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Emerging Infectious Diseases in the Water Supply and How that Affects Immunocompromised Persons: 

Emerging Infectious Diseases in the Water Supply and How that Affects Immunocompromised Persons Educational Objectives: Why are Elderly Persons at a higher risk for infectious diseases? Understand the factors that lead to increases in water-borne infectious diseases Factors are different for the developed versus the developing world Discuss a disease example for each

Emerging Infectious Diseases and Water What has changed?: 

Emerging Infectious Diseases and Water What has changed? More centralized water sources Better detection methods Increase in immunocompromised people Food imported from developing countries, using unclean water for irrigation and washing Global conflicts creating increasing refuge camps

Increasing Numbers of Immunocompromised Persons: 

Increasing Numbers of Immunocompromised Persons HIV is still increasing worldwide Older persons (aging baby boomers) Patients treated for cancer, transplants, diabetes, etc. 13 Factors of Emerging Infectious Diseases: Human Demographics and Behavior Human Susceptibility to Infections Technology and Industry

Impact of Aging on Infections : 

Impact of Aging on Infections Physiological Changes of Aging: Immune changes increase infection risks (e.g. TB) Organ changes increase infections risks -skin -stomach acid reduced- first line a/ enteric pathogenes -bladder changes increase UTIs Age-related diseases (e.g. cancer, diabetes, dementia etc.) increase infection risks

Immune Changes with Age: 

Immune Changes with Age Protective immunity drops with age -poor priming to new antigens (efficacy of immunization is decreased) -poor recall of old antigens (i.e. antigens you saw when you were young) -poor affinity maturation- low IgG (i.e. not high affinity) Poor proliferation of T cells, poor IL-2 production Many changes in later cytokine production (IL-4, IFN) T cell subsets: naïve are down and memory are up T cell microclones-as much as 50% of T cells are clones (5000 to 10,000 each) thus not a broad repartee

Physiological Changes of Aging: 

Physiological Changes of Aging Organ changes in older persons: -produce less stomach acid (1st defense a/ enterics) -organ transplants or plastic and metal parts internally these increase chances for infection Older persons spend more time in hospital, exposing them to more infectious diseases Older persons have more medical procedures performed e.g. catheterization increases UTIs Institutionalization (nursing homes) increases infections e.g. aspiration pneumonia, infected pressure ulcers

Chronic Diseases with Infectious Etiology: 

Chronic Diseases with Infectious Etiology Does chronic inflammation from infectious diseases make other diseases worse? (Alzheimer’s) Infections cause or contribute to chronic diseases and cancers. -Helicobacter pylori -linked with stomach ulcers cancer -Borrelia burgdorferi (Lyme disease) is linked to arthritis -Chlamydia pneumoniae is linked to atheroslerosis -Hepatitis B and C are linked to liver cancer -Schistosoma is linked to colon and bladder cancers If disease is caused by infection, is it easier to treat?

U.S. Drinking Water: 

U.S. Drinking Water Our drinking water supply is normally safe. Diseases are spread when: -there’s a water main break or interruption  -you camp or travel -you swim or play in lakes, streams, pools, or waterparks? Parasites cause the majority of problems: Cryptosporidium, Giardia, sometimes Toxoplasma But also can have Escherichia coli O157:H7, and Viral Hepatitis A

Water and Food Connection: 

Water and Food Connection Fecal contamination of water used for crop irrigation, processing, and preparation. “If people don’t have clean water to drink…imagine with they irrigate and wash their crops with”-Michael Osterholm Rapid increase in aquaculture -7 million tons in 1984 to 23 million tons in 1996 -in developing countries, it is 87% of fish production -in the U.S. it is still only 15% but rising

Parasites and Water in the U.S.: 

Parasites and Water in the U.S. CDC estimates 2.5 million cases annually due to food and beverage parasites Especially the long-surviving encysted forms In the U.S., the CDC links 71% of waterborne disease to two parasites: Giardia lamblia and Cryptosporidium Cryptosporidium is in the subclass coccidians including Eimeria, Plasmodium, Toxoplasma, Cyclospora, Babesia, Isospora

Cryptosporidium parvum : 

First described in 1907 as an intracellular protozoan parasite In 1976 two cases of human diarrhea Increased dramatically with the AIDS epidemic, by 1986 4% of AIDS patients had cryptosporidiosis with a 61% fatality rate In 1993 national attention was focused on Cryptosporidium -Milwaukee over 400,000 cases -Las Vegas thousands more CDC says that currently there are at least 30,000 cases of Cryptosporidium annually Cryptosporidium parvum

Cryptosporidium: 

Cryptosporidium Cryptosporidium is in the subclass coccidians which includes Plasmodium (malaria), Toxoplasma, Cyclospora, Babesia, Sarcocystis, Isospora, and Eimeria Large reservoir of wild animals and livestock Lifecycle is completed within a single host Diagnoses can now be done by immunofluorescence

Immunofluorescence of Cryptosporidium Cysts: 

Steve J. Upton, PhD Kansas State University Immunofluorescence of Cryptosporidium Cysts

Lifecycle of Cryptosporidium: 

Steve J. Upton, PhD Kansas State University Lifecycle of Cryptosporidium

Cryptosporidium in Human Disease: 

Transmission is fecal/oral: outbreaks associated with faulty water purification 1-2 week incubation with PROFUSE watery diarrhea (12L/day) We shead oocysts in stool; cysts are very rubust, resistant to chlorination must boil Self-limiting except in immunocompromised patients No effective drugs; treat with oral rehydration Cryptosporidium in Human Disease

Cryptosporidium Prevention: 

Cryptosporidium Prevention Existing water testing and treatment methods fail to reliably detect or remove it EPA estimates that over the next 20 years, $138.4 billion is needed to upgrade or replace our drinking water infrastructure Cryptosporidiosis has been linked to drinking and recreational water, food, person to person and farm animal contact -Over 3000 cases in NY’s Seneca Lake Park (Coon Lake MN) Low doses can lead to infection in healthy volunteers (3000 cysts) HIV-infected patients with fewer than 200 CD4 cells/mm3 should drink boiled or bottled water

Slide17: 

Cyclospora Previous underestimate of foodborne illness attributed to parasites: lack of effective monitoring. Underdeveloped scientifically: cannot culture most parasites and lack of natural models. Cyclospora, like Cryptosporidium, cannot be grown in the lab Cyclospora outbreaks highlight the role of international food distribution and the emergence of previously unknown pathogens CDC says that are 15,000 cases of Cyclospora annually

Slide18: 

Cyclosporiasis and Raspberries Outbreaks in 1995, 1996, 1997, and 2000 (Canada) associated with Guatemala raspberries Last 1980s USAID pushed Guatemala after their civil war to grow raspberries for U.S. markets First bushes went in 1988-1989, first years birds were “berry naïve”, then they started to eat a lot of them Where is the Cyclospora coming from? What is the reservoir? 1) contaminated irrigation or washing water 2) birds…birds come to eat the raspberries and poop Cyclospora is related to Eimeria (chicken coccidious) Raspberries have tiny hairs, nearly impossible to wash

Slide19: 

Cholera Descriptions of epidemics on the Indian subcontinent in the 1400s but it did not spread to Europe and the Americas ‘til 1800s Cholera was prevalent in the U.S. during the 1800s, but has been virtually eliminated by modern sewage and water treatment Currently it is common in Asia, Africa, and Latin America (growing problem in the former Soviet Union, Iran, and Pakistan current outbreak in Africa (110 new cases per day) As of Sept 28, 2006 there are 22,101 cases with 219 deaths in Ethiopia Angola has had >50,000 with 2089 deaths Sudan has had >5,000 with 165 deaths .

Cholera: 

Cholera Etiological agent is Vibrio cholerae- serogroups O1 (El Tor) or O139 (Bengal) that produce cholera toxin Clinical features vary from asymptomatic to profuse watery diarrhea with vomiting, circulatory collapse and shock 25-50% of cases at fatal if untreated- treatment is oral rehydration therapy (sugar and salt mixed with clean water) hard to deliver in remote areas and during epidemics Risk group is persons living in poverty in the developing world, low risk for travelers, virtually no risk for persons in the U.S.

Cholera cont.: 

Cholera cont. Transmission is through contaminated drinking water or food -large epidemics often related to fecal contamination of water or street vended foods -occasional transmission from undercooked shellfish that have been naturally contaminated Ongoing global pandemic in Asia, Africa, and Latin America (Iraq) since 1995, >80% have occurred in Africa In Africa 2005-Nigeria: up to 100 dead in Benue State by the Benue River Conflict in Sudan has MANY cases in the refugee camps In DRC-1420 cases, 29 dead, Guinea-Bissau- 280 deaths, 18,000 sick (50 cases/day) Senegal had 23,325 cases and 321 deaths, Muslim pilgrimage in the city of Touba In developing countries, population migrations into urban centers have strained the existing water and sanitation infrastructure

The O1- El Tor Strain: 

The O1- El Tor Strain Isolated in 1905 from Mecca pilgrims at the El Tor quarantine camp Since 1961 the El Tor variant has spread across Asia, Africa, the Middle East, and recently into parts of Europe In 1969, first seen in the Ganges Delta (heartland of cholera) and by 1974 it had replaced the “classic” cholera strain In 1982 in Bangladesh mix of classic and El Tor = O139 (Bengal) In January 1991, the El Tor variant broke out in Peru and quickly spread throughout Latin America (currently large epidemics) -carried over on ships from Africa and came out of the bilge

Phenotypes of the El Tor Strain: 

Phenotypes of the El Tor Strain The El Tor strain has been isolated as free-living bacteria or with phytoplankton, zooplankton, crustacea, and mollusks The El Tor strain can produce a “rugose” phenotype which is exopolysaccharide production that confers chlorine resistance and biofilm formation The survival of El tor is decreased if the seawater is filtered Attachment to surfaces is important for marine organisms -surfaces absorb and concentrate scarce nutrients -biotic surfaces (chitin) can be degraded by attached bacteria

Colony Morphology and EPS Production: 

Colony Morphology and EPS Production Yildiz F.H. et.al. 2001 J. Bact. 183 p.1716-26

Biofilms: 

Biofilms Definition “a structured community of bacterial cells enclosed in self-produced polymeric matrix and adherent to an inert or living surface 3 ingredents: microbes, a surface, and glycocalyx (called the slime layer or force field) Sessile (inner dormant) bacteria differ profoundly from the planktonic (floating) bacteria

Biofilm Structure Cartoon: 

Biofilm Structure Cartoon

Cholera Prevention: 

Cholera Prevention Epidemics are markers for poverty and lack of basic sanitation Need infrastructure for sanitation and safe water handling - addition of sodium hypochlorite solution Vaccine offers incomplete protection for a short duration: - no multivalent vaccine for O139 strain - O139 has changed its antigenic surface Natural reservoir in warm costal waters makes eradication highly unlikely - How did Bengal replace El Tor? Now they co-exist? Travelers should “Boil it, cook it, peel it, or forget it” - drink water that has been boiled or treated - eat only foods that have been cooked and are still hot - eat food that you peel yourself

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