De acordo com o segundo parágrafo,
Leia o texto para responder às questões
Prescriptions for fighting epidemics
Epidemics have plagued humanity since the dawn of
settled life. Yet, success in conquering them remains patchy.
Experts predict that a global one that could kill more than 300
million people would come round in the next 20 to 40 years.
What pathogen would cause it is anybody’s guess. Chances
are that it will be a virus that lurks in birds or mammals, or
one that that has not yet hatched. The scariest are both highly
lethal and spread easily among humans. Thankfully, bugs that
excel at the first tend to be weak at the other. But mutations
– ordinary business for germs – can change that in a blink.
Moreover, when humans get too close to beasts, either
wild or packed in farms, an animal disease can become a
human one.
A front-runner for global pandemics is the seasonal
influenza virus, which mutates so much that a vaccine must
be custom-made every year. The Spanish flu pandemic of
1918, which killed 50 million to 100 million people, was a
potent version of the “swine flu” that emerged in 2009. The
H5N1 “avian flu” strain, deadly in 60% of cases, came about
in the 1990s when a virus that sickened birds made the jump
to a human. Ebola, HIV and Zika took a similar route.
(www.economist.com, 08.02.2018. Adaptado.)
Leia o texto para responder às questões
Prescriptions for fighting epidemics
Epidemics have plagued humanity since the dawn of
settled life. Yet, success in conquering them remains patchy.
Experts predict that a global one that could kill more than 300
million people would come round in the next 20 to 40 years.
What pathogen would cause it is anybody’s guess. Chances
are that it will be a virus that lurks in birds or mammals, or
one that that has not yet hatched. The scariest are both highly
lethal and spread easily among humans. Thankfully, bugs that
excel at the first tend to be weak at the other. But mutations
– ordinary business for germs – can change that in a blink.
Moreover, when humans get too close to beasts, either
wild or packed in farms, an animal disease can become a
human one.
A front-runner for global pandemics is the seasonal
influenza virus, which mutates so much that a vaccine must
be custom-made every year. The Spanish flu pandemic of
1918, which killed 50 million to 100 million people, was a
potent version of the “swine flu” that emerged in 2009. The
H5N1 “avian flu” strain, deadly in 60% of cases, came about
in the 1990s when a virus that sickened birds made the jump
to a human. Ebola, HIV and Zika took a similar route.
(www.economist.com, 08.02.2018. Adaptado.)
Gabarito comentado
A) Não podemos afirmar que o vírus H5N1 é uma mutação do vírus HIV, porque no trecho das últimas linhas lemos que: "A pandemia de gripe espanhola de 1918, que matou de 50 a 100 milhões de pessoas, foi uma versão potente da "gripe suína" que surgiu em 2009. A linhagem da H5N1 "gripe aviária", fatal em 60% dos casos, surgiu na década de 90, quando um vírus que adoecia pássaros contaminou um humano. (The Spanish flu pandemic of 1918, which killed 50 million to 100 million people, was a potent version of the “swine flu" that emerged in 2009. The H5N1 “avian flu" strain, deadly in 60% of cases, came about in the 1990s when a virus that sickened birds made the jump to a human.)
B) O fato do vírus influenza ser sazonal, não quer dizer que ele se espalhe facilmente, mas sim, que tem curto período sem se alterar, uma vez que lemos no seguinte excerto, que ele sofre tantas mutações que a cada ano é necessário uma vacina diferente. (A front-runner for global pandemics is the seasonal influenza virus, which mutates so much that a vaccine must be custom-made every year.)
