WHO Study Explores Environmental Factors Behind Diseases with Significant IVD Markets

WHO Study Explores Environmental Factors Behind Diseases with Significant IVD Markets

Amidst rising threats posed by climate change and inadequate utilites infrastructure even in the developed world, the World Health Organization (WHO) released the second edition of its decadal global assessment of diseases impacted by environmental risks. The comprehensive WHO study summates the fraction of deaths and morbidity attributable to environmental factors such as air, water and soil pollution; radiation; occupational risks; built environments; agricultural methods; and climate and ecosystem change. Environmental risk factors were identified in the report for infectious diseases including respiratory infections, diarrheal or gastrointestinal infections, and numerous high-burden pathogens; neonatal conditions; cancers; cardiovascular disease; mental and neurological disorders; and numerous forms of injury.

Compared with the 2006 edition of WHO’s global assessment, the more recent findings reflect the progress in several regions in the control and prevention of infectious diseases, the persistence or emergence of other environmental escalators of infectious disease, and the mounting challenge of non-communicable diseases in societies across the world.

Compared with the 2006 edition of WHO’s global assessment, the more recent findings reflect the progress in several regions in the control and prevention of infectious diseases, the persistence or emergence of other environmental escalators of infectious disease, and the mounting challenge of non-communicable diseases in societies across the world. Kalorama Information in reports including The World Market for Infectious Disease Diagnostic Tests and The Worldwide Market for In Vitro Diagnostic Tests, 9th Ed. reviewed these trends in infectious and non-communicable diseases. Several diseases with strong contributing factors from the environment - cardiovascular diseases, cancers and malaria - also support significant IVD markets. As a result of environmental risk factors for these diseases, markets for associated tests continue to grow through the infusion of new diagnostic products and emergence of demand in the developing world.

Several diseases with strong contributing factors from the environment - cardiovascular diseases, cancers and malaria - also support significant IVD markets.

Climate change will have profound implications on human health with infectious disease epidemiology representing only one facet of its overall impact. Vector-borne diseases have been frequent targets of study at the interface between health and climate change, shown to be sensitive to climatic conditions such as rainfall, humidity, and ambient temperature.

Vector-borne diseases, particularly those transmitted by mosquitoes, are highly sensitive to climate change.  Threshold or minimum temperatures needed to support the mosquito life cycle and transmission of disease are expected to be met on a wider range around the world as climate change progresses, in effect extending the endemic range of diseases such as dengue and malaria. In its just-released study into environmental risk factors, the WHO estimated that roughly 40% of malaria cases were attributable to a lack of environmental vector management in 2012. Other studies cited in the report linked cases of malaria resurgence to land-use changes (43% of events) and climate and weather (25%).

Vector-borne diseases, particularly those transmitted by mosquitoes, are highly sensitive to climate change.  Threshold or minimum temperatures needed to support the mosquito life cycle and transmission of disease are expected to be met on a wider range around the world as climate change progresses, in effect extending the endemic range of diseases such as dengue and malaria.

Studies have shown a positive correlation between malaria incidence and higher temperatures and rainfall in Rwanda; higher rainy season median temperatures and dengue fever prevalence in Mexico; and higher malaria incidence and average temperatures at high-elevation regions in Papua New Guinea and Mexico. In equatorial Peru, the seasonality of malaria transmission has been affected by relatively small fluctuations in temperature of only 1-2°C. Accompanying seasonal temperature fluctuations and higher rainfalls have been noted to expand the endemic range of Aedes aegypti mosquitoes that serve as the principal vectors for dengue. Higher temperatures may also accelerate the reproduction of pathogens in mosquitoes and cause the vectors to more frequently seek blood meals.

Mosquito-borne diseases have attracted the most attention recently in respect to climate change-driven epidemiology. The deluge of rain across large parts of Texas in 2015 was expected to support larger populations of mosquitoes able to breed in standing pools of floodwater. Regional experts expect to see elevated rates of West Nile and St. Louis encephalitis, and potentially dengue and malaria depending upon other climatic factors. Zika virus is a new threat to the United States in the midst of unique El Niño climatic conditions.

Dengue has been singled out as a disease with a likely expanded reach over the next century due to climate change. The disease is expected to more regularly affect parts of Europe and the southern United States. Today, roughly 40% or 2.5-3 billion people live in areas with dengue transmission risk. According to climate change projections, approximately 50-60% of the global population could be at risk for dengue transmission by 2085.

Today, roughly 40% or 2.5-3 billion people live in areas with dengue transmission risk. According to climate change projections, approximately 50-60% of the global population could be at risk for dengue transmission by 2085.

Cancer represents a more predominant healthcare issue in the developed world than in the developing world - the International Agency for Research on Cancer (IARC) estimates that one fifth of people worldwide and one third of people in the industrialized world are diagnosed with cancer in their lifetime. In a 2011 study, the WHO estimated that nearly 20% of cancers were attributable to environmental factors. Lung cancer in particular is caused by air pollution, a problem in both developing and industrialized countries through both ambient pollution from particulate matter (exhaust from industrial and transportation fossil fuels) and household air pollution associated with open fire or solid fuel cooking. Second-hand smoke is an additional risk factor.

In China, for instance, lung cancer became the most lethal form of cancer by the middle of the last decade, surpassing liver cancer in the number of deaths. While smoking has been the lead contributor to lung cancer in the country, air pollution is another significant factor. Experts believe that ambient air pollution will replace smoking as the leading cause of lung cancer in China in the coming years. Worldwide, air pollution is  estimated by the WHO to be attributable to 17% (household air pollution), 14% (ambient air pollution) and 2% (second-hand smoke) lung cancer cases.

While smoking has been the lead contributor to lung cancer in [China]… air pollution is another significant factor. Experts believe that ambient air pollution will replace smoking as the leading cause of lung cancer in China in the coming years.

Lung cancer has spurred significant innovation in therapeutics and has been a major target in the development of next-generation sequencing (NGS) tests using cell-free DNA (cfDNA) or ‘liquid biopsied’ blood samples. Such tests are used to characterize the form of lung cancer in order to implement personalized therapy for the aggressive and often lethal disease. Lung cancer diagnostics, often companion diagnostics used to implement therapy, are heavily represented in recent cancer diagnostics innovations. China’s rapidly building clinical NGS infrastructure could be more consistently utilized in the future for lung cancer therapy.

Household and ambient sources of air pollution can also represent significant risk factors for heart disease and were attributable to 18% and 24% of cases worldwide in 2012 according to WHO. Air pollution increases the risk of the development of cardiovascular disease (CVD) and occurrence of acute events such as myocardial infarction and stroke. While traditionally a significant disease burden of the developed world, CVD is a quickly rising problem in middle-income countries and the developing world. Cardiovascular diseases are a growing problem in those countries due to rising standards of living affecting diet and physical activity and industrialization that has impacted air quality.

In studies of the IVD markets in China and Malaysia, rates of heart disease and stroke were found to be sharply rising. Associated events of heart attack or MI and a lack of routine care for many patients in both countries are likely to bolster usage of acute care cardiac tests including rapid tests for CK-MB, troponins, BNP, lipids and d-Dimer.

Other IVD-significant diseases attributable to environmental factors include respiratory infections (including tuberculosis); gastrointestinal (GI) or diarrheal diseases; Chagas disease; leishmaniasis; dengue; HIV and STDs (occupational risk factor); and skin cancers.