Presentation on theme: "Office of Epidemiology and Disease Control"— Presentation transcript:
1 The Possible Effect of Climate Change on Selected Infectious Diseases in South Florida Office of Epidemiology and Disease ControlMiami-Dade County Health DepartmentJuan A. SuarezRegional Environmental EpidemiologistPresentation at the Medical Campus ofMiami Dade CollegeJanuary 28, 2008
2 ContributorsThis presentation was adapted from a November 2007 version prepared by:Fermin Leguen, MD, MPH, DirectorOffice of Epidemiology and Disease ControlJuan A. SuarezRegional Environmental EpidemiologistMenhel Kinno, MPH candidate, Intern OEDCSome additional data slides from the Bureau of Community Environmental Health-FDOH
3 IntroductionClimate change in the form of global warming and extreme weather are increasingly mentioned in the media and journal articles as issues to be dealt with in the next decades.Human health will be affected by changes in the environment of insects and microorganisms that in turn are vectors or agents for disease in man.
4 AssumptionsThe following discussion assumes rise in sea levels, global increase in temperature, and intrusion of the ocean water on fresh bodies of water and drinking water wells.The science behind these assumptions is based on observations but also on predictions.Causes of these effects remain controversial. Anthropogenic vs. natural variations.The physical results are based on the Intergovernmental Panel on Climate Change’s report.
7 Dengue Fever & Dengue Hemorrhagic Fever genus FlavivirusThere are four serotypes of the virus that cause the disease.Transmitted by Aedes aegypti (a domestic, day-biting mosquito, has a world wide distribution in tropical area)Clinical features:High Fever, headache,Backache, joint pain, eye pain,RashNausea and vomitingHemorrhagic manifestation (DHF) which is potentially lethal.No specific treatment is available.No vaccination is available.Mosquito control.Two competent mosquito vectors, Ae. aegypti and Aedes albopictus, are present and, under certain circumstances, each could transmit dengue viruses.The disease is now endemic in more than 100 countries in Africa, the Americas, the Eastern Mediterranean, South-east Asia and the Western Pacific. South-east Asia and the Western Pacific are most seriously affected. Before 1970 only nine countries had experienced DHF epidemics, a number that had increased more than four-fold by 1995.Source: CDC, 2007
8 Dengue Fever & Dengue Hemorrhagic Fever In 2005, 2.5 billion people at risk of Degue fever.The Aedes mosquito has a worldwide distribution in the tropical and sub-tropical areas.In 2005, dengue is the most important mosquito-borne viral disease affecting humans; its global distribution is comparable to that of malaria, and an estimated 2.5 billion people live in areas at risk for epidemic transmissionSource: CDC, 2005
9 Yellow Fever Genus Flavivirus It is also transmitted by Aedes mosquito.This virus is restricted to only 2 regions: Africa and South America.Clinical Features (incubation period of 3-6 days):Asymptomatic.Acute phase: Fever (sometimes Paradoxical fever with low pulse rate), aches, Nausea and vomiting,15% Toxic phase: jaundice, abdominal pain with vomiting. Bleeding can occur from the mouth, nose, eyes and/or stomach. ½ die within days.Three types of transmission cycle:Sylvatic (jungle): sporadic cases in forest.Intermediate yellow fever: in Africa only.Urban yellow fever: epidemics.No specific treatment is available.Prevention: Vaccination and mosquito controlThirty-three countries, with a combined population of 508 million, are at risk in Africa. These lie within a band from 15°N to 10°S of the equator. In the Americas, yellow fever is endemic in nine South American countries and in several Caribbean islands. Bolivia, Brazil, Colombia, Ecuador and Peru are considered at greatest risk.WHO, Fact Sheet, 2001
10 West Nile Fever: Genus Flavivirus Transmitted by female Culex pipiens mosquitoesClinical Features:Incubation period: 2-15 daysfever, headache, tiredness, and body aches, occasionally with a skin rash and swollen lymph glands1 in 150 ( Neuro-invasive disease, West Nile encephalitis or meningitis or West Nile poliomyelitis)Treatment: no specific treatment (antiviral “Ribravirin”)Prevention: mosquito control, vaccination only available for horses.CDC, 2007
11 2007 West Nile Virus Activity in the United States (Reported to CDC as of November 6, 2007) Source: CDC, 2007
12 Malaria Parasitic infection by Plasmodium Human malaria is caused by four species:Plasmodium vivax & ovaleP. malariaeP. falciparum41% of the global population lives in area at risk of malaria.Malaria is transmitted by female anopheles mosquito.Clinical Feature (incubation period of days):FeverRigorSweatingTreatment: anti-malarial medication and supportive therapyPrevention: prophylactic treatment and mosquito control.WHO, 2007; CDC, 2007
13 Lyme disease Bacterial infection by Borrelia burgdorferi. It usually lives in small animals (mice, squirrels,Transmitted by: Ixodes scapularis, Ixodes pacificus (blacklegged ticks)Clinical Feature (incubation period 3-30 days):fever, headache, fatigueErythema migrans (characteristic rash in 70-80%).In untreated patient it can cause a wide ray of symptoms (Nervous system, heart, and joint).Treatment: oral antibiotics, intravenous AB in severe casesPrevention: vaccine is no longer available, tick controlThis disease may be more of an issue in the Northeast/Central states, unclear if South Florida would be affected.
14 Reported Cases of Lyme Disease by Year, United States, 1991-2005 Source: CDC, 2005
15 Chagas disease It is a parasitic infection by Trypanosoma cruzi Transmitted by kissing bud (triatomine vector).Clinical Feature:Acute: occurs after infection and it is characterized by fever or swelling around the site of inoculationChronic Intermediate: asymptomatic stage.Chronic (30%): life-threatening chronic complications (dilated cardiomyopathy, dilated esophagus, toxic megacolon)Treatment:Prevention: insect control.Chagas disease is endemic throughout much of Mexico, Central America, and South America where an estimated 8 to 11 million people are infected.CDC, 2007
16 Why there will be an increase in Vector Transmitted disease? Warm temperature and surface water are essential for insect breeding (especially mosquito)Stagnant water with humid condition are both necessary for breeding.Warmer temperature leads to:Enhance vector breeding,Increase vector survival,Increase vector biting rate,Reaching higher altitude,and reduce the pathogen’s maturation period with the vector.Very hot temperature with dry condition can reduce the survival of insects.WHO, 2007
17 Water & Food borne diseases: GiardiasisCholera and other VibriosSalmonella
18 Giardiasis Parasitic infection by Giardia lamblia Transmitted mainly through contaminated water.Clinical Feature (incubation period 1-2 weeks):Asymptomatic.Diarrhea, Nausea and Vomiting, gas and flatulence, abdominal crampsChronic diarrhea and malabsorption and weight loss.Treatment: oral antibioticsPrevention: good hygiene, avoidance of contaminated water and food.CDC, 2007
19 Cholera Causative agent: Vibrio cholera It is mainly a water-borne diseaseClinical symptoms:Acute, watery (rice water like) diarrhea.VomitingLeg crampsRapid loss of body fluids and dehydration that might lead to death within hours without treatment.Treatment: antibiotics and IV fluidsPrevention: oral vaccine, avoid contaminated water and food.Rainfall and the IOI affect the aquatic environment in which Vibrio cholera develop, where the cholera bacillus lives in contact with elements of the zooplankton. These tiny aquatic crustaceans, known as copepods, comprise the main reservoir of the bacterium and feed upon microscopic algae called phytoplankton. Therefore, they collect in areas where the density of phytoplankton is highest. Understanding this relationship provides a way of monitoring areas rich in phytoplankton using remote sensing, allowing scientists to identify potential reservoirs for Vibrio cholera from space.WHO, 2007
20 Salmonella Bacterial infection by Salmonella Water & food borne diseaseClinical features:FeverDiarrhea, and abdominal crampsReiter's syndromeChronic carriersTreatment: oral antibioticsPrevention: avoidance of raw or undercooked eggs, poultry, or meat.WHO, 2007
21 Vibrio vulnificus Causative agent: marine bacterium Vibrio vulnificus Water-borne (wounds) and consumption of raw oysters and shellfishIncubation: hoursClinical picture:Septicemia in immunosuppressed, or chronic liver disease, or hemochromatosis, or cirrhosisCase fatality from 50-90%Cellulitis, myositis, shock, hypotension, bullous skin lesions, intravascular coagulation, thrombocytopeniaTreatment: antibioticsPrevention: avoid contact of wounds with seawater and avoid eating raw or undercooked oysters and shellfish
22 Vibrio vulnificus in Florida, 1990-2006 Exposure# CasesWound211Oysters156Unknown55Crab7Clams3Shrimp1Total433
23 Deaths from Vibrio vulnificus in Florida, 1990-2006 Exposure# Deaths% Total CasesOysters6615.2Wound245.5Unknown205.2Crab20.5Shrimp10.3ClamsTotal11426.4
24 Vibrio vulnificus Cases and Deaths from Various Exposures, Florida 1990-2006 Deaths % Total CasesWound211245.5%Oysters1566615.3%Unknown55204.6%Crab720.5%Clams310.2%ShrimpTotal43311426.4%
26 Plague Bacterial infection Yersinia pestis Transmitted by: Flea bite Contact with infected rodentInhalation or ingestion of infected material.It is still widely distributed in the tropics and subtropics and in warmer areas of temperate countries.Clinical Feature:Bubonic form (most common type in which the disease is transmitted by flea and it mainly affects the lymph nodes (bubo) which became painful and may suppurate)Septicaemic formPneumonic form (least common but most virulent)Treatment: antibiotics and supportive therapyPrevention: rodent control, flea control, vaccination only for high risk group.WHO, Fact Sheet, 2005
27 Rabies Viral infection by Animal bite (domestic and wild animals). Clinical Feature:Initially, non-specific symptomsAcute stage, signs of hyperactivity (furious rabies) or paralysis (dumb rabies) predominate.paralysis eventually progresses to complete paralysis followed by coma and death in all cases, usually due to respiratory failure.Without intensive care, death occurs during the first seven days of illness.Treatment: immediate cleaning of the wound, and post-exposure vaccinationPrevention: vaccination of domestic animals, vaccination of individuals at high risk, avoidance and control of wild animals.WHO, Fact Sheet, 2006
28 Control MeasuresControl measures for these diseases and their vectors are well known and established. However, new challenges will be encountered in the control of insects and microorganisms under the new environmental conditions and new methods must be researched and implemented.
29 SummaryThe true effects that climate change will have on infectious diseases will be hard to predict but we can, with the present knowledge, estimate which of these will be more of a problem.We must also not forget that today’s challenges with other issues in infectious diseases, not related to climate change, may also continue. Examples include antibiotic resistance, limited resources, and new emerging pathogens.
30 UN Millennium Development Goals Ensure environmental sustainability:Integrate the principles of sustainable development into country policies and programmes; reverse loss of environmental resourcesReduce by half the proportion of people without sustainable access to safe drinking waterAchieve significant improvement in lives of at least 100 million slum dwellers, by 2020
31 Dr. Julie Gerberding, CDC Oct 2007 Many of the activities needed to protect Americans from the health effects of climate change are mutually beneficial for overall public health….it is also important that potential health effects of environmental solutions be fully considered.
32 I am persuaded that global climate change is one of the most important issues that we will face this century. With almost 1,200 miles of coastline and the majority of our citizens living near that coastline, Florida is more vulnerable to rising ocean levels and violent weather patterns than any other state…Florida will provide not only the policy and technological advances, but the moral leadership, to allow us to overcome this monumental challenge."
33 ReferencesIPCC, 2007: Summary for Policymakers. In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning,Z. Chen, M. Marquis, K.B. Averyt, M.Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.
34 ReferencesControl of Communicable Diseases Manual, 18th Ed. David L. Heymann, MD, Editor, APHA, WHO.Centers for Disease Control and PreventionEnvironmental Protection AgencyWorld Health OrganizationUnited Nations. UN Millennium Development Goals.