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Lassa fever is a zoonotic disease identified by the World Health Organization (WHO) as having pandemic potential. This study estimates the health-economic burden of Lassa fever throughout West Africa and projects impacts of a series of vaccination campaigns. We also model the emergence of "Lassa-X" - a hypothetical pandemic Lassa virus variant - and project impacts of achieving 100 Days Mission vaccination targets. Our model predicted 2.7M (95% uncertainty interval: 2.1M-3.4M) Lassa virus infections annually, resulting over ten years in 2.0M (793.8K-3.9M) disability-adjusted life years (DALYs). The most effective vaccination strategy was a population-wide preventive campaign primarily targeting WHO-classified "endemic" districts. Under conservative vaccine efficacy assumptions, this campaign averted $20.1M ($8.2M-$39.0M) in lost DALY value and $128.2M ($67.2M-$231.9M) in societal costs (International dollars 2021). Reactive vaccination in response to local outbreaks averted just one-tenth the health-economic burden of preventive campaigns. In the event of Lassa-X emerging, spreading throughout West Africa and causing approximately 1.2M DALYs within two years, 100 Days Mission vaccination averted 22% of DALYs given a vaccine 70% effective against disease, and 74% of DALYs given a vaccine 70% effective against both infection and disease. These findings suggest how vaccination could alleviate Lassa fever's burden and assist in pandemic preparedness.
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Over past decades, there has been increasing geographical spread of Lassa fever (LF) cases across Nigeria and other countries in West Africa. This increase has been associated with significant morbidity and mortality despite increasing focus on the disease by both local and international scientists. Many of these studies on LF have been limited to few specialised centres in the country. This study was done to identify sociodemographic and clinical predictors of LF disease and related deaths across Nigeria. We analysed retrospective surveillance data on suspected LF cases collected during January-June 2018 and 2019. Multivariable logistic regression analyses were used to identify the factors independently associated with laboratory-confirmed LF diagnosis, and with LF-related deaths. There were confirmed 815 of 1991 suspected LF cases with complete records during this period. Of these, 724/815 confirmed cases had known clinical outcomes, of whom 100 died. LF confirmation was associated with presentation of gastrointestinal tract (aOR 3.47, 95% CI: 2.79-4.32), ear, nose and throat (aOR 2.73, 95% CI: 1.80-4.15), general systemic (aOR 2.12, 95% CI: 1.65-2.70) and chest/respiratory (aOR 1.71, 95% CI: 1.28-2.29) symptoms. Other factors were being male (aOR 1.32, 95% CI: 1.06-1.63), doing business/trading (aOR 2.16, 95% CI: 1.47-3.16) and farming (aOR 1.73, 95% CI: 1.12-2.68). Factors associated with LF mortality were a one-year increase in age (aOR 1.03, 95% CI: 1.01-1.04), bleeding (aOR 2.07, 95% CI: 1.07-4.00), and central nervous manifestations (aOR 5.02, 95% CI: 3.12-10.16). Diverse factors were associated with both LF disease and related death. A closer look at patterns of clinical variables would be helpful to support early detection and management of cases. The findings would also be useful for planning preparedness and response interventions against LF in the country and region.
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BACKGROUND: Large outbreaks of Lassa fever (LF) occur annually in Nigeria. The case fatality rate among hospitalised cases is ~ 20%. The antiviral drug ribavirin along with supportive care and rehydration are the recommended treatments but must be administered early (within 6 days of symptom onset) for optimal results. We aimed to identify factors associated with late presentation of LF cases to a healthcare facility to inform interventions. METHODS: We undertook a retrospective cohort study of all laboratory confirmed LF cases reported in Nigeria from December 2018 to April 2019. We performed descriptive epidemiology and a univariate Cox proportional-hazards regression analysis to investigate the effect of clinical (symptom severity), epidemiological (age, sex, education, occupation, residential State) and exposure (travel, attendance at funeral, exposure to rodents or confirmed case) factors on time to presentation. RESULTS: Of 389 cases, median presentation time was 6 days (IQR 4-10 days), with 53% attending within 6 days. There were no differences in presentation times by sex but differences were noted by age-group; 60+ year-olds had the longest delays while 13-17 year-olds had the shortest. By sex and age, there were differences seen among the younger ages, with 0-4-year-old females presenting earlier than males (4 days and 73% vs. 10 days and 30%). For 5-12 and 13-17 year-olds, males presented sooner than females (males: 5 days, 65% and 3 days, 85% vs. females: 6 days, 50% and 5 days, 61%, respectively). Presentation times differed across occupations 4.5-9 days and 20-60%, transporters (people who drive informal public transport vehicles) had the longest delays. Other data were limited (41-95% missing). However, the Cox regression showed no factors were statistically associated with longer presentation time. CONCLUSIONS: Whilst we observed important differences in presentation delays across factors, our sample size was insufficient to show any statistically significant differences that might exist. However, almost half of cases presented after 6 days of onset, highlighting the need for more accurate and complete surveillance data to determine if there is a systemic or specific cause for delays, so to inform, monitor and evaluate public health strategies and improve outcomes.
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Antivirales/uso terapéutico , Fiebre de Lassa/tratamiento farmacológico , Fiebre de Lassa/epidemiología , Fiebre de Lassa/prevención & control , Ribavirina/uso terapéutico , Tiempo de Tratamiento , Adolescente , Adulto , Niño , Preescolar , Estudios de Cohortes , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Nigeria/epidemiología , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Adulto JovenRESUMEN
Lassa fever cases have increased in Nigeria since 2016 with the highest number, 633 cases, reported in 2018. From 1 January to 28 April 2019, 554 laboratory-confirmed cases including 124 deaths were reported in 21 states in Nigeria. A public health emergency was declared on 22 January by the Nigeria Centre for Disease Control. We describe the various outbreak responses that have been implemented, including establishment of emergency thresholds and guidelines for case management.
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Brotes de Enfermedades/prevención & control , Fiebre de Lassa/prevención & control , Brotes de Enfermedades/estadística & datos numéricos , Urgencias Médicas/epidemiología , Guías como Asunto , Personal de Salud/estadística & datos numéricos , Humanos , Fiebre de Lassa/epidemiología , Fiebre de Lassa/mortalidad , Virus Lassa , Nigeria/epidemiología , Factores de TiempoRESUMEN
BACKGROUND: An estimated 75% of Nigerians are at risk of hepatitis B virus (HBV) exposure. In an attempt to reduce the menace, the assessment of risk factors associated with HBV infection and general perception of infected individuals is a step in that direction. AIM OF THE STUDY: This study, therefore, identified exposure to risk factors and general perceptions associated with HBV infection in infected individuals in Zaria, Nigeria. METHODOLOGY: Four milliliters of blood were collected in ethylenediaminetetraacetic acid container from each of 165 HBV surface antigen (HBsAg)-positive participants recruited purposively from the gastroenterology clinic of ABUTH Zaria from May to August 2017. Plasma was separated and used to screen for HBsAg with Fastep® rapid strip. Epi Info® questionnaire database was used to collate data on sociodemographics, risk factors, and perception indices. GraphPad Prism 6 was used for statistical analysis. RESULTS: The median interquartile range age of the participants was 31.0 (25.5-39.0) years with 107 (64.8%) male participants. Sharing hair clippers, commercial pedicure, and body piercing among others were some of the risks that the study participants reported to be exposed to. One-quarter of health workers involved in the study had needlestick injury. Less than half of the study participants (47.7%) knew of hepatitis B before testing HBsAg seropositive. Knowledge of the HBV vaccine before testing and adherence was generally poor (38.6% and 44.6%, respectively). There was a significant linear relationship between the level of education and knowledge of hepatitis B. CONCLUSION: Considering the myriads of already established risks of HBV seen in Zaria, massive enlightenment campaigns need to be embarked on continuously through all available media, including social media.
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BACKGROUND: The World Health Assembly adopted the Global Action Plan on Antimicrobial Resistance, which includes improving the knowledge base through surveillance and research. Noteworthily, the World Health Organization has advocated a Global Antimicrobial Resistance Surveillance System to address the plan's surveillance objective, with most African countries enrolling in or after 2017. AIM: The aim of this article was to review prior data on antimicrobial resistance of Vibrio cholerae from sub-Saharan Africa with a view for future control and intervention strategies. METHODS: We used the Preferred Reporting Items for Systematic Review and Meta-Analysis (or 'PRISMA') guidelines to search the PubMed and African Journals Online databases, as well as additional articles provided by the Nigeria Centre for Disease Control, for articles reporting on the antibiotic susceptibility of V. cholerae between January 2000 and December 2017. RESULTS: We identified 340 publications, of which only 25 (reporting from 16 countries within the sub-Saharan African region) were eligible. The majority (20; 80.0%) of the cholera toxigenic V. cholerae isolates were of the serogroup O1 of the El Tor biotype with Ogawa and Inaba serotypes predominating. Resistance was predominantly documented to trimethoprim-sulphamethoxazole (50% of the studies), ampicillin (43.3% of the studies), chloramphenicol (43.3% of the studies) and streptomycin (30% of the studies). Resistance mechanisms were reported in 40% of the studies. CONCLUSION: Our results demonstrate a documented antimicrobial resistance of V. cholerae to multiple antibiotic classes, including cell wall active agents and antimetabolites with evidence of phenotypic/genotypic resistance to fluoroquinolones.
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BACKGROUND: Asymptomatic malaria parasitaemia remains an effective transmission pool for malaria during pregnancy, which can result in placenta parasitaemia and adverse pregnancy outcomes. This study examined asymptomatic malaria parasitaemia among pregnant women in the antenatal clinic in General Hospital, Nassarawa-Eggon, Nasarawa State, Nigeria. MATERIALS AND METHODS: A cross-sectional hospital based survey was carried out among 242 apparently healthy pregnant women presenting for booking in an antenatal clinic between June and August 2014. An interviewer-administered semi-structured questionnaire was used to obtain information on socio-demographic data and possible risk factors for asymptomatic malaria parasitaemia. These women should not have taken antimalarial medicines two weeks prior to the interview. Microscopy was used to identify malaria parasites and haemoglobin levels were estimated. Data was analysed using Epi Info 3.5.3. Descriptive statistics such as means, standard deviations, proportions, and range were used to summarise the data and the Chi square test was used to test association between categorical explanatory variables and outcome variables. RESULTS: Mean age (± SD) was 25.5 ± 5.5 years, 118 (48.8%) of the women were in the 25-34 years age group, while 153 (63.2%) were multigravidae. Asymptomatic Plasmodium falciparum infection was found in 55 women (22.7%; 95% CI: 18.0-28.7%) Among these, 36 (65.5%) were anaemic [OR: 2.0, CI: 1.1-3.8]. Long lasting insecticidal net (LLIN) was not used by 17 (30.9%) of the respondents. Younger age group (below 25 years) [AOR: 2.4, CI: 1.2-4.9] and non-usage of LLIN [AOR: 2.4, CI: 1.1-5.1] were significant predictors of asymptomatic malaria parasitaemia. CONCLUSION: Asymptomatic malaria parasitaemia is a health challenge among pregnant women, especially in the younger age group and can predispose them to maternal anaemia. The supply and appropriate use of LLIN should be intensified.
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Hepatitis B virus (HBV) infection accounts for about 1 million deaths worldwide annually. This study was to determine the prevalence, distribution of HBV, and factors associated with infection in an apparently healthy population in Nigeria. A cross-sectional study among the general population was conducted employing a multistage sampling technique. Data on demographic, social, and behavioral indicators were collected using questionnaires and blood samples tested for HBV seromarkers. Descriptive, bivariate, and multivariate analyses were done. Prevalence of hepatitis B infection was 12.2% (confidence interval [CI] = 10.3-14.5). Of the participants, more than half, 527 (54.6%), had evidence of previous exposure to HBV, while 306 (31.7%) showed no serologic evidence of infection or vaccination. Only 76 (7.9%) participants showed serologic evidence of immunity to HBV through vaccination. Factors associated with testing positive for HBV infection were dental procedure outside the health facility (odds ratios [OR] = 3.4, 95% CI = 1.52-7.70), local circumcision (OR = 1.73, 95% CI = 1.17-2.57), and uvulectomy (OR = 1.65, 95% CI = 1.06-2.57). With logistic regression, only dental procedure outside the health facility (adjusted OR = 3.32, 95% CI = 1.38-7.97) remained significant. This first national survey on seroprevalence of hepatitis B describes the epidemiology and high prevalence of HBV infection in Nigeria and highlights the need for improved vaccination against HBV.
Asunto(s)
Anticuerpos contra la Hepatitis B/inmunología , Antígenos de Superficie de la Hepatitis B/inmunología , Hepatitis B Crónica/epidemiología , Enfermedad Aguda , Adolescente , Adulto , Anciano , Transfusión Sanguínea/estadística & datos numéricos , Niño , Circuncisión Masculina/estadística & datos numéricos , Estudios Transversales , Atención Odontológica/estadística & datos numéricos , Femenino , Hepatitis B/epidemiología , Hepatitis B/inmunología , Hepatitis B/prevención & control , Vacunas contra Hepatitis B/uso terapéutico , Hepatitis B Crónica/inmunología , Hepatitis B Crónica/prevención & control , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Nigeria/epidemiología , Oportunidad Relativa , Prevalencia , Factores de Riesgo , Estudios Seroepidemiológicos , Úvula/cirugía , Adulto JovenRESUMEN
BACKGROUND: Malaria in pregnancy remains a public health problem in Nigeria. It causes maternal anaemia and adversely affects birth outcome leading to low birth weight, abortions and still births. Nigeria has made great strides in addressing the prevention and control of malaria in pregnancy. However, recent demographic survey shows wide disparities in malaria control activities across the geopolitical zones. This situation has been compounded by the political unrest and population displacement especially in the Northeastern zone leaving a significant proportion of pregnant women at risk of diseases, including malaria. The use of malaria preventive measures during pregnancy and the risk of malaria parasitaemia, anaemia and low birth weight babies were assessed among parturient women in an insurgent area. METHODS: A cross-sectional survey was conducted among 184 parturient women at Federal Medical Centre, Nguru in Yobe state, between July and November 2014. Information on demographics, antenatal care and prevention practices was collected using an interviewer-administered questionnaire. Maternal peripheral and the cord blood samples were screened for malaria parasitaemia by microscopy of Giemsa-stained blood films. The presence of anaemia was also determined by microhaemocrit method using the peripheral blood samples. Data was analysed using descriptive and analytical statistics. RESULTS: Prevalence of malaria parasitaemia, anaemia and low birth weight babies was 40.0, 41.0 and 37.0 %, respectively, and mothers aged younger than 25 years were mostly affected. Eighty (43.0 %) of the women received up to two doses of sulfadoxine-pyrimethamine for intermittent preventive treatment (IPTp-SP) during pregnancy and most, 63 (83.0 %) of those tested malaria positive received less than these. Presence of malaria infection at antenatal clinic enrollment (OR: 6.6; 95 % CI: 3.4-13.0), non-adherence to direct observation therapy for administration of IPTp-SP (OR: 4.6; 95 % CI: 2.2-9.5) and receiving Asunto(s)
Control de Enfermedades Transmisibles/métodos
, Transmisión de Enfermedad Infecciosa/prevención & control
, Investigación sobre Servicios de Salud
, Malaria/epidemiología
, Malaria/prevención & control
, Complicaciones Infecciosas del Embarazo/epidemiología
, Complicaciones Infecciosas del Embarazo/prevención & control
, Adolescente
, Adulto
, Estudios Transversales
, Femenino
, Accesibilidad a los Servicios de Salud
, Humanos
, Microscopía
, Nigeria/epidemiología
, Parasitemia/diagnóstico
, Embarazo
, Mujeres Embarazadas
, Encuestas y Cuestionarios
, Centros de Atención Terciaria
, Adulto Joven
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OBJECTIVE: To evaluate the case-based measles surveillance system in Kaduna State of Nigeria and identify gaps in its operation. INTRODUCTION: In Africa, approximately 13 million cases, 650,000 deaths due to measles occur annually, with sub-Saharan Africa having the highest morbidity and mortality. Measles infection is endemic in Nigeria and has been documented to occur all year round, despite high measles routine and supplemental immunization coverage. The frequent outbreaks of measles in Kaduna State prompted the need for the evaluation of the measles case-based surveillance system. METHODS: We interviewed stakeholders and conducted a retrospective record review of the measles case-based surveillance data from 2010 - 2012 and adapted the 2001 CDC guidelines on surveillance evaluation and the Framework for Evaluating Public Health Surveillance Systems for Early Detection of Outbreaks, to assess the systems usefulness, representativeness, timeliness, stability, acceptability and data quality. We calculated the annualized detection rate of measles and non-measles febrile rash, proportion of available results, proportion of LGAs (Districts) that investigated at least one case with blood, proportion of cases that were IgM positive and the incidence of measles. We compared the results with WHO(2004) recommended performance indicators to determine the quality and effectiveness of measles surveillance system. RESULTS: According to the Stakeholders, the case-based surveillance system was useful and acceptable. Median interval between specimen collection and release of result was 7days (1 - 25 days) in 2010, 38 days (Range: 16 - 109 days) in 2011 and 11 days (Range: 1 - 105 days) in 2012. The annualized detection rate of measles rash in 2010 was 2.1 (target: 32), 1.0 (target: 32) in 2011 and 1.4 (target: 32) in 2012. The annualized detection rate of non-measles febrile rash in 2010 was 2.1 (target: 32), 0.6 (target: 32) in 2011 and 0.8 (target: 32) in 2012. Case definitions are simple and understood by all the operators. CONCLUSION: This evaluation showed that the surveillance system was still useful. Also, the efficiency and effectiveness of the laboratory component as captured by the "median interval between specimen collection and the release of results improved in 2010 and 2012 compared to 2011. However, there was a progressive decline in the timeliness and completeness of weekly reports in the years under review.
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On July 20, 2014, the first known case of Ebola virus disease (Ebola) in Nigeria, in a traveler from Liberia, led to an outbreak that was successfully curtailed with infection control, contact tracing, isolation, and quarantine measures coordinated through an incident management system. During this outbreak, most contacts underwent home monitoring, which included instructions to stay home or to avoid crowded areas if staying home was not possible. However, for five contacts with high-risk exposures, group quarantine in an observation unit was preferred because the five had crowded home environments or occupations that could have resulted in a large number of community exposures if they developed Ebola.