Department of Clinical Laboratory, Ningbo Women and Children's Hospital, Ningbo, Zhejiang, China.
Neonatal Intensive Care Unit, Ningbo Women and Children's Hospital, Ningbo, Zhejiang, China.
PLoS Negl Trop Dis. 2020 Oct 5;14(10):e0008732. doi: 10.1371/journal.pntd.0008732. eCollection 2020 Oct.
Non-typhoidal Salmonella (NTS), a common cause of diarrheal enterocolitis, may also cause severe invasive diseases. Limited information on NTS infections in children is available in China.
We performed a retrospective study of children admitted to the Ningbo Women and Children's Hospital with culture-confirmed NTS infections between January 2012 and December 2019. Clinical and microbiological information were collected. We compared demographic, clinical and antibiotic resistance variables of invasive NTS (iNTS) infections and non-invasive NTS (non-iNTS) infections, and explored associations between hospitalizations for pediatric NTS infections and temperature and rainfall.
A total of 166 pediatric hospitalizations due to NTS infection were identified during the 8-year study period. Most of the 166 children were <5 years old (93.4%). The primary serotype was Salmonella Typhimurium (62.6%). Of 166 children with NTS infections, 11 had invasive infection. Compared to 155 children with non-iNTS infections, we found that iNTS infections were more likely to occur in infants ≤6 months or children with an underlying medical condition of leukemia at admission, but iNTS infections less often presented with a symptom of diarrhea (P <0.05 in all cases). The resistance rates of non-iNTS isolates to ceftazidime, ceftriaxone, cefepime, and aztreonam were significantly higher than those of iNTS isolates (P <0.05 in all cases). In addition, compared with iNTS isolates, non-iNTS isolates were significantly associated with resistance to ≥4 CLSI (Clinical and Laboratory Standard Institute) classes (P = 0.041, OR: 0.089, 95% CI: 0.009-0.901) and ≥2 first-line treatment agents (P = 0.040, OR: 0.159, 95% CI: 0.028-0.916). On the other hand, we found that seasonal NTS hospitalizations were positively associated with average seasonal temperature (r = 0.961, P = 0.039) and average monthly rainfall (r = 0.921, P <0.001).
Non-iNTS accounts for the majority of infections in this study; infants ≤6 months and children with underlying medical conditions of leukemia are more likely to have invasive infection. The rates of antibiotic resistance in the iNTS isolates are generally lower than those in the non-iNTS isolates. On the other hand, high temperatures and heavy rainfall are positively associated with NTS hospitalizations among children in Ningbo.
非伤寒沙门氏菌（NTS）是一种常见的腹泻性肠结肠炎病原体，也可能引起严重的侵袭性疾病。中国有关儿童 NTS 感染的信息有限。
我们对 2012 年 1 月至 2019 年 12 月期间在宁波妇女儿童医院确诊为 NTS 感染的住院患儿进行了回顾性研究。收集了临床和微生物学信息。我们比较了侵袭性 NTS（iNTS）感染和非侵袭性 NTS（non-iNTS）感染的人口统计学、临床和抗生素耐药变量，并探讨了儿科 NTS 感染与温度和降雨量之间的关系。
在 8 年的研究期间，共发现 166 例儿童 NTS 感染住院病例。166 例患儿中，93.4%的患儿年龄<5 岁。主要血清型为鼠伤寒沙门氏菌（62.6%）。在 166 例 NTS 感染患儿中，有 11 例发生侵袭性感染。与 155 例非 iNTS 感染患儿相比，我们发现 iNTS 感染更可能发生在≤6 个月的婴儿或入院时患有白血病等基础疾病的患儿中，但 iNTS 感染较少出现腹泻症状（所有情况下 P<0.05）。非 iNTS 分离株对头孢他啶、头孢曲松、头孢吡肟和氨曲南的耐药率明显高于 iNTS 分离株（所有情况下 P<0.05）。此外，与 iNTS 分离株相比，非 iNTS 分离株与对≥4 个 CLSI（临床和实验室标准协会）类别的耐药性显著相关（P=0.041，OR：0.089，95%CI：0.009-0.901）和对≥2 种一线治疗药物的耐药性显著相关（P=0.040，OR：0.159，95%CI：0.028-0.916）。另一方面，我们发现季节性 NTS 住院与平均季节性温度呈正相关（r=0.961，P=0.039），与平均每月降雨量呈正相关（r=0.921，P<0.001）。
本研究中，非 iNTS 感染占多数；≤6 个月的婴儿和患有白血病等基础疾病的儿童更有可能发生侵袭性感染。iNTS 分离株的抗生素耐药率普遍低于非 iNTS 分离株。另一方面，高温和大雨与宁波儿童 NTS 住院呈正相关。
