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.

Immunophenotyping of Nigerian cases of non-Hodgkin's lymphomas on paraffin sections

One hundred cases of routinely fixed and processed non-Hodgkin's lymphoma from Nigeria were immunostained with a small panel of monoclonal antibodies against B-, T- and macrophage antigens. The aims of the study were to assess the suitability of stored material from a country like Nigeria for immunohistochemical examination and the ability of the antibody panel to evaluate the distribution of B- and T-cell neoplasms. Eighty-seven of the 100 cases gave interpretable immunostaining, with 75 being B-cell and 12 T-cell neoplasms. Eighty-seven of the 100 cases gave interpretable immunostaining, with 75 being B-cell and 12 T-cell neoplasms. There were no tumours of macrophage lineage. Four cases gave satisfactory staining of reactive lymphoid cells but no reactivity with malignant cells and thus were not phenotyped. The remaining nine cases gave no staining of neoplastic or reactive cells, suggesting that they were unsuitable for immunohistochemical study, presumably because of inappropriate fixation and handling. We concluded that a panel of three monoclonal antibodies is suitable for routine immunostaining of conventionally fixed and processed blocks in Third World countries and will give diagnostically useful information in approximately 95% of cases.