Isolating visibly ill patients is very effective in controlling in the spread of an infection, not as much when infected people do not show symptoms
If there is no effective vaccine or treatment for an infection, health agencies have two basic options to reduce the spread of infection: make sure people with disease symptoms are properly isolated, and trace the people with whom patients have recently come into contact so they can be tested for the disease.
During the SARS outbreak, many infected people reduced their movements and social interactions, helping to bring the epidemic under control. Analyzing the SARS outbreak using mathematical models, the researchers found that isolating patients had proven very effective in controlling in the infection. Many infected people reduced their movements and social interactions too, which also helped to bring the epidemic under control.
The World Health Organization declared the SARS epidemic to be under control on 5 July 2003. But the Imperial College researchers still wanted to know why isolation had been so successful and whether it would work for other infections too. The group developed a mathematical model to see how much isolating patients affected disease transmission and found that the effectiveness depended not just on the reproduction number but also on the proportion of infections that occur before symptoms appear.
During the SARS outbreak, people were most infectious after they became visibly ill. This is why isolation was effective: once people with symptoms were contained, there were very few opportunities for infection. The situation is very different for influenza, where people without symptoms are responsible for a large chunk of infections. In a flu outbreak, isolation and quarantine will be less effective because there is a good chance the patient will have infected others before they became ill.
Source : The calculus of contagion, 16 September 2014, Aeon.co
Mariners had painstakingly mapped the coastlines of the continents. Geographers had translated these findings into charts and globes. Photographs of ...
It's the idea that people living close to nature tend to be noble. It's seeing all those sunsets that does it. You can't watch a sunset and then go off and set fire to your neighbor's tepee. Living close to nature is wonderful for your mental health.
But we can easily extend this hypothesis [that nature has beneficial effects on the physical, cognitive and emotional well-being of individuals] to the conservation of biodiversity. [Ecologists] refer to the extinction of the experience of nature, which they have mainly applied in urban areas. The idea is as follows: from generation to generation, young people live less and less in contact with nature (because there are fewer of them and because their lifestyles limit such contact), at the very moment they are building their identity. The part of their identity that integrates their intimate relationships with their natural environment would therefore diminish from generation to generation. Not because of a lack of education, but mainly because of a decline in opportunities and desires to experience nature without constraint, freely and in their own personal way.
The consequences of this decrease appear in adulthood: with a weaker environmental identity, they are less in demand for nature in their daily lives, they integrate it less in their actions. (...) But if we do not collectively take biodiversity into consideration in our lifestyles, then we will suffer.
Source : Mobilizing against the extinction of nature experience (french), july 2015, Espaces naturels
An inefficient virus kills its host. A clever virus stays with it.