Gasparinho Carolina, Piedade João, Mirante Maria Clara, Mendes Cristina, Mayer Carlos, Vaz Nery Susana, Brito Miguel, Istrate Claudia
Centro de Investigação em Saúde de Angola (CISA), Caxito, Província do Bengo, Angola.
Global Health and Tropical Medicine (GHTM), Unidade de Microbiologia Médica, Instituto de Higiene e Medicina Tropical (IHMT), Universidade NOVA de Lisboa (UNL), Lisbon, Portugal.
PLoS One. 2017 Apr 19;12(4):e0176046. doi: 10.1371/journal.pone.0176046. eCollection 2017.
Rotavirus group A (RVA) is considered the leading cause of pediatric diarrhea, responsible for the high burden of diarrheal diseases in sub-Saharan Africa. Despite recent studies, the existent data are scarce for some African countries like Angola, a country with one of the highest RVA-related death estimates. The aim of this study was to determine the RVA detection rate and circulating genotypes in children less than five years of age with acute gastroenteritis attended at the Bengo General Hospital in Caxito, Bengo province, Angola, before vaccine introduction.
Between September 2012 and December 2013, 342 fecal specimens were collected from children enrolled. Positive samples for RVA by immunochromatographic rapid test were G and P-typed by hemi-nested type-specific multiplex PCR, and subgrouped for the VP6 gene. VP4 and VP7 genes from a subset of samples were sequenced for phylogenetic analysis.
During the study period, a high RVA detection rate was registered (25.1%, 86/342). The age group most affected by RVA infection includes children under 6 months of age (p<0.01). Vomiting was highly associated with RVA infection (72.1%; p<0.001). From the 86 RVA-positive samples, 72 (83.7%) were genotyped. The most prevalent genotype was G1P[8] (34/72; 47.2%), followed by the uncommon G1P[6] (21/72; 29.2%), and G2P[4] (9/72; 12.5%). Only two G-types were found: G1 (60/72; 83.3%) and G2 (11/72; 15.3%). Among the P-genotypes, P[8] was the most prevalent (34/72; 47.2%), followed by P[6] (22/72; 30.6%) and P[4] (9/72; 12.5%). In the phylogenetic trees, the identified G and P-types clustered tightly together and with reference sequences in specific monophyletic groups, with highly significant bootstrap values (≥92%).
This pre-vaccination study revealed, for the first time for Bengo province (Angola), the RVA genotype profile, including phylogenetic relationships, and a high RVA detection rate, supporting the immediate introduction of a RVA vaccine in the national immunization programme.
A组轮状病毒（RVA）被认为是小儿腹泻的主要病因，是撒哈拉以南非洲腹泻病高负担的原因。尽管有近期的研究，但对于安哥拉等一些非洲国家来说，现有数据仍然匮乏，安哥拉是RVA相关死亡估计数最高的国家之一。本研究的目的是确定在安哥拉本戈省卡西托的本戈综合医院就诊的小于五岁的急性胃肠炎儿童在引入疫苗之前的RVA检出率和流行基因型。
2012年9月至2013年12月期间，收集了342名登记儿童的粪便标本。通过免疫层析快速检测呈RVA阳性的样本，采用半巢式型特异性多重PCR进行G和P分型，并对VP6基因进行亚组分析。对一部分样本的VP4和VP7基因进行测序以进行系统发育分析。
在研究期间，RVA检出率较高（25.1%，86/342）。受RVA感染影响最大的年龄组包括6个月以下的儿童（p<0.01）。呕吐与RVA感染高度相关（72.1%；p<0.001）。在86份RVA阳性样本中，72份（83.7%）进行了基因分型。最常见的基因型是G1P[8]（34/72；47.2%），其次是不常见的G1P[6]（21/72；29.2%）和G2P[4]（9/72；12.5%）。仅发现两种G型：G1（60/72；83.3%）和G2（11/72；15.3%）。在P基因型中，P[8]最为常见（34/72；47.2%），其次是P[6]（22/72；30.6%）和P[4]（9/72；12.5%）。在系统发育树中，鉴定出的G型和P型紧密聚集在一起，并与特定单系群中的参考序列聚集在一起，具有高度显著的自展值（≥92%）。
这项疫苗接种前研究首次揭示了本戈省（安哥拉）的RVA基因型谱，包括系统发育关系，以及较高的RVA检出率，支持在国家免疫规划中立即引入RVA疫苗。
