INTRODUCTION

The 2024 floods in Bangladesh represent a significant public health crisis, heightening the risk of waterborne diseases and additional health complications. This disaster affects millions, particularly vulnerable populations, and intensifies issues such as environmental disruption, population displacement, and the strain on healthcare resources. This communication offers an analysis of the public health threats posed by these floods, underpinned by data and an exploration of the underlying risk factors.

OVERVIEW OF THE FLOOD SITUATION

As of September 2024, the National Disaster Response Coordination Centre has reported 71 fatalities and over 582 000 families affected by severe flooding. More than 5.8 million people across 11 districts are grappling with the aftermath of this disaster. The floods have submerged 311 419 hectares of land, completely destroyed 26 991 houses, and left 307 443 houses partially damaged. Additionally, 6542 kilometres of roads and 1066 bridges have suffered significant damage, disrupting vital transport links between Dhaka and the affected areas. The economic toll includes estimated losses of US$34 million in livestock and US$121.6 million in fisheries [1].

Waterborne Disease: Urgent Risks During and After Flooding

The current floods have led to the inundation of latrines, sewage systems, and agricultural land, significantly contaminating drinking water sources such as rivers, ponds, and wells with faecal matter. A similar situation occurred after the 2020 floods in Bangladesh, where many people struggled to find safe water, food, and medicine. As a result, a significant outbreak of diarrhoea was reported, with many households experiencing cases among their members [2]. Alongside these challenges, floods also disrupt water treatment facilities, making it difficult to purify water and allowing harmful pathogens to remain in the supply [3]. The environmental impact of the floods damages natural filtration systems, resulting in a serious public health threat and emphasizing the urgent need for effective response measures.

Cholera

Cholera, caused by Vibrio cholerae, spreads through contaminated water or food and can lead to severe watery diarrhoea, resulting in significant fluid loss and potentially hypovolemic shock. This condition becomes particularly concerning during floods. In the current flood situation in Bangladesh, the risk of cholera outbreaks has increased. Many water sources have been contaminated with faecal matter, especially in densely populated and poorly sanitized areas, heightening the public health threat.

Enterotoxigenic E. coli diarrhoea

Enterotoxigenic Escherichia coli (ETEC) diarrhoea is characterized by sympoms of watery or bloody diarrhoea, transmitted through contaminated food and water. The incidence of ETEC infections tends to rise during floods. In Bangladesh, both ETEC and cholera are significant contributors to diarrhoea cases during such times [4]. Additionally, rising temperatures and heavy rainfall have been associated with higher rates of diarrhoeagenic E. coli infections, highlighting the importance of vigilant monitoring and intervention during flood-related health emergencies.

Shigellosis

Shigellosis is an acute intestinal infection caused by Shigella bacteria. It is primarily transmitted through the faecal-oral route and often results in bloody diarrhoea, abdominal pain, and fever. This condition poses a significant health risk, particularly in areas with limited medical care, and certain strains can have a mortality rate of 5-15%.

During floods, the risk of shigellosis increases because floodwaters can introduce pollutants into local water supplies. This drastic compromise in water quality facilitates the spread of enteric pathogens, including those responsible for bacillary dysentery.

Hepatitis

Hepatitis A and E are both viral infections transmitted through the faecal-oral route, which is particularly concerning during and after floods [5]. Hepatitis A can easily spread through contaminated food and water, targeting the liver and causing symptoms such as fever, jaundice, fatigue, abdominal pain, anorexia, and nausea. The crowded and often unhygienic conditions in flood shelters can accelerate the spread of hepatitis A virus, particularly where hygiene practices are inadequate. Hepatitis E, more likely to cause outbreaks after heavy rains and flooding, poses a significant risk, especially in regions where it is endemic. It can be particularly dangerous for pregnant women, with case-fatality rates reaching up to 25% [6].

Vector-borne Diseases: Emerging Threats Post-flooding

Vector-borne diseases also pose a significant threat after a flood. Stagnant water left by the flood creates prime breeding sites for mosquitoes, particularly the Anopheles and Aedes species, which are known to spread malaria, chikungunya, and dengue fever, respectively. Additional risks include overcrowded living conditions, weakened public health systems, and interruptions to vector control efforts, all of which can further exacerbate the spread of these diseases.

Malaria

Malaria continues to be a significant public health issue in Bangladesh, particularly in areas affected by flooding and in the hill tracts. The World Malaria Report 2020 indicates that Bangladesh represents 2.6% of malaria cases and 5.6% of malaria deaths in the South-East Asia Region, underscoring the persistent endemic nature of the disease in the country [7].

Dengue fever

Dengue fever surges commonly occur after floods, particularly in regions where it is already prevalent. The stagnant water left by floods provides perfect breeding grounds for mosquitoes, and the crowded conditions in shelters housing displaced populations further facilitate the spread of the dengue virus due to increased exposure to and transmission by mosquitoes [8].

Over the past 50 years, dengue has experienced a thirtyfold increase, making it the fastest-growing mosquito-borne viral disease worldwide, with an estimated 50-100 million infections each year [9]. The symptoms of dengue can vary from mild, such as fever and headache, to severe, life-threatening conditions like dengue haemorrhagic fever or dengue shock syndrome.

Healthcare Infrastructure and Service Disruption

Flooding disrupts healthcare services by damaging facilities and increasing the demand for care due to injuries, infections, and waterborne diseases. Damage to infrastructure impedes access to care, delays emergency responses, and hampers the early detection and treatment of diseases. This raises the risk of outbreaks and higher mortality rates, particularly affecting vulnerable groups such as children, the elderly, and those with comorbidities.

Mental Health Impact and Considerations

The psychological impact of floods represents a significant public health concern. The loss of homes and livelihoods, combined with stress and uncertainty about the future, can lead to a variety of mental health issues, including anxiety, depression, and posttraumatic stress disorder [10]. Flooding can have enduring effects on health and well-being, with communities that are severely affected facing substantial mental health challenges. Effective recovery necessitates prioritizing mental health care in conjunction with physical health interventions.

Public Health Response: Immediate and Long-term Strategies

Given the potential health risks outlined above, a comprehensive public health response is required to mitigate the impact of the 2024 floods. This would include: (1) Immediate steps to restore clean drinking water involve distributing purification tablets, establishing mobile purification units, and encouraging the boiling of water to prevent waterborne diseases. (2) Surveillance efforts should concentrate on monitoring waterborne and vector-borne diseases, with rapid response teams ready to be deployed to manage outbreaks. (3) Repairing damaged healthcare facilities, setting up mobile clinics, and ensuring the availability of essential medications and medical supplies. (4) Mental health services should be incorporated into disaster response efforts, emphasizing the provision of psychological first aid, counselling, and support for individuals and communities impacted by floods. (5) Launch a public health education campaign to increase awareness of the risks associated with communicable diseases and to emphasize the importance of hygiene and sanitation.

CONCLUSION

The 2024 flood in Bangladesh poses a complex public health challenge that necessitates a coordinated and multifaceted response. The heightened risk of waterborne and vector-borne diseases, along with the disruption of healthcare services and the impact on mental health, calls for immediate and sustained action. By implementing the strategies outlined in this communication, public health authorities can mitigate the effects of the floods and support the recovery of affected communities. Additionally, the lessons learned from this disaster should inform future preparedness efforts, ensuring that Bangladesh is better equipped to handle similar events in the future.

Ethics Statement

This study is a perspective article based on secondary sources and does not require ethical approval.

Notes

Conflict of Interest

The authors have no conflicts of interest associated with the material presented in this paper.

Funding

None.

Author Contributions

Both authors contributed equally to conceiving the study, analyzing the data, and writing this paper.

Acknowledgements

REFERENCES

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