Aminu M, Esona M D, Geyer A, Steele A D
Department of Microbiology, Faculty of Science, Ahmadu Bello University, Zaria-Nigeria.
Ann Afr Med. 2008 Dec;7(4):168-74. doi: 10.4103/1596-3519.55658.
Recent estimates attribute 527,000 deaths in children less than five years of age to rotavirus diarrhea annually, with 145,000 occurring in sub-Saharan Africa. Human astroviruses have been identified as one of the most frequent causes of infantile diarrhea, second in incidence only to rotavirus. This study was conducted to determine the prevalence of rotavirus and astrovirus and also to establish the circulating strains of rotavirus in a community in Nigeria where most diarrheic patients do not visit clinics or health care centers.
A total of 154 stool samples (134 diarrheic and 20 non-diarrheic) were collected from infants and young children less than 5 years of age from January-March 2002. Samples were obtained by house-to-house visit in randomly selected districts in Zaria, Northwestern Nigeria. The samples were screened for rotavirus and astrovirus antigens using commercially available Enzyme Linked Immunosorbent Assay (ELISA) kits. All positive group A rotavirus samples were further subjected to VP6 sub-group ELISA, Polyacrylamide gel electrophoresis (PAGE) to determine their RNA electropherotypes and Reverse transcription polymerase chain reaction (RT-PCR) to determine their VP7 and VP4 genotypes.
Rotavirus and astrovirus antigens were detected in 9% (12) and 5% (7) of the 134 diarrheic stool samples respectively. No viral antigen was detected in the non-diarrheic stools. Rotavirus infection was more common in younger children than astrovirus infection. VP6 sub-group II specificity (58.3%), long RNA electropherotypes (41.6%), VP7 genotype G1 (33.3%) and VP4 genotype P [6] (33.3%) were the most common strains in circulation at that time in the community. Of significance is the fact that a large proportion of the rotavirus strains in circulation could not be assigned either a VP6 subgroup or RNA electrophoretic pattern probably as a result of low viral load.
In this community-based study, rotavirus and astrovirus were significantly associated with diarrhea. However, the prevalence of rotavirus infection among children appears to be low while that of astrovirus falls in the range seen in hospital-based studies around the continent.
最近的估计表明，每年有52.7万例5岁以下儿童死于轮状病毒腹泻，其中14.5万例发生在撒哈拉以南非洲地区。人类星状病毒已被确定为婴儿腹泻最常见的病因之一，发病率仅次于轮状病毒。本研究旨在确定尼日利亚一个社区中轮状病毒和星状病毒的流行情况，并确定轮状病毒的流行毒株，该社区大多数腹泻患者不去诊所或医疗保健中心就诊。
2002年1月至3月期间，从尼日利亚西北部扎里亚随机选取的地区挨家挨户收集了154份5岁以下婴幼儿粪便样本（134份腹泻样本和20份非腹泻样本）。使用市售酶联免疫吸附测定（ELISA）试剂盒对样本进行轮状病毒和星状病毒抗原筛查。所有A组轮状病毒阳性样本进一步进行VP6亚组ELISA、聚丙烯酰胺凝胶电泳（PAGE）以确定其RNA电泳型，以及逆转录聚合酶链反应（RT-PCR）以确定其VP7和VP4基因型。
在134份腹泻粪便样本中，分别有9%（12份）和5%（7份）检测到轮状病毒和星状病毒抗原。在非腹泻粪便中未检测到病毒抗原。轮状病毒感染在幼儿中比星状病毒感染更常见。VP6亚组II特异性（58.3%）、长RNA电泳型（41.6%）、VP7基因型G1（33.3%）和VP4基因型P[6]（33.3%）是当时该社区最常见的流行毒株。值得注意的是，由于病毒载量低，很大一部分流行的轮状病毒毒株无法确定其VP6亚组或RNA电泳模式。
在这项基于社区的研究中，轮状病毒和星状病毒与腹泻显著相关。然而，儿童轮状病毒感染的患病率似乎较低，而星状病毒的患病率则在非洲大陆各地基于医院的研究中所见的范围内。
