Drinking water in development projects and during the emergencies

Dr. Dino SgarabottoInfectious and Tropical Diseases Dept.

Padova General and University Hospital - Italy

Waterborne Diseases and Epidemics

Water as a vehicle of infection

• 500 liters of water a year are used by an average adult

• Fecal-oral transmission happens when food or water are contaminated by human or animal excrements which contain pathogenic microorganisms

• Contaminated water can be a source of infections waterborne diseases: sporadic cases or epidemic outbreaks

Waterborne micro-organisms

• Bacteria–Vibrio cholerae–Salmonella typhi–Shigella spp–Escherichia coli (enterotoxigenic) –Campylobacter jejuni

Waterborne micro-organisms

• Viruses–Rotavirus–Norovirus–Adenovirus and enterovirus–Hepatitis A and E virus

Waterborne micro-organisms

• Protozoa–Giardia Lamblia–Entamoeba histolytica–Cryptosporidium–Microsporidium–Ciclospora, Isospora

Clinical features• Fever (low grade or high) or no fever• Diarrhea ( in most cases) either

secretory or inflammatory (with mucus or blood) or no diarrhea (typhoid fever)• Jaundice (yellow skin and eyes)• Abdominal pain• Nausea and vomiting

Drinking Water Treatment• The occurrence of diseases such as cholera and typhoid fever has

dropped dramatically. In 1900, the occurrence of typhoid fever in the United States was approximately 100 cases per 100,000 people. By 1920, it had decreased to 33.8 cases per 100,000 people. In 2006, it had decreased to 0.1 cases per 100,000 people (only 353 cases) with approximately 75% occurring among international travelers.

• In 1908, Jersey City, New Jersey was the first city in the United States to begin routine disinfection of community drinking water. Over the next decade, thousands of cities and towns across the United States followed suit in routinely disinfecting their drinking water, contributing to a dramatic decrease in disease across the country

Infectious Diseases Mortality in USA

Cholera and Typhoid Fever are monsters in a cage in the western world

Cholera epidemics• 6 pandemics between 1816 and 1923 (1816–1826,

1829–1851, 1852–1860, 1863–1875, 1881–1896, 1899-1923) with 38 millions deaths. Lack of treatment of human feces and lack of treatment of drinking water greatly facilitate its spread.

• Pandemics in 20th century (1961–1975)• 15 notable outbreaks between 1991 and 2014

mainly in Africa, South America and South-East Asia

Water potabilization:Chlorine added to drinking water

• Different sensitivity of the micro-organisms to chlorine (most widely used method of potabilization)

• Bacteria and viruses are highly sensitive• Protozoa are poorly sensitive: water filtration

or ozone may be needed

Geographic distribution of Cholera

Cholera in Haiti after the earthquake

• October 2010 – January 2012, Haiti and Dominican Republic: Late in October 2010, a cholera outbreak was reported in Haiti. As of November 16, the Haitian Health Ministry reported the number of dead to be 1,034, with hospitalizations for cholera symptoms totaling over 16,700.

• The outbreak was blamed on a camp of Nepalese United Nations peacekeepers, but this was disputed. Scientists have found that Vibrio cholera bacteria can survive between outbreaks in brackish warm water, and it exists in Haitian waterways. The outbreak started on the upper Artibonite River.; people first contracted the disease from this river.

• Scientists think the hurricane and weather conditions in Haiti worsened the consequences of the outbreak, and damaged sanitation systems allowed it to spread. By November 2010, the disease had spread into the neighboring Dominican Republic. As of January 2012, the epidemic has sickened nearly 500,000 people and killed nearly 7,000 in Haiti.

Geographic distribution of Typhoid Fever

WHO 201420 million cases

Typhoid fever epidemics in Europe and US

• 1897 in Maidstone (England) 2.000 cases with 141 deaths related to water contamination

• 1937 in Croydon (England): 341 cases and 43 deaths were associated with a failure to chlorinate water during repairs to a well

• 1963 in Zermatt (Switzerland): 437 cases and 31 deaths including skiers from all over Europe

• 1964 in Aberdeen (Scotland): 507 cases and 42 deaths• 1973 in Dade Country (Florida) 230 cases may have

originated from water contaminated by a typhoid carrier.• 1983 in Kos (Greece): 58 cases from several European states • Reduced death rate from 30% to less than 1% with antibiotics

The “Cage” controlling typhoid fever and cholera

• Water potabilization: chlorine (most widely used disinfectant), chloramine, ozonation, etc.

• Vaccination: against typoid fever since 1897 (firstly used in the British and US army)

• Antibiotics: chloramphenicol introduced in 1948 (less important in cholera where rehydration therapy comes firstly)

Antibiotic resistance of Salmonella typhi

• Chloramphenicol was used universally to treat typhoid fever from 1948 until the 1970s, when widespread resistance occurred

• Ampicillin and trimethoprim-sulfamethoxazole (TMP-SMZ) then became treatments of choice. However, in the late 1980s, some strains (MDR: multidrug resistant) developed simultaneous plasmid-mediated resistance to all three of these agents

• Fluoroquinolones are highly effective against susceptible organisms, yielding a better cure rate than cephalosporins. Unfortunately, resistance to first-generation fluoroquinolones is widespread in many parts of Asia where are now used third-generation cephalosporins, particularly in south Asia and Vietnam.

• Ceftriaxone “creep” (reduced efficacy) not yet ESBL

Waterborne Diseases new outbreaks “in our backyard”

Major outbreaks in North America

• 1993 Milwaukee Cryptosporidium outbreak in USA: 400.000 people with watery diarrhea

• 2000 Walkerton E. coli O157/H7outbreak in Canada: 2.300 people with bloody diarrhea

• 2001 North Battleford Cryptosporidium outbreak (Saskatchewan, Canada): 6.100 people with watery diarrhea

• Thereafter only minor outbreaks of Giardia, Campylobacter and Norovirus causing about 6.000 cases of diarrhea in 10 years

Causes of new outbreaks• Most outbreaks are smaller (case clustering)

and food-related• When water-related, potabilization failure is

often due to human factors or climate changes like haevy rains and hurricans reducing the “safe distance” between sewage and water storage

• However, in most African countries, South East Asia and parts of South America public water is not safe and waterborne disease are endemic.

Conclusions• Public health implementation in the field of

drinking water and sewage should be high in the agenda of most countries

• Cost effective solutions should be found even in low income countries

• Vaccinations are available for some but not all waterborne diseases

• Antibiotics are only the last medical answer to an established case

Thank you for your attention

Any question??

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