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Natural Water Disasters

Natural Water Disasters. Microbiology and Disease Kelley E. Capocelli, MD October 28, 2005. THIS HAS BEEN A RECORD YEAR FOR WATER DISASTERS. HURRICANE KATRINA. HURRICANE RITA. AND IF THAT WASN’T ENOUGH…. HURRICANE WILMA COMES ALONG. Infectious Disease after Natural Water Disaster.

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Natural Water Disasters

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  1. Natural Water Disasters Microbiology and Disease Kelley E. Capocelli, MD October 28, 2005

  2. THIS HAS BEEN A RECORD YEAR FOR WATER DISASTERS

  3. HURRICANE KATRINA

  4. HURRICANE RITA

  5. AND IF THAT WASN’T ENOUGH…

  6. HURRICANE WILMA COMES ALONG

  7. Infectious Disease after Natural Water Disaster • Flooding is associated with an increased risk of infection, however this risk is low unless there is significant population displacement and/or water sources are compromised • The major risk factor for outbreaks associated with flooding is the contamination of drinking-water facilities

  8. Infectious Disease after Natural Water Disaster • Infectious disease outbreaks are rare following natural disasters, especially in developed countries • Specific etiologies are usually predictable, reflecting infectious diseases endemic to the affected region before the disaster • Injury and soft tissue infections are expected during the first few days after a disaster • In contrast, airborne, waterborne, and foodborne diarrheal illness that is easily spread in densely populated communities can be anticipated after a natural disaster

  9. Health Issues Waterborne illnesses Vectorborne illnesses Skin infections Airborne illnesses Mold/Mildew Human Remains Infectious Disease After Hurricane

  10. Waterborne Diseases • Common waterborne diseases in the United States include: • Amebiasis • Campylobacteriosis • Cryptosporidiosis • Giardiasis • Hepatitis A • Salmonellosis • Shigellosis • Viral gastroenteritis

  11. Amebiasis • Caused by Entamoeba histolytica • Disease is expressed most often as ulcerative and inflammatory lesions of the colon resulting in a complete spectrum of colonic signs and symptoms • Occasionally, amebas gain access to extraintestinal sites, most commonly the liver, where marked tissue destruction occurs • Risk factors that predispose to infection • Crowding • No indoor plumbing • Persons living communally

  12. Amebiasis • Amebiasis (cont.) • Factors attributing to increased severity of disease • Children (esp. neonates) • Pregnancy • Corticosteroid use • Malignancy • Malnutrition • Organism morphology • Trophozoites range in size from 10 to 60 µm • Have a single 3- to 5-µm nucleus containing fine peripheral chromatin and a central nucleolus • Often have ingested erythrocytes • Cysts average 12 µm in diameter and contain one to four nuclei with morphology identical to that of trophozoite nuclei

  13. Campylobacteriosis • Among the most common bacterial infections of humans in all parts of the world, campylobacters cause both diarrheal and systemic illnesses • Excreta from infected animals may contaminate soil or water • Untreated surface water has been responsible for both endemic and epidemic campylobacteriosis • Motile, non-spore forming, comma-shaped, gram-negative rods

  14. Cryptosporidiosis • A diarrheal disease caused by microscopic parasites of the genus Cryptosporidium • Cryptosporidium parvum and Cryptosporidium hominis are the most common disease causing species • Once an animal or person is infected, the parasite lives in the intestine and passes in the stool • Millions of crypto organisms can be released in a bowel movement from an infected human or animal • The parasite is protected by an outer shell that allows it to survive outside the body for long periods of time and makes it very resistant to chlorine-based disinfectants

  15. Cryptosporidiosis • Life cycle • Sporulated oocysts, containing 4 sporozoites, are excreted by the infected host through feces and possibly through other routes, such as respiratory secretions • Following ingestion by a suitable host, excystation occurs

  16. Cryptosporidiosis • Life cycle (cont.) • The sporozoites are released and parasitize epithelial cells of the GI or respiratory tract • Undergo both asexual and sexual multiplication • Two oocysts are produced • Thick-walled – commonly excreted from the host • Thin-walled – involved in autoinfection • Sites of infection • Small intestine, most commonly • Other digestive tract organs, the lungs, and the conjunctiva

  17. Giardiasis • Diarrheal illness caused by a one-celled, microscopic parasite, Giardia intestinalis • A protozoan flagellate (Diplomonadida) • Worldwide distribution • Infection occurs by the ingestion of cysts in contaminated water, food, or by fecal-oral route • The cysts are hardy and can survive several months in cold water

  18. Giardiasis • Life cycle • In the small intestine, encystation releases trophozoites (each cyst produces two trophozoites) • Trophozoites multiply by longitudinal binary fission, remaining in the lumen of the proximal small bowel where they can be free or attached to the mucosa by a ventral sucking disk • Encystation occurs as the parasites transit toward the colon • The cyst is the stage found most commonly in nondiarrheal feces

  19. Hepatitis A • Small, unenveloped symmetrical RNA virus • The cause of infectious or epidemic hepatitis transmitted by the fecal-oral route • Person to person the most common route • Quickly spread through close contact, particularly within families and institutions • Food and water borne outbreaks also occur frequently and although almost any food can be implicated the most common sources are: • Shellfish eaten raw or poorly cooked from sewage-polluted water. • Foods handled without sufficient hygiene and not cooked subsequently.

  20. Salmonellosis • Salmonella typhimurium and Salmonella enteritidis are the most common types in the United States • Usually associated with diarrheal disease, rarely associated with bacteremia, endocarditis, and wound infections • Gram negative, non-spore forming, facultatively aerobic bacilli 2 to 3 by 0.4 to 0.6 µm in size • Most often, acquisition of organisms occurs by ingestion of food or water contaminated with human excreta • Usually, waterborne transmission involves the ingestion of fewer microorganisms and, as a result, has a longer incubation period and lower attack rate than foodborne transmission

  21. Shigellosis • In the United States, over two thirds of shigellosis cases are caused by Shigella sonnei, and Shigella flexneri causes most of the remaining cases • Outbreaks of shigellosis in the U.S. are typically caused by S. sonnei and occur in crowded settings • Personal hygiene limited • Contaminated food and water • Fecal-oral transmission causing diarrhea (often bloody), fever, and stomach cramps • Gram negative rod, non-lactose fermenter

  22. Escherichia coli • Infection spreads to people through contact with human or animal feces • Contaminated water or food or through person-to-person contact • Usually associated with self-limited diarrhea • Eschericia coli bacteria, not O157:H7, were measured in flood waters after Hurricane Katrina • these “generic” E. coli are normally found in all streams, lakes, and canals • When there is flooding along with a hurricane, the waters may contain fecal material from overflowing sewage systems and agricultural and industrial waste

  23. Viral Gastroenteritis • Enterovirus • RNA virus • can be found respiratory secretions and stool • Norovirus (Caliciviridae) • A group of viruses that cause gastroenteritis • Nonenveloped RNA virus • Small round structured viruses • Waterborne outbreaks have been caused by sewage contamination of wells and recreational water • Also associated with food poisoning due to fecal-oral transmission • Rotavirus • More commonly in infants and young children • Fecal-oral transmission

  24. Documented Infection • Gastroenteritis • CDC received reports of clusters of diarrheal disease among persons in evacuation centers in Louisiana, Mississippi, Tennessee, and Texas • Have diagnosed norovirus, nontyphoidal Salmonella, nontoxigenic V. cholerae O1 • More than 1,000 people were treated for diarrhea, vomiting, or both symptoms between September 2 and September 12, 2005, according to the CDC • No confirmed cases of Shigella dysentery, typhoid fever, or infection by toxigenic V. cholerae O1 • Large dilution factor in the flood water—not enough pathogens to cause disease

  25. Documented Infection • Conditions that facilitate virus transmission • Crowding • Insufficient sanitation in lavatories • Lack of adequate number of hand-washing facilities • Delays in cleaning and decontaminating soiled areas and bedding

  26. Vibrio Infections • Vibrio parahaemolyticus • Primarily causes gastrointestinal illness (rarely wound infections) • About half of cases reported to CDC every year • The most common Vibrio species isolated from humans • Most people become infected by eating raw or undercooked shellfish, particularly oysters, or other food contaminated by raw shellfish • Vibrio vulnificus is a bacterium that is a rare cause of illness in the United States • Persons who develop wound infections do so following contamination of a pre-existing wound or through an injury acquired while exposed to warm coastal waters

  27. Vibrio Infections • Vibrio cholerae • Have a natural reservoir in sea and coastal waters • In an epidemic, the source of contamination is usually the feces of an infected person • The disease can spread rapidly in areas with inadequate treatment of sewage and drinking water • Associated with serogroup O1 (toxin-producing) and non-O1 (in the United States) • If there is a clinical suspicion of infection with Vibrio, use of a selective media thiosulfate-citrate-bile salts-sucrose (TCBS) is recommended

  28. Vibrio Infections • Vibrio cholerae (cont.) • Gastroenteritis • Non-O1 = mild to severe watery diarrhea • O1 = fever and bloody diarrhea • Sepsis • Non-O1 = in immunocompromised people and in people with liver disease • Wound infections • Non-O1 = rarely

  29. Vibrio Infections • During August 29-September 11, 2005, surveillance identified 22 new cases of Vibrio with five deaths • Caused by V. vulnificus, V. parahemolyticus, and nontoxigenic V. cholerae • Eighteen wound-associated Vibrio cases were reported • Mississippi = 7 • Louisiana = 5 • Texas = 2 (from Louisiana) • Arkansas = 2 (from Louisiana) • Arizona = 1 (from Louisiana) • Florida = 1 (from Mississippi)

  30. Vibrio Infections • Non-wound associated illnesses • Four persons were reported with non-wound associated Vibrio infections • Mississippi = 2 • Nontoxigenic V. cholerae gastroenteritis (non O1 subtype) • Two month old boy and an adult • Louisiana = 1 • Arizona (from Louisiana) = 1

  31. Vibrio Infections • Speciation • V. vulnificus = 14 • V. parahemolyticus = 4 • Deaths • V. vulnificus = 3 • V. parahemolyticus = 2 • An underlying condition that might have increased risk for severe Vibrio illness was reported in 13 of the patients with wounds • Heart disease = 7 • Diabetes mellitus = 4 • Renal disease = 3 • Alcoholism = 3 • Liver disease = 2 • Peptic ulcer disease = 1 • Immunodeficiency = 1 • Malignancy = 1

  32. Leptospirosis • Leptospirosis—a zoonotic bacterial disease • Caused by the bacteria Leptospira • a flexible, spiral-shaped, Gram-negative spirochete with internal flagella • Leptospirosis is a worldwide zoonosis affecting many wild and domestic animals • Humans acquire the infection by contact with the urine of infected animals • Human-to-human transmission is extremely rare • Between 1965 and 1993, the incidence rate of leptospirosis in Louisiana ranged from 1 to 14 per 100,000 people per year • Outbreaks of leptospirosis have occurred following flood events

  33. Leptospirosis • Clinical presentation • Wide variety of clinical manifestations, ranging from a mild flu-like illness to a serious and sometimes fatal disease • May occur in two phases • Phase 1 – fever, chills, severe headache, muscle aches, vomiting, or diarrhea • Also jaundice, abdominal pain, or a rash • Patient may recover for a time but become ill again • Phase 2 – Weil’s syndrome • Jaundice, renal failure, hemorrhage, and myocarditis with arrhythmias

  34. Leptospirosis • Clinical criteria for leptospirosis: 1. Fever > 38.0°C (100.4°F) 2. AND at least TWO from COLUMN A or ONE from COLUMN B COLUMN A COLUMN B Headache Aseptic meningitis Myalgias Acute renal failure Jaundice Hemorrhagic pneumonitis Chills/Rigors Cardiac arrhythmias, EKG abnormalities Skin rash Liver failure Conjunctival suffusion without Jaundice with acute renal failure purulent discharge

  35. Vector-borne Illnesses • Floods may indirectly lead to an increase in vector-borne diseases through the expansion in the number and range of vector habitats • Standing water caused by heavy rainfall or overflow of rivers/oceans can act as breeding sites for mosquitoes • Enhance the potential for exposure of the disaster-affected population and emergency workers to infections such as dengue, malaria, and West Nile fever • Flooding may initially flush out mosquito breeding but it comes back when the waters recede—lag time is usually around 6-8 weeks before the onset of a malaria epidemic

  36. West Nile Virus • A single-stranded RNA virus of the family Flaviviridae, genus Flavivirus • Flaviviruses share a common size (40-60 nm), symmetry (enveloped, icosahedral nucleocapsid), nucleic acid (positive-sense, single stranded RNA approximately 10,000-11,000 bases), and appearance in the electron microscope. • WNV is a member of the Japanese encephalitis virus antigenic complex • includes Japanese encephalitis, St. Louis encephalitis, Murray Valley encephalitis, and Kunjin, an Australian subtype of WNV.

  37. West Nile Virus • West Nile Virus (cont.) • Hurricanes brought no increase in West Nile cases • The storm blew away most of the established mosquito population • Predicted that survivors will soon repopulate the area and old eggs now submerged in water will hatch and pupate quickly • The increase in the insect population will bring back many bird species probably including those carrying West Nile and St. Louis encephalitis.

  38. West Nile Virus • Documented West Nile Infection • Thirty cases reported in Louisiana in the second week of October 2005 • Approximately the same number of cases as in 2004 • Louisiana 2005 = 129 West Nile cases, 6 deaths • Louisiana 2004 = 114 West Nile cases, 7 deaths • Mississippi 2005 = 60 West Nile cases, 4 deaths • Post-hurricane cases mostly occurred in the Baton Rouge area and the north shore area of Lake Pontchartrain, where the virus was heavily present before the hurricanes

  39. Skin Infections • Methicillin Resistant Staphylococcus aureus • September 26, 2005 (MMWR Dispatch) • 30 pediatric and adult patients at an evacuee facility in Dallas, Texas • Majority were skin infections, including pimples and boils • Three cases confirmed with culture • Tinea corporis • Military personnel from two locations working in the wet environment of early evacuation efforts • Folliculitis • Erythematous, papular, and pustular lesions among military personnel in Mississippi

  40. Airborne Illnesses • Upper respiratory infections and pneumonias • Pertussis in a 2-month old infant who was rescued from a rooftop in New Orleans and evacuated to Tennessee • Tuberculosis • A homeless person without a diagnosis of TB who was evacuated from New Orleans to Philadelphia • Eight other patients initially identified as having TB were subsequently determined to have other conditions • Lung cancer • Nontuberculous mycobacteria (including one with MAC from Denver Health)

  41. Airborne Illnesses • Known TB patients • A total of 195 persons known by the public health authorities in Alabama, Mississippi, and Louisiana to be undergoing treatment for TB • Sought out by TB program staff to assure that therapy continued • 42 TB patients from Louisiana not yet located • 41 assumed to be noncontagious at the time the hurricane made landfall • Decision based on disease site, treatment duration, or smear status

  42. Legionnaires’ Disease • Caused by Legionella bacteria • Thrive in stagnant, warm water • Favor a temperature of 25-42 C (77-108 F) for growth • Outbreaks of this disease have been associated with cooling towers, evaporative condensers, showers, faucets, hot tubs/whirlpool spas, and other sources of aerosolized water • Because many buildings and cooling towers were shut down during hurricanes Katrina and Rita, the water in those systems has been sitting stagnant for days to weeks, providing an increased risk of Legionnaires’ disease once the systems are restarted

  43. Legionnaires’ Disease • Legionnaires’ disease is contracted when people breathe in mist or vapor that has been contaminated with the bacteria • The bacteria are NOT spread from person to person • Causes death in up to 30% of cases

  44. Mold/Mildew • Health Effects of Mold • Infection • Particularly in people with suppressed immune systems • Allergy • Fever • Skin rash • Exacerbation of respiratory illnesses • Toxin-mediated disease

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