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.

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.

Corrigendum: Caseload and Case Fatality of Lassa Fever in Nigeria, 2001-2018: A Specialist Center's Experience and Its Implications.

[This corrects the article DOI: 10.3389/fpubh.2019.00170.].

Caseload and Case Fatality of Lassa Fever in Nigeria, 2001-2018: A Specialist Center's Experience and Its Implications.

Background: The general lack of comprehensive data on the trends of Lassa fever (LF) outbreaks contrasts with its widespread occurrence in West Africa and is an important constraint in the design of effective control measures. We reviewed the contribution of LF to admissions and mortality among hospitalized patients from 2001 to 2018 in the bid to address this gap. Methods: Observational study of LF caseload and mortality from 2001 to 18 in terms of the contribution of confirmed LF to admissions and deaths, and case fatality (CF) among patients with confirmed LF at a specialist center in Nigeria. The diagnosis of LF was confirmed using reverse transcription polymerase chain reaction (RT-PCR) test, and medians and frequencies were compared using Kruskal-Wallis, Mann-Whitney and χ2 tests, with p-values <0.05 taken as significant. Results: The contribution of confirmed LF to deaths (362/9057, 4.0%) was significantly higher than to admissions (1,298/185,707, 0.7%; OR [95% CI] = 5.9 [5.3, 6.7], p < 0.001). The average CF among patients with confirmed LF declined from 154/355 (43%) in 2001-09 to 183/867 (21.1%) (OR [95% CI] = 2.9 [2.2, 3.7], p < 0.001) in 2011-18. The annual CF declined from 94% in 2001 to 15% in 2018 whereas the caseload increased from 0.3 to 3.4%. The outbreaks were characterized by irregular cycles of high caseload in 2005-2007, 2012-2014, and 2016-2018, and progressive blurring of the seasonality. Conclusion: LF outbreaks in Nigeria have upgraded spatially and temporally, with the potential for cycles of increasing severity. The strategic establishment of LF surveillance and clinical case management centers could be a pragmatic and cost-effective approach to mitigating the outbreaks, particularly in reducing the associated CF. Urgent efforts are needed in reinvigorating extant control measures while the search for sustainable solutions continues.

Discovery of novel rhabdoviruses in the blood of healthy individuals from West Africa.

Next-generation sequencing (NGS) has the potential to transform the discovery of viruses causing unexplained acute febrile illness (UAFI) because it does not depend on culturing the pathogen or a priori knowledge of the pathogen's nucleic acid sequence. More generally, it has the potential to elucidate the complete human virome, including viruses that cause no overt symptoms of disease, but may have unrecognized immunological or developmental consequences. We have used NGS to identify RNA viruses in the blood of 195 patients with UAFI and compared them with those found in 328 apparently healthy (i.e., no overt signs of illness) control individuals, all from communities in southeastern Nigeria. Among UAFI patients, we identified the presence of nucleic acids from several well-characterized pathogenic viruses, such as HIV-1, hepatitis, and Lassa virus. In our cohort of healthy individuals, however, we detected the nucleic acids of two novel rhabdoviruses. These viruses, which we call Ekpoma virus-1 (EKV-1) and Ekpoma virus-2 (EKV-2), are highly divergent, with little identity to each other or other known viruses. The most closely related rhabdoviruses are members of the genus Tibrovirus and Bas-Congo virus (BASV), which was recently identified in an individual with symptoms resembling hemorrhagic fever. Furthermore, by conducting a serosurvey of our study cohort, we find evidence for remarkably high exposure rates to the identified rhabdoviruses. The recent discoveries of novel rhabdoviruses by multiple research groups suggest that human infection with rhabdoviruses might be common. While the prevalence and clinical significance of these viruses are currently unknown, these viruses could have previously unrecognized impacts on human health; further research to understand the immunological and developmental impact of these viruses should be explored. More generally, the identification of similar novel viruses in individuals with and without overt symptoms of disease highlights the need for a broader understanding of the human virome as efforts for viral detection and discovery advance.

Age-related cytokine profile in uncomplicated malaria infection / Perfil de citoquina relacionado con la edad en la infección no complicada de malaria

Objective: Malaria infection is severe in children who are believed to be more at risk because of their relative poor immunity against the disease. Some cytokine levels (IFN-g, IL-2, IL-4, and IL-10) of children, adolescents, and adults were assessed in this study. Methods: Cytokine levels were assayed by using Enzyme Linked Immunosorbent Assay (ELISA). Malaria diagnosis and blood parameters were carried out by using standard parasitological and haematological techniques. Results: The mean cytokine levels were significantly elevated in children, adolescent, and adult subjects when compared to their respective healthy controls (p<0.05). Also, mean IFN-g and IL-2 levels were significantly higher in children than in adults (IFN-g: 57.31±77.79 pg/ml vs. 20.37± 2.95 pg/ml, and IL-2: 108.75±63.53 pg/ml vs. 66.09±45.34 pg/ml) (p<0.05) and adolescents (IFN-g: 20.37± 2.95 pg/ml and IL-2: 66.09±45.34 pg/ml) respectively. Furthermore, mean IL-10 level was significantly lower in children (7.39±15.08 pg/ml) than mean level in adults (22.73±13.89 pg/ml). The mean haematological parameters revealed significant increase in total white blood cell, CD4, and CD8 count and significant decrease in the hematocrit of children in relation to adolescent and adult subjects (p<0.05). However, mean monocyte count was significantly higher in subjects than in their respective healthy controls (p<0.05). Conclusion: Findings in this study revealed better Th1 driven immune response in children than in adolescents and adults.

Objetivo: La infección por malaria es grave en los niños debido a su relativa baja inmunidad contra la enfermedad. Se evaluaron en este estudio algunos niveles de citoquinas (IFN-g, IL-2, IL-4 e IL-10) en niños, adolescentes y adultos. Métodos: Se analizaron los niveles de citocinas mediante ensayo inmunoabsorbente ligado a enzimas (ELISA). El diagnóstico de malaria y sanguíneas se llevó a cabo utilizando las técnicas parasitológicas y hematológicas. Resultados: Los niveles de citoquinas eran significativamente elevados en los niños, adolescentes y adultos en comparación con sus respectivos controles sanos (p<0.05). Además, la media de IFN-g y los niveles de IL-2 fueron significativamente mayores en niños que en adultos (IFN-g: 57.31 ± 77.79 pg/ml vs. 20.37 ± 2.95 pg/ml e IL-2: 108.75 ± 63.53 pg/ml vs. 66.09 ± 45.34 pg/ml) (p<0,05) y adolescentes (IFN-g: 20.37 ± 2.95 pg/ml e IL-2: 66.09 ± 45.34 pg/ml). Por otra parte, la media de IL-10 fue significativamente menor en los niños (7.39 ± 15.08 pg/ml) que en nivel medio en los adultos (22.73 ± 13.89 pg/ml). La media de los parámetros hematológicos reveló un aumento significativo en la celda total de color blanco, CD4, CD8 y disminución significativa en el hematocrito de los niños en relación con los adolescentes y los adultos (p<0.05). No obstante, el número promedio de monocitos fue significativamente mayor en los sujetos que en sus respectivos controles sanos (p<0.05). Conclusión: Los hallazgos en este estudio revelaron una mejor respuesta inmune Th1 en niños que en adolescentes y adultos.