Virology Unit, Institut Pasteur in Cambodia, Phnom Penh, Cambodia.
Influenza Other Respir Viruses. 2012 Nov;6(6):442-8. doi: 10.1111/j.1750-2659.2012.00338.x. Epub 2012 Feb 17.
Very little is known regarding the persistence of highly pathogenic avian influenza H5N1 viruses in natural settings during outbreaks in tropical countries, although environmental factors may well play a role in the persistence and in the transmission of H5N1 virus.
To investigate various environmental compartments surrounding outbreak areas as potential sources for H5N1 virus transmission.
Environmental specimens were collected following outbreaks of avian influenza in Cambodia between April 2007 and February 2010. The methods used to concentrate H5N1 virus from water samples were based either on agglutination of the virus with chicken red blood cells or on adsorption on glass wool, followed by an elution-concentration step. An elution-concentration method was used for mud specimens. All samples that tested positive by real-time RT-PCRs (qRT-PCRs) targeting the HA5, M and NA1 genes were inoculated into embryonated hen eggs for virus isolation.
Of a total of 246 samples, 46 (19%) tested positive for H5N1 by qRT-PCRs. Viral RNA was frequently detected in dust, mud and soil samples from the farms' environment (respectively, 46%, 31% and 15%). Samples collected from ponds gave a lower proportion of positive samples (6%) as compared to those collected from the farms (24%). In only one sample, infectious virus particles were successfully isolated.
During H5N1 virus outbreaks, numerous environmental samples surrounding outbreak areas are contaminated by the virus and may act as potential sources for human and/or animal contamination.
在热带国家暴发高致病性禽流感 H5N1 期间，人们对病毒在自然环境中的持续存在情况知之甚少，尽管环境因素很可能在 H5N1 病毒的持续存在和传播中发挥作用。
调查暴发地区周围的各种环境样本，以确定其是否可能成为 H5N1 病毒传播的来源。
2007 年 4 月至 2010 年 2 月柬埔寨暴发禽流感期间，收集了环境样本。从水样中浓缩 H5N1 病毒的方法基于病毒与鸡红细胞的凝集作用，或吸附在玻璃棉上，然后进行洗脱浓缩步骤。泥浆样本则采用洗脱浓缩法。所有通过针对 HA5、M 和 NA1 基因的实时 RT-PCR（qRT-PCR）检测呈阳性的样本都接种到鸡胚中进行病毒分离。
在总共 246 个样本中，有 46 个（19%）通过 qRT-PCR 检测呈 H5N1 阳性。灰尘、泥浆和土壤样本中经常检测到农场环境中的病毒 RNA（分别为 46%、31%和 15%）。与农场采集的样本（24%）相比，池塘采集的样本阳性率较低（6%）。只有一个样本成功分离到了有感染性的病毒颗粒。
在 H5N1 病毒暴发期间，暴发地区周围的大量环境样本受到病毒污染，可能成为人类和/或动物污染的潜在来源。
