Earth Hour 2017 - Saturday 25 March

Once again it's Earth Hour - continuing environmental awareness, now in its tenth year. From 8.30pm to 9.30 pm. In this age of energy consciousness, the relevance is greater than ever. The website link is: Earth Hour website

CRISPR - genetic engineering has arrived

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The ability to precisely alter, delete and rearrange the DNA of any living organism, including humans - once the realm of science fiction or futurists it has become a reality with the development of the biotechnology known as CRISPR or in its extended form, CRISPR-Cas9. The non abbreviated version is 'clustered regularly interspaced short palindromic repeats' with the Cas9 part referring to a particular enzyme. CRISPR has a number of existing and potential applications such as:

• disease control and discovering the DNA sequences for viruses, thus opening the way for new treatments.
• influencing ecology by introducing disease-resistant genes into wild populations of parasitic insects reducing pathogen transmission to humans.
• adding climate and pest resistant characteristics into food crops.
• editing hereditary disease susceptible genes in humans.

CRISPR operates by using a cellular scalpel, an enzyme Cas9, to cut DNA. The enzyme is guided to its destination by a RNA guide that ensures that Cas9 cuts out the target nucleotides of DNA allowing the insertion of a different chain of nucleotides which were included in the CRISPR package. The potential changes as a result of this biotechnology are profound and in many cases hard to accurately foresee. Vectors for diseases could be genetically altered and rendered harmless (such as mosquitoes), food crops could be made climate change and pest resistant, threatened species of animals could be made hardier to survive and human hereditary health conditions prevented.

There are also dangers with this biotechnology - the risk of the unknown: for example, inadvertently shifting viruses and other pathogens from one species to another thus creating diseases for which there is no known protection or treatment. But will the advantages gained outweigh the risks ?

Mosquitoes - the threat expands with a warmer climate

The Summer warnings in NSW in early 2017 of the potential for an outbreak of Ross River Fever again underscores the risks posed by pathogens carried by mosquitoes who readily benefit from warmer and moister weather. Ross River Fever was first isolated in the Ross River region near Townsville, Queensland, over half a century ago. Since that time the condition has been identified as being fairly endemic across Australia in warmer regions and in near neighbouring countries such as Papua New Guinea. During periods of colder temperatures the risk is minimised as the carrier mosquitoes are limited in their breeding cycle however with milder temperatures, longer Summers and intense periods of storm activity with higher humidity, the mosquito's geographic range is expanded. Matched with a longer breeding season due to these same conditions, the propensity for greater disease outbreaks is very real.

Across the planet similar concerns are being expressed in relation to various species of mosquito which are vectors for a range of dangerous pathogens either endangering life or causing serious debilitating effects.  Only a handful of the known 3,500 species of mosquito feed on human blood and these are only female as male mosquitoes live off plants. This handful are, nonetheless, devastating in impact for diseases such as malaria alone kills over 400,000 people a year. The chief culprits are listed on the table below: 

Mosquito species	Pathogens carried
Aedes aegypti Found in cities, this species feeds almost exclusively from human blood.	Zika virus Chikungunya Yellow Fever Dengue Fever
Aedes albopictus An aggressive, adaptable species which can colonise the habitats of other mosquitoes.	Zika virus Chikungunya Dengue fever
Haemagogus A major carrier of yellow fever, they can be identified by their metallic sheen.	Yellow Fever
Anopheles This species has long front feelers and is the only genus that transmits malaria.	Malaria Lymphatic filariasis
Culex quinquefasciatus Common around the world, this species are night feeders and lay their eggs in dirty water.	Lymphatic filariasis West Nile fever

Zika virus has become the most recent addition to the list of dangerous pathogens in North and South  America but it is not alone. In Brazil, Mayaro, a monkey virus is now infecting people in the North West of that country as a result of mosquito transmission. As much of the debate on climate change focusses on energy generation and adaptation technology and design, an equal amount of effort is needed on examining the public health ramifications across a range of impacts. Ultimately these may have a much earlier effect.