Week 5 Part 1: Waterborne Diseases and Water Treatment: Microbiology and Public Health

Waterborne Disease

A disease caused by pathogens present in contaminated water.

Pathogens

Microorganisms that can cause disease.

Escherichia coli

A Gram-negative rod, normal flora of GIT, with strains that can cause travellers diarrhea.

Shigella

A human pathogen causing shigellosis (dysentery) with a low infective dose.

Salmonella

A genus with over 2,000 serotypes pathogenic to humans, causing mild gastroenteritis to severe illness.

Vibrio cholerae

A bacterium causing severe vomiting, diarrhea, and dehydration, primarily in central & South America, Asia, and Africa.

Legionella pneumophila

A bacterium that causes pneumonia and respiratory failure, more resistant to chlorine than E. coli.

Cryptosporidium parvum

A protozoan causing severe dehydration and diarrhea, highly resistant to chlorine.

Giardia lamblia

A flagellated protozoan similar to Cryptosporidium but less severe, also highly resistant to chlorine.

Adenovirus

A virus causing respiratory disease, conjunctivitis, and gastroenteritis, concentrated in sewage.

Enteroviruses

A group of viruses including poliovirus and coxsackivirus, primarily affecting humans.

Water as a Reservoir

Water that supports the life and multiplication of pathogens, especially in untreated sewage.

Faecal contamination

The presence of feces in water, a major source of infectious agents.

Waterborne transmission

The spread of disease through contaminated water.

Opportunistic bacterial pathogens

Bacteria that cause infections primarily in immunocompromised individuals.

Pseudomonas aeruginosa

An opportunistic pathogen found in water systems.

Aeromonas

A genus of bacteria that can cause infections in humans.

Nocardia

A genus of bacteria that can cause opportunistic infections.

Low infectious dose

A small number of pathogens required to cause disease.

Immunocompromised

Individuals with weakened immune systems, at higher risk for infections.

Cooling towers

Water systems that can harbor pathogens like Legionella.

Children's wading pools

Potential sources of Cryptosporidium contamination.

Untreated wastewater

Water that has not been adequately treated to remove contaminants.

Global significance of waterborne disease

The widespread impact of diseases transmitted through contaminated water on public health.

Hepatitis viruses

ssRNA viruses that cause inflammation of the liver, specifically types A and E.

Viral gastroenteritis

A condition caused by viruses such as Reovirus, Rotavirus, Calicivirus, Astrovirus, Coronavirus, and Norwalk viruses, leading to vomiting and diarrhea.

Cyanobacteria

Also known as 'blue-green algae', includes species like Anabaena, Microcystis, Lyngbya, Nostoc, Oscillatoria, and Cylindrospermopsis, which can cause taste and odor problems and produce hepatotoxins.

Microcystins

Water-soluble toxins produced by cyanobacteria that can enter the bloodstream via bile and act as neurotoxins and cytotoxins.

Australian Drinking Water Guidelines

Provide a framework for the good management of drinking water supplies to assure the safety of drinking water.

Public Health Act 2005

Legislation that includes drinking water quality requirements based on the Australian Drinking Water Guidelines.

Public Health Regulations 2005

Regulations that outline the quality requirements for drinking water in accordance with the Public Health Act.

Water consumption in North America

Average of 400 liters per person per day.

Water consumption in Europe

Average of 200 liters per person per day.

Water consumption in Brisbane

Average of 170 liters per person per day.

Water consumption in the developing world

Average of 10 liters of water per person per day.

SDG Target 6.1

Aims to achieve universal and equitable access to safe and affordable drinking water for all by 2030.

Access to safe water

Around 800 million people (1 in 8) do not have access to safe water.

Diarrhoea

A common waterborne disease directly related to water and sanitation, leading to childhood death.

Cholera

An acute bacterial infection affecting 4 million people, with a fatality rate of less than 1% with proper treatment.

Water-stressed countries

In 2021, over 2 billion people live in water-stressed countries, a situation expected to worsen due to climate change and population growth.

Contaminated drinking water

In 2022, at least 1.7 billion people used a drinking water source contaminated with faeces, posing the greatest risk to drinking-water safety.

Microbial contamination

Contamination of drinking water with faeces, which can transmit diseases such as diarrhoea, cholera, dysentery, typhoid, and polio.

Diarrhoeal deaths

Estimated to cause approximately 505,000 diarrhoeal deaths each year.

Safely managed drinking-water service

In 2022, 73% of the global population (6 billion people) used a drinking-water service that is located on premises, available when needed, and free from contamination.

Fetching water in rural Africa

Households spend an average of 26% of their time fetching water, which can weigh up to 20 kg.

Access to proper sanitation

2.6 billion people (1 in 3) do not have access to proper sanitation.

Safely managed sanitation service

In 2022, 57% of the global population (4.6 billion people) used a safely managed sanitation service.

Waterborne diseases

In developing countries, 80% of illnesses are caused by waterborne diseases.

Water-related illness

A person dies every 30 seconds from a water-related illness.

Schistosomiasis

Caused by parasitic flatworm; affects around 200 million people, 20 million suffer severe consequences; adequate water supply and sanitation could reduce infection rates by 77%.

Guinea worm disease

Drinking contaminated water (Dracunculus medinensis); causes months of crippling pain, adults unable to work, children unable to go to school.

Human cases of Dracunculiasis

Decreased from an estimated 3.5 million in 1986 to 15 cases in 2021; 13 human cases identified in 2022; and 3 during January-June 2023.

Trachoma

Bacterial eye infection (Chlamydia trachomatis); 41 million infected every year, 7 million blind today because of trachoma (affecting women two to three times more than men); improved water supply reduces infection by 25%.

Typhoid fever

Bacterial infection caused by ingesting contaminated food or water (Salmonella typhi); headaches, nausea, loss of appetite, liver damage; affects 9 million people every year infected (2019); 110 thousand deaths.

Malaria

Serious disease (fever, coma, death) caused by Plasmodium carried by mosquitoes; in 2021: 247 million new cases; 619 thousand deaths; 95% of all malaria cases are in WHO African Region; a child in Africa dies every minute from malaria.

Improved sanitation

Reduces diarrhoea death rates by a third.

Hygiene education

Promotion of hand washing can reduce diarrhoea cases by up to 45%.

Access to clean drinking water

Access to groundwater using water pumps (tubewells) reduces walking distance to water source, improves water quality (natural filtration) and reliability.

Small piped systems

A method of accessing clean drinking water.

Rainwater harvesting

A method of accessing clean drinking water.

Bottled water

A method of accessing clean drinking water.

Latrines

A method of improved sanitation.

Septic systems

A method of improved sanitation.

Enclosed sewerage pipes

A method of improved sanitation.

Acute diarrhea

Gastroenteritis caused by various viruses (incl astrovirus, adenovirus etc).

Hepatitis A

Caused by Hepatitis A virus; symptoms include fatigue, diarrhea, liver damage.

Polio

Caused by Poliovirus; symptoms include headaches, paralysis, death.

Botulism

Caused by Clostridium botulinum; symptoms include paralysis, respiratory failure, death.

Campylobacteriosis

Caused by Campylobacter; symptoms include severe diarrhea, fever.

E. coli infection

Caused by Escherichia coli; symptoms include diarrhea.

Dysentry

Caused by Shigella, Salmonella; symptoms include severe diarrhea, blood in feces, death.

Legionnaires' disease

Caused by Legionella; symptoms include fever, pneumonia, diarrhea, death.

Leptospirosis

Caused by Leptospira; symptoms include fever, chills, headaches, meningitis, liver damage, renal failure, death.

Salmonellosis

Caused by various Salmonella; symptoms include diarrhea, fever, vomiting.

Vibrio illness

Caused by various Vibrio; symptoms include severe diarrhea, vomiting, fever.

Amoebiasis

Caused by Entamoeba histolytica; symptoms include fever, diarrhea, fatigue.

Cryptosporidiosis

Caused by Cryptosporidium parvum; symptoms include diarrhea, nausea, bloating.

Giardiasis

Caused by Giardia lamblia; symptoms include severe diarrhea, vomiting, bloating.

Arsenicosis

Caused by Arsenic; symptoms include skin lesions, cancer.

Fluorosis

Caused by Fluoride; symptoms include dental and skeletal malformations.