Method for simulating spreading rule of African swine fever virus aerosol in pig farm

Abstract

The invention discloses a method for simulating a spreading rule of African swine fever virus aerosol in a pig farm, and relates to the technical field of animal epidemic disease spreading simulation. Comprising the following steps: selecting fluorescent microspheres, and preparing a fluorescent microsphere suspension; building a fluorescent microsphere suspension release system; dividing a pig farm into a plurality of cells, and arranging a sampling network in the pig farm; starting all the samplers of the sampling network, idling for a certain time, and closing all the samplers after measuring the environment background concentration; synchronously starting a fluorescent microsphere suspension release system and samplers of all sampling networks, and synchronously recording environment temperature and humidity, wind speed and wind direction; and performing quantitative analysis on the fluorescence of the pig farm at different time points, and generating a distribution diagram and a dynamic change diagram of the fluorescence in the pig farm according to an analysis result. According to the invention, by releasing the fluorescent microspheres with matched particle sizes and combining with a gridding monitoring network, a distribution diagram and a dynamic change diagram during virus diffusion are dynamically generated, and data support is provided for pig farm ventilation optimization and accurate disinfection.

Description

Technical Field

[0001] The present invention relates to the technical field of animal disease transmission simulation, and in particular to a method for simulating the transmission pattern of African swine fever virus aerosol in a pig farm. Background Art

[0002] African swine fever (ASF) has occurred, spread, and become epidemic in many countries around the world. ASF is an acute, febrile, highly contagious disease caused by the African swine fever virus (ASFV), with a morbidity and mortality rate as high as 100%. ASFV belongs to the Assurviridae family and the genus Assurvirus. With a size of approximately 0.26 μm, it is the only member of the Assurviridae family and has no closely related viruses.

[0003] The latest research has found that ASFV can be transmitted through aerosols and air, but the spread of AFSV through air and aerosols has not yet been reported. Therefore, it can only be filtered and disinfected indiscriminately through air filtration and air purification.

[0004] Therefore, it is an urgent problem for those skilled in the art to propose a method to simulate the propagation pattern of African swine fever virus aerosol in pig farms to solve the difficulties existing in the existing technology. Summary of the Invention

[0005] In view of this, the present invention provides a method for simulating the spread of African swine fever virus aerosols in pig farms. By releasing fluorescent microspheres with matching particle sizes and combining them with a grid monitoring network, the method dynamically generates distribution maps and dynamic change maps of the virus during diffusion, providing data support for ventilation optimization and precise disinfection of pig farms.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for simulating the spread of African swine fever virus aerosols in pig farms, comprising:

[0008] S1. Select fluorescent microspheres and prepare a fluorescent microsphere suspension;

[0009] S2, build a fluorescent microsphere suspension release system;

[0010] S3, divide the pig farm into several cells and set up a sampling network in the pig farm;

[0011] S4, turning on all the samplers of the sampling network and idling them for a certain period of time, measuring the ambient background concentration, and then turning off all the samplers;

[0012] S5. Synchronously start the fluorescent microsphere suspension release system and the samplers of all sampling networks, and simultaneously record the ambient temperature, humidity, wind speed, and wind direction;

[0013] S6. Quantitatively analyze the fluorescence of the pig farm at different time points, generate a distribution map and dynamic change map of the fluorescence in the pig farm based on the analysis results, and derive the propagation pattern of African swine fever virus aerosol in the pig farm.

[0014] In the above method, optionally, in S1, the fluorescent microspheres are made of polystyrene latex;

[0015] The particle size of fluorescent microspheres is: 0.2μm-50μm;

[0016] Fluorescent dyes include rhodamine B or fluorescein sodium;

[0017] Prepare fluorescent microsphere suspension with a concentration of 10 6 -10 7 particles / mL.

[0018] In the above method, optionally, in S2, the release system includes: a liquid storage tank, a peristaltic pump, a compressed air source, a pressure regulating valve, an atomizer, a 40°C heating drying tube, and a release tower connected in sequence;

[0019] The pressure of the pressure regulating valve is stable at 0.3MPa, the atomizer is TSI 3450, the release tower height is 1.5m, and the release position is the air inlet of the pig house.

[0020] In the above method, optionally, in S3, in the sampling network, the samplers selected are: an optical particle counter to measure the real-time concentration distribution of fluorescent microspheres, an Anderson impactor to measure the particle size classification deposition of fluorescent microspheres, and a membrane sampling pump for environmental background correction;

[0021] Sampler location: An optical particle counter and an Anderson impact sampler are set up 1m downwind from the release point, 1m away from the release source, and at a height of 0.8m; two optical particle counters are set up at a height of 0.8m in the animal activity area, in the cells divided by the pig farm; two Anderson impact samplers are set up at a height of 1.2m in the ventilation dead corner; a membrane sampling pump is set up directly in front of the fan at the exhaust outlet.

[0022] In the above method, optionally, in S4, the sampler is idle for 30 minutes or other set time to measure the ambient background concentration. The background particle concentration must be less than 1000 particles / m³.

[0023] The above method, optionally, in S5, synchronously starting the fluorescent microsphere suspension release system and the samplers of all sampling networks, and synchronously recording the ambient temperature, humidity, wind speed and wind direction;

[0024] The release mode of the release system is pulse release;

[0025] The synchronous triggering of the release system and the sampling network uses the IoT time synchronizer;

[0026] Environmental monitoring: A set of temperature, humidity, wind speed and wind direction data is recorded synchronously every minute.

[0027] The above method, optionally, in S6, quantitatively analyzes the fluorescence of the pig farm at different time points, specifically:

[0028] The fluorescence value of the fluorescent microspheres of the samplers in the sampling network at different time points is monitored to obtain the monitoring value, and the environmental background concentration is subtracted to obtain the fluorescent microsphere acquisition value;

[0029] Generate the distribution map and dynamic change map of fluorescent microspheres in the pig farm based on the obtained values ​​of fluorescent microspheres;

[0030] Different ranges of obtained values ​​are represented by different colors.

[0031] The above method, optionally, in S6, the fluorescence of the pig farm at different time points is quantitatively analyzed, the filter membrane is dissolved with ethyl acetate in the filter sampling pump and then centrifuged and concentrated, and the fluorescent spots are counted under blue light excitation using a Nikon ECLIPSE Ti2 microscope for environmental background correction.

[0032] It can be seen from the above technical solution that compared with the existing technology, the present invention provides a method for simulating the transmission law of African swine fever virus aerosols in pig farms, which has the following beneficial effects: dynamic monitoring of the distribution law of simulated African swine fever virus aerosols in pig houses or factory environments can be carried out to provide a theoretical basis for the prevention and control of African swine fever virus; adding sampling points at key obstacles such as fans can avoid errors caused by obstructions of complex structures; and providing laboratory-level field evidence for the risk assessment of African swine fever transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0034] Figure 1 This is a flow chart of a method provided by the present invention for simulating the transmission pattern of African swine fever virus aerosols in pig farms. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0036] In this application, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. The terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or apparatus comprising the element.

[0037] Reference Figure 1 As shown, the present invention discloses a method for simulating the propagation law of African swine fever virus aerosol in a pig farm, comprising:

[0038] S1. Select fluorescent microspheres and prepare a fluorescent microsphere suspension;

[0039] S2, build a fluorescent microsphere suspension release system;

[0040] S3, divide the pig farm into several cells and set up a sampling network in the pig farm;

[0041] S4, turning on all the samplers of the sampling network and idling them for a certain period of time, measuring the ambient background concentration, and then turning off all the samplers;

[0042] S5. Synchronously start the fluorescent microsphere suspension release system and the samplers of all sampling networks, and simultaneously record the ambient temperature, humidity, wind speed, and wind direction;

[0043] S6. Quantitatively analyze the fluorescence of the pig farm at different time points, generate a distribution map and dynamic change map of the fluorescence in the pig farm based on the analysis results, and derive the propagation pattern of African swine fever virus aerosol in the pig farm.

[0044] Furthermore, in S1, the fluorescent microspheres are made of polystyrene latex with a density of 1.05 g / cm 3 (Close to virus-containing droplets);

[0045] The particle size of fluorescent microspheres is 0.2μm-50μm. The particle size of African swine fever virus is 0.26μm. The virus will combine with aerosols such as dust in the air to form particles of different sizes. Therefore, choosing fluorescent excitation materials of different particle sizes can more comprehensively and accurately simulate the distribution of aerosols.

[0046] Fluorescent dyes should be Rhodamine B or fluorescein sodium, and food-grade fluorescent dyes must be used (e.g. Rhodamine B must comply with GB1886.291);

[0047] Prepare fluorescent microsphere suspension with a concentration of 10 6 -10 7 particles / mL, ensuring that the background noise is more than 100 times.

[0048] Furthermore, in S2, the release system includes: a liquid storage tank, a peristaltic pump, a compressed air source, a pressure regulating valve, an atomizer, a 40°C heating drying tube, and a release tower connected in sequence;

[0049] The pressure of the pressure regulating valve is stable at 0.3MPa, the atomizer is TSI 3450, the release tower height is 1.5m, the release position is the air inlet of the pig house, and the release rate is controlled at an aerosol flow rate of 0.5-2L / min.

[0050] Furthermore, in S3, in the sampling network, the samplers used are: an optical particle counter to measure the real-time concentration distribution of fluorescent microspheres, an Anderson impactor to measure the size-classified deposition of fluorescent microspheres, and a membrane sampling pump for environmental background correction;

[0051] Sampler location: An optical particle counter and an Anderson impact sampler are set up 1m downwind from the release point, 1m away from the release source, and at a height of 0.8m; two optical particle counters are set up at a height of 0.8m in the animal activity area, in the cells divided by the pig farm; two Anderson impact samplers are set up at a height of 1.2m in the ventilation dead corner; a membrane sampling pump is set up directly in front of the fan at the exhaust outlet.

[0052] Furthermore, in S4, the sampler is idle for 30 minutes or other set time to measure the environmental background concentration and eliminate background aerosol interference. The background particle concentration measured before release must be lower than 1000 particles / m³.

[0053] Furthermore, in S5, the fluorescent microsphere suspension release system and the samplers of all sampling networks are started synchronously, and the ambient temperature and humidity, wind speed, and wind direction are recorded synchronously;

[0054] The release system adopts pulsed release mode, with a release time of 10 minutes and a decay time of 50 minutes, which can be cycled multiple times;

[0055] The synchronous triggering of the release system and the sampling network uses the IoT time synchronizer;

[0056] Environmental monitoring: A set of temperature, humidity, wind speed and wind direction data is recorded synchronously every minute.

[0057] Furthermore, in S6, the fluorescence of the pig farm at different time points was quantitatively analyzed, specifically:

[0058] The fluorescence value of the fluorescent microspheres of the samplers in the sampling network at different time points is monitored to obtain the monitoring value, and the environmental background concentration is subtracted to obtain the fluorescent microsphere acquisition value;

[0059] Generate the distribution map and dynamic change map of fluorescent microspheres in the pig farm based on the obtained values ​​of fluorescent microspheres;

[0060] Different ranges of obtained values ​​are represented by different colors.

[0061] Furthermore, in S6, the fluorescence of the pig farm at different time points was quantitatively analyzed. In the filter membrane sampling pump, the filter membrane was dissolved with ethyl acetate and then concentrated by centrifugation. The fluorescent spots were counted under blue light excitation using a Nikon ECLIPSE Ti2 microscope for environmental background correction. The discarded filter membrane was treated as hazardous waste.

[0062] In a specific embodiment, the pig house is divided into several 1m 2 or 4m 2 The square cells can be adjusted according to the size of the pig house. Pig houses are generally flat ground structures. Dividing the pig house into multiple square cells for simulation monitoring can more comprehensively monitor the different areas of the entire pig house and make the operation more convenient. Fluorescent microspheres continue to spread in the pig house over time. The concentration of fluorescent microspheres in the pig farm is detected and quantified through a sampling network. The detection time points are 30 minutes, 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, 48 ​​hours, and 96 hours after the start of the experiment. The monitoring time can also be extended according to production needs. Basic physical information such as wind speed, air pressure, temperature, humidity, weather, and season during monitoring are recorded. The distribution map and dynamic change map of fluorescent microspheres in the pig farm are generated according to the obtained values ​​of fluorescent microspheres. The pig farm area is divided according to the size of the obtained values ​​of fluorescent microspheres and represented by different colors. The color division ranges are 0, 0.01-0.50, 0.50-5.00, 5.00-10.00 and above 10. When the obtained value is above 10, the number or content of fluorescent microspheres enriched in this area is higher. Under the same conditions, it is considered that African swine fever virus particles are more likely to accumulate in this area.

[0063] Each embodiment in this specification is described in a progressive manner. The same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments. In particular, for system or system embodiments, since they are basically similar to method embodiments, the description is relatively simple. For relevant parts, refer to the partial description of the method embodiment. The system and system embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. A person of ordinary skill in the art can understand and implement it without expending creative work.

[0064] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for simulating the spread of African swine fever virus aerosol in a pig farm, characterized in that: include: S1. Select fluorescent microspheres and prepare a fluorescent microsphere suspension; S2, build a fluorescent microsphere suspension release system; S3, divide the pig farm into several cells and set up a sampling network in the pig farm; S4, turning on all the samplers of the sampling network and idling them for a certain period of time, measuring the ambient background concentration, and then turning off all the samplers; S5. Synchronously start the fluorescent microsphere suspension release system and the samplers of all sampling networks, and simultaneously record the ambient temperature, humidity, wind speed, and wind direction; S6. Quantitatively analyze the fluorescence of the pig farm at different time points, generate a distribution map and dynamic change map of the fluorescence in the pig farm based on the analysis results, and derive the propagation pattern of African swine fever virus aerosol in the pig farm.

2. The method for simulating the spread of African swine fever virus aerosol in a pig farm according to claim 1, characterized in that: In S1, the fluorescent microspheres are made of polystyrene latex; The particle size of fluorescent microspheres is: 0.2μm-50μm; Fluorescent dyes include rhodamine B or fluorescein sodium; Prepare fluorescent microsphere suspension with a concentration of 10 6 -10 7 particles / mL.

3. The method for simulating the spread of African swine fever virus aerosol in a pig farm according to claim 1, characterized in that: In S2, the release system includes: a liquid storage tank, a peristaltic pump, a compressed air source, a pressure regulating valve, an atomizer, a 40°C heating drying tube and a release tower connected in sequence; The pressure of the pressure regulating valve is stable at 0.3MPa, the atomizer is TSI 3450, the release tower height is 1.5m, and the release position is the air inlet of the pig house.

4. The method for simulating the spread of African swine fever virus aerosol in a pig farm according to claim 1, characterized in that: In S3, in the sampling network, the samplers used are: optical particle counter to measure the real-time concentration distribution of fluorescent microspheres, Anderson impactor to measure the deposition of fluorescent microspheres according to particle size, and membrane sampling pump for environmental background correction; Sampler location: An optical particle counter and an Anderson impact sampler are set up 1m downwind from the release point, 1m away from the release source, and at a height of 0.8m; two optical particle counters are set up at a height of 0.8m in the animal activity area, in the cells divided by the pig farm; two Anderson impact samplers are set up at a height of 1.2m in the ventilation dead corner; a membrane sampling pump is set up directly in front of the fan at the exhaust outlet.

5. The method for simulating the spread of African swine fever virus aerosol in a pig farm according to claim 1, characterized in that: In S4, the sampler is idle for 30 minutes or other set time to measure the environmental background concentration. The background particle concentration must be less than 1000 particles / m³.

6. The method for simulating the spread of African swine fever virus aerosol in a pig farm according to claim 1, characterized in that: In S5, the fluorescent microsphere suspension release system and the samplers of all sampling networks were started synchronously, and the ambient temperature, humidity, wind speed, and wind direction were recorded synchronously; The release mode of the release system is pulse release; The IoT time synchronizer is used to synchronize the release system and the sampling network.

7. The method for simulating the spread of African swine fever virus aerosol in a pig farm according to claim 1, characterized in that: In S6, the fluorescence of the pig farm at different time points was quantitatively analyzed, specifically: The fluorescence value of the fluorescent microspheres of the samplers in the sampling network at different time points is monitored to obtain the monitoring value, and the environmental background concentration is subtracted to obtain the fluorescent microsphere acquisition value; Generate the distribution map and dynamic change map of fluorescent microspheres in the pig farm based on the obtained values ​​of fluorescent microspheres; Different ranges of obtained values ​​are represented by different colors.

8. The method for simulating the spread of African swine fever virus aerosol in a pig farm according to claim 4, characterized in that: In S6, the fluorescence of the pig farm at different time points was quantitatively analyzed. In the filter sampling pump, the filter membrane was dissolved in ethyl acetate and concentrated by centrifugation. The fluorescent spots were counted under blue light excitation using a Nikon ECLIPSE Ti2 microscope for environmental background correction.

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