1. Training for health professionals
Module – Food & Waterborne diseases

2. Outline training Objective Definitions
Effect climate change on Food & Waterborne Diseases (F&WD)
Specific information for each F&WD
Health effects
Current situation
Future situation
Actions needed
Summary
Text
Before continuing to the training topics, I (presenter) will give a short overview on the training outline. First, I will show you the training objective and I will explain some definitions that will be used during this trainings module. Then, the training really starts: first the effects of climate change on vector borne diseases (VBD) will be discussed. Thereafter we will continue with more detailed information for each VBD: the health effects, current situation, future situations and actions needed in the future. We will end with a short summary of what you (supposed to) have learned during this course.
Additional background information
Not applicable 2 2 2

3. Training objective
To learn how to be prepared for changes in public health due to climate change
Take home message
Health impact
Mitigation and adaptation
Preventive measures on individual & community level
Text
Target audience for this training: public health professionals*
- public health services
- managers in the health care sector
Therefore, the focus will be on community level. In addition, climate-TRAP focuses on adaptation and mitigation will only be mentioned briefly.
Additional background information
*Note: There will be a separate training module for clinical health professionals (e.g. General Practitioners (GP), emergency doctors and hospital personnel, and health care workers)
**Note: difference between public and clinical health professionals
Public health: population level, prevention
Clinical health: individual level, cure/treatment 3 3 3

4. Definitions
Mitigation = reducing the severity of climate change (reducing greenhouse gas concentrations)
Adaptation = preparing for change (adjusting our systems to reduce harm from climate effects)
Text
Read definitions out loud
Mention that mitigation will not be discussed during this training.
Source definitions: The climate connection. Presentation “3CC_Health_Improvement_and_Mitigation_Mar09[1]”. Slide 3
Additional background information
Below you can find the definition used by WHO (2005)
“In the terminology of climate change, ‘mitigation’ refers to actions that limit the amount and rate of climate change (the exposure) by constraining the emissions of greenhouse gases or enhancing their sinks. Adaptation refers to any actions undertaken to avoid, prepare for or respond to the detrimental impacts of observed or anticipated climate change.” 4 4 4

5. Climate change
Climate change will alter the hydrological cycle not only by altering mean meteorological measures but also by increasing the frequency of extreme events such as excessive floods and droughts.
Affect both water availability and water quality.
Climate directly has an impact on waterborne infectious diseases through effects on precipitation patterns (variability and intensity) and water temperature.

6. Water-borne diseases
Water-borne outbreaks have the potential to be rather large but the actual disease burden in Europe is difficult to approximate and most likely underestimated (Bartram et al, 2002). In 2006, only 17 water-borne outbreaks were reported by five European countries, obviously an incomplete reporting.

7. Exposure Overflow and run-offs
Some regions problems with extreme amounts of rain and unpredictable flood discharges.
The combined sewer systems continue to pose a major threat to water quality: designed to carry both storm water and sanitary wastewater through the same pipe to a sewage treatment plant. During periods of extreme rainfall, the volume of water in the sewer system can exceed the capacity of the system or treatment plant.
In such situations, the system will overflow and discharge the excess wastewater into surface water bodies.
Often the sewers overflow directly into a surface water body, introducing fecal contaminants, including bacteria, protozoa, and viruses (Delpla et al, 2009). Separate sewage and drainage water systems is a better solution than the old combined systems. In the river Ouse in southeast England (U.K.) presumptive E. coli and presumptive intestinal enterococci levels were logs higher during storm events than during dry weather conditions, and levels of the faecal indicator organisms were closely associated with increased turbidity levels (Nnane et al, 2011).
The combined sewer systems, still used in many communities, continue to pose a major threat to water quality.
Also separate systems can cause overflow and runoff of street dirt to collection point.

8. Exposure Drinking water system
Drought in summer may increase the problems with too low water pipe pressure. Low and negative pressure in the water distribution net may result in intrusion of pathogenic microorganisms if a source of contamination is present, e.g. a leaking sewer main.
Drop in the consumption of public sector water leads to increased residence time in the distribution network. This may affect the water quality through the development of biofilm sheltering opportunistic pathogens
Drinking water system
Drought in summer may increase the problems with too low water pipe pressure. Low and negative pressure in the water distribution net may result in intrusion of pathogenic microorganisms if a source of contamination is present, e.g. a leaking sewer main.
These emerging conditions can reduce the raw water quality. The impact on drinking water will to a large extent depend on protection of raw water sources and the water treatment plants and the efficiency at removing pathogens and hazardous chemicals.
The need to save water is already customary in some countries, and water-saving actions have resulted in a decrease in consumption as well as in production in some cities. A drop in the consumption of public sector water leads to increased residence time in the distribution network. This may affect the water quality through the development of biofilm sheltering opportunistic pathogens
Disinfection by-products are expected to increase with climate change. Run-offs or low water levels causing microbial contamination, also increase organic precursors in surface water courses (Janus, 2010). Higher summer temperatures will probably also result in higher chlorine doses to balance the effect of temperature on the dynamics of chlorine consumption in distribution networks.

9. Exposure Drinking water system
Disinfection by-products are expected to increase with climate change. Run-offs or low water levels causing microbial contamination, also increase organic precursors in surface water courses.
Higher summer temperatures will probably also result in higher chlorine doses to balance the effect of temperature on the dynamics of chlorine consumption in distribution networks.
Drinking water system
Drought in summer may increase the problems with too low water pipe pressure. Low and negative pressure in the water distribution net may result in intrusion of pathogenic microorganisms if a source of contamination is present, e.g. a leaking sewer main.
These emerging conditions can reduce the raw water quality. The impact on drinking water will to a large extent depend on protection of raw water sources and the water treatment plants and the efficiency at removing pathogens and hazardous chemicals.
The need to save water is already customary in some countries, and water-saving actions have resulted in a decrease in consumption as well as in production in some cities. A drop in the consumption of public sector water leads to increased residence time in the distribution network. This may affect the water quality through the development of biofilm sheltering opportunistic pathogens
Disinfection by-products are expected to increase with climate change. Run-offs or low water levels causing microbial contamination, also increase organic precursors in surface water courses (Janus, 2010). Higher summer temperatures will probably also result in higher chlorine doses to balance the effect of temperature on the dynamics of chlorine consumption in distribution networks.

10. Exposure Surface or recreational water
The frequency of cyanobacterial blooming is expected to increase.
Increasing water temperatures may change the ecology of freshwater ecosystems: more algal blooms and degradation of water quality.
Toxins with a potential to cause acute poisoning of consumers.
Reduced rainfall during summer periods and droughts in coastal areas and on islands may increase salinisation of freshwater lakes and ground water used for drinking water.
The frequency of cyanobacterial blooming is expected to increase with a warmer climate. Increasing water temperatures may change the ecology of freshwater ecosystems and this may give more algal blooms and degrade water quality due to their toxins with a potential to cause acute poisoning of consumers. (Delpla et.al. 2009). The toxin production may also be affected by a warmer climate, but the effect is not well known. To put restrictions for fertilizer use is one approach to deal with the cyanobacterial threat water sources.
Reduced rainfall during summer periods and droughts in coastal areas and on islands may increase salinisation of freshwater lakes and ground water used for drinking water. Climatic forcing scenarios show that Lake IJsselmeer in the Netherlands is vulnerable to climate-induced salinisation. Drought may in the future result in chloride concentrations well above the maximum allowable concentration of 150 mg/l for chloride in drinking water (Bonte & Zwolsman, 2010).

11. Waterborne disease outbreaks
Figure The number of waterborne disease outbreaks associated with recreational
water use reported in the Netherlands, , in relation to the number of
warm, summer and tropical days in summer.

12. Pathogens Water-borne pathogens: parasites bacteria Giardia
Cryptosporidium
bacteria
Vibrio-bacteria
Often the sewers overflow directly into a surface water body, introducing fecal contaminants, including bacteria, protozoa, and viruses (Delpla et al, 2009). Separate sewage and drainage water systems is a better solution than the old combined systems. In the river Ouse in southeast England (U.K.) presumptive E. coli and presumptive intestinal enterococci levels were logs [H1] higher during storm events than during dry weather conditions, and levels of the faecal indicator organisms were closely associated with increased turbidity levels (Nnane et al, 2011).  [H1]in nromal numbers?

14. Transmission
There are different water-transmitted pathogens such as bacteria, viruses, parasites, amoebas or algae. The way they are transmitted via water differs.
Pathogens that are water-transmitted may follow various routes, ranging from water ingestion to transmission via insect vectors, and are classified into four different categories.
according to Bradley (1977) (de Roda, 2010).

15. Water-transmitted infectious diseases
Table: divided into four categories according to their transmission route. Adapted from Bradley (1977)
Category
Transmission
Examples
Waterborne
Ingestion of water contaminated by human or animal faeces or urine containing pathogenic bacteria, viruses or parasites
Gastroenteritis, enteric hepatitis, amoebic and bacillary dysentery, cholera, leptospirosis, poliomyelitis, typhoid/paratyphoid fever
Water-washed
Skin, ear or eye contact with contaminated water and poor personal hygiene
Conjunctivitis, trachoma, intestinal helminth infections, leprosy, scabies
Water-based
Parasitical worm infections, the parasites are found in intermediate organisms living in water
Dracunculiasis, schistosomiasis, (tricho)bilharziasis
Water-related
Insect vectors breeding in water or biting near water
Dengue, lymphatic filariasis, malaria, onchocerciacis, trypanosomiasis, yellow fever

16. Some water-transmitted pathogens, such as species of non-faecally derived bacteria, amoebas and algae, can grow in aquatic environments. In contrast, other so-called enteric bacteria, viruses and parasites that are faecally derived cannot multiply in water.
Growth of water-transmitted pathogens in aquatic environments depends on environmental conditions including climate, and on the pathogen characteristics (WHO, 2006).
Growth of water-transmitted pathogens in aquatic environments depends on environmental conditions including climate, and on the pathogen characteristics (WHO, 2006).

17. Pathogens
Recreational water-associated (non-)faecally-derived pathogens. From WHO (2006)

18. .
Bacteria
Health significancea
Persistence in raw water suppliesb
Resistance to chlorinec
Relative infectivityd
Important animal source
Campylobacter jejuni
High
Moderate
Low
Yes
Escherchia coli –pathogenic
E.coli – Enterohaemorrhagic
Legionella spp.
May multiply No
Salmonellae
Shigella spp.
Short
Yersinia enterocolitica
Long
Viruses
Adenovirus
Enterovirus
Astrovirus
Norovirus
Potentially
Sapovirus
Rotavirus
Protozoa
Cryptosporidium parvum
Giardia intestinalis
a Health significance relates to the severity of health impact, including association with outbreaks .
b Detection period for infective stage in water at 20°C. Short meaning up to 1 week; moderate, 1 week to 1 month and long, over 1 month.
c Resistance to conventional treatment with chlorine at drinking water plants. Low means 99% inactivation at 20°C generally in < 1 minute; moderate 1-30 minutes and high > 30 minutes. Consideration should be taken for those organisms that survive and grow in biofilms since they will be protected from chlorination.
d The relative infectivity dose is established from experiments with human volunteers, from epidemiological evidence and animal studies. High means the infective dose can be organisms or particles; moderate ⁴ and low > 10⁴.

19. Impact on health care
Increased risk of pathogens in drinking or surface water:
infants, elderly, pregnant women, and people with immune systems severely weakened by chemotherapy, AIDS, chronic illness such as diabetes, or pre-infection by another agent
The loss of immunity with advancing age makes elderly more at risk of infection due to faecal pathogens. Infections are also more dangerous for frail or immuno-suppressed persons.

20. Impact on health care
Mainly on general practitioners and medical specialists in the gastro-intestinal care.
Increased medication.
The loss of immunity with advancing age makes elderly more at risk of infection due to faecal pathogens. Infections are also more dangerous for frail or immuno-suppressed persons.

21. Infectious diseases –waterborne diseases
Likely increase in cases of Cryptosporidiosis
Impact of increased temperature on water quality & disinfection
Infectious diseases:
Cases of
food poisoning (salmonellosis, campylobacter) and
water borne disease (cryptosporidiosis) linked to warm weather are likely to increase 21

22. Surface water
Cyanobacteria may produce a large number of toxins under warm weather conditions in surface water.
Acute poisoning of consumers .
Cyanotoxins which are abundant in Europe are microcystine. These can have an oral intake, and uptake in the ileum and are then distributed to the liver.
Another cyanobacterium which is seen in central Europe is the Cylindrospermopsis raciborskii. This pathogen has seen to be spreading in a northern direction in Europe .

23. Table Effect of climate change on the environment and fate and behaviour of recreational water-transmitted pathogens

24. What action’s are needed?
To put restrictions for fertilizer use is one approach to deal with the cyanobacterial threat water sources.

25. What action’s are needed?
Surveillance of health impacts associated with drinking water should include both water quality and health outcomes.
Technologies such as:
molecular fingerprinting to track contaminant sources
satellite remote sensing to detect algal blooms
Acute gastrointestinal illness monitored in relation to extreme weather
Indicators of drinking water quality to identify local associations.
Water quality monitoring and health surveillance need to be intensified.
Time-series studies (US, France, Russia) possibilities of using on-line water operation data (e.g. turbidity) as indicators of fluctuations of faecal water contamination;
and detect associations with acute gastro-intestinal illness in the population.

26. Foodborne diseases

27. Climate change
Climate change will alter the incidence of foodborne diseases
Climate has directly an impact on foodborne infectious diseases through effects on temperature.

28. What influences occurrence of food-borne diseases?
Food source
Food storage
Food preparation
Food handlers

29. Food hygiene vs food safety
Food hygiene – microbiological safety of food
Food safety – absence of chemicals/residues

30. What influences occurrence of food-borne diseases?
Food source: maybe climate related
Food storage: climate related
Food preparation
Food handlers

31. What influences occurrence of food-borne diseases?
Time-temperature abuse
Infected food handlers or inadequate hygiene during handling of food
Consumption/use of unsafe food sources

32. Introduction Causes of food-borne diseases:
Chemical toxins (‘residues’)
Biotoxins – endotoxins & exotoxins
Infectious agents – exogenous & endogenous (‘zoonoses’)

33. Pathogens Foodborne pathogens: Bacteria Salmonella Campylobacter
Often the sewers overflow directly into a surface water body, introducing fecal contaminants, including bacteria, protozoa, and viruses (Delpla et al, 2009). Separate sewage and drainage water systems is a better solution than the old combined systems. In the river Ouse in southeast England (U.K.) presumptive E. coli and presumptive intestinal enterococci levels were logs [H1] higher during storm events than during dry weather conditions, and levels of the faecal indicator organisms were closely associated with increased turbidity levels (Nnane et al, 2011).  [H1]in nromal numbers?

34. Water and Food-borne Disease: Climate-Susceptible Pathogens
Rising temperatures
Increasing rainfall
Shifts in
reservoir ranges
Sea level changes
Salmonella X
Campylobacter
Vibrio
Leptospira
Enteroviruses
Naergleria fowleri
Cryptosporidium
Giardia

35. Salmonellosis and temperature rise
Modelled association between temperature and number of reported cases of salmonellosis in England and Wales (adjusted for outbreaks, seasonal factors and holidays)
© S. Kovats (Data supplied by HPA) 35

36. Salmonella
(Sources: Kovats, Cullen)

37. Foodborne diseases Summary Likely increase in cases of food poisoning
Incidence dependent on future food hygiene behaviour
Evidence confirms the effect of temperature on salmonellosis
Role of temperature in Campylobacter transmission remains uncertain
Infectious diseases:
Cases of
food poisoning (salmonellosis, campylobacter) and
water borne disease (cryptosporidiosis) linked to warm weather are likely to increase 37

38. Endotoxins & exotoxins
Introduction
Endotoxins & exotoxins
lipopolysaccharide (LPS) : protein
part of bacterium : extracellular
no toxoid : toxoid
low potency : high potency
low specificity : high specificity

39. Mode of action of some bacterial toxins
S. aureus – A
(alpha-toxin)
E. coli – B
(shiga toxin)
C. botulinum – C
(exo-enzyme)

40. Pathways for Weather to Affect Health: Example = Diarrheal Disease
Distal Causes
Proximal Causes
Infection Hazards
Health Outcome
Temperature
Humidity
Precipitation
Survival/ replication
of pathogens in the
environment
Consumption of
contaminated water
Incidence of
mortality and
morbidity
attributable
to diarrhea
Living conditions
(water supply and
sanitation)
Contamination of
water sources
Consumption of
contaminated food
This diagram shows the various pathways by which weather and other factors can influence the morbidity and mortality due to diarrheal diseases.
Contamination of food sources
Contact with
infected persons
Food sources and
hygiene practices
Vulnerability
(e.g. age and
nutrition)
Rate of person
to person contact
Source: WHO

41. Health effects Upper GIT – nausea & vomiting
Lower GIT – cramps & diarrhoea
Neurological signs
General symptoms

42. Nausea, retching, vomiting, abdominal pain, diarrhoea & prostration
Symptoms
Upper GIT signs
Nausea, retching, vomiting, abdominal pain, diarrhoea & prostration
S. aureus and its toxins
B. cereus and its toxin

43. Lower abdominal cramps & diarrhoea
Symptoms
Lower GIT signs
Lower abdominal cramps & diarrhoea
Clostridium perfringens, Bacillus cereus
Salmonella, Shigella, ET E. coli, Yersinia enterocolitica, Campylobacter jejuni, Vibrio cholera

44. Lower abdominal cramps & diarrhoea
Symptoms
Lower GIT signs, continued
Lower abdominal cramps & diarrhoea
Giardia intestinalis
Cryptosporidium parvum

45. Visual disturbances, vertigo, tingling sensation & paralysis
Symptoms
Neurological signs
Visual disturbances, vertigo, tingling sensation & paralysis
Clostridium botulinum

46. Types of illnesses/diseases
General symptoms
Fever, chills, malaise, prostration, aches, swollen lymph nodes
S. typhi, L. monocytogenes, C. jejuni
Hepatitis A

47. Pathogenic Bacteria Salmonella spp. - GIT / skin E. coli O157:H7 - GIT
Campylobacter spp. - GIT (esp. poultry)
Staphylococcus aureus toxin - Human (nostrils and hands)
Yersinia enterocolitica - GIT
Listeria monocytogenes - Soil, skin, faecal material
C. botulinum, C. perfringens - Soil, skin, faecal material

48. Risks of contracting food-borne disease depend on:
Host susceptibility
Age
General health

49. Risk assessment – variable infective doses
Interaction – food substrate & environment
pH susceptibility
Type and strain

50. Impact on food safety Impacts on food safety
Climate change and variability may have an impact on the occurrence of food safety hazards at various stages of the food chain, from primary production through to consumption.
Module 3. Impacts of climate change on agro-ecosystems and food production 50

51. Impact on food safety Impacts on food safety
Climate change and variability may have an impact on the occurrence of food safety hazards at various stages of the food chain, from primary production through to consumption.
Which?
Module 3. Impacts of climate change on agro-ecosystems and food production 51

52. Impact on food safety Impacts on food safety
Some potential impacts include:
Increasing microbial food contamination and associated food-borne diseases;
Increasing animal diseases and vectors of transfer of animal pathogens from animals to humans;
Modifying the patterns of fungi and mycotoxin contamination;
Increasing harmful algal blooms in coastal areas;
Increasing environmental contaminants and chemical residues in the food change;
Increasing illnesses due to food contamination in emergencies.
Module 3. Impacts of climate change on agro-ecosystems and food production 52

53. Impacts on food safety - example
Mycotoxins in maize in Europe
Maize can support different mycotoxin-producing moulds, such as F. graminearum, F. verticillioides, and A. flavus.
In 2003, prolonged hot and dry weather in Europe caused an outbreak of A. flavus, with consequent problems of aflatoxin contamination (aflatoxins are extremely toxic, mutagenic, and carcinogenic compounds) in forage and silage, an uncommon occurrence in Europe.
Aflatoxins, produced by few species belonging to Aspergillus are expected to become more prevalent with the foreseen climate change.
Source: Climate change and food safety: An emerging issue with special focus on Europe.
Aspergillus flavus in maize.
Photo: CIMMYT. Taken from Maize diseases: a guide for field identification .
Module 3. Impacts of climate change on agro-ecosystems and food production 53

54. Prevention of Food Poisoning WHO ‘ten golden rules’
Food processed for safety
Thoroughly cook
Eat immediately
Store carefully
Reheat thoroughly

55. Prevention of Food Poisoning WHO ‘ten golden rules’
No contact between raw & cooked
Wash hands
Keep food preparation surfaces clean
Protect from pests
Use potable water