BackgroundOutbreaks of human infection with a new avian influenza A H7N9 virus occurred in China in the spring of 2013. Control and prevention of a new human infectious disease outbreak can be strongly affected by public reaction and social impact through the Internet and social media.ObjectiveThis study aimed to investigate the potential roles of Internet surveillance in control and prevention of the human H7N9 outbreaks.MethodsOfficial data for the human H7N9 outbreaks were collected via the China National Health and Family Planning Committee website from March 31 to April 24, 2013. We obtained daily posted and forwarded number of blogs for the keyword “H7N9” from Sina microblog website and a daily Baidu Attention Index (BAI) from Baidu website, which reflected public attention to the outbreak. Rumors identified and confirmed by the authorities were collected from Baidu search engine.ResultsBoth daily posted and forwarded number and BAI for keyword H7N9 increased quickly during the first 3 days of the outbreaks and remained at a high level for 5 days. The total daily posted and forwarded number for H7N9 on Sina microblog peaked at 850,000 on April 3, from zero blogs before March 31, increasing to 97,726 on April 1 and to 370,607 on April 2, and remaining above 500,000 from April 5-8 before declining to 208,524 on April 12. The total daily BAI showed a similar pattern of change to the total daily posted and forwarded number over time from March 31 to April 12. When the outbreak locations spread, especially into other areas of the same province/city and the capital, Beijing, daily posted and forwarded number and BAI increased again to a peak at 368,500 and 116,911, respectively. The median daily BAI during the studied 25 days was significantly higher among the 7 provinces/cities with reported human H7N9 cases than the 2 provinces without any cases (P<.001). So were the median daily posted and forwarded number and daily BAI in each province/city except Anhui province. We retrieved a total of 32 confirmed rumors spread across 19 provinces/cities in China. In all, 84% (27/32) of rumors were disseminated and transmitted by social media.ConclusionsThe first 3 days of an epidemic is a critical period for the authorities to take appropriate action through Internet surveillance to prevent and control the epidemic, including preparation of personnel, technology, and other resources; information release; collection of public opinion and reaction; and clarification, prevention, and control of rumors. Internet surveillance can be used as an efficient and economical tool to prevent and control public health emergencies, such as H7N9 outbreaks.

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We developed a new simple and sensitive assay for lysozyme based on gold nanoparticle plasmon resonance light scattering (PRLS) measurement and naked-eye detection using for the first time the lysozyme DNA aptamer as the recognition element. Lysozyme DNA aptamer could stabilize gold nanoparticles (AuNPs) at high ionic strength. Introducing lysozyme to the system easily triggered the aggregation of AuNPs, producing a red-to-blue color change of the solution, red-shifted plasmon absorption, and enhanced plasmon resonance light scattering. The linear range was found to be 0.2∼4 nM for 0.7 nM AuNPs, 0.3∼6 nM for 1.4 nM AuNPs and 0.6∼8 nM for 2.1 nM AuNPs. About 0.1 nM lysozyme can produce an observable enhancement of PRLS signal. For visual detection, 1 nM lysozyme can produce a very distinctive color change. Satisfactory recoveries were obtained for simulated saliva and diluted urine samples, indicating that the method has potential for analyses of clinical samples. The simplicity and high sensitivity that are consistent with the resources and needs of many laboratories makes this method a good choice for routine analysis.

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movement of horses 6,7. Importation of carrier animals with no obvious signs of disease is a major risk factor for the introduction of EP into non-enzootic areas 1. Therefore, developing sensitive and specific diagnostic methods is essential for identifying asymptomatic equines carrying these parasites. Current diagnostic methods include aetiological diagnostics 8,9 , immunological diagnostics 10-14 and molecular diagnostics 9,15-33. Of these, molecular diagnostics is widely recognized due to its accuracy and sensitivity 9,34. Cortes et al. developed a multinested PCR assay for simultaneous detection of the equine piroplasmids T. equi and B. caballi by amplification of five genetic markers (18S rRNA, β-tubulin, cytB, ema-1 and rap-1) 23. To identify the species of piroplasmid in an infected horse, nested PCR assay is commonly used to amplify long fragments of 18S rRNA, followed by sequence analysis 22. However, PCR-based diagnosis requires a thermocycler, skilled personnel and a long detection time, which made it inappropriate for field diagnostic applications. As an alternative, recombinase polymerase amplification (RPA) has emerged as a novel isothermal technique for molecular diagnosis of various infectious diseases 35 , including the protozoan parasites 36 Theileria annulata 37 and Babesia gibsoni 38. Compared to PCR-based assay and loop-mediated isothermal amplification (LAMP), RPA is more rapid (<20 min), simpler to perform as it requires a lower temperature (37-42 °C) and has an acceptable sensitivity 39,40. RPA-lateral flow assay has been used for rapid detection of Trichinella 41 , Perkinsus beihaiensis 42 , Plasmodium knowlesi 43 , Babesia gibsoni 38 , Protozoan parasites 36 , Theileria annulata 37 , Fasciola hepatica 44 , Schistosoma japonicum 45 , Schistosoma haematobium 46 , Leishmania donovani 47 , Intestinal Protozoa 48 , Giardia 49 , Plasmodium falciparum 50. To avoid the "ghost band" and the false-positive results, the primers, probes and the detection procedure have to be carefully designed 39. To speed up the clearance of an imported horse at a port, or detect a piroplasmosis infection in the field or in low-resource underserved rural communities, we also adapted RPA to develop a duplex detection of both T. equi and B. caballi as an alternative to duplex qPCR 26,30. Various genomic sites have been used in species identification, phylogenetic and genotype studies of both T. equi and B. caballi with PCR-based molecular techniques, including the small subunit ribosomal RNA gene (18S rRNA) 11,22,51-54 ; and genomic sites targeted by qPCR assay have included the ema-1 gene of T. equi and the 48 kDa merozoite rhoptry protein (bc48) gene of B. caballi 30. These sites have been used to create a duplex real-time PCR for simultaneous detection of both parasites using the ema-1 gene of T. equi and the bc48 gene of B. caballi 30 ; or the 18S rRNA gene of B. caballi and the ema-1 gene of T. equi 26. In this study, we designed primers and fluorescent probes to target the 18S rRNA gene of both T. equi and B. ...

Toxoplasma gondii is an opportunistic pathogen widely distributed within the world, poses a huge threat to human health, and causes significant economic losses to the livestock industry. Herein, we developed a portable one-pot detection of T. gondii by combining recombinase polymerase amplification (RPA) and a clustered regularly interspaced short palindromic repeats (CRISPR)/Cas12a system. A glass microfiber filter device used for the first step can efficiently extract T. gondii from lowconcentration samples. The lyophilized RPA reagents and Cas12a/crRNA reagents are prestored in one Eppendorf tube, and both reactions can be performed on a low-cost thermal controller (∼37 °C), avoiding the drawbacks of the step-by-step addition of components. The developed RPA/CRISPR/Cas12a system exhibits a high selectivity toward the B1 gene amplicon of T. gondii over other parasites with a limit of detection of 3.3 copies/μL. The visual signal readout can be easily realized by a fluorometer or lateralflow strip. A portable suitcase containing the minimum equipment and lyophilized reagents was adopted for the rapid determination of T. gondii in heavily polluted landfill leachate. This system presents rapidness, robustness and on-site features for the detection of nucleic acids of the parasite, making it a promising tool for field applications in remote areas.