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Despite humanity's recent success at managing diseases such as [[SARS]], [[coronavirus]], and [[Ebola]] – historical data is by no means a guarantee of the future success of confrontation given that each new disease brings its own set of [[Impact of the COVID-19 pandemic on the environment|challenges as seen in with the ongoing pandemic regarding COVID-19]]. There is no direct evidence that COVID-19 is worsened or is caused by climate change.
Despite humanity's recent success at managing diseases such as [[SARS]], [[coronavirus]], and [[Ebola]] – historical data is by no means a guarantee of the future success of confrontation given that each new disease brings its own set of [[Impact of the COVID-19 pandemic on the environment|challenges as seen in with the ongoing pandemic regarding COVID-19]]. There is no direct evidence that COVID-19 is worsened or is caused by climate change.


== Impact on human health ==
== Background ==
The [[World Health Organization]] and [[United Nations Environment Programme]] established the [[Intergovernmental Panel on Climate Change]] (IPCC) in 1988 because there was little knowledge about health issues caused by global climate change.<ref name="WHO Climate Change and Human Health 2003" /> [[Intergovernmental Panel on Climate Change]] has presented three assessment reports. [[IPCC First Assessment Report]], [[IPCC Second Assessment Report]] and [[IPCC Third Assessment Report]] wrote about climate change, potential health risks caused by climate change and early evidence of actual health impacts.<ref name="WHO Climate Change and Human Health 2003" /> IPPC and other policy-related assessments at the regional and national levels stimulated scientific studies to understand the climate-health relationships.<ref name="WHO Climate Change and Human Health 2003">{{Cite book|url=https://apps.who.int/iris/bitstream/handle/10665/42749/9241590815.pdf|title=Climate change and human health - risks and responses. Summary.|vauthors=WHO, WMO, UNEP|publisher=World Health Organization|year=2003|isbn=9241590815|location=Geneva, Switzerland|chapter=International consensus on the science of climate and health: the IPCC Third Assessment Report|type=Summary of other published book|access-date=2020-06-28|chapter-url=https://www.who.int/globalchange/summary/en/index2.html}}</ref>
The [[World Health Organization]] and [[United Nations Environment Programme]] established the [[Intergovernmental Panel on Climate Change]] (IPCC) in 1988 because there was little knowledge about health issues caused by global climate change.<ref name="WHO Climate Change and Human Health 2003" /> [[Intergovernmental Panel on Climate Change]] has presented three assessment reports. [[IPCC First Assessment Report]], [[IPCC Second Assessment Report]] and [[IPCC Third Assessment Report]] wrote about climate change, potential health risks caused by climate change and early evidence of actual health impacts.<ref name="WHO Climate Change and Human Health 2003" /> IPPC and other policy-related assessments at the regional and national levels stimulated scientific studies to understand the climate-health relationships.<ref name="WHO Climate Change and Human Health 2003">{{Cite book|url=https://apps.who.int/iris/bitstream/handle/10665/42749/9241590815.pdf|title=Climate change and human health - risks and responses. Summary.|vauthors=WHO, WMO, UNEP|publisher=World Health Organization|year=2003|isbn=9241590815|location=Geneva, Switzerland|chapter=International consensus on the science of climate and health: the IPCC Third Assessment Report|type=Summary of other published book|access-date=2020-06-28|chapter-url=https://www.who.int/globalchange/summary/en/index2.html}}</ref>


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The rising of new diseases and worsening of diseases due to climate change have been a wake up call for the science community. The collection of data on how climate changes over the years and how these changes are affecting health were stimulated by Science Diplomacy organizations because this information helped scientists to raise awareness about the situation nationally and internationally so action can be taken. This is shown by the actions that were taken during the malaria and dengue outbreak. However, Science Diplomacy organizations need more support from the world so a better solution can be reached to solve the climate change issue because new infectious diseases will emerge. These new infectious diseases could be the end of humanity if they are not addressed properly and on time.
The rising of new diseases and worsening of diseases due to climate change have been a wake up call for the science community. The collection of data on how climate changes over the years and how these changes are affecting health were stimulated by Science Diplomacy organizations because this information helped scientists to raise awareness about the situation nationally and internationally so action can be taken. This is shown by the actions that were taken during the malaria and dengue outbreak. However, Science Diplomacy organizations need more support from the world so a better solution can be reached to solve the climate change issue because new infectious diseases will emerge. These new infectious diseases could be the end of humanity if they are not addressed properly and on time.

Climate change may lead to dramatic increases in prevalence of a variety of infectious diseases. Beginning in the mid-'70s, there has been an "emergence, resurgence and redistribution of infectious diseases".<ref name=Epstein>{{Cite journal|author=P. Epstein|s2cid=19299458|year=2002|title=Climate Change and Infectious Disease: Stormy Weather Ahead?|journal=[[Epidemiology (journal)|Epidemiology]]|volume=13|issue=4|pages=373–375|doi=10.1097/00001648-200207000-00001|pmid=12094088}}</ref> Reasons for this are likely multi-causal, dependent on a variety of social, environmental and climatic factors, however, many argue that the "volatility of infectious disease may be one of the earliest biological expressions of climate instability".<ref name=Epstein/> Though many infectious diseases are affected by changes in climate, vector-borne diseases, such as malaria, [[dengue fever]] and leishmaniasis, present the strongest [[Causality|causal relationship]]. One major reason that change in climate increases the prevalence of vector borne disease is that temperature and rainfall play a key role in the distribution, magnitude, and viral capacity of mosquitoes, who are primary vectors for many vector borne diseases. Observation and research detect a shift of pests and pathogens in the distribution away from the equator and towards Earth's poles.<ref>{{Cite journal|author1=Daniel P. Bebber |author2=Mark A. T. Ramotowski |author3=Sarah J. Gurr |year=2013|title=Crop pests and pathogens move polewards in a warming world|doi=10.1038/nclimate1990|journal= Nature Climate Change|bibcode = 2013NatCC...3..985B|volume=3|issue=11 |pages=985–988}}</ref> A tool that has been used to predict this distribution trend is the Dynamic Mosquito Simulation Process (DyMSiM). DyMSiM uses [[Epidemiology|epidemiological]] and [[Entomology|entomological]] data and practices to model future mosquito distributions based upon climate conditions and mosquitos living in the area.<ref>{{cite journal|author1=Butterworth, M. K.|author2=Morin, C. W.|author3=Comrie, A. C.|date=2016|title=An Analysis of the Potential Impact of Climate Change on Dengue Transmission in the Southeastern United States|journal=Environmental Health Perspectives|volume=125|issue=4|pages=579–585|pmc=5381975|pmid=27713106|doi=10.1289/EHP218}}</ref> This modeling technique helps identify the distribution of specific species of mosquito, some of which are more susceptible to viral infection than others.

Beyond distribution, rising temperatures can decrease viral incubation time ''in vivo'' in vectors increasing the viral transmissibility leading to increases in infection rates.<ref>{{cite journal|author1=Wu, J.Y.|author2=Lun, Z.R.|author3=James, A.A.|author4=Chen, X.G.|date=2010|title=Review: dengue fever in mainland China|journal=American Journal of Tropical Medicine and Hygiene|volume=83|issue=3|pages=664–671|doi=10.4269/ajtmh.2010.09-0755|pmid=20810836|pmc=2929067}}</ref>

====Malaria====
Increased [[precipitation]] like [[rain]] could increase the number of [[mosquito]]s indirectly by expanding larval habitat and food supply. Malaria, which kills approximately 300,000 children (under age 5) annually, poses an [[imminent threat]] through temperature increase.<ref name=malaria>{{Cite journal |author1=J. Patz |author2=S. Olson |year=2006|title=Malaria Risk and Temperature: Influences from Global Climate Change and Local Land Use Practices|journal=[[Proceedings of the National Academy of Sciences]]|volume=103|issue=15|pages=5635–5636|doi=10.1073/pnas.0601493103 | pmid=16595623 | pmc = 1458623|bibcode = 2006PNAS..103.5635P }}</ref> Models suggest, conservatively, that risk of malaria will increase 5–15% by 2100 due to climate change.<ref name=Bhattacharya>{{Cite journal |author1=S. Bhattacharya |author2=C. Sharma |author3=R. Dhiman |author4=A. Mitra |year=2006|title=Climate Change and Malaria in India|journal=[[Current Science]]|volume=90|issue=3|pages=369–375}}</ref> In Africa alone, according to the [[The Mars Project|MARA Project]] (Mapping Malaria Risk in Africa),<ref name="mara">{{cite web |url= http://www.mara.org.za/pdfmaps/NgaSeasonality.PDF |archive-url= https://web.archive.org/web/20051210185537/http://www.mara.org.za/pdfmaps/NgaSeasonality.PDF |url-status=dead |archive-date= 2005-12-10 |title= Nigeria: Duration of the Malaria Transmission Season |access-date= 24 January 2007 |date= July 2001 |work= mara.org.za |publisher= MARA/ARMA (Mapping Malaria Risk in Africa / Atlas du Risque de la Malaria en Afrique) }}</ref> there is a projected increase of 16–28% in person-month exposures to malaria by 2100.<ref>{{Cite journal |author1=J. Patz |author2=D. Campbell-Lendrum |author3=T. Holloway |author4=J. Foley |year=2005|title=Impact of Regional Climate Change on Human Health|journal=[[Nature (journal)|Nature]]|volume=438|issue=7066|pages=310–317|doi=10.1038/nature04188|pmid=16292302 |bibcode = 2005Natur.438..310P|s2cid=285589 }}</ref>
[[File:Aedes aegypti CDC9253.tif|thumb|''Aedes aegypti'', the mosquito that is the vector for dengue transmission.]]

====Non-climatic determinants====
Sociodemographic factors include, but are not limited to: patterns of [[human migration]] and travel, effectiveness of [[public health]] and medical infrastructure in controlling and treating disease, the extent of [[Malaria|anti-malarial]] [[drug resistance]] and the underlying health status of the population at hand.<ref name=infectious>{{Cite journal |author1=J. Patz |author2=A.K. Githeko |author3=J.P. McCarty |author4=S. Hussein |author5=U. Confalonieri |author6=N. de Wet |year=2003|title=Climate Change and Infectious Diseases |editor1=A. McMichael|journal=Climate Change and Human Health: Risks and Responses|editor2=D. Campbell-Lendrum |editor3=C. Corvalan |editor4=K. Ebi |editor5=A. Githeko |editor6=J. Scheraga |editor7=A. Woodward}}</ref> Environmental factors include: changes in [[Land use|land-use]] (e.g. deforestation), expansion of agricultural and water development projects (which tend to increase mosquito breeding habitat), and the overall trend towards urbanization (i.e. increased concentration of human hosts). Patz and Olson argue that these changes in landscape can alter local weather more than long term climate change.<ref name=malaria/> For example, the [[deforestation]] and cultivation of natural swamps in the African highlands has created conditions favourable for the survival of mosquito larvae, and has, in part, led to the increasing incidence of malaria.<ref name=malaria/> The effects of these non-climatic factors complicate things and make a direct causal relationship between climate change and malaria difficult to confirm. It is highly unlikely that climate exerts an isolated effect.{{citation needed|date=August 2020}}

====Dengue====

Dengue incidence has increased in the last few decades, and is projected to continue to do so with changing climate conditions.<ref name=":5">Banu, S., Wenbiao H., Yuming G., Hurst, C., & Tong, S.(2014). "Projecting the Impact of Climate Change on Dengue Transmission in Dhaka, Bangladesh". Environment International (63): 137-142. DOI: 10.1016/j.envint.2013.11.002

</ref> [[Dengue fever]] is spread by the bite of the female mosquito known as ''[[Aedes aegypti]].'' This species of mosquito can travel up to 400 meters in search of water to lay their eggs, but often remain closer to human habitation. A [[mosquito]] becomes infected with dengue when it bites and takes the blood of an infected human. After approximately one week, the mosquito can then transmit the dengue infection to other humans through her bite. While dengue cannot be spread from person to person, an infected person can infect more mosquitos, thus, furthering the spread of the disease. Overall, the female mosquito is a highly effective vector of this disease.<ref>{{Cite web|url=https://www.who.int/denguecontrol/faq/en/|title=WHO {{!}} Dengue/Severe dengue frequently asked questions|website=WHO|access-date=2019-07-25}}</ref>

Once infected with the dengue virus, humans experience severe flu-like symptoms. Also known as "break-bone fever", dengue can affect infants, children, and adults and can be fatal. Those infected exhibit a [[high fever]] (40&nbsp;°C/ 104&nbsp;°F) along with at least two of the following symptoms: severe headache, pain behind the eye, nausea, vomiting, swollen glands, muscle and joint pains, and rash. These symptoms usually last 2–7 days. Dengue can become fatal due to plasma leaking, fluid accumulation, respiratory distress, severe bleeding, or organ impairment. Warning signs of this include a decrease in temperature decrease (below 38&nbsp;°C/ 100&nbsp;°F) in conjunction with: severe abdominal pain, persistent vomiting, rapid breathing, bleeding gums, blood in vomit, and/or fatigue and restlessness.<ref>{{Cite web|url=https://www.who.int/denguecontrol/human/en/|title=WHO {{!}} The human|website=WHO|access-date=2019-07-25}}</ref>

Where the mosquito, ''Aedes aegypti'', lives and the amount of mosquitos present is strongly influenced by the amount of water-bearing containers or pockets of standstill water in an area, daily temperature and variation in temperature, moisture, and solar radiation.<ref>Patz, J. A., Campbell-Lendrum, D., Holloway, T., & Foley, J. A. (2005). Impact of regional climate change on human health. ''Nature, 438''(7066), 310-317. doi:10.1038/nature04188</ref> While dengue fever is primarily considered a tropical and subtropical disease, the geographic ranges of the aedes aegypti are expanding. Globalization, trade, travel, demographic trends, and warming temperatures are all attributed to the recent spread to this primary vector of dengue.<ref name=":2">Ebia, K.L. & Nealon, J. (2016). Dengue in a changing climate. ''Environmental Research, 151, 115-123.''</ref>

Dengue is now ranked as the most important vector-borne viral disease in the world. Today, an estimated 50–100 million dengue fever infections occur annually. In just the past 50 years, transmission has increased drastically with new cases of the disease (incidence) increasing 30-fold.<ref name=":2" /> Once localized to a few areas in the tropics, dengue fever is now endemic in over 100 countries in Southeast Asia, the Americas, Africa, the Eastern Mediterranean, and the Western Pacific with Southeast Asia and the Western Pacific regions being the most seriously affected. Recently the number of reported cases has continually increased along with dengue spreading to new areas. Explosive outbreaks are also occurring. Moreover, there is the possible threat of outbreak in Europe with local transmission of dengue being reported for the first time in France and Croatia in 2010.<ref>World Health Organization. (n.d.) Neglected tropical diseases: dengue. Retrieved from: [http://www.searo.who.int/entity/vector_borne_tropical_diseases/data/data_factsheet/en Dengue Fact Sheet]</ref>
One country that has seen significant impacts from dengue is [[Bangladesh]].<ref name=":3">{{cite journal|author=Rahman, A.|date=2008|title=Climate Change and its Impact on health in Bangladesh|journal=Regional Health Forum|volume=12|pages=16–26|url=http://ngof.org/wdb_new/sites/default/files/Climate%20change%20and%20its%20Impact%20on%20Health%20in%20Bangladesh.pdf}}</ref>


== References ==
== References ==

Revision as of 01:20, 30 April 2021

Global climate change has resulted a wide range of impacts on the spread of infectious diseases is a prominent instance due to ‘climate-sensitive’ characterization.[clarification needed] Like other climate change impacts on human health, climate change both exacerbates existing inequalities and challenges in managing infectious disease while increasing the likelihood of certain kinds of new infectious disease challenges.

Documented infectious disease impacts of climate change, include increased malaria and dengue, which are expected to worsen as the global climate changes directly result in extreme weather conditions and higher temperatures. Not only will it propagate their spread, but climate change will probably bring forth new infectious diseases,[1] and change the epidemiology of many existing diseases.[citation needed]

Despite humanity's recent success at managing diseases such as SARS, coronavirus, and Ebola – historical data is by no means a guarantee of the future success of confrontation given that each new disease brings its own set of challenges as seen in with the ongoing pandemic regarding COVID-19. There is no direct evidence that COVID-19 is worsened or is caused by climate change.

Background

The World Health Organization and United Nations Environment Programme established the Intergovernmental Panel on Climate Change (IPCC) in 1988 because there was little knowledge about health issues caused by global climate change.[2] Intergovernmental Panel on Climate Change has presented three assessment reports. IPCC First Assessment Report, IPCC Second Assessment Report and IPCC Third Assessment Report wrote about climate change, potential health risks caused by climate change and early evidence of actual health impacts.[2] IPPC and other policy-related assessments at the regional and national levels stimulated scientific studies to understand the climate-health relationships.[2]

A noticeable effect of the global climate change is the increase of temperature. In 1895, the record-keeping of temperature in the U.S began and it has increased by 1.3 °F to 1.9 °F.[3]: 26  This is because the concentrations of greenhouse gases increase.[4] Based on this information the annual average U.S temperatures are expected to increase by 3 °F to 10 °F having direct effects on human health.[4] The extreme temperatures (hot and/or cold) affect the body by compromising its ability to regulate its internal temperature and by worsening chronic conditions such as cardiovascular and respiratory diseases.[4] Respiratory diseases also worsen by the air quality. Air quality becomes poor because of climate change, which produces higher concentrations of CO2, higher temperatures and changes in precipitation.[5] Climate change affects the growing season and the pollen because the start or duration of the growing season becomes extended, and the quantity, the allergenicity and the spatial distribution of pollen increase.[5] Climate change affects vector-borne diseases by affecting the survival, distribution and behavior of vectors such as mosquitoes, ticks and rodents.[3]: 29  The viruses, bacteria and protozoa are carried by these vectors transferring it from carrier to another.[6] Vector and pathogen can adapt to the climate fluctuations by shifting and expanding their geographic ranges, which can alter the rate of new cases of disease depending on vector-host interaction, host immunity and pathogen evolution.[7] This means that climate change affects infectious diseases by impacting their length of the transmission season and their geographical range.[8] Vector-borne diseases are a concern because they have played a significant role in human history by determining the rise and fall of civilizations.[8] This is why the World Health Organization considers climate change as one of the greatest threats to human health.[8]

Dengue

Climate change has created conditions favorable to the spread of the dengue virus. The virus is borne by the Aedes Aegypti mosquito[9] and transmission peaks during the rainy season when mosquitoes breed.[10] The dengue virus was first isolated in 1943 by scientists Ren Kimura and Susumu.[11]

The dengue disease is deadly and affects people all over the world, especially those living in warmer climates. Symptoms in mild cases are vomiting, rash, high fever (40 °C/104 °F), joint pain, eye pain. Severe cases (fever 38 °C/100 °F) may lead to death.[12]

From the end of the industrial revolution to the present day, the levels of carbon dioxide have risen from 280 parts per million to 412 parts per million within the last 150 years.[13] The World Health Organization (WHO) has reported an increase from a thousand to one million confirmed cases between 1955 and 2007.[12] Coincidentally, due to climate change, a greenhouse barrier has formed in the earth's atmosphere, composed of gases such as nitrous oxide, methane, and carbon dioxide.[13] The greenhouse gases trap sun rays that should be reflected back out into the universe, thereby causing the Earth's temperature to elevate.[13] The increasing temperatures mostly affect countries that are closer to water since water can absorb a lot of energy from the sun and can release it in the form of vapors. As the evaporated water condenses, the amount of condensation increases and the likelihood of precipitation increases as well. As a result, climate change causes higher raining seasons, temperature, and humidity. These conditions are favorable for Aedes aegypti mosquito population since these conditions form habitats that are accessible for laying eggs and spreading the transmission of the dengue virus to people.

There are other organizations that are preventing climate change and the spread of new viruses. For example, The Intergovernmental Panel on Climate Change (IPPC) provides scientific evaluations based on climate change impact, adaption and alleviation options, and future risks. The information from IPPC is the most reliable source when it comes to climate change. IPPC reports are used as a foundation for policymaking. The United Nations Environment Programme (UNEP) and World Meteorological Organization (WMO) are other organizations that work toward mitigating climate change.[14] UNEP works on seven different areas of climate change and is the leading international environmental authority. In addition, the seven areas that UNEP mainly focuses on are climate change, managing ecosystems, natural disasters and conflicts, environmental policies, chemicals, and wastes, monitor the financial output of environmental conditions, and the study of many environmental conditions.[citation needed] This organization is known for mitigating environmental conditions and trends at a global, regional, and national level. Also, they have created programs that help to fight against climate change such as REDD+ program (Reducing emissions from deforestation and forest degradation), Climate and Clean Air Coalition (Climate and Clean Air Coalition to Reduce Short-Lived Climate Pollutants), and Climate Technology Centre and Network. WMO specifically monitors weather, climate, and water. WMO dedicates their time to bring international awareness and cooperation, pertaining to the earth’s atmosphere. This organization focuses on reducing the risk of disasters and provides vital information about meteorological, climatological, hydrological, and oceanographic activities. In 2014, a global foundational fund known as the Green Climate Fund was created.[15] This fund focuses on underdeveloped countries, islands, and many African states, which have been affected the most due to climate change. Another fund is the Climate Investment Funds, which supports economies that are trying to minimize the use of carbon in order to prevent climate change. There are also support groups that are fighting for environmental causes. 350.org is a support group that fights against fossil fuel industries and the mining in various parts of Brazil.[16] Another organization is the C40 Cities Climate Leadership Group, which is trying to develop solutions to reduce greenhouse gas emissions and climate change.[17]

Ebola

Ebola is one of the deadliest viruses, starting out as a small outbreak and eventually turning into a major global issue. The average case fatality rate of the Ebola virus is approximately 40% and to date, there have been more than 28,600 cases with 11,310 deaths.[18] Recent studies are holding climate change liable for the uptick in Ebola. Many researchers are linking deforestation to the disease, observing that change in the landscape increases wildlife contact with humans.[19] Ebola virus is typically found in animals of the wild and can be transmitted from these animals to humans when exposed to infected bodily fluids.[18] The virus can also be transmitted from another human when in direct contact with the virus hosts blood, vomit, or feces. Seasonal droughts alongside strong winds, thunderstorms, heat waves, floods, landslides, and a change in rainfall patterns also impact the wildlife migration. These conditions pull them away from their natural environment and closer to human proximity.[20] One example of an Ebola outbreak caused by climate change or a shift in nature was seen during the drought of Central Africa. This ultimately amplified food insecurity leading West African communities to eat animals such as bats who were infected with the virus.[19]

Outbreaks such as Ebola are transnational threats. Viral diseases like Ebola, have no remorse for any border or country. It's a battle that no country can face alone. Global health diplomacy helps bring together the regulation of public health, law, foreign affairs, economics, and puts the limelight on negotiations that can help build and manage policies for global environmental health. In 2014, Cuba sent 461 doctors to West Africa to help combat the outbreak of Ebola.[21] Cuba was one of the first countries that have supplied as many trained health professionals to the Ebola outbreak than any other nation. This kind of gesture helped form the start of some Ebola diplomacy between Cuba and the United States.[22] Consequently, the World Health Organization (WHO) assembled an emergency convention with many health ministers from eleven countries to reveal an alliance to help fight the Ebola epidemic.[23] The World Bank Group and the Economic Community of West African States (ECOWAS) declared aid money to help the epidemic and the World Food Programme helped distribute food for approximately one million people who were living in restricted areas.[24] Other organizations have also provided aid in an attempt to control the spread of the Ebola disease. For instance, the humanitarian aid organization Médecins Sans Frontières also known as Doctors Without Borders became the prominent organization that was responding to the crisis by having many health centers in the area. Another non-governmental organization is the Samaritan's Purse who provided direct patient care and medical aid in Liberia.[25]

Emergence of new infectious diseases

In recent decades, experts began to sound the alarm that climate change could be associated with changes to the epidemiology of infectious diseases. This viewpoint focuses on a threat where there is a strong possibility that new, previously unknown infectious diseases will emerge from warmer climates as microbes adapt to higher global temperatures that can defeat our endothermy thermal barrier. Human defenses against microbial diseases rely on advanced immunity, which includes innate and adaptive arms and endothermy. This creates a thermal restriction zone for many microbes. Given that microbes can adapt to higher temperatures, there is a concern that global climate change will select for microbes with higher temperature tolerance that can defeat our immune defenses and cause new infectious diseases to emerge.

There is a specific concern about the emergence of new diseases from the fungal kingdom. Mammals are extraordinary among animals in their endothermy and homeothermy, which allows us to maintain elevated body temperature through life; but it can be defeated if the fungi were to adapt to higher temperatures and survive in the body.[26] Research has shown that fungi that are pathogenic for insects can be experimentally adapted to replicate at mammalian temperatures through cycles of progressive warming. This demonstrates that fungi are able to adapt rapidly to higher temperatures. The emergence of Candida Auris on three continents is proposed to be as a result of global warming and has raised the danger that increased warmth by itself will trigger adaptations on certain microbes to make them pathogenic for humans.[27]

If these threats materialize, medicine will need to conform to new infectious diseases for which it has no previous knowledge or experience. As seen with the recent pandemic of the novel coronavirus (COVID-19); control measures, therapeutics, and effective responses take time, where countless lives are lost in the meantime. However, if proper measures are taken today, it could increase the preparedness for confronting new infectious diseases.

Though climate change will almost certainly bring forth new infectious diseases and change the epidemiology of many existing diseases, it is important to note that humanity has successfully confronted new deadly diseases in recent years, such as SARS, coronavirus, and Ebola. Prior success is no guarantee for future success given that each new disease brings its own set of challenges as seen in with the ongoing pandemic, COVID-19. There is no proof that COVID-19 worsens or is caused by climate change, however, we’ve seen how a new infectious disease can change the way we live as humans in such a short span of time and also the number of deaths that resulted from the pandemic. The best solution against future threats is continued investment in surveillance, antimicrobial therapeutics, epidemiology, and research into mechanisms of these microbes.

The rising of new diseases and worsening of diseases due to climate change have been a wake up call for the science community. The collection of data on how climate changes over the years and how these changes are affecting health were stimulated by Science Diplomacy organizations because this information helped scientists to raise awareness about the situation nationally and internationally so action can be taken. This is shown by the actions that were taken during the malaria and dengue outbreak. However, Science Diplomacy organizations need more support from the world so a better solution can be reached to solve the climate change issue because new infectious diseases will emerge. These new infectious diseases could be the end of humanity if they are not addressed properly and on time.

Climate change may lead to dramatic increases in prevalence of a variety of infectious diseases. Beginning in the mid-'70s, there has been an "emergence, resurgence and redistribution of infectious diseases".[28] Reasons for this are likely multi-causal, dependent on a variety of social, environmental and climatic factors, however, many argue that the "volatility of infectious disease may be one of the earliest biological expressions of climate instability".[28] Though many infectious diseases are affected by changes in climate, vector-borne diseases, such as malaria, dengue fever and leishmaniasis, present the strongest causal relationship. One major reason that change in climate increases the prevalence of vector borne disease is that temperature and rainfall play a key role in the distribution, magnitude, and viral capacity of mosquitoes, who are primary vectors for many vector borne diseases. Observation and research detect a shift of pests and pathogens in the distribution away from the equator and towards Earth's poles.[29] A tool that has been used to predict this distribution trend is the Dynamic Mosquito Simulation Process (DyMSiM). DyMSiM uses epidemiological and entomological data and practices to model future mosquito distributions based upon climate conditions and mosquitos living in the area.[30] This modeling technique helps identify the distribution of specific species of mosquito, some of which are more susceptible to viral infection than others.

Beyond distribution, rising temperatures can decrease viral incubation time in vivo in vectors increasing the viral transmissibility leading to increases in infection rates.[31]

Malaria

Increased precipitation like rain could increase the number of mosquitos indirectly by expanding larval habitat and food supply. Malaria, which kills approximately 300,000 children (under age 5) annually, poses an imminent threat through temperature increase.[32] Models suggest, conservatively, that risk of malaria will increase 5–15% by 2100 due to climate change.[33] In Africa alone, according to the MARA Project (Mapping Malaria Risk in Africa),[34] there is a projected increase of 16–28% in person-month exposures to malaria by 2100.[35]

Aedes aegypti, the mosquito that is the vector for dengue transmission.

Non-climatic determinants

Sociodemographic factors include, but are not limited to: patterns of human migration and travel, effectiveness of public health and medical infrastructure in controlling and treating disease, the extent of anti-malarial drug resistance and the underlying health status of the population at hand.[36] Environmental factors include: changes in land-use (e.g. deforestation), expansion of agricultural and water development projects (which tend to increase mosquito breeding habitat), and the overall trend towards urbanization (i.e. increased concentration of human hosts). Patz and Olson argue that these changes in landscape can alter local weather more than long term climate change.[32] For example, the deforestation and cultivation of natural swamps in the African highlands has created conditions favourable for the survival of mosquito larvae, and has, in part, led to the increasing incidence of malaria.[32] The effects of these non-climatic factors complicate things and make a direct causal relationship between climate change and malaria difficult to confirm. It is highly unlikely that climate exerts an isolated effect.[citation needed]

Dengue

Dengue incidence has increased in the last few decades, and is projected to continue to do so with changing climate conditions.[37] Dengue fever is spread by the bite of the female mosquito known as Aedes aegypti. This species of mosquito can travel up to 400 meters in search of water to lay their eggs, but often remain closer to human habitation. A mosquito becomes infected with dengue when it bites and takes the blood of an infected human. After approximately one week, the mosquito can then transmit the dengue infection to other humans through her bite. While dengue cannot be spread from person to person, an infected person can infect more mosquitos, thus, furthering the spread of the disease. Overall, the female mosquito is a highly effective vector of this disease.[38]

Once infected with the dengue virus, humans experience severe flu-like symptoms. Also known as "break-bone fever", dengue can affect infants, children, and adults and can be fatal. Those infected exhibit a high fever (40 °C/ 104 °F) along with at least two of the following symptoms: severe headache, pain behind the eye, nausea, vomiting, swollen glands, muscle and joint pains, and rash. These symptoms usually last 2–7 days. Dengue can become fatal due to plasma leaking, fluid accumulation, respiratory distress, severe bleeding, or organ impairment. Warning signs of this include a decrease in temperature decrease (below 38 °C/ 100 °F) in conjunction with: severe abdominal pain, persistent vomiting, rapid breathing, bleeding gums, blood in vomit, and/or fatigue and restlessness.[39]

Where the mosquito, Aedes aegypti, lives and the amount of mosquitos present is strongly influenced by the amount of water-bearing containers or pockets of standstill water in an area, daily temperature and variation in temperature, moisture, and solar radiation.[40] While dengue fever is primarily considered a tropical and subtropical disease, the geographic ranges of the aedes aegypti are expanding. Globalization, trade, travel, demographic trends, and warming temperatures are all attributed to the recent spread to this primary vector of dengue.[41]

Dengue is now ranked as the most important vector-borne viral disease in the world. Today, an estimated 50–100 million dengue fever infections occur annually. In just the past 50 years, transmission has increased drastically with new cases of the disease (incidence) increasing 30-fold.[41] Once localized to a few areas in the tropics, dengue fever is now endemic in over 100 countries in Southeast Asia, the Americas, Africa, the Eastern Mediterranean, and the Western Pacific with Southeast Asia and the Western Pacific regions being the most seriously affected. Recently the number of reported cases has continually increased along with dengue spreading to new areas. Explosive outbreaks are also occurring. Moreover, there is the possible threat of outbreak in Europe with local transmission of dengue being reported for the first time in France and Croatia in 2010.[42] One country that has seen significant impacts from dengue is Bangladesh.[43]

References

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