To understand the impacts of climate change, firstly, it is critical to .. Observed relationships between levels of precipitation and malaria . Malaria control in Papua New Guinea results in complex epidemiological changes. Several studies suggest the potential for climate change to increase malaria incidence in intensity exhibit clear, non-linear relationships with temperature. change on malaria transmission are potentially complex, and the. These models have been applied to climate change impacts on malaria, We need to learn more about the underlying complex causal relationships, and apply .
It is estimated that for the cost of saving one life by cutting down on carbon, 78, lives may be saved annually by using mosquito nets, environmentally safe indoor DDT sprays, and subsidies for effective, new combination therapies. In addition to early diagnosis and prompt, effective treatment, selective vector control and capacity building to prevent epidemics and control transmission have been the other areas of focus.
All these efforts ensured that surveillance, including early detection and prompt treatment of cases and capacity building, together with preparedness, were given priority. The elimination of malaria from selected countries is stated explicitly in the targets of the Global Malaria Action Plan.
Climate Change and Malaria - A Complex Relationship
Byat least eight to ten countries currently in the elimination stage are expected to achieve zero incidence of locally transmitted infection. Beyondcountries currently in the pre-elimination stage are expected to move into the elimination phase.
Consistent with the goals of the Global Malaria Action Plan, as ofthree countries that were in the elimination phase -- Armenia, Egypt and Turkmenistan -- have reported no locally acquired cases for more than three years, and have moved into the phase of prevention of reintroduction. Six countries -- Azerbaijan, Georgia, Kyrgyzstan, Tajikistan, Turkey and Uzbekistan -- all from the WHO European Region, had moved from the pre-elimination stage to a nationwide elimination approach by Increasing temperatures and global travel have the potential to reintroduce or increase transmission of malaria in tropical and temperate countries that have either eliminated or controlled transmission.
Such countries would be prone to epidemics, since surveillance and preparedness for malaria control may not be as intense as when malaria was a major public health problem in these countries.
It is in this context that surveillance and preparedness need to be emphasized, not compromised. This is especially true in developing countries that have to balance competing interests for scarce resources, some of which need not necessarily be health related.
Let's not forget the setbacks of the eradication era, which showed much promise in the initial phases, but had to be abandoned later -- the classic example being the near elimination of malaria from Sri Lanka in Impacts, Adaptations and Vulnerability. Morse ,"A weather driven model of malaria transmission", Malaria Journal Lubovich, Climate change, adaptation, and conflict: A preliminary review of the issues. Yan, "Climate variability and malaria epidemics in the highlands of East Africa", Trends in Parasitology, 21 Bouma, "Malaria resurgence in the East African highlands: Malaria, Weather, Climate, Papua New Guinea, Climate change Background Papua New Guinea PNG is a malaria endemic country where all four human Plasmodium species Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, and Plasmodium ovale circulate in the population with varying distribution and degrees of endemicity [ 1 ].
In the nation, malaria is the leading cause of outpatient visits, the fourth leading cause of hospital admissions, and the third most common cause of death [ 2 ]. Despite significant reductions of malaria morbidity and mortality in many Pacific and Asian countries, the disease remains a serious public health issue in PNG, and instead, a localized increase in malaria prevalence has been reported over recent decades in the country [ 3 ].
Surveys in the s and s showed no cases in highland region, but began to report malaria from the s [ 45 ]. One of the possible contributors for the localized increase is global warming as the changes in the disease distribution and intensity of transmission have been witnessed following warming temperatures in other highland areas around the globe [ 6 — 8 ].
- Is Global Warming likely to cause an increased incidence of Malaria?
As a coastal country lying in the tropical Pacific Ocean, PNG is regarded highly vulnerable to the effects of climate change. In fact, rising sea levels and warming trends in both annual and seasonal mean air temperatures have already been reported for Port Moresby [ 9 ].
To understand the impacts of climate change, firstly, it is critical to know the current condition of associations between malaria and climate. However, in PNG, there is limited information only available from descriptive assessments, and few epidemiological studies have ever focused on the topic in depth. The present study was therefore developed to investigate how and what local weather and global climate variability are associated with malaria among different regions in PNG.
Local weather factors of our interest in this study include rainfall and temperature. The dependence of malaria transmission on those weather factors is a well-accepted fact due to their significant roles in population dynamics of mosquito vectors. Generally, a minimal volume of rainfall is essential to create the water pools necessary for vector breeding and larval habitats, and minimum ambient temperatures are required below which mosquito vectors, and parasites within them, are biologically unable to develop [ 510 ].
In a preceding study, temperature is described as the primary determinant of malaria incidence as endemicity is dependent on altitude on which temperatures also depend [ 11 ]. As the extent of local weather factors, global climate variability was also taken into consideration in the present study.
Is Global Warming likely to cause an increased incidence of Malaria?
Because precipitation and temperature conditions are linked to ocean-atmosphere phenomena, the potential indirect impacts of ocean-atmosphere phenomena on malaria transmission in the other parts of the world have been documented elsewhere [ 12 — 15 ].
In PNG, local weather has a very significant relationship with sea surface temperature SST as the average monthly air temperature and year-to-year variability in rainfall are highly impacted by ENSO [ 9 ]. Considering those relationships between local weather and global climate variability, global climate seems more likely to indirectly influence malaria transmission in PNG through the local weather factors.
However, a typical IOD event is characterized by cooler SST in the eastern part of the Indian Ocean near Indonesia and often results in a decrease of precipitation in the neighboring country, Australia [ 18 ]. With a view to improve understanding of global climatic determinants of malaria incidence in geographically distinct foci of PNG, a comprehensive assessment of these ocean-atmospheric phenomena was performed. Four administrative provinces and one district were included in this study.
All study locations were located in the coastal lowlands, except for Eastern Highlands province. Western province and Port Moresby are located at the southern coastal area, and East Sepik and Madang provinces are on the northern coast. Data on local weather factors e. SAM, also known as the Antarctic Oscillation, refers to the alternating pattern of strengthening and weakening westerly winds with high and low pressure bands between the mid and high latitudes in the Southern Hemisphere [ 19 ].
The data for those three climate indices and the measurements described above were obtained from the U.Is Climate Change Aiding Spread Of Infectious Diseases?