L’Organització de Nacions Unides per a l’Alimentació i l’Agricultura (FAO) estima que les plagues destrueixen cada any fins al 40% de la producció global de cultius, mentre que les malalties que pateixen les plantes costen anualment a l’economia mundial més de 220 000 milions de dòlars, i els insectes invasors a el menys 70 000 milions de dòlars, d’acord amb un estudi comissionat per aquesta entitat de l’ONU.
Les xifres de Salut Pública d’Anglaterra mostren que el nombre d’infeccions per variants de Delta a les escoles i col·legis va augmentar dràsticament al maig.
La variant Delta Covid-19 s’ha començat a estendre a les escoles i col·legis de tota Anglaterra, segons s’ha revelat, després que Public Health England publiqués noves dades, exigides pels sindicats de professors i personal, sobre els brots de la variant. Les noves dades, que abasten del 26 d’abril al 30 de maig, mostren que el nombre d’infeccions per variants de Delta a les escoles o altres entorns educatius augmenta ràpidament durant tot el període, amb un total de 140 incidents.
Prof Christina Pagel, director of University College London’s clinical operational research unit, said the figures were evidence that schools were now “a major source” of transmission, after the government last month dropped its requirement for secondary school pupils to wear masks in classrooms.
Dr William Welfare, deputy director of health protection at Public Health England (PHE), said that while outbreaks in schools are still at low levels, “we have seen a slight increase over recent weeks”, in line with the higher levels of variants being detected in the community.
“The latest PHE data suggest that there have been 97 confirmed Covid-19 outbreaks in primary and secondary schools that have had at least one variant case linked to them over the most recent four-week period. This represents around one in 250 schools.
“Public Health England’s health protection teams continue to work with local authorities and schools to carry out surveillance of Covid-19 cases in schools to understand and reduce transmission in these settings,” Dr Welfare said.
Of the Delta variant, the number of confirmed outbreaks or clusters found in primary and secondary schools has risen from just three at the end of April to 39 in the final week of May. The combined number of outbreaks and clusters of all variants has also grown at pace, from 24 at the end of April to 93 by the end of last month.
Pagel said: “It is clear that schools are a major source of transmission and that outbreaks in primary and secondary schools have been growing a lot, week on week.
“Meanwhile, the government removed the mask mandate on 17 May and the PHE surveillance report this week shows that the number of tests being done in secondary schools – the government’s main mitigation now for schools – is decreasing all the time. The government needs to get serious about reducing cases in schools.”
Last week the leaders of eight trade unions representing school staff, including the four main teaching unions, wrote to the Department for Education asking that the data on variants in schools and colleges be released.