Esnt final exam review

what are the different types of mosquitoes

• house mosquitos = globally distributed, breed in stagnant water, carry west Nile and serval encephalitis vrisues ( those that cause the swelling of the brain)

• Aedes aegypti = common In the tropics, carry yellow fever and dengue fever viruses

• Asian Tiger mosquitoes = carry encephalitis, dengue fever, yellow fever, and west niles viruses

• Anopheles = mosquitoes that carry malaria, which is caused by a plasmodium protozoan parasite

describe the mosquito life cycle

• eggs mature to an adult in little as 5 days

• adult female lay eggs in still water

• free swimming larva feed on mirogranism & breathe through tubes at surface

• pupa do not feed, breaths through tubes

• metamorphoses into adult form

• only female requires blood meals

describe the disease that house mosquitos and Asian Tiger mosquitoes transmit

• west nile disease:

• spread by clux & aedes species

• first indeified In uganda in 1937

• first indeified case in the U.S was in 1999

• the disease infects birds which act like amplified host

• mosquitoes feed off the birds in which they transmit the disease from birds to dogs, cats, horses, cattle and humans

• since 2020 there has been an increase in deaths and cases

what are the types of mosquito control methods:

→ source reduction: remove standing waters such as pools and gutters 

→Biocontrol:  introduce/ encourage  natural predator  species to kill and eat the mosquitos  + insecticidal plants ( natural pesticide that kills mosquitoes) + soil bacteria interferes with larval digestion 

→ chemical control : insecticides + DEET repellent 

→ avoidance behavior ( when present) : avoid tree, bushes, and high grass + wear long- sleeved shirts and long plants

ticks

• hard ticks: dog ticks, wood tick, deer tick, lone star tick

• soft ticks: fowl tick and relapsing fever tick ( several species carry bacteria causing relapsing fever)

• all ticks live hematophagy ( blood feeding) on mammals, birds and sometimes reptiles and amphibians

• inject saliva as anesthetic, anticoagulant and adhesive

lyme disease

• first identified in lyme connecticut 1975 when an unusual high rate of childhood rheumatoid arthritis was identified

• Spirochete bacteria is the cause of the condition 

• Most common in the north east but present in all 50 states    

life cycle of lym disease

1. Female adult ticks lay eggs 

2. Larva form with 6 legs from eggs 

3. Larvae feed on small animals such as field mice in the summer. This is when the tick becomes infected with the bacteria causing disease 

4. Larvae become dormant in the fall and winter 

5. Larvae become 8 legged nymphs on spring of year 2 

6. Nymph feed on animals or humans who brush up on grass and shrubs, transferring the infection and producing lyme disease 

7. Nymph become adult ticks 

8. Adult ticks feed on deer and after the blood meal the ticks mate 

factors that contrbute to the transmission of lyme disease

• ( increases rates of transmission) Forest fragmentation: as a result of suburban sprawl. The action favors white footed mice 

• ( lowers the rates of transmission) Dilution effect:  high species diversity in the community of tick host reduce rates of infection of ticks by diluting the effects of the white footed mouse. 

disease progression of lyme disease

• Early detection: disease is localized at site of the tick bite with expanding red bull’s eye 

• Left untreated: bacteria can spread to the heart and nervous system causing palsies and meningitis 

• Left unchecked for a long time: causes cause motor and sensory damage, could lead to paralysis and joint and swelling pain ( arthritis)

• Antibiotics are available to treat it 

• Vaccine was pulled from shelves in 2002 

Rocky Mountain spotted fever 

• Caused by ticks 

• Bacterial infection 

• Idenfited in 1930s 

• Dog and rocky mountain wood tick are vectors of the bacteria 

• Zoonotic disease : spread by dogs and other large animals 

• Where endemic, only 1-3% of ticks carry the bacteria  ( hypoendemic) 

• symptoms : fever, headache, muscle pain and rash 

• Can be treated with an antibiotic 

what can loan star ticks cause

• an allergic reaction to meat

• habitat of the loan star disease is expanding

locust grasshopper

• type of grasshopper that typically live a solitary life, but when environmental condition turn to wet conditions and favor population growth, they start interacting with each more and change their behavior into swarming around each other

• swarming decimate crops

pest control methods

• Sanitation ( keeping things clean)

• Hygiene ( keeping ourselves clean)

• Exclusion ( keeping ourselves in an enclosed areas)

• Avoidance ( avoiding ares where pest frequent)

• Mechanical Control ( Having mechanical types of control tools: fly traps)

• Biological control ( natural pest control)

• Chemical Control ( using

Biological pest control methods

• bioengineers crops:

—> bioenginer crops that include BT which is a bacteria that repels pest

—> Round-Up ready include glyphosate which typically kills weeds, however plants are modified to be tolerant to the glyphosate and only kill the pest

chemical pest control

• organochlorines

• organophosphates

• phenoxy herbicides

• carbamates

• pyrethroids

• neonicotinoids

organochlorines

• contact poisons that target the central nervous system

• toxic to broad array of insects and animals ( kills more than what you want to)

• intensely lipophilic/hydrophobic - bioaccumulates and biomagnifies

• slow acting and long lasting

organophosphates

• very toxic

• hydrophilic ( water loving)

• readily degraded by chemical/ microbial process so not environmentally persistent

• cause of the most accidental deaths of all pesticides

• chronic exposure linked to memory loss, disorientation, depression and adhd

phenoxy herbicides

• moa: plant hormone that stimulates uncontrolled growth which eventually kills the plant

• has low toxicity to mammals and birds and humans

• not a carcinogen but is suspected as an endocrine disruptor

• used on food crop, lawns, gardens etc

Carbamates

• different mixes are acutely toxic to mammals, birds, and fish

• brand name= sevin

• classified as a likely carcinogen

• kills beneficial insects and crustacean species

pyrethroids

• similar insecticides similar to naturally occurring pyrethrin in chryasnthemums

• photolyzed by sunlight so last in the environment

• toxic to fish if applied to water and harmful to many beneficial insects

neonicotinoids

• nicotine based, reduced toxicity to brids and mammals, but increased toxicity to insects

• liked to honey bee decline

reasons as to why the effiecny of chemical pest controls are being reversed?

1) insects developed resistance to intestsicdes

2) insect control programs have been halted or underfunded

3) inexpensive pesticides has been reduced due to environmental concerns

4) urbanization with poverty and overpopulation lead to poor sanation allowing for greater opportunity for insect proliferation

5) habitat destruction eliminated natural predators ( allowing insects to proliferate)

6) climate change including warming trends, has promoted expansion in many insect population

prolems with pesticide

• harmful effects on non-target species : insects, crustacera, fish, birds, humans

• health effects from long term or repeated manufactures application exposure ex: farm workers, chemical employees, proff pest control workers

• enviromental persistence/ accumulation/ magnification

Emerging disease:

• an infectious disease whose incidence In humans has increased over the past two decades or will increase In the future

- can be novel ( previously unknown to humans)

-can be changing in severity or adapted to historical control measures

factors that lead emerging disease

• adaptaion of an existing animals disease agents to new human host ( crossing xenographic barrier - transfer one species to another)

• mobility of human populations transport disease beyond historic rangesn

• transport of raw materials/ goods introduce animal vectors such as mosquitos/ ticks

• climate change expands habitable ranges/ lengthens the season of

what does it mean “ victims of our own success” ?

• through advancement of technology and the work of public health programs we have improved the eradication and reduction of many diseases and food aid

• this work has lead to a population crisis which has led more overcrowding, inadequate sanitation

• leading to the expansion of some diseases, made more people vulnerable to diseases more than before, and increased food insecurity

factors that contribute to the emergency of infectious disease

• ecological changes

• human demograhic changes

• travle

• technology and industry ( globalization)

• microbal adabption/change

• break down of public health measuress

how does ecological changes contribute to the emergence of infectious disease

• increased agricultural and subran development which is required to accommodate population growth

• modifications to the enviroment increase human to animals interaction which causes us to be closer to host animals- more at risk

• decline in natural predators

climates:

• extreme weather patterns result in disease outbreak such as El nino - wet and dry years —> increase in hanta virus

• increased incidence of server hurricans can contaminate waters and disrupt public services

what to dieases does climate change increase the incidence of ?

malaria and dengue

dengue fever

• primarly an urban tropical disease with serve flou like symptoms that cause high fever, frontal headache and nausea —> called break bone fever

• four different type of infections that do not provide cross immunity

• no vaccine

• incidence rates haveincreased due to population growth, Urbanization, and global warming

denguge hemorrhagic fever

• multiple infections lead to the fever

• after the fever ease some symptoms experience leaky capillary syndrome - blood vessels leak into tissues

• if left untreated patients go into shock and die

how does human demographic changes increase the emergence of infectious disease

• increase of population over exceeds clean water supplies, proper sanitary conditions, and adequate housing—→ increase opportunity for the emergence of highly contagious disease associated with poor environmental conditions

what is the public health pardoxx?

the people most susceptible to disease have the worst facilities

what is the single largest factor allowing for the

• travel and transportation

• increased travel has contributing to the notion of disease without boundaries as a disease Is in no longer geographically bound to a place

• we can have disease many days before we show symptoms

• number of flights increased globally throughout time

what is a disease that has been exacerbated by travel?

• SARS ( serve acute respiratory syndrome)

SARS

• caused by the class of Corona viruses

• mers is the middle east version of SARS

• near pandemic during 2002- 2003

• mortality rates were higher for older people

• case fatality rate was 9.6%

how was the Crona vrisus confirmed to the be the cause of SARS

• scientist in the netherlands demonstrated coronavirus fulfilled koch’s postulates confirming it was a causative agent

• macaques were infected with the virus and developed the same symptoms as humans

how can SARS be treated

• working on treating the fever like symptoms as antibiotics do not work since the disease is is not a bacterial one but rather a respiratory diseases

How has globalization contribute to the increase of emerging diseases

• diseases are moving rapidly around the world because technology and economic interdependence has increased

~ international travel

~ international nature of food processing and handling

~ movement of raw and processed materials

How has microbial adaption and change contribute to the increase emerging diseases?

• we are breading resistant microorganism and bacteria with the usage of antibiotics as not all microorganism are getting eliminated and those are the one that are resistant

• when resistant bacteria are being breed, typically antibiotics do now work anymore which can lead to the rapid spread of disease

how are anitbotics used 80% of the time in the U.S?

• preventive treatment and growth promotion of live stock

• antibiotic residue end up in the meat/milk in which we consume and animal manure which enters water ways that cause sensitive bacteria In the environment to die and allow for the resistant bacteria to stay continuing the process of developing resistant bacteria

What is MRSA

MRSA= Methicilian- Resistant Staphylococcus arurenus

• strain of bacteria that is resistant to antibiotic treatment ( many of them such as penicillin)

• there are two types: Health Care associated MRSA ( HA-MRSA) and Community Associated MRSA ( CA-MRSA)

What is HA-MRSA

• people pick up MRSA in a healthcare setting

• More resistant than CA-MRSA

• people with open wounds, invasive medical devices and weakened immune systems are at greater risk as it it easier for the bacteria to enter their body

What Is CA-MRSA

• people pick up MRSA in a setting where there is a lot of people in close proximity