Plasma zinc and selenium levels in adult inpatients with Lassa fever in Nigeria: A case-controlled study

Objectives

Lassa fever (LF), a viral hemorrhagic disease endemic to West Africa, carries a high mortality. Scanty studies indicate that micronutrients may play a role in immunity to LF. We performed a case-controlled study to evaluate plasma zinc and selenium levels in hospitalized patients with LF.

Methods

A cross-sectional controlled study of adults with confirmed LF and healthy controls presenting to the Institute of Lassa Fever Research and Control, Irrua Specialist Teaching Hospital, Nigeria, was performed between January and April 2023. After informed consent, blood samples were obtained, and LF was confirmed using a real-time polymerase chain reaction assay. Plasma zinc and selenium levels in plasma were measured using the AA500 Atomic Absorption Spectrophotometer. Data analysis was performed using SPSS version 21.0, comparing zinc, selenium, urea, and blood urea nitrogen levels of patients with LF and healthy control patients.

Results

We enrolled 124 patients: 64 patients with LF and 60 healthy controls. There was no difference in mean age (37.6 years vs 35.2 years, P = 0.10) and gender (male 53% vs 56%, P = 0.82). Mean plasma zinc levels were significantly lower in patients with LF (0.97 mg/ml, SD = 0.12) compared with controls (1.85 mg/ml, SD = 0.13; P <0.0001). A consistent depletion of zinc levels was seen across the moderately severe cases (n = 28) and severe cases (36 cases) compared with healthy controls (0.97 ± 0.19 vs 0.96 ± 0.10, P = 0001). Plasma selenium levels were also significantly lower in patients with LF (mean: 76.80 ng/ml, SD: 6.66, % coefficient of variation: 8.67) compared with controls (mean: 93.10 ng/ml, SD: 12.46, % coefficient of variation: 13.38) (P = 0.008). Selenium levels in severe LF cases were 73.47 ± 14.68 and 80.98 ± 18.60 in moderately severe cases (P = 0.26).

Conclusions

Significantly low levels of zinc and selenium were observed in patients with LF compared with healthy controls, suggesting a role in susceptibility and pathogenesis. Given that zinc and selenium are essential trace elements for optimal functioning of the immune system, they may play a role in improving management outcomes.