Tag Archives: virus

Global Warming… and Smallpox?

    Heatwaves, droughts, freaky weather, and rising sea levels are just some of the extreme consequences we can expect as global temperatures continue to rise over the next few years. However, according to some scientists, we can add another potential disaster to that list: the introduction of new diseases.

    Researchers based in France and Russia retrieved and analyzed a 30,000 year-old permafrost core, in which was contained a sample of giant DNA viruses. These are viruses that are so big that some are visible underneath light microscopes. This giant DNA virus, which the researchers named Pithovirus sibericum, is believed to have been last active during the previous Ice Age.

The Chukotka region of Sibera, where the permafrost core was taken from. (Source: Wikipedia)

    Researchers were able to bring the sample “back to life” in the lab and believe that its protein coat was a factor in protecting it and ensuring that it could tolerate 30,000 years of being encased in permafrost.

 

    Although this virus only infects amoebas and is therefore harmless to humans, this does have grave implications for people: as permafrost begins to melt across the globe, more viruses with the same protective coating could be introduced again. Some of these viruses may in fact be able to infect humans and we may likely immunity to them (seeing as some have disappeared into the ground before Homo sapiens eventually came about).

Microscopic image of Pithovirus sibericum. (Source: Julia Bartolia and Chantal Abergel of UGS and CNRS-AMU)

    One concern expressed in the comments section is smallpox: although the last case of smallpox was in 1977, many smallpox victims of the 1800’s were buried in northern Canada, where they are encased in permafrost. As temperatures continue to rise and ice continues to melt, many of these bodies may be exposed to the surface. Could smallpox survive? Hopefully not. But in a worst-case scenario, we could see the re-emergence of smallpox and although it would be relatively brief (because of our access to vaccines), it would still be devastating to many.

    However, people must be wary of these alarmist attitudes. For example, we don’t know how likely it is that smallpox could survive. Even if it could, could it be re-animated? Pithovirus sibericum needed the help of a lab to start functioning again. So even if these viruses were exposed to the surrounding environment, could they function and infect people? The ability to infect people is an adaptation: many of these viruses would be older than us, so how would they have to ability to infect humans?

   Global warming is a frightening thought, but we don’t need to scare ourselves silly thinking about things that may be more suited for the script of a science fiction movie.

 – Nicholas MacDonald

Flu Virus

Flu is a common name for influenza, an infectious disease found in mammals and birds, caused by the RNA viruses. Its symptoms include sore throat, runny nose, headache, fever, coughing, and chills. The two modes of transmission for flu include the air through sneezes or coughs, and direct contact through touching contaminated surfaces or nasal secretions and bird droppings. Disinfectants, sunlight and detergents can inactivate the flu virus. Occasionally, pneumonia may develop as a result of flu, either viral pneumonia that is direct or bacterial pneumonia that is secondary. A common sign that flu is developing into pneumonia in both children and adults is when the flu patient seems to be recovering but starts having trouble in breathing or with high fever. However, sometimes flu is confused with an illness like common cold.

Flu spreads in seasonal epidemics leading to severe illnesses and deaths every year. Three flu epidemics occurred in the 20th Century, having been caused by a new virus strain in humans leading to millions of deaths. Most commonly, the strain occurs when the virus spreads form animals to humans. It occurs when new genes from pigs’ or birds’ virus are picked up by human strains. However, there are three common types of influenza that include influenzavirus A, influenzavirus B, and influenzavirus C. Each of these genus have on species, influenza A virus, influenza B virus, and influenza C virus.

Picture of ducks (Source: commons.wikimedia.org)

Influenzavirus A is naturally hosted by wild aquatic birds but the same is spread to other bird species causing a severe outbreak in domesticated poultry. This may be subdivided into serotypes depending on the response of antibodies to the virus. In humans, the confirmed serotypes that cause deaths include H1N1, H2N2, H3N2, H5N1, H7N7, H1N2, H9N2, H7N2, H7N3, H10N7, and H7N9. Influenzavirus B is not as common as influenzavirus A and it infects humans exclusively. However, the only animals known to be susceptible to this flu virus include the ferret and the seal. Influenzavirus B mutates twice to thrice slower than influenzavirus A. Also, it has less genetic diversification, with one influenza serotype. Influenzavirus C is found in pigs, humans and dogs and sometimes causes local epidemics and severe illnesses. It is not as common as other types of influenza viruses with a mild cause of the disease among children.

CDC scientist transferring H7N9 (Source: commons.wikimedia.org)

Therefore, since the modes of transmission for the flu virus include the air through sneezes or coughs, and direct contact through touching contaminated surfaces or nasal secretions and bird droppings, it is advisable that good personal hygiene should be maintained. The hygiene habits include frequent washing of hands, avoidance of touching the mouth, nose and eyes, avoiding contact with patients, avoiding spiting, the use of gloves and face masks when taking care of patients, avoiding smoking as it raises risks of infection, and surface sanitizing.