Deng Y C, Dong C X, Chen S, Mo L Y, Huang C Z
Department of Laboratory Medicine,The Affiliated Children's Hospital of Xiangya School of Medcine, Central South University (Hunan Children's Hospital),Changsha 410007,China.
Department of Infectious Diseases, The Affiliated Children's Hospital of Xiangya School of Medcine, Central South University (Hunan Children's Hospital),Changsha 410007,China.
Zhonghua Yu Fang Yi Xue Za Zhi. 2024 Oct 6;58(10):1580-1586. doi: 10.3760/cma.j.cn112150-20240510-00372.
To study the correlation between the level of Bordetella pertussis nucleic acid and clinical features of the disease in infants and young children and to investigate the risk factors for the development of severe pertussis. Using retrospective research methods, children aged 1 month-3 years who came to Hunan Children's Hospital from August 2023 to February 2024 and were diagnosed with pertussis for analysis. According to the logarithmic value of BP-DNA (log copies/ml), 35 cases were divided into the low load group, 78 cases were divided into the medium load group and 94 cases were divided into the high load group; 54 cases were divided into the severe whooping cough group and 153 cases were divided into the general group according to the severity of the disease; the clinical characteristics and laboratory data of the groups were compared, and the risk factors for the occurrence of severe whooping cough were analyzed at the same time. The ROC was used to evaluate the predictive efficacy of BP-DNA and WBC count for the development of severe pertussis. The results showed that in the high-dose group, the WBC count(22.59×10/L), L/N ratio(3.31), and hospitalization days(9.0 d) were significantly higher than those in the medium-dose group and low-dose group (=6.309, 2.825, 15.149, all <0.05). The hospitalization rate (100%), combined infection rate (64.96%), incidence of severe whooping cough (31.9%), pyrexia rate (29.8%), and corticosteroid use rate (57.4%) were also significantly higher than the other two groups (²=25.977, 9.163, 9.371, 8.299, 20.332, all <0.05), and the complete immunity rate (9.6%) was significantly lower than the other two groups (²=11.632, <0.05). Compared with the group of common whooping cough, the proportion of children under 1 year old (100%, ²=9.581), the BP-DNA load (6.56 log copies/ml, =4.004), the WBC count(31.34×10L, =7.513), the PCT level(0.07 ng/ml, =2.626), the IL-6 level (6.65 ng/ml, =4.336), the combined infection rate (88.9%, ²=36.536), the incidence of wheezing or dyspnea (55.6%, ²=42.972), the rate of no improvement of symptoms with macrolides prior to the visit (77.8%, ²=26.266), and the incidence of fever (55.6%, ²=42.972) were all significantly higher;the complete immunity rate was significantly lower (5.6%, ²=9.581) in the severe whooping cough group, the differences were all statistically significant(all <0.05).The result of logistic regression analysis showed severe elevation of BP-DNA, high leukocyte count, co-infection, wheezing or shortness of breath, pyrexia and no improvement of symptoms with macrolides before the treatment were the risk factors for the development of severe pertussis and the logistic regressive model predicts a sensitivity and specificity of 0.83 and 0.90 for severe whooping cough, respectively. The sensitivity of BP-DNA>1.91×10 copies/ml, WBC count >19.97×10/L and the binominal combined test to predict the occurrence of severe pertussis were 0.87, 0.61 and 0.80, and the specificity were 0.43, 0.86 and 0.73, respectively. In conclusion, nucleic acid load in infants with pertussis correlated with clinical characteristics such as the active immunity status, fever, co-infections and hospitalisation and days in hospital. Children with high nucleic acid load, high white blood cell counts, co-infections, fever and no improvement of symptoms with macrolides prior to seeing a doctor were more likely to develop the severe pertussis. When BP-DNA >1.91×10 copies/ml or WBC counts>19.97×10/L, they have the highest predictive efficacy for severe pertussis respectively, and combined detection is better.
研究婴幼儿百日咳博德特氏菌核酸水平与疾病临床特征之间的相关性，并探讨重症百日咳发生的危险因素。采用回顾性研究方法，对2023年8月至2024年2月来湖南省儿童医院就诊且确诊为百日咳的1至3岁儿童进行分析。根据BP - DNA的对数值（log拷贝/ml），将35例分为低载量组，78例分为中载量组，94例分为高载量组；根据疾病严重程度，将54例分为重症百日咳组，153例分为普通组；比较各组的临床特征和实验室数据，同时分析重症百日咳发生的危险因素。采用ROC评估BP - DNA和白细胞计数对重症百日咳发生的预测效能。结果显示，高剂量组的白细胞计数（22.59×10⁹/L）、L/N比值（3.31）及住院天数（9.0 d）均显著高于中剂量组和低剂量组（F = 6.309、2.825、15.149，均P < 0.05）。其住院率（100%）、合并感染率（64.96%）、重症百日咳发生率（31.9%）、发热率（29.8%）及使用糖皮质激素率（57.4%）也显著高于其他两组（χ² = 25.977、9.163、9.371、8.299、20.332，均P < 0.05），而完全免疫率（9.6%）显著低于其他两组（χ² = 11.632，P < 0.05）。与普通百日咳组相比，重症百日咳组1岁以下儿童比例（100%，χ² = 9.581）、BP - DNA载量（6.56 log拷贝/ml，t = 4.004）、白细胞计数（31.34×10⁹/L，t = 7.513）、降钙素原水平（0.07 ng/ml，t = 2.626）、白细胞介素 - 6水平（6.65 ng/ml，t = 4.336）、合并感染率（88.9%，χ² = 36.536）、喘息或呼吸困难发生率（55.6%，χ² = 42.972）、就诊前大环内酯类药物治疗症状无改善率（77.8%，χ² = 26.266）及发热发生率（55.6%，χ² = 42.972）均显著更高；完全免疫率显著更低（5.6%，χ² = 9.581），差异均有统计学意义（均P < 0.05）。Logistic回归分析结果显示，BP - DNA严重升高、白细胞计数高、合并感染、喘息或呼吸急促、发热及治疗前大环内酯类药物治疗症状无改善是重症百日咳发生的危险因素，Logistic回归模型预测重症百日咳的敏感度和特异度分别为0.83和0.90。BP - DNA > 1.91×10⁹拷贝/ml、白细胞计数>19.97×10⁹/L及二者联合检测预测重症百日咳发生的敏感度分别为0.87、0.61和0.80，特异度分别为0.43、0.86和0.73。综上所述，百日咳患儿核酸载量与主动免疫状态、发热、合并感染及住院时间等临床特征相关。核酸载量高、白细胞计数高、合并感染、发热及就诊前大环内酯类药物治疗症状无改善的儿童更易发生重症百日咳。当BP - DNA > 1.91×10⁹拷贝/ml或白细胞计数>19.97×10⁹/L时，它们对重症百日咳的预测效能分别最高，联合检测效果更佳。
