﻿1 00:00:08,630 --> 00:00:13,490 Hello! My name is Rolf Ypma. I study avian influenza, 2 00:00:13,490 --> 00:00:18,650 a disease carried by many wild birds. Although it usually doesn't cause severe 3 00:00:18,650 --> 00:00:20,420 illness in wild birds, 4 00:00:20,420 --> 00:00:25,320 the virus can be transferred to poultry, to whom it's highly infectious and lethal. 5 00:00:25,320 --> 00:00:29,840 The virus can kill humans as well, luckily the probability of getting 6 00:00:29,840 --> 00:00:31,630 infected is extremely low. 7 00:00:31,630 --> 00:00:36,400 Still, it's obviously important that any outbreak of the virus is detected and 8 00:00:36,400 --> 00:00:38,290 stopped as quickly as possible, 9 00:00:38,290 --> 00:00:43,220 to halt further spread. The only viable way we currently have of stopping an 10 00:00:43,220 --> 00:00:46,160 outbreak is preemptive culling of healthy animals. 11 00:00:46,160 --> 00:00:51,210 For example, in a large epidemic in the Netherlands in 2003, 12 00:00:51,210 --> 00:00:56,480 30 million birds had to be culled. If we want to stop the virus more efficiently 13 00:00:56,480 --> 00:01:01,090 we'll need a better understanding of how it spreads. One possibility is that 14 00:01:01,090 --> 00:01:04,229 virus particles are blown to new farms by wind. 15 00:01:04,229 --> 00:01:09,820 This hypothesis can be tested from the 2003 outbreak by reconstructing the 16 00:01:09,820 --> 00:01:12,340 transmissions between farms of the virus. 17 00:01:12,340 --> 00:01:17,250 Such a reconstruction is possible using the viral DNA we obtained from all 18 00:01:17,250 --> 00:01:18,660 infected farms. 19 00:01:18,660 --> 00:01:23,780 My part of the study was to use this DNA to calculate viral movements. 20 00:01:23,780 --> 00:01:28,410 I did this by formulating mathematical equations that describe both how the 21 00:01:28,410 --> 00:01:29,810 virus transmits, 22 00:01:29,810 --> 00:01:34,729 and how it mutates. We then compared the transmissions between farms with the 23 00:01:34,729 --> 00:01:37,229 wind direction at time of transmissions. 24 00:01:37,229 --> 00:01:41,280 We found that the two were suspiciously often in the same direction, 25 00:01:41,280 --> 00:01:45,470 which led to our conclusion that wind plays a role in spreading the disease. 26 00:01:45,470 --> 00:01:48,830 This information can be used to halt the virus, 27 00:01:48,830 --> 00:01:53,140 for example by installing special filters that stop virus particles from 28 00:01:53,140 --> 00:01:53,590 getting through.