Enteric Viruses Group, ICMR-National Institute of Virology, Pune, India.
Pediatric Research Unit, KEM Hospital, Pune, India.
Infect Genet Evol. 2019 Jun;70:45-52. doi: 10.1016/j.meegid.2019.02.014. Epub 2019 Feb 20.
Rotavirus infections in neonates are generally nosocomial, and differ from pediatric infections both clinically and epidemiologically. These infections are predominantly asymptomatic and often associated with unusual strains. Globally, so far limited data is available on rotavirus infections in neonates admitted at Neonatal Intensive Care Unit. The aim of the present study is to determine the prevalence of rotavirus among neonates and to study their genetic characteristics. Stool specimens (n = 701) collected from neonates (n = 621) admitted during April 2016 to March 2018 mainly for prematurity, low birth weight and associated respiratory distress syndrome from two hospitals from Pune were tested for rotavirus, genotyped and representative strains were sequenced for the genes encoding outer capsid proteins, VP7 and VP4. Rotavirus was detected in 24.31% neonates. Majority of rotavirus infected neonates (98.68%) were asymptomatic. Peak rotavirus antigen detection (91.38%) occurred during the first 2 weeks of admission. Low, very low and normal birth weight neonates with gestational age ≥28 weeks had significantly higher rotavirus infection than those with extreme low birth weight with gestational age <28 weeks. Rotaviral infections occurred almost evenly throughout the year without an apparent peak in colder months. Predominance of unusual G12P[11] strains (97.1%) was observed. Phylogenetic analysis of the partial VP7 coding gene revealed all G12 strains clustered in lineage III and shared 96.94%-100% (nucleotide) and 96.26%-100% (amino acid) identities among themselves, and 95.69%-98.98% (nucleotide) and 94.77%-98.98% (amino acid) with other lineage III G12 strains respectively. Similarly VP4 partial gene sequences of P[11] study strains shared 97.5%-100% (nucleotide and amino acid) identities among themselves and highest 93.34%-94.53% (nucleotide) and 93.57%-94.64% (amino acid) identity with vaccine strain 116E, G9P[11]. The study highlights high frequency of unusual G12P[11] strains among neonates for the first time in western India and reaffirms limited strain diversity in this population. The knowledge of neonatal strains is important for estimating the efficacies of rotavirus vaccines.
轮状病毒感染在新生儿中通常是医院获得性的，与儿科感染在临床和流行病学方面均有所不同。这些感染主要是无症状的，且通常与不常见的菌株相关。目前，全球仅有有限的数据可用于研究在新生儿重症监护病房住院的新生儿的轮状病毒感染。本研究旨在确定轮状病毒在新生儿中的流行情况，并研究其遗传特征。从浦那的两家医院收集了 2016 年 4 月至 2018 年 3 月期间主要因早产、低出生体重和相关呼吸窘迫综合征住院的 621 名新生儿（n=621）的粪便标本（n=701），用于检测轮状病毒，并对其进行基因分型，选择代表株用于测序编码外壳蛋白 VP7 和 VP4 的基因。在 24.31%的新生儿中检测到轮状病毒。大多数感染轮状病毒的新生儿（98.68%）无症状。轮状病毒抗原检测的高峰（91.38%）出现在住院的前 2 周。出生体重低、极低和正常，胎龄≥28 周的新生儿与胎龄<28 周的极低出生体重新生儿相比，轮状病毒感染率显著更高。轮状病毒感染几乎全年都有发生，在寒冷月份没有明显的高峰。观察到优势的不常见 G12P[11]株（97.1%）。部分 VP7 编码基因的系统发育分析表明，所有 G12 株均聚类于谱系 III，彼此之间共享 96.94%-100%（核苷酸）和 96.26%-100%（氨基酸）的同一性，与其他谱系 III G12 株分别共享 95.69%-98.98%（核苷酸）和 94.77%-98.98%（氨基酸）的同一性。同样，P[11]研究株的 VP4 部分基因序列彼此之间共享 97.5%-100%（核苷酸和氨基酸）的同一性，与疫苗株 116E、G9P[11]共享最高 93.34%-94.53%（核苷酸）和 93.57%-94.64%（氨基酸）的同一性。该研究首次在印度西部强调了新生儿中不常见的 G12P[11]株的高频率，并再次证实了该人群中菌株多样性有限。对新生儿株的了解对于评估轮状病毒疫苗的疗效很重要。
