Weather and climate have a significant influence on human health.The changes in exposure to heat waves, winter cold, increases in floods, cyclones, storm surges, droughts, increased productions of air pollutants and aeroallergens like spores and molds are all considered to have direct impacts on the health sector in Bangladesh in terms of lives lost, injuries, and disease outbreaks.Weather and climate conditions significantly impact the incidence and geographical distribution of several diseases. Extreme weather events such as heatwaves, floods, and droughts alter disease transmission ecologies and population vulnerability, thereby influencing risk for climate-sensitive disease. For example, increased temperature and rainfall induced by climate change and extreme weather events (such as storms or cyclones) are projected to increase the risk of malaria due to a greater geographical range for the Anopheles mosquito vector, a longer season, and enhanced vector breeding and disease transmission rates.
Risk monitoring and mitigation strategies are therefore importance to preserve the health of populations. Developing integrated surveillance can greatly enhance the capacity of health systems to prepare and adapt to climate-sensitive diseases. Integrated surveillance involves the integration of multiple surveillance systems (e.g. disease surveillance and weather surveillance) to improve the use of information for detecting, investigating and responding to public health threats. This integration of data, therefore, improves the flow of surveillance information throughout the health system. Importantly, climate-informed surveillance can enhance the preparedness of health systems via early warning systems. Early warning systems aim to anticipate risks and trigger early warning responses to avoid or reduce impact and prepare for effective response. In the context of a rapidly changing environment and risk landscape, early warning systems are a valuable tool for building the adaptive capacity and climate-resilience of health system.
In Bangladesh, gaps exist in the current disease surveillance system with regard to linking to the impact of climatic parameters. Insufficient meteorological and epidemiological data and limited monitoring of climate sensitive diseases impedes the health system to provide early warnings, forecasts and adequate responses to potential outbreaks. The 2011 health vulnerability assessment revealed a strong correlation between climatic variable and some vector-borne diseases, but this valuable information could not be shared and used across the health programs due to insufficient coordination between programs and institutions. Overall, there is no mechanism to measure the quality of data, including collection methods, thus leaving the health information system weak. Climate sensitive diseases cannot be monitored separately, and climate/weather data has not been integrated with health data.
The Government of Bangladesh has identified the development of surveillance systems for existing and new disease risks areas as an important intervention to address the adverse impacts of climate change. “The Third National Communication of Bangladesh to the United Nations Framework Convention on Climate Change (UNFCCC)” addresses that improved surveillance systems and monitoring can be an elementary approach to adapt to climate change. The sensitive index of impact by any specific disease can be found out from data provided by primary care facilities. However, the surveillance system of morbidity varies from locality to locality and for specific diseases. The communication report also strongly suggested that in order to understand the potential health penalties of climate change, we need to have surveillance based knowledge on population specific historical analogue studies to estimate and forecast the risks of diseases and potential health effects due to comparable exposures and to use existing theory to develop bio-physical models of future health outcomes.
The overall purpose of the HNAP is to support the development of a climate-resilient health system, as well as mainstream climate risks into health planning, policies, and programming. It strongly suggested the establishment of a climate-sensitive disease surveillance system in the section “Component 4: Integrated risk monitoring and early warning”. According to the HNAP integrated risk monitoring refers to the use of tools and epidemiological surveillance for early detection in conjunction with direct and remote sensing technologies for surveillance of the environmental determinants of health (e.g. water and air quality, variability in ambient temperature and humidity or incidence of extreme weather events). The overarching aim of this component is to use integrated disease surveillance and monitoring of a broad range of signals around a health risk and early warning systems to identify changing conditions more quickly to anticipate outbreaks and emergencies related to weather and climate.
While climate change is recognized as a public health priority, the organization of the public health response remains difficult. Many threats are monitored by different programs, but we still need to strengthen our surveillance systems, to gain knowledge on possible impacts and to foresee which tools could be useful to detect emerging threats. Effective policy measures should be taken to create a viable climate-smart health surveillance system in climate vulnerable areas and the main objectives of that surveillance system should be to collect, analyze, and interpret data on climate-sensitive environmental risks and epidemiological trends on a continual basis and respond to identified risks continuous; to report information on climate change impacts, vulnerability, migration, response capacity, and emergency preparedness over time; to communicate timely warnings to health decision-makers, the media, and the public and translate information into effective action to prevent negative health outcomes. A better knowledge of the exposure patterns would be a key to understand adaptation and should be promoted.