O'Grady Kerry-Ann F, Whiley David M, Torzillo Paul J, Sloots Theo P, Lambert Stephen B
Queensland Children's Medical Research Institute, Queensland University of Technology, Herston Road HERSTON QLD, 4029 Herston, Australia.
BMC Infect Dis. 2013 Nov 14;13:543. doi: 10.1186/1471-2334-13-543.
Surveillance programs and research for acute respiratory infections in remote Australian communities are complicated by difficulties in the storage and transport of frozen samples to urban laboratories for testing. This study assessed the sensitivity of a simple method for transporting nasal swabs from a remote setting for bacterial polymerase chain reaction (PCR) testing.
We sampled every individual who presented to a remote community clinic over a three week period in August at a time of low influenza and no respiratory syncytial virus activity. Two anterior nasal swabs were collected from each participant. The left nare specimen was mailed to the laboratory via routine postal services. The right nare specimen was transported frozen. Testing for six bacterial species was undertaken using real-time PCR.
One hundred and forty participants were enrolled who contributed 150 study visits and paired specimens for testing. Respiratory illnesses accounted for 10% of the reasons for presentation. Bacteria were identified in 117 (78%) presentations for 110 (79.4%) individuals; Streptococcus pneumoniae and Haemophilus influenzae were the most common (each identified in 58% of episodes). The overall sensitivity for any bacterium detected in mailed specimens was 82.2% (95% CI 73.6, 88.1) compared to 94.8% (95% CI 89.4, 98.1) for frozen specimens. The sensitivity of the two methods varied by species identified.
The mailing of unfrozen nasal specimens from remote communities appears to influence the utility of the specimen for bacterial studies, with a loss in sensitivity for the detection of any species overall. Further studies are needed to confirm our finding and to investigate the possible mechanisms of effect.
Australia and New Zealand Clinical Trials Registry Number: ACTRN12609001006235.
澳大利亚偏远社区急性呼吸道感染的监测项目和研究因将冷冻样本储存和运输到城市实验室进行检测存在困难而变得复杂。本研究评估了一种将鼻拭子从偏远地区运输至城市进行细菌聚合酶链反应（PCR）检测的简单方法的敏感性。
在8月流感发病率较低且无呼吸道合胞病毒活动期间，我们对在三周内前往偏远社区诊所就诊的每一个人进行了采样。从每位参与者处采集两支前鼻拭子。左侧鼻孔样本通过常规邮政服务邮寄至实验室。右侧鼻孔样本则冷冻运输。使用实时PCR对六种细菌进行检测。
招募了140名参与者，他们进行了150次研究就诊并提供了配对样本用于检测。呼吸道疾病占就诊原因的10%。在110名（79.4%）个体的117次（78%）就诊中检测到细菌；肺炎链球菌和流感嗜血杆菌最为常见（各在58%的病例中被检测到）。邮寄样本中检测到任何细菌的总体敏感性为82.2%（95%可信区间73.6，88.1），而冷冻样本的敏感性为94.8%（95%可信区间89.4，98.1）。两种方法的敏感性因所鉴定的细菌种类而异。
从偏远社区邮寄未冷冻的鼻样本似乎会影响样本在细菌学研究中的效用，总体上对任何细菌的检测敏感性都会降低。需要进一步研究来证实我们的发现并探究可能的影响机制。
澳大利亚和新西兰临床试验注册号：ACTRN12609001006235。
