Multivariate analysis demonstrated that the following factors were associated with the occurrence of pleural effusion in scrub typhus: older age (odds ratio [OR] = 1.029, P = 0.037, confidence interval [CI] = 1.002–1.056); male gender (OR = 1.924, P = 0.020, CI = 1.109–3.340); presence of heart failure (OR = 2.628, P = 0.039, CI = 1.052–6.565); and lower albumin (OR = 0.107, P ≤ 0.001, CI = 0.058–0.196). The gene discussed is ALB; the disease is Pleural effusion.