Evandro Chagas Institute, Health Surveillance Secretariat, Belém, Brazil.
Clinical Research Institute Evandro Chagas, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
J Med Virol. 2015 Aug;87(8):1303-10. doi: 10.1002/jmv.24183. Epub 2015 Apr 16.
The monovalent human rotavirus (RV) vaccine, RIX4414 (Rotarix™, GlaxoSmithKline Biologicals) was introduced into Brazil's Expanded Program on Immunization in March 2006. One year after vaccine introduction, the G2P[4] strain was found to be predominant, with an apparent extinction of many non-G2 strains. This study investigated the diversity of circulating strains in the three years following RIX4414 introduction. Between May 2008 and May 2011, stool samples were collected from children aged ≥12 weeks who were hospitalized for severe lab confirmed RV-gastroenteritis (≥3 liquid or semi-liquid motions over a 24-h period for <14 days, requiring ≥1 overnight hospital stay and intravenous rehydration therapy) in Belém, Brazil. RV-gastroenteritis was detected by ELISA and the G- and P-types were determined by RT-PCR assays. During the first year of surveillance nucleotide sequencing was used for typing those samples not previously typed by RT-PCR. A total of 1,726 of 10,030 severe gastroentertis hospitalizations (17.2%) were due to severe RVGE. G2P[4] was detected in 57.2% of circulating strains over the whole study period, however it predominated during the first 20 months from May 2008 to January 2009. G1P[8] increased in the last part of the study period from May 2010 to May 2011 and represented 36.6% (112/306) of the circulating strains. G2P[4] was the predominant RV strain circulating during the first 20 months of the study, followed by G1P[8]. These findings probably reflect a natural fluctuation in RV strains over time, rather than a vaccine-induced selective pressure.
单价人轮状病毒（RV）疫苗，RIX4414（RotarixTM，葛兰素史克生物制品公司）于 2006 年 3 月被引入巴西扩大免疫规划。疫苗引入一年后，发现 G2P[4] 株占主导地位，许多非 G2 株似乎已灭绝。本研究调查了 RIX4414 引入后三年循环株的多样性。2008 年 5 月至 2011 年 5 月，从巴西贝伦因严重实验室确诊的 RV 胃肠炎住院的≥12 周龄儿童收集粪便样本（24 小时内有≥3 次液体或半液体便，持续时间＜14 天，需要至少 1 晚住院和静脉补液治疗）。通过 ELISA 检测 RV 胃肠炎，通过 RT-PCR 检测 G 型和 P 型。在监测的第一年，对那些以前未通过 RT-PCR 分型的样本进行核苷酸测序以进行分型。在整个研究期间，共有 10030 例严重胃肠炎住院病例中有 1726 例（17.2%）是由严重 RVGE 引起的。在整个研究期间，循环株中 57.2%检测到 G2P[4]，但在 2008 年 5 月至 2009 年 1 月的前 20 个月中占主导地位。G1P[8]在研究后期（2010 年 5 月至 2011 年 5 月）增加，占循环株的 36.6%（112/306）。在研究的前 20 个月，G2P[4]是循环的主要 RV 株，其次是 G1P[8]。这些发现可能反映了 RV 株随时间的自然波动，而不是疫苗诱导的选择压力。
