Report: Climate Change Spreads Infectious Disease in Bangladesh

Weather variations from climate change are linked to the spread of infectious diseases and mental health problems in Bangladesh, officials and experts said Friday, agreeing with a new report by the World Bank that highlights such a connection.

Changing and erratic weather patterns have affected people’s health, leading to an increase in respiratory diseases, mosquito-borne diseases like dengue, along with deteriorating mental health conditions in the South Asian nation, according to the Climate Afflictions Report, released on Thursday.

“The World Bank has rightly pointed out the impending health burdens caused by climate change that Bangladesh is going to face,” Mirza Shawkat Ali, the director of the climate change cell at the Ministry of Environment, Forest, and Climate Change, told BenarNews.

In 2018, Bangladesh’s government published a study, which looked into how health problems could develop in the coming decades as a result of climate change, he said. It found that an increase in the frequency of vector-borne diseases, such as kala-azar, dengue, and malaria, and waterborne diseases, like cholera and diarrhea, were likely to happen because of the changing climate.

“Climate change will also result in under-nutrition, food insecurity, and mental health problems,” Ali said, adding that government agencies were working to strengthen the resilience of people and communities as well as bolster the health system to adapt to climate change.

The likelihood of contracting an infectious disease is about 20 percent higher in the monsoon season, which has become longer in Bangladesh in recent decades due to climate change, compared with the dry season, the World Bank report said.

According to analyses of primary data collected from 3,600 homes, a quarter of households suffered from vector-borne diseases like dengue, malaria, and associated symptoms in the monsoon season compared with 14 percent in the dry season.

For a 1 degree Celsius increase in mean temperature, the likelihood of a respiratory illness increases by 5.7 percent, the report found, while for a 1 percent increase in humidity, the chances of catching a respiratory infection rise by 1.5 percent.

The report found that incidences of respiratory diseases can increase due to extreme temperatures that aggravate airborne allergens and pollution.

Mental health can also be affected because the increase in mean humidity and mean temperature increases the probability of anxiety by 0.3 percent and 0.8 percent, respectively, the report said.

Nazrul Islam, a former chairman of the virology department at the Bangabandhu Sheikh Mujib Medical University in Dhaka, said the global temperature increase is “a huge health burden.”

“There is a close relationship between temperature and spread of vectors and vector-borne diseases,” Islam told BenarNews. “This year, we have seen an increasing number of dengue patients and deaths.”

The World Bank report said that climate change had contributed to the number of dengue cases recorded annually doubling every decade since 1990. Dengue is a disease spread by mosquitoes.

Changing seasons in Bangladesh

According to the report’s findings, summers in the South Asian country are getting hotter and longer, winters are warmer, and the monsoon seasons now go from February to October instead of March to September.

“With these changes, Bangladesh appears to be losing its distinct seasonal variations,” the report said.

Bangladesh has gotten warmer over the past 44 years, with an increase in annual mean temperature by 0.5 degrees Celsius between 1980 and 2019, the report said.

By 2050, the temperatures are predicted to rise by 1.4 degrees Celsius in Bangladesh, the report said, while the annual rainfall is expected to increase by 74 millimeters by 2040-59.

“The deleterious effects on human physical and mental health are likely to escalate” due to the projected changes in climate, the report said.

“Bangladesh has remarkably tackled climate change challenges, despite being among the most vulnerable countries. It has built resilience against natural disasters and introduced homegrown solutions to improve agricultural productivity,” Mercy Tembon, the World Bank’s country director for Bangladesh and Bhutan, said in a statement on Thursday.

“With more evidence showing a pronounced impact of climate change on physical and mental health, Bangladesh needs to build on its success in adaptations to ensure a stronger health system that averts outbreaks of emerging climate-sensitive diseases.”

Bangladesh ranked seventh on the list of countries most vulnerable to climate change, according to the Global Climate Risk Index 2021, created by Germanwatch, an environmental NGO.

According to the World Bank, Bangladesh has the highest mortality rate in the world caused by natural disasters, with more than half a million people lost to disaster events since 1970.

The report said that these extreme weather events, including severe floods, cyclones, storms, are expected to be exacerbated by the effects of climate change. That means more physical and mental health issues are likely to emerge.

“The most vulnerable are children and the elderly, and those living in large cities like Dhaka and Chattogram,” the report said.

A 2019 dengue outbreak in Dhaka, where 77 percent of the country’s total dengue-related deaths occurred, could be partially explained by weather patterns – uncharacteristically heavy rainfall in February, the report said.

The rain was followed by high temperatures and humidity levels conducive to mosquito breeding, from March to July 2019.

“With falling humidity levels, rising temperatures, and increasing rainfall in the summer months, the risk of spread of dengue may be higher in Dhaka city in the future,” the report forecast.

“[B]y ensuring stronger data collection, Bangladesh can better track the evolution of climate-sensitive diseases,” Iffat Mahmud, a co-author of the report, said in a statement.

“Particularly by recording accurate weather data at local levels and linking it with health data, it will be possible to predict potential disease outbreaks and to establish a climate-based dengue early warning system.”