Enviro. Health (H) Ch. 5B Review
La Crosse Encephalitis
*•La Crosse virus (LACV) is a California (CAL) serogroup virus, in the genus Bunyavirus, family Bunyaviridae.* -Members of the family Bunyaviridae have three segments of single-stranded RNA; the virus particles are spherical or oval, enveloped, and are 90-100 nm in diameter •Almost all recognized CAL serogroup virus disease cases are caused by LACV -Other CAL serogroup viruses rarely cause recognized human illness
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SLIDE 15 Florida has mosquitoes that transmit
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SLIDE 28 6 cases locally acquired 2014
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This is a deer mouse, Peromyscus maniculatus, a hantavirus carrier that becomes a threat when it enters human habitation in rural and suburban areas •The main host for the hantavirus is the deer mouse--Peromyscus manicualtus, which is found throughout north America Found everywhere America Southwest No cure High fatalist rate
Ebola virus hemorrhagic fever
https://www.livescience.com/48218-ebola-hemorrhagic-fever.html (picture-slide 29) •Highly fatal, acute, dramatic disease •Sudden fever, headache diarrhea, vomiting, external and internal bleeding •1st recognized in 1976 in the Sudan and Zaire •1995 outbreak in Kikwit, Zaire -315 cases and 244 deaths •Outbreak among monkeys in quarantine facility in the United States acute- comes on quick=kills you Depends on what strain Ebola is sexually transmitted mostly male to female Fatality rate in Africa is higher Starts as a low grade fever 99/100 Not known to be airborne but was in DC-burnt down lab
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picture *1964-2010* Neuroinvasice disease includes cases reported as encephalitis, meningoencephalitis, or meningitis> Most reported cases of California serogroup virus neuroinvasive are due to La Crosse encephaliti svirus. Cases are reported by state of residence.
Dengue Fever
•3 types: -Dengue Fever (DF) -Dengue Hemorrhagic Fever (DHF) -Dengue Shock Syndrome (DSS) •Range from mild to severe -DF- high fever, severe headache, eye pain, muscle pain, joint pain, rash, mild bleeding -DHF- life threatening, fever (lasts 207 days) abdominal pain, bleeding -DSS- symptoms of DHF plus shock (hypotension, rapid, weak pulse) --When not treated fatality rate as high as 40-50% DF= bone breaking disease, don't usually die, everything hurts DHF= bleeding, ebola like symptoms, can die DSS= most deadly, hypotension=low blood pressure, all others + shock, no treatment- life support/induce coma, rapid
Other zoonotic diseases
•Anthrax -Causative agent is spore forming bacteria Bacillus anthracis -Most common among sheep, cattle, goats -Most at risk are veterinarians, agricultural workers -3 forms: --Cutaneous- itching, skin lesions, 5-20% fatality rate --Inhalation- respiratory distress, fever, shock, high fatality rate >75% --Gastrointestinal- nausea, anorexia, abdominal pain, high fatality rate of 25-60% •Treatment- antibiotics •Bioterrorism Agent Only kills people exposed to it Contact with spores Droughts= airborne Naturally in florida soil Not an infectious disease Case in FL after 9/11 White powder Cutaneous- touch Gastrointestinal- swallow, digestive track Inhalation!
Arboviral Encephalitides
•Caused by a virus that produces an acute inflammation of: -Sections of the brain -Spinal cord -Meninges •Severe illness: headache, high fever, disorientation, coma, paralysis, death •Among the etiologic agents are viruses associated with many forms of encephalitis, including: -St. Louis encephalitis -Western equine encephalitis -Venezuelan equine encephalitis -Eastern equine encephalitis -Lacrosse Virus -Japanese encephalitis Encephalitis- brain in your head Headache and fever= first symptoms Disorientation, coma, paralysis, death= if not treated right away including...=common Chickens St louis and western equine= treated for all the time.
West Nile Virus
•Classified as mosquito-borne arboviral fever, the etiologic agent is a Flavivirus* •Mosquitoes are the carriers that become infects when they feed on infected birds-can spread rapidly across wide geographical regions •Health effects vary from no symptoms to very severe symptomatology (Elderly more likely to develop severe symptoms) Virus Really common in South florida 90-90% no symptoms shown New York= 1st place in US (dead birds) Africa= 1st place Think its a cold Trouble breathing Colorado Stagnant water FL= sentinel chickens Mosquito control
La Crosse Encephalitis
•Discovered in 1963, after the virus was isolated from stored brain and spinal tissue of a child who died of an unkown infection in La Crosse, Wisconsin in 1960* *•Transmitted to humans by the bite of an infected mosquito -Aedes triseriatus -Aedes albopictus (in SE US)* •Incubation period is 5-15 days *•Most cases of LACV disease occur in the upper Midwestern and mid-Atlantic and southeastern states* •Many people infected with LACV have no apparent symptoms -Among people who become ill, initial symptoms include fever, headache, nausea, vomiting, and tiredness -Some of those who become ill develop severe neuroinvasive disease (disease that affects the nervous system) --Severe LACV disease often involves encephalitis (an inflammation of the brain) and can include seizures, coma, and paralysis --Severe disease occurs most often in children under the age of 16 -In rare cases, long-term disability or death can result form La Crosse encephalitis
Arthropod-borne viral diseases (arboviral diseases)
•Four Main Clinical Symptoms of Arboviral Disease 1. Acute CNS [central nervous system] illness 2. Acute self-limited fevers, with and without exanthum [rash] 3. Hemorrhagic fevers, may be accompanied by liver damage, jaundice 4. Polyarthritis (5 or more joints simultaneously) and rash, with or without fever and of variable duration Common symptoms of flu Hands, knees, get joint & muscle pain Arboviral disease by mosquito- Dengue
Zika Virus
•History *•First discovered in 1947 and named after the Zika Forest in Uganda* *•1952- first human cases detected and since then there have been outbreaks in tropical Africa, Southeast Asia, and the Pacific Islands*
La Crosse Encephalitis
•In the United States, approximately *80-100 La Crosse* encephalitis virus (LACV) neuroinvasive disease cases are reported each year •There is *significant under-diagnosis* and under-reporting of less severe cases of LACV disease, therefore reported LACV neroinvasive disease cases are used to compare trends over time and place •There is no specific treatment for LACV infection--care is based on symptoms of severe LACV disease or any symptoms causing you concern, consult a healthcare provider for proper diagnosis *-Fewer that 1% of cases are fatal*
Other zoonotic disease
•Monkeypox -Rare viral disease that occurs mostly in central and western Africa *-1st found in 1958 in laboratory monkeys* -Same group of viruses that causes smallpox and cowpox -Symptoms : similar to smallpox, but milder and swollen lymphnodes -Multistate outbreak 2003- Illinois, Indiana, Wisconsin --Shipment of Gambian giant rats from Ghana which in turn infected prairie dogs, rabbits --Over 50 people ill, no deaths Eradicated in world In Africa infected dogs, infected human
Chikungunya virus
•Most people infected with chikungunya virus will develop some symptoms •Symptoms usually begin 3-7 days after being bitten by an infected mosquito The most common symptoms are fever and joint pain •Other symptoms may include headache, muscle pain, joint swelling, or rash •Chikungunya disease does not often result in death, but the symptoms can be severe and disabling •Most patients feel between within a week. In some people, the joint pain may persist for months •People at risk for more severe disease include newborns infected around the time of birth, older adults (≥65 years), and people with medical conditions such as high blood pressure, diabetes, or heart disease -One a person has been infected, he or she is likely to be protected form future infections Non descript disease
Other zoonotic diseases
•Rabies (Hydrophobia) -Acute and highly fatal disease of the CNS- -Caused by virus transmitted though saliva form bites of infected animals -Symptoms: fever, headache, malaise, hallucinations, paralysis, difficulty swallowing, fear of water, encephalopathy, respiratory paralysis, death •Hosts: mostly wild animals (including carnivores and bats); prior to 1960 mostly domesticated dogs, cats, cattle •Vaccines for animals; PEPs (post exposure prophylaxis) •1-2 fatal cases in US each year Virus Malaise= tired foaming at the mouth bats Dehydrated byt scared to drink Hydrophobia in humans Deterioration of brain (encephalopathy?) Not treated within 12 hrs very possible death
Emerging Zoonoses
•Refers to zoonotic diseases that are caused by either apparently new agents or by known agents that occur in locales or species that previously did not appear to be affected by these known agents •Factors Associated with the Rise of Emerging Zoonoses -Ecological changes that result from agricultural practices (e.g., deforestation, conversion of grasslands, and irrigation) -Other factors include changes in the human population and human behavior (e.g., wars, migration, and urbanization) Global climate change- new diseases being discovered. Ceg- melting ice ?? Deforestation-potential diseases to be exposed Urbanization- more people, disease easier to spread
Hantavirus Pulmmontary Syndrome (HPS)
•Represents a highly fatal condition that is transmitted by rodent vectors •The causative agent is the hantavirus, part of the viral family known as Bunyaviridae •May be transmitted when aerosolized (airborne) urine and droppings from infected rodents are inhaled •Primary vectors are four species of rodents: cotton rat, rice rat, white-footed mouse, and deer mouse Pulmonary= lungs Not treatable Agent= virus
Zika Virus
•Symptoms -Fever, rash, joint pain, conjunctivitis *(pink eye)*, muscle pain, headache -Can last for several days to a week -Rarely sick enough to go to the hospital Viral so drops won't fix it
Zika Virus
•Transmission -Mosquitoborne- Day biting mosquitoes: Aedes aegypti and Aedes albopictus *-Can be passed form a pregnant woman to her fetus resulting in severe brith defects in some cases* -Sexually transmitted -Blood transfusion? •Currently no vaccine or medicine available •In the US, it is travel acquired and some locally acquired cases Makes their heads small-brain does't grow Predominant in Miami, FL Men can transmit for longer, not as long for women Day biting mosquitoes Most dangerous Casually carry your diseases
Arboviral Encephalitides (continued)
•Transmitted by the bite of an arthropod vector (primarily mosquitoes) •The reservoir hosts for some forms of encephalitis viruses consists of nonhuman vertebrate hosts (e.g., wild birds and small animals). •Cost of arboviral encephalitides is approximately $150 million per year, including vector control and surveillance activities •US cases: 150 to 3,000 cases per year Spraying pesticides Vertebrate Check chicken blood cases= depending on climate change and time in year mosquitoes like water Cold/dry= not a lot of cases
Chikungunya virus
•Transmitted to people though mosquito bites •Mosquitoes become infected when they feed on a person already infected with the virus •Infected mosquitoes can then spread the virus to other people through bites •Aedes aegypti and Aedes albopictus mosquitoes -These are the same mosquitoes that transmit dengue virus -They bite mostly during the daytime
Other zoonotic diseases
•Tularemia -Also known as rabbit fever -Bacterial disease -Occurs in all US states except Hawaii -Found in rural areas and linked to wild animals such as rodents, rabbits, hares -Transmitted by arthropod vector, contact with infected animal carcasses, ingesting contaminated water/food, inhalation of bacterium -Symptoms: skin ulcers, swollen lymph nodes, painful eyes, sore throat, fever, muscle aches, dry cough, pneumonia, progressive weakness, liver necrosis -Treatment: antibiotics --Sever and fatal if not treated --Possible use as a Bioterrorism Agent Necrosis- death (liver tissue death) Weapoinzation
Control and prevention of mosquito-borne diseases
•Use sentinel chickens to monitor for presence of viruses •Drain standing water •Introduce mosquito-eating fish into ponds •Wear repellents and protective clothing •Repair window screens •Follow the 4 Ds -Deet -Dress -Drain -Dawn/Dusk Deet- pesticide (kills mosquitoes) Standing water- pots, bird bath,
Viral Hemorrhagic fevers
•Used to describe a severe multisystem shutdown -Overall vascular system is damaged -Body's ability to regulate itself is impaired -Hemorrhaging- not usually life-threatening -Severe, life-threatening disease -Most are caused by zoonotic viruses -Principal reservoirs are rodents and arthropods -Causative viruses are found throughout the world -In most instances, no known cure for VHFs --Examples: Ebola, Marburg, Hantavirus, Dengue Virus Hantavirus= in US. Most dangerous. *Dengue= 3 forms, Hemorrhagic= most deadly*
Dengue Fever
•Vector transmission from a day-biting mosquito -Aedes aegypti •Presently, one of the most significant mosquito ....(it got cut off)... diseases that afflict humans -Caused by *flavivirus* •50-100 million cases each year -Primarily in tropical and subtropical areas of the world, for example, Southeast Asia, tropical Africa, and South America •In US most cases are imported by travelers -•However, several locally acquired in southern Florida this year (and last couple years) •Global emergence due to lack of effective mosquito control, rapid population growth, urbanization, poor or nonexistent systems for the treatment of water and human wastes, international travel. Day biter We stopped using DDT, which kills them. ugh!
Arthropod-borne viral diseases (arboviral diseases)
•Viral diseases that can be acquired when blood-feeding arthropod (insects) vectors infect a human host •Typically, the complex cycle involves a non0human vertebrate (reservoir host) and an arthropod vector -Ticks, sand flied, biting midges, mosquitoes --Mosquitoes are the most common vector •More than 100 viruses are known at present as arbovirus that produce disease in humans
