$ 53,854,660.87. The non-labour-related cost was 89.21% of the total intervention costs. The overall intervention’s investment was 374.15% of the estimated national and subnational systems’ annual budget for diarrhoeal diseases, and the outbreak response period attracted the highest costs (53%) of the total intervention. In conclusion, intervention against NTS was beneficial (benefit – cost ratio: 17.29), hence justifying the need for multisectoral surveillance-response against NTS in Nigeria. Complex sectoral silos must give way to coordinated collaborations to optimize benefits; and over-centralization of health interventions’ associated delays must be removed through decentralized sub-national-focused framework that empowers rapid investigation, response, control, data collection, and analyses. It should assist anticipatory planning, and outbreak investigation and reduce critical response time. Anticipatory planning tools, when applied pre-emptively, can benefit budgeting, identify gaps, and assist in the delivery of cost-saving and effective measures against infectious disease.

Molecular epidemiology and genetic evolution of avian influenza H5N1 subtype in Nigeria, 2006 to 2021.

Nigeria recorded one of the earliest outbreaks of the Highly Pathogenic Avian Influenza (HPAI) virus H5N1 in 2006, which spread to other African countries. In 2023, 18 countries reported outbreaks of H5N1 in poultry, with human cases documented in Egypt, Nigeria, and Djibouti. There is limited information on the molecular epidemiology of HPAI H5N1 in Nigeria. We determined the molecular epidemiology and genetic evolution of the virus from 2006 to 2021. We investigated the trend and geographical distribution across Nigeria. The evolutionary history of 61 full-length genomes was performed from 13 countries worldwide, and compared with sequences obtained from the early outbreaks in Nigeria up to 2021. MEGA 11 was used to determine the phylogenetic relationships of H5N1 strains, which revealed close ancestry between sequences in Nigeria and those from other African countries. Clade classification was performed using the subspecies classification tool for Bacterial and Viral Bioinformatics Research Center (BV-BRC) version 3.35.5. H5N1 Clade 2.2 was observed in 2006, with 2.3.2, 2.3.2.1f clades observed afterwards and 2.3.4.4b in 2021. Our findings underscore the need for genomics surveillance to track antigenic variation and clades switching to monitor the epidemiological of the virus and safeguard human and animal health.Impacts Specific variations in the hemagglutinin (HA) and neuraminidase (NA) genes of Avian influenza virus are consistent in different geographical regions. H5N1 Clade 2.2 was reported in 2006, with 2.3.2, 2.3.2.1f afterwards and 2.3.4.4b in 2021. Nigeria is an epicentre for avian influenza with three major migratory routes for wild birds transversing the country. It is plausible that the Avian influenza in Northern Nigeria may be linked to wild bird sanctuaries in the region.

Perceptions of policymakers and ethicists on ethical considerations in the conduct of research during disease outbreaks in Nigeria

Background There is a dearth of literature on the perspectives of stakeholders from countries in Africa on the institution of a research culture as part of a holistic system of pandemic preparedness and response. This study aimed to explore the perspectives of policymakers, representatives from Research Ethics Committees (RECs), and international bioethics experts on the ethics of conducting research during infectious disease outbreaks in Nigeria. Methods We conducted structured interviews with six policymakers actively engaged in disease outbreak response. The interview themes included systems and structures for research, local researcher competency, regulatory oversight, study types, ethical review approaches, and integrating research into outbreak response. We further engaged 12 participants including REC members from Nigeria and Liberia, international bioethics experts, and study co-investigators in a structured discussion to appraise and expand on themes identified during the interviews at a 2-day meeting in December 2018. We also held two virtual consultations afterwards. The findings from these processes were synthesized to develop a comprehensive report. Results Participants stressed the significance of conducting research during disease outbreaks to understand causal factors, evaluate public health measures, and inform future prevention and treatment strategies, and identified the need for clear ethical guidelines for RECs during outbreaks. Participants proposed a sliding scale for prioritizing categorized studies, emphasizing immediate solutions over future-focused research. Discussants proposed a "systems approach" to ethics review, emphasizing interdependence, governance structures, communication infrastructure, effective communication with policymakers, and a funding structure. Conclusion Conducting ethical research during disease outbreaks requires a comprehensive, context-dependent approach, involving stakeholders, and ensuring robust ethical oversight through proficient RECs. The proposed "System Approach" offers a model for sustainable and effective ethics review during outbreaks, fostering locally relevant and socially valuable research while prioritizing the well-being of research participants and communities.

The Re-emergence of Diphtheria Amidst Multiple Outbreaks in Nigeria.

Diphtheria, a vaccine-preventable disease, has resurfaced in Nigeria, where many outbreaks have been reported in recent years. The outbreaks have occurred across the country, including in areas with high vaccination coverage. Corynebacterium diphtheriae, the causal agent, is a highly contagious bacteria that can cause severe respiratory and systemic symptoms and can be fatal if not treated. The reemergence of diphtheria in Nigeria is most likely due to a combination of factors, including gaps in routine immunization regimens. The outbreak is further aggravated by multiple epidemics, which have diverted resources and attention away from the emergency of other infectious diseases. Furthermore, there is a lack of awareness of diphtheria in Nigeria. With a focus on the difficulties in controlling the disease, methods of diagnosis, available treatments, and preventive measures, this study provides a thorough analysis of diphtheria, covering its historical context, clinical presentation, associated complications, and current outbreaks. It emphasizes how important vaccination, early detection, and better access to healthcare are in reducing diphtheria outbreaks. The study highlights the serious effects of diphtheria on public health, particularly in regions with scarce resources and vaccine resistance, and offers a number of suggestions to overcome these challenges and prevent further outbreaks.

Detection of hepatitis viruses in suspected cases of Viral Haemorrhagic Fevers in Nigeria.

There have been several Viral Hemorrhagic Fever (VHF) outbreaks in Nigeria which remains a public health concern. Despite the increasing number of suspected cases of VHF due to heightened surveillance activities and growing awareness, only a few cases are laboratory-confirmed to be VHF. Routinely, these samples are only tested for Lassa virus and Yellow fever virus with occasional testing for Dengue virus when indicated. The aetiology of the disease in these VHF suspected cases in Nigeria which are negative for Lassa, Yellow fever and Dengue viruses remains a puzzle. Since the clinical features exhibited by suspected VHF cases are like other endemic illnesses such as Hepatitis, there is a need to investigate the diversity and co-infections of hepatitis viruses as differentials and possible co-morbidity in suspected cases of VHFs in Nigeria. A total of three hundred and fifty (350) blood samples of 212 (60.6%) males and 138 (39.4%) females, aged <1-70 years with a mean age of 25 ±14.5, suspected of VHFs and tested negative for Lassa, Yellow fever and Dengue viruses were investigated for Hepatitis A, B, C and E viruses at the Centre for Human and Zoonotic Virology (CHAZVY), College of Medicine, University of Lagos (CMUL) using serologic and molecular techniques. The serologic analysis of these VHF suspected cases samples revealed that 126 (36%) were positive for at least one hepatitis virus. Individual prevalence for each of the hepatitis virus screened for showed that 37 (10.6%), 18 (5.1%) and 71 (20.3%) were positive for HBV, HCV and HEV respectively. All the samples were negative for HAV. A co-infection rate of 11.9% was also observed, with HCV/HEV co-infections being the most prevalent and the Northern region having the greatest burden of infection. The evidence of hepatitis virus infections in suspected cases of VHF was documented. Thus, their associations as co-morbidities and/or mortalities in this category of individuals require further investigations in endemic countries such as Nigeria. Therefore, the possible inclusion of screening for hepatitis viruses and other aetiologic agents that could mimic infections in suspected cases of VHFs in Nigeria should be thoroughly evaluated to guide informed policy on the diagnosis and management of these cases.

Addressing the Dengue fever challenges in Nigeria: A narrative review and recommendations for control.

Dengue fever is a mosquito-borne viral infection that continues to pose a significant public health threat globally, including Nigeria. Here, we provided a review of dengue fever outbreaks in Nigeria from 1972 to 2023, examining the epidemiology, prevention strategies, challenges faced in combating the disease, and recommendations to mitigate its spread and transmission. We utilized scholarly databases such as PubMed and Google Scholar in writing this paper. The search keywords like, "dengue fever", "break-bone fever", "dengue fever virus" "outbreak", "Nigeria", "prevalence", and "epidemiology", were used to get appropriate published articles about the subject areas. Over the past five decades, Nigeria has experienced intermittent outbreaks of dengue fever, with varying degrees of severity and geographic distribution. Factors such as urbanization, climate change, and inadequate healthcare infrastructure have contributed to the resurgence and spread of the disease in the country. Despite efforts to control dengue transmission through vector control measures and public health interventions, challenges persist, including limited surveillance capacity, diagnostic delays, and gaps in vector control strategies. The emergence of new dengue virus serotypes and the potential for co-circulation with other arboviruses further complicate control efforts. This review highlights the importance of strengthening surveillance systems, enhancing vector control measures, improving diagnostic capabilities, and increasing public awareness to effectively mitigate the burden of dengue fever in Nigeria. Collaboration between government agencies, healthcare providers, researchers, and international partners is crucial in addressing the growing threat of dengue fever and reducing its impact on public health in Nigeria.

Understanding the Trend of Diphtheria Outbreak in Nigeria from 1941-2023: A Narrative Review

Diphtheria is a contagious infection caused by Corynebacterium diphtheriae spread through respiratory droplets, typically from coughing or sneezing, and characterized by difficulty in breathing, heart rhythm challenges, and even death. Objective: This narrative review explored the trend of Diphtheria outbreaks in Nigeria and suggested a way to forestall reoccurrence. We search two bibliographic databases, PubMed and Scopus, to identify studies using the keywords “Diphtheria” and “Nigeria”. Approximately eighty-two (82) years after isolating virulent strains of Corynebacterium diphtheriae in Nigeria, the country still suffers recurrent outbreaks of Diphtheria, a vaccine-preventable infection. Between the years 1974 to 2021, the World Health Organization (WHO) documented 40258 reported cases of diphtheria in Nigeria, although it missed 117 cases reported in Lagos, Benin, Katsina, and Borno between 2007 and 2017, where a 21.4% fatality was recorded in Borno alone. The current outbreak, labeled as one of the most severe outbreaks in Nigeria in recent years, so far, has 798 cases and 10% case fatality with the northern part of the country being particularly hard hit. The recurrence of the Diphtheria outbreak in Nigeria is attributed to incomplete vaccination exacerbated by poor vaccination coverage (e.g., &lt; 50% in 2016), waning vaccine-induced immunity, maternal knowledge, and poverty. Incomplete immunization resulting from poor immunization coverage, poor sensitization, and lack of access to healthcare facilities is undoubtedly the single predominant determinant of Diphtheria outbreaks in Nigeria. There is an urgent need to promote complete immunization to prevent resurgence and re-emergence.

How can machine learning predict cholera: insights from experiments and design science for action research.

Cholera is a leading cause of mortality in Nigeria. The two most significant predictors of cholera are a lack of access to clean water and poor sanitary conditions. Other factors such as natural disasters, illiteracy, and internal conflicts that drive people to seek sanctuary in refugee camps may contribute to the spread of cholera in Nigeria. The aim of this research is to develop a cholera outbreak risk prediction (CORP) model using machine learning tools and data science. In this study, we developed a CORP model using design science perspectives and machine learning to detect cholera outbreaks in Nigeria. Nonnegative matrix factorization (NMF) was used for dimensionality reduction, and synthetic minority oversampling technique (SMOTE) was used for data balancing. Outliers were detected using density-based spatial clustering of applications with noise (DBSCAN) were removed improving the overall performance of the model, and the extreme-gradient boost algorithm was used for prediction. The findings revealed that the CORP model outcomes resulted in the best accuracy of 99.62%, Matthews's correlation coefficient of 0.976, and area under the curve of 99.2%, which were improved compared with the previous findings. The developed model can be helpful to healthcare providers in predicting possible cholera outbreaks.

Recurrent diphtheria outbreaks in Nigeria: A review of the underlying factors and remedies.

The introduction of the diphtheria-tetanus-pertussis (DTP) vaccine into childhood immunization programs resulted in its widespread elimination in high-income countries. However, Nigeria is currently experiencing an outbreak. The primary cause of diphtheria outbreaks and its high mortality rates in Nigeria was waning herd immunity due to low DTP coverage and a lack of diphtheria antitoxin (DAT), respectively. However, the underlying causes of Nigeria's low DTP coverage and DAT supply remain unknown. Relevant studies and reports included in our review were obtained by a search through Google Scholar, PubMed, and organization websites using the terms "Diphtheria-Pertussis-Tetanus vaccine OR Diphtheria antitoxin and Nigeria OR Diphtheria Outbreak." All articles considering diphtheria outbreaks, DTP vaccine, and DAT supply in Nigeria were considered without time restriction due to the paucity of data. We used the narrative synthesis approach to critically appraise, analyze, and draw inferences from the selected articles. The main causes of low DTP coverage are insufficient supply, an inefficient cold chain system, and low uptake due to poor health literacy and negative sociocultural and religious beliefs, whereas the key barriers to DAT availability are insufficient production by pharmaceutical industries because of low demand and priority. The underlying causes of Nigeria's low DTP coverage and DAT supply are multifactorial. Both short-term and long-term measures are needed to control this outbreak and prevent future occurrences.

Rational approach to vaccination against highly pathogenic avian influenza in Nigeria: a scientific perspective and global best practice.

Since 2006, highly pathogenic avian influenza (HPAI) subtypes H5Nx have adversely affected poultry production in Nigeria. Successive waves of infections in the last two decades have raised concerns about the ability to contain infections by biosecurity alone, and evidence of recurrent outbreaks suggests a need for adoption of additional control measures such as vaccination. Although vaccination can be used to control virus spread and reduce the morbidity and mortality caused by HPAI, no country using vaccination alone as a control measure against HPAI has been able to eliminate or prevent re-infection. To inform policy in Nigeria, we examined the intricacies of HPAI vaccination, government regulations, and scientific data regarding what kind of vaccines can be used based on subtype, whether inactivated or live attenuated should be used, when to deliver vaccine either proactively or reactively, where to apply vaccination either in disease control zones, regionally, or nationally, and how to vaccinate the targeted poultry population for optimum success. A resurgence of HPAI outbreaks in Nigeria since 2018, after the country was declared free of the epidemic following the first outbreak in 2006, has led to enhanced intervention. Controlled vaccination entails monitoring the application of vaccines, the capacity to differentiate vaccinated from infected (DIVA) flocks, and assessing seroconversion or other immune correlates of protection. Concurrent surveillance for circulating avian influenza virus (AIV) and analyzing AIV isolates obtained via surveillance efforts for genetic and/or antigenic mismatch with vaccine strains are also important. Countries with high investment in commercial poultry farms like Nigeria may identify and zone territories where vaccines can be applied. This may include ring vaccination to control HPAI in areas or production systems at risk of infection. Before adoption of vaccination as an additional control measure on commercial poultry farms, two outcomes must be considered. First, vaccination is an admission of endemicity. Secondly, vaccinated flocks may no longer be made accessible to international poultry markets in accordance with WOAH trade regulations. Vaccination must therefore be approached with utmost caution and be guided by science-based evidence throughout the implementation strategy after thorough risk assessment. Influenza vaccine research, development, and controlled application in addition to biosecurity may be a precautionary measure in the evolving HPAI scenario in Nigeria.

Modeling the Lassa fever outbreak synchronously occurring with cholera and COVID-19 outbreaks in Nigeria 2021: A threat to Global Health Security.

Nigeria struggles with seasonal outbreaks of Lassa fever (LF), with 70 to 100% of its states affected annually. Since 2018, the seasonal dynamics have changed with a stark increase in infections, though the pattern in 2021 differed from the other years. Nigeria had three outbreaks of Lassa Fever in 2021. In that year, Nigeria also experienced substantial burdens from COVID-19 and Cholera. There is potential that these three outbreak events interacted with each other. This may have been from community disruption and so changes in how people access the health system, how the health system responds, or overlapping biological interactions, misclassification, social factors, misinformation, and pre-existing disparities and vulnerabilities. We assessed the syndemic potential of Lassa Fever, COVID-19, and Cholera through modeling their interactions across the 2021 calendar year employing a Poisson regression model. We included the number of states affected and the month of the year. We used these predictors to forecast the progression of the outbreak using a Seasonal Autoregressive Integrated Moving Average (SARIMA) model. The Poisson model prediction for the confirmed number of Lassa fever cases was significantly dependent on the number of confirmed COVID-19 cases, the number of states affected, and the month of the year (p-value < 0.001), and the SARIMA model was a good fit, accounting for 48% of the change in the number of cases of Lassa fever (p-value < 0.001) with parameters ARIMA (6, 1, 3) (5, 0, 3). Lassa Fever, COVID-19, and Cholera 2021 case curves have mirrored dynamics and likely interact. Further research into common, intervenable aspects of those interactions should be performed.

A Systematic Review of Yellow Fever Outbreaks and Public Health Responses in Nigeria.

Yellow fever (YF) outbreaks continue to occur in Nigeria with a high mortality rate despite a well-established mode of transmission and the availability of a potent vaccine. This review is aimed at describing the epidemiology, determinants, and public health responses of yellow fever outbreaks in Nigeria from 1864 to 2020. The guidelines for the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) were used to conduct the review from November 2020 to April 2021. PubMed database, WHO library databases, and Google Scholar were used to search for relevant published materials including original and reviewed articles, conference papers and case reports from 1864 to 2020. Forty - eight articles and reports were included in the final reviews. Twenty - three outbreaks were described involving 33,830 suspected, presumptive, or confirmed cases of yellow fever and 8,355 deaths. The outbreaks occurred in every state of Nigeria including the Federal Capital Territory mostly during the rainy season. Low immunity in the population or low vaccination coverage, poor vector control, rainforest or savanna vegetation, rural-urban migration, and imported virus by travelers were common determinants noted. Public health responses have been through, centrally coordinated laboratory support, case management, emergency immunization, vector control, and surveillance. Yellow fever outbreaks have increased in frequency and geographical spread with associated mortality rates. To stem the tide, mass immunization with 17D vaccines is encouraged, planned urbanization with adequate vector control measures enforced, effective case definition, vector surveillance, and effective awareness campaigns should be emphasized.

A looming epidemic: combating the recurrent outbreaks of diphtheria in Nigeria.

Nigeria has endured several diphtheria outbreaks over the last few decades, mirroring a suboptimal population immunity across several demographics within the country. The country's northern region has been affected mainly by this infectious disease; it directly depicts the effect of poor DPT vaccine uptake amongst children in this region compared to other geopolitical zones in Nigeria. Whilst pharmaceutical intervention and surveillance activities have commenced as directed by the NCDC, to combat this public health menace, top leaders of the Nigerian healthcare system - public and private sectors, must understudy the predisposing factors gearing the recurrence of diphtheria in Nigeria and provide robust, research-based and scientific mechanisms to arrest the root causes of the incessant outbreaks. This article discusses the factors promoting the recurrent diphtheria outbreaks in Nigeria, the preexisting interventions with their existential deterrents, and new strategies recommended to curb the further resurgence of the disease.

Association between Conflict and Cholera in Nigeria and the Democratic Republic of the Congo.

Cholera outbreaks contribute substantially to illness and death in low- and middle-income countries. Cholera outbreaks are associated with several social and environmental risk factors, and extreme conditions can act as catalysts. A social extreme known to be associated with infectious disease outbreaks is conflict, causing disruption to services, loss of income, and displacement. To determine the extent of this association, we used the self-controlled case-series method and found that conflict increased the risk for cholera in Nigeria by 3.6 times and in the Democratic Republic of the Congo by 2.6 times. We also found that 19.7% of cholera outbreaks in Nigeria and 12.3% of outbreaks in the Democratic Republic of the Congo were attributable to conflict. Our results highlight the value of providing rapid and sufficient assistance during conflict-associated cholera outbreaks and working toward conflict resolution and addressing preexisting vulnerabilities, such as poverty and access to healthcare.

Tackling Cholera Outbreak Amidst COVID-19 Pandemic in Nigeria: Challenges and Recommendations.

Background: Since the first confirmed case of the Novel Coronavirus Disease 2019 (COVID-19) in Nigeria, the pandemic has become a major public health challenge, affecting different sectors of the country. While Nigeria is battling to control the spread of COVID-19, the eruption of new cholera cases has put additional pressure on the strained healthcare system. Evidence: We showed how the overwhelming focus on COVID-19 has jeopardized key cholera containment measures such as disease surveillance, risk communication, and case management. Policy Options and Recommendations: We recommend provision and universal access to safe water and sanitation as key cholera preventive and control measures. However, these are resources that developing countries including Nigeria find rather challenging to provide. We also proposed the implementation of well-coordinated multi-sectoral interventions that involve strengthening disease surveillance including access to safe drinking water, vaccines, and treatment, especially in vulnerable communities. Conclusion: This policy brief provides evidence for policymakers, which if acted upon, will foster sustainable solutions to the lingering cholera outbreaks in Nigeria.

HIV and Sexually Transmitted Infections Among Persons with Monkeypox - Eight U.S. Jurisdictions, May 17-July 22, 2022.

High prevalences of HIV and other sexually transmitted infections (STIs) have been reported in the current global monkeypox outbreak, which has affected primarily gay, bisexual, and other men who have sex with men (MSM) (1-5). In previous monkeypox outbreaks in Nigeria, concurrent HIV infection was associated with poor monkeypox clinical outcomes (6,7). Monkeypox, HIV, and STI surveillance data from eight U.S. jurisdictions* were matched and analyzed to examine HIV and STI diagnoses among persons with monkeypox and assess differences in monkeypox clinical features according to HIV infection status. Among 1,969 persons with monkeypox during May 17-July 22, 2022, HIV prevalence was 38%, and 41% had received a diagnosis of one or more other reportable STIs in the preceding year. Among persons with monkeypox and diagnosed HIV infection, 94% had received HIV care in the preceding year, and 82% had an HIV viral load of <200 copies/mL, indicating HIV viral suppression. Compared with persons without HIV infection, a higher proportion of persons with HIV infection were hospitalized (8% versus 3%). Persons with HIV infection or STIs are disproportionately represented among persons with monkeypox. It is important that public health officials leverage systems for delivering HIV and STI care and prevention to reduce monkeypox incidence in this population. Consideration should be given to prioritizing persons with HIV infection and STIs for vaccination against monkeypox. HIV and STI screening and other recommended preventive care should be routinely offered to persons evaluated for monkeypox, with linkage to HIV care or HIV preexposure prophylaxis (PrEP) as appropriate.

Changing epidemiology of yellow fever virus in Oyo State, Nigeria

BackgroundYellow Fever is an acute viral hemorrhagic disease endemic in tropical Africa and Latin America and is transmitted through infected mosquitoes. The earliest outbreak of yellow fever in Nigeria was reported in Lagos in 1864 with subsequent regular outbreaks reported until 1996. A large epidemic of yellow fever occurred in Oyo State in April and May 1987 following an epidemic of sylvatic yellow fever in Eastern Nigeria the previous year. For 21 years, no further confirmed cases were reported until September 2017 following which Nigeria has been responding to successive outbreaks. The renewed onset of yellow fever outbreaks in Nigeria followed a global trend of reports and from other African countries. Yellow Fever disease has no cure, but control is through vaccination and vector control. Eliminating Yellow fever Epidemic (EYE) strategy to improve high-risk countries’ prevention, preparedness, detection, management, and response to yellow fever outbreaks was developed by the WHO in 2017 and launched in Nigeria in April 2018. Yet, poor vaccination coverage continues to be a cause for concern.Materials and methodsWe conducted a retrospective cross-sectional study that examines the resurgence of Yellow fever cases and outbreaks from 2013 to 2020 in Oyo State, Nigeria. The Yellow Fever data for both surveillance and routine Expanded Programme on Immunization (EPI) were the focus of the review. Surveillance data were retrieved from the State’s database reported by all 33 LGAs, maintained by the State and supported by the World Health Organization at the Zonal and State levels. The routine EPI data were retrieved from District Health Information Software (DHIS_2). The proportion of LGAs reporting at least one case of suspected yellow fever with a blood specimen and the number of suspected cases reported for each year within the period under review was measured. We also assessed the trend of confirmed cases and the incidence per 100,000 persons. Also, suspected cases of yellow fever were categorized into four age groups and their vaccination status was assessed. The State’s annual administrative routine vaccination coverage for yellow fever vaccine was compared with the number of confirmed cases for each year.ResultsThe proportion of LGAs reporting at least a case of suspected yellow fever, with blood samples collected, ranged from 6.1 to 84.9% between 2014 and 2020 while a total of 9 confirmed (8 cases) and probable (1 case) cases of yellow fever were recorded. However, there were no confirmed cases from the year 2013 to 2016, including 2018 but an upward trend of incidence of the disease per 100,000 persons from 0% to 2013 through 2018, to 3.5% in 2019, and then to 5.6% in 2020 was observed. 93 of 240 (39%) suspected yellow fever cases reported during the given period were observed to have received yellow fever vaccine.ConclusionsIn conclusion, the increase in the circulation of the yellow fever virus in the state reiterates the state is at a high risk of yellow fever transmission and underlines the need for viable interventions such as environmental hygiene to rid the environment of the disease vector’s ecological niche and improving routine EPI coverage to provide population immunity.

Spatiotemporal Modelling of Endemic-epidemic Cholera in Nigeria

This study used a multivariate negative binomial model to capture the Spatiotemporal endemic-epidemic of infectious disease and explore the spatial and temporal patterns of cholera outbreaks in Nigeria. The model for the epidemic part measured spatial weights for the disease spread across the geographical neighboring regions and the endemic part accounted for temporal variation of disease incidence. Weekly count data on cholera from the Nigeria Department of Disease Control and Monitoring Epidemiology (NCDC SED) between January 1st and November 19th, 2018 was used to illustrate the model. In fitting the model, the study has shown that the model with seasonality and autoregressive components provided an adequate fit for the cholera count data and also perform better than the model without seasonality and autoregression for modelling the Spatiotemporal dependency structure of cholera disease

Descriptive epidemiology of the burden of human monkeypox in Nigeria: a retrospective review 2017-2021

INTRODUCTION: Sporadic outbreak of human monkeypox (hMPX) has been reported in 20 non-endemic countries as of the first quarter of 2022. One of these cases was epidemiologically linked to an individual with a history of previous visits to Nigeria. The purpose of this study was to determine the burden of hMPX in Nigeria, determine its hotspots and epidemic threshold from 2017-2021. METHODS: we reviewed reports on the outbreak of hMPX disease from the Nigerian centre for disease control (NCDC) between 2017-2021. We identified States affected, determined the number of confirmed monkeypox cases, and conducted a Geospatial analysis with Arc Geographical information system (ArcGIS), to describe the Hotspots of hMPX outbreaks in Nigeria classified as (major/high, medium, minor/low) clusters based on disease burden in affected states. We calculated the epidemic threshold (EPT) of outbreaks based on cumulative sum, (CUSUM) statistics, (C1-C3) for October 2017-2021. The epidemic threshold was based on the formula; EPT equals (=) Mean(α) + 3 standard deviations(δ) of seven past surveillance points of the year under consideration skipping over the two surveillance points before the month under consideration. RESULT: in 2017, 88 confirmed cases of hMPX were reported in Nigeria in 15 States, River State accounts for 25(28%) of cases, Bayelsa State 19(22%) was identified as major hotspots for hMPX, 13 States reported minor clusters of 44 cases, individuals aged 21-30 years 34(39%), were at higher risk. In 2018, 49 confirmed cases of hMPX were reported in Nigeria in 13 States, River State accounts for 14(29%) of cases, Bayelsa State 11(21%) were major hotspots for hMPX, 11 States reported minor clusters of 24 cases, individuals aged 31-40 years 17(35%) were at higher risk. In 2019, 47 confirmed cases of hMPX were reported in Nigeria in 11 States, Lagos State accounts for 15(32%) of cases, Delta State, 10(21%) were major hotspots for hMPX, Rivers and Bayelsa State accounts for 7(15%) and 7(15%) of cases were medium clusters of hMPX, 7 other States reported minor clusters of 8 cases, individual aged 31-40 years 22(47%) were most affected. In 2020, 8 confirmed cases of hMPX were reported in Nigeria in 5 States Lagos State with 4(50%) of cases, was a major hotspot for hMPX, four other States accounted for minor clusters of four cases, individual aged 21-30 and 31-40years 4(50%), 4(50%) respectively were most affected. In 2020, 34 confirmed cases of hMPX were reported in Nigeria in 9 States, Delta State accounts for 9(27%) of cases, Lagos State, 6(18%), and Bayelsa 6(18%) were the major hotspots. Rivers and Edo State with 5(15%) and 4(12%) of cases were medium clusters, four other states had minor clusters of four cases, individuals aged 31-40 years, 13(38%) were at high risk. The epidemic threshold for hMPX was (12, 8, 1, and 4) respectively. CONCLUSION: monkeypox is endemic in Nigeria, 226 confirmed Human Monkeypox (hMPX) cases were reported with 8 fatalities across 20 States. Young adults aged 21-30 years are at a higher risk of infection. The disease is clustered in two geopolitical zones (South-west/South-south) of Nigeria. The observed hMPX cases were higher than the epidemic threshold in 2020 and 2021 such may have contributed to the sustained sporadic outbreak of monkeypox reported as of the first quarter of 2022, the risk factors included consumption of giant rats/monkeys, occupational hazard amongst health care workers, individual who frequent crowded social gathering. Consequently, improved screening for hMPX at the border post, and enhanced in-country surveillance may ensure early detection, and prevent the spread of hMPX. Furthermore, training of health care workers on increased risk perception of hMPX may reduce occupational hazards. These measures should be complemented with public enlightenment of high-risk populations.