Bihar floods: How it could become breeding ground for diseases

The flood crisis in Bihar has become a serious health concern as stagnant water from breached rivers like the Kosi, Gandak, and Bagmati creates a fertile environment for waterborne diseases.
With nearly a million people affected and embankments washed away, displaced populations are forced into crowded relief camps with limited sanitation.
SPREAD OF WATERBORNE, VECTOR-BORNE DISEASES
In such conditions, diseases like cholera, dysentery, and typhoid can spread rapidly, as floodwaters often mix with sewage, contaminating drinking water sources.
Mosquito breeding also intensifies in waterlogged areas, increasing the risk of vector-borne diseases such as malaria and dengue, especially in districts like West Champaran and Darbhanga.
Heavy rainfall from Nepal and river overflows have worsened the flood situation in northern Bihar, leaving vast swathes of farmland submerged and making healthcare access difficult.

People move to a safer place on a makeshift boat in a flood-affected area in Patna. (Photo: PTI)

Relief efforts by National and State Disaster Response Forces (NDRF and SDRF) are ongoing, yet the sheer scale of the crisis raises concerns about the spread of infections.
As per the National Centre for Disease Control, the state is prone to climate-sensitive illnesses like waterborne diseases (acute diarrhea), food-borne illnesses (hepatitis, bacillary dysentery, typhoid), vector-borne diseases like (dengue, malaria, Japanese encephalitis) and acute respiratory illnesses.
IMPACT OF POOR SANITATION
Poor drainage and sanitation infrastructure in flood-affected areas exacerbate the problem, making public health interventions crucial to prevent outbreaks.

Poor drainage and sanitation infrastructure in flood-affected areas exacerbate the problem. (Photo: PTI)

According to an article published in a peer-reviewed journal, Bihar’s rural drinking water supply relies heavily on groundwater, which can become easily contaminated during floods.
CLIMATE CHANGE AND TROPICAL DISEASES
Over the last decade, climate change has not only increased the incidence of floods and droughts in Bihar but also tropical diseases like lymphatic filariasis (elephantiasis), dengue, and kala azar.
Kala-azar is a parasitic disease caused by Leishmania parasites and transmitted by sandfly bites. It primarily affects the spleen, liver, and bone marrow, leading to fever, weight loss, and anemia. It is endemic in parts of India, especially Bihar and Jharkhand.

Villagers move to a safer place at a flood-affected area in Hajipur. (Photo: PTI)

Elephantiasis, or lymphatic filariasis, is another parasitic infection caused by microscopic worms transmitted through mosquito bites.
It leads to severe swelling, typically in the legs, arms, or genital area, due to lymphatic system damage. This causes thickened skin and enlarged body parts, severely impairing mobility.
Bihar has recorded the highest incidence of kala azar in India, with 335 cases in 2023 and 175 cases reported in 2024.
The combination of overcrowded relief camps, water contamination and poor sanitation could trigger widespread outbreaks, complicating the recovery process further.