| Objective To provide the relationship between infectious mononucleosis (IM) and Epstein-barr virus(EBV) DNA load, and analyzing the risk factors for the severe infectious mononucleosis(severe IM).Methods Clinical data was evaluated retrospectively in 346 patients of IM. Common IM and severe IM were analyzed by case-control study, and the risk factors for the presence of severe IM were analyzed.Results (1) 55.8% of the patients were 3 years old to 7 years old. The ratio of boys versus girls was 4:3. Seasonal peak was in summer and autumn(from July to October). (2) Increases with EBV DNA load, febrile duration, moderate to severe hepatosplenomegaly ratio and average hospitalization time gained; The blood system, liver and myocardial were damaged more severely(P<0.05). (3) Row in the top four of damaged system were digestive system (91.8%), respiratory system (56.9%), cardiovascular system (28.3%) and blood system (8.28%). (4) The main symptoms and signs of the patients included (severe IM vs common IM) fever (100% vs 93.5%), eyelid edema (61.9% vs 59.1%), isthmitis (71.4% vs 49.5%), nasal resistance (52.4% vs 60.6%), jaundice (30.8% vs 0.7%), lymphadenectasis (4.8% vs 31.1%) and hepatosplenomegaly (95.2% vs 89.2%). Higher incidence of fever, eyelid edema, isthmitis, jaundice and hepatosplenomegaly was found in severe IM. (5) The main abnormal assistant examination of the patients included (severe IM vs common IM) WBC, hemoglobin (Hb) or platelet (PLT) of hemanalysis decline (90.5% vs 2.8%), elevated C-reactive protein (CRP) (33.3% vs 31.9%), variation lymphocytes percentage > 10% (72.2% vs 42.6%), abnormal liver function (100% vs 64.9%), myocardial enzyme abnormal (52.6% vs 26.6%), EBV IgM assay positive (73.3% vs 61.8%), heterophile antibody assay positive (100% vs 60.0%), EBV DNA load positive (90.5% vs 81.5%), bone marrow cytology (100% vs 94.9%), abdominal B-sonography (100% vs 91.1%), et al. Higher incidence of all abnormal assistant examination was found in severe IM. (6) X2 test for 17 influence factors of severe IM was made. The results indicated that high fever (>40℃), jaundice, WBC, Hb or PLT of hemanalysis decline, abnormal liver function, myocardial enzyme abnormal and EBV DNA load>5.0×106copies/mL had significant differences(P<0.05). (7) The risk factors of severe IM were analyzed by univariate logistic regression analysis. The results indicated that high fever (>40℃), jaundice, WBC, Hb or PLT of hemanalysis decline, myocardial enzyme abnormal and EBV DNA load>5.0×106copies/mL had significant differences(P<0.05). (8) Screening out five risk factors of severe IM were analyzed by stepwise logistic regression analysis. The results indicated that the odds ratio of high fever (>40℃) (X1) was 6.630 (95%CI=2.436～18.047 , P<0.01) , and the odds ratio of jaundice (X2) was 0.889 (95%CI=2.085～209.274,P<0.05). The logistic regress equation of severe IM risk factors wasLogit(P)=β0(-3.545)+β1(1.892)x1+β2(3.039)x2 (x2=31.058,P<0.01). The sensitivity of equation was 57.1%, and the specificity was 85.9%. Conclusions (1) Most patients of IM were 3 years old to 7 years old. The male patients were more than female. Seasonal peak was in summer and autumn. (2) Disease severity gradually deteriorated with the increasing EBV DNA load. (3) Row in the top four of damaged system were digestive system, respiratory system, cardiovascular system and blood system. (4) High fever (>40℃), jaundice, WBC, Hb or PLT of hemanalysis decline , abnormal liver function, myocardial enzyme abnormal and EBV DNA load > 5.0×106copies/mL could help determine if severe IM would happen. (5) High fever (>40℃), jaundice, WBC, Hb or PLT of hemanalysis decline, myocardial enzyme abnormal and EBV DNA load > 5.0×106copies/mL were the risk factors of severe IM. Jaundice and EBV DNA load > 5.0×106copies/mL were the high-risk factors. (6) The logistic regress equation of severe IM risk factors wasLogit(P)=β0(-3.545)+β1(1.892)x1+β2(3.039)x2 (x2=31.058,P<0.01). The specificity was higher than the sensitivity. So we must comprehensive analyzed high-risk factors combined with other risk factors when determine whether happen severe IM. |
