1.c disease dilemmas - natural hazards can influence the outbreak and spread of diesease - case study

Bangladesh - background

• Highly vulnerable due to most of country being low-lying delta land at the confluence of Ganges, Brahmaputra, and Meghna rivers.

• monsoon water spreads across a very wide area rather than staying local.

• 4-5m above sea level

• About 70% of country flooded a year.

• More than 200 rivers help wash down fertile soil from Himalayas.

• 22% of the country is flooded every monsoon season.

• Delatic country (nation who’s territory is formed and sustained by river deltas)

• Approx 1366 people per sq/km

• 700 rivers

How do monsoons affect the risk and outbreak of water-borne diseases?

• The flooding mixes sewage, waste, animal carcasses and dirty surface water with drinking supplies, sharply increasing the risk of diarrhoea, typhoid, and hepatitis.

• Around 1/8 of wells were contaminated making safe water a limited and unrealistic reality for most.

• Natural hazard acted as a trigger that converted physical vulnerability into a major public health emergency.

How do monsoons affect the risk and outbreak of water-borne diseases?

• The flooding mixes sewage, waste, animal carcasses and dirty surface water with drinking supplies, sharply increasing the risk of diarrhoea, typhoid, and hepatitis.

• Around 1/8 of wells were contaminated making safe water a limited and unrealistic reality for most.

• Natural hazard acted as a trigger that converted physical vulnerability into a major public health emergency.

What happened in August 2007?

• Intense monsoon rainfall combined with swollen rivers and Himalayan meltwater to produce severe flooding.

• Around 60% of the country was inundated and roughly 14 million people were displaced or directly affected.

• 1/8 wells became contaminated by bacteria in flood water making access to safe water unrealistic and unattainable for a large percentage of the population.

Human factors affecting the spread of the disease in Bangladesh.

• Lots of deforestation, more surface runoff

• The river Granges often get clogged up with silt.

• Impoverished - difficult to get policy in place

• High population density - 1366ppl per km/sq - bad living conditions cannot access adequate sanitation and are likely to be exposed to different diseases.

• Cramped - easy transmission

Impacts of disease on resident populations

• 3.3m people were affected

• 700,000 affected by diarrhoea and dehydration

• 750,000 homes waterlogged

• 110,000 hectares of crops destroyed

• 1900+ schools were affected, fully or partially

• 4500 became ill due to contaminated water

• Approx 1000 died from drowning and waterborne diseases

• 2007 - 100,000 hospital admissions

• 2007 - 9m people made homeless

Strategies/responses to minimise the impact of disease at national and international scales

• Bangladesh gov and NGOs provided emergency relief life food aid and water purification tablets

• UNICEF provided drugs and saline solution

• Repair of roughly 93,000 damaged wells, new tube wells.

• Millions of water-purification tablets

• Short term - food aid, water purification tablets, free seed given to farmers.

• Long term - building embankments, building raised flood shelters, introducing flood warning systems, reducing deforestation

• Many of these are difficult for an LIDC to maintain and therefore may not be as effective as anticipated.

• Saved around 70,000 people.

Overall responses…

Short term relief reduced mortality, but the case study shows that disease risk remained structurally high because delta location, monsoon exposure, weak sanitation and poverty were not fully removed.