Water, Sanitation and Environmental health in Cholera.ppt

Water, Sanitation and

Environmental Health MeasuresEnvironmental Health Measures

Dr. Homero Silva

Environmental Health Advisor

PAHO/WHO Jamaica

Cholera is the result of the existing

social debt in water and sanitation in

many countriesmany countries

Cholera reflects the existing

inequities in Water and Sanitation in

and within countriesand within countries

Drinking Water Coverage Comparison

Haiti and Dominican Republic

70

80

90

100

0

10

20

30

40

50

60

Urban Rural Total

% Water Coverage

Haiti

Dominican Republic

Sanitation Coverage Comparison

Haiti and Dominican Republic

70

80

90

100

0

10

20

30

40

50

60

Urban Rural Total

% Coverage

Haiti

Dominican Republic

Cholera Cases Frequency by Epi Week Dominican Republic

2010-2011

Total Number of cases Haiti and

Dominican Republic

• Haiti 243,197

• Dominican Republic 572

The Great Caribbean RegionEstados Unidos de América

Cuba

Haiti

Belice

República Dominicana

Jamaica Puerto Rico

Las Bahamas

Islas Caimán

Anguila

Turks & Caicos Is.

30N

20N

25N Golfo de

MéxicoOcéano

Atlantico

Colombia

Venezuela

México

Guyana

Honduras

Surinam

Nicaragua

Guatemala

Panamá

Guyana Francesa

Costa Rica

Belice Jamaica Puerto Rico

Trinidad & Tobago

Guadalupe

MartinicaSta. Lucía

BarbadosGranada

Antigua & Barbuda

Anguila

Dominica

San Kitts & Nevis

San Vincente & Las Granadinas

Montserrat

5N

10N

15N

65

W

95

W

55

W

50

W

70

W

75

W

80

W

85

W

90

W

60

W

0 500 1,000250 Km

Mar Caribe

Océano

Pacifico

Division of the Great Caribbean Region in 5

sub-regions

The Risks

• Outside Threats

– People and Goods movement

– Sea Currents

– Ballast Water

• Inside Threats• Inside Threats

– Water

– Excreta

– Food

– Hygiene Conditions

Common Sources of Infection

• Drinking−water that has been contaminated at its source or during storage, and ice made from contaminated water.

• Food contaminated during or after preparation. e.g. milk, cooked rice, lentils, potatoes, beans, eggs, and chicken.

• Seafood. Particularly shellfish, taken from contaminated water and eaten raw or insufficiently cooked.

• Fruit and vegetables grown at or near ground level and fertilized with night−soil, irrigated with water containing human waste, or "freshened" with contaminated water, and then eaten raw.

Drinking Water Coverage

70

80

90

100

0

10

20

30

40

50

60

Ha

iti

Dom

inic

an

Rep

ub

lic

Suri

na

me

Gu

yan

a

Ja

maic

a

Tri

nid

ad a

nd

To

ba

go

Ca

ym

an

Belize

Sa

int K

itts

an

d

Ne

vis

Mon

serr

at

Ba

rba

do

s

Tu

rks a

nd

Ca

ico

s

% Coverage

Water Treatment and Disinfection

• Chlorine Disinfection is very effective for

Vibrio Cholera;

Factors affecting Disinfection

– Turbidity

– Nitrogen Content– Nitrogen Content

– Organic Matter (BOD5)

Figure No 4 .What are the Trihalomethanes (THM)?

• Trihalomethanes (THM) are a group of four chemicals that are formed along with other disinfection by products when chlorine or other disinfectants used to control microbial contaminants in drinking water react with naturally occurring organic and inorganic matter in water.

• The trihalomethanes are chloroform, bromodichloromethane, dibromochloromethane, and bromoform.

• They are Cancer Group B carcinogens (shown to cause cancer in laboratory animals). Trichloromethane (chloroform) is by far themost common in most water systems. Dibromochloromethane is the laboratory animals). Trichloromethane (chloroform) is by far themost common in most water systems. Dibromochloromethane is the most serious cancer risk, (0.6 ug/l to cause a 10-6 cancer risk increase) followed in order by Bromoform (4 ug/l), and Chloroform (6 ug/l).

• WHO Drinking water guidelines, third edition recommends the following maximum allowable concentration:– Chloroform 0.2 mg/litre,

– Bromoform 0.1 mg/litre,

– Dibromochloromethane 0.1 mg/litre (DBCM) and

– Bromodichloromethane 0.06 mg/litre (BDCM)

Supplies and Equipment for

Drinking WaterDrinking Water

Digital Residual Chlorine

Rapid Tests for Total Coliforms with

no incubation

System SURE Plus measures

Adenosine triphosphate (ATP).

The universal energy molecule

found in all animal, plant,

bacterial, yeast and mold cells.

Residues, particularly food or

organic residue, contain large

amounts of ATP.

COD Tester

Straw Filters

• The LifeStraw is a plastic tube 31 centimeters long and 30 millimeters in diameter, and costs around $ 5.50 plus shipping

• Water that is drawn up through the straw first passes through hollow fibers that filter water particles down to 15 through hollow fibers that filter water particles down to 15 microns across, using only physical filtration methods and no chemicals.

• The entire process is powered by suction, similar to using a conventional drinking straw, and filters up to 1000 liters of water.

• While the initial model of the filter did not remove Giardia Liamblia, later models (starting—date/reference needed--) do remove a minimum of 99.9% of waterborne protozoan parasites including giardia and cryptosporidium

Filters 18,000 liters ofwater.About 2 years, family Of five, 5 l/day

Double Container Filters

Double Container Filters

Sanitation

Sanitation Coverage in some

Caribbean Countries

60

70

80

90

100

0

10

20

30

40

50

60

Ha

iti

Gu

ya

na

Do

min

ica

n

Re

pu

blic

Ja

ma

ica

Su

rin

am

e

Be

lize

Tri

nid

ad

an

d

To

ba

go

Ca

ym

an

Sa

int K

itts

an

d

Ne

vis

Mo

nse

rra

t

Gre

na

da

An

gu

illa

Ba

rba

do

s

Ba

ha

ma

s

Excreta Disposal

On-site

Sewerage

Wastewater Treatment Plants

Excreta Disposal

• Latrines

• Septic Tanks

• Sewerage Systems• Sewerage Systems

– Sewage Treatment Plants

– Ocean outfalls

Excreta Disposal in CTUs

Pollution by In-situ Treatment

Removal of Vibrio Cholera

• Septic Tanks Poor

• Stabilization Ponds Good

• Activated Sludge, • Activated Sludge,

oxidation ditch,

pacakage Plants, etc. Poor

• Ocean Outfalls Poor

• Disinfection is required

Factors affecting Disinfection

– Turbidity

– Nitrogen Content– Nitrogen Content

– Organic Matter (BOD5)

Ocean Outfall

The Great Caribbean RegionEstados Unidos de América

Cuba

Haiti

Belice

República Dominicana

Jamaica Puerto Rico

Las Bahamas

Islas Caimán

Anguila

Turks & Caicos Is.

30N

20N

25N Golfo de

MéxicoOcéano

Atlantico

Colombia

Venezuela

México

Guyana

Honduras

Surinam

Nicaragua

Guatemala

Panamá

Guyana Francesa

Costa Rica

Belice Jamaica Puerto Rico

Trinidad & Tobago

Guadalupe

MartinicaSta. Lucía

BarbadosGranada

Antigua & Barbuda

Anguila

Dominica

San Kitts & Nevis

San Vincente & Las Granadinas

Montserrat

5N

10N

15N

65

W

95

W

55

W

50

W

70

W

75

W

80

W

85

W

90

W

60

W

0 500 1,000250 Km

Mar Caribe

Océano

Pacifico

Division of the Great Caribbean Region in 5

sub-regions

Pollution Loads by SubregionSource: UNEP 2009

Sanitation in Great Caribbean Region

• 5.6 million persona (8%) no sanitation

• 42 million (60%) raw wastewater

discharged into the seadischarged into the sea

Sea Currents

Marine Traffic

VIBRIO CHOLERAE

EXCRETION

ASYMPTOMATIC PATIENTASYMPTOMATIC PATIENT 100 100 -- 100,000/g100,000/gASYMPTOMATIC PATIENTASYMPTOMATIC PATIENT 100 100 -- 100,000/g100,000/g

DELICATE STATE PATIENTDELICATE STATE PATIENT 101066 -- 101099/ml/ml

FAECES VOLUME FAECES VOLUME 12 12 -- 20 L20 L

INFECTIVE DOSEINFECTIVE DOSE

ENDEMIC ZONES 104 - 106 (51-75%)

AVERAGE 1000 (25%)

WEAK PERSONS 100Fuente: Dizon y otros, 1967

Greig, 1914Smith, Freter y Sweeney, 1961

The Environmental State

Favourable Conditions for Vibrio

Development and Survival

Temperature (oC)

Growing 16 – 42Growing

Optimum

16 – 42

37

pH 6.4 to 9.6

Nutrients Carbon Organic

Compounds (BOD)

Resistance to Sodium Chloride Concentration < 4%

Sea Surface Temperatures

Surface Salinity

Chlorophyll Concentration

Aragonite Saturation State

Coral Calcification Rates

Survival Time Cholera

Survival times of excreted pathogens in the environment at 20-30°Ca

Water <30 but usually <10 days

Sea Water/Estuaries Years

Sewage <30 but usually <10 days

Soil <20 but usually <10 daysSoil <20 but usually <10 days

Crops <5 but usually <2 days

Milk (Refrigerator)b 2 to 4 weeks

Meat (Refrigerator)b 1 week

Fish and aquatic products(Refrigerator)b 1 to 3 weeks

Fresh Vegetables(Room Temperature)b 1 to 5 days

Glass, porcelain, plastic and metal (Room Temperature)b Less than 4 days

Cutting board and clothb Long time

a WHO (1 989) as summarized from Feachem et al. (1983).

b Symptoms of vibrio cholerae, http://www.health-writings.com/symptoms-vibrio-cholerae/

New Theory Cholerae in Peru

• It has emerged recently

• May be able to answer the long standing question

of how the disease occurred in several places at

the same time along the Pacific northern region of the same time along the Pacific northern region of

Peru.

• This new indicates a strong possibility, and one

that would fit the known observations, is the

association of Vibrio cholerae and marine

plankton

Marine Currents

Cholera in Fresh Water

• In regard to cholera in fresh water environments, V. cholerae has been found to concentrate on the surface of the water hyacinth, and of the water hyacinth, and Lemna minor, a common duckweed found in freshwater environments.

• Temperature and Nutrients have been found are the major factors governing the distribution of cholerae

Ecology of Cholera Survival and

Development

• Pathogenic vibrios are known to be associated

with zooplankton such as copepods with chitin

exoskeletons and with shellfish, including crabs,

shrimp, and crayfish.shrimp, and crayfish.

• Vibrio cholerae is part of the natural flora of the

gut of these animals and has a powerful chitinase

that enhances its growth on the surfaces of

plankton and shellfish.

Sea Currents

Ecology of Cholera Survival and

Development

• Vibrio cholerae will survive in seawater for months or years

• The bacterium can be transported by ocean currents over very long distances. currents over very long distances.

• Work done with phytoplankton, including blue-green algae, suggests that pathogenic vibrios may survive on both zooplankton and phytoplankton in the aquatic environment, but zooplankton act as amplifiers, increasing the numbers to those sufficient to trigger an epidemic.

Ecology of Cholera

Jamaica Coastal Deterioration

• Coastal waters have been progressively deteriorating for a number of years.

• Eutrophication has become a general phenomenon in the past decade. in the past decade.

• Eutrophication has been so serious that many reefs which formerly had more than 95% live coral cover are now more than 95% algae covered.

• Overgrowth of reef corals and "good" sand-producing algae by "bad" fleshy algae took place at different times in different places.

Progress of Coral Reef Affectation

Area Year

Kingston 1950 and 1960

Montego Bay and Ocho Rios 1970Montego Bay and Ocho Rios 1970

Rio Bueno to Runaway Bay 1980

Negril and parts of Western Jamaica 1990

–

THE TOURISM FACTOR

Tour Operators use disease info in

selecting tourist destinations

CARIBBEAN TOURISM�$US21.5Bn industry

�23 million stay-over arrivals

�18 million cruise ship arrivals

�252,300 hotel rooms; 2,200 hotels�252,300 hotel rooms; 2,200 hotels

�Contribution to Caribbean GDP = 15%

�Contribution to Caribbean employment = 15.5%

�Majority of hard currency earnings

Recommendations

• Strengthen Surveillance– Water, wastewater discharges, hospitals WWTP, Raw agricultural products, fish

industry, patients, etc.

• Improve O&M Sewage Treatment Plants– Training operators

– Re conditioning– Re conditioning

• Disinfection of water– Home treatment

• Safe excreta Disposal– Emergency latrines

– Construction of new in-situ technologies (latrines, septic tanks

• Massive Public Education

• Ensure food safety– Cooked food

– Less raw food

– Shelfish

– Food street vending

Thanks