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Med Microbio Exam 3 part 3 (vector borne)

Terms in this set (112)

What are two main examples of viral hemorrhagic fevers and what do they cause?
Yellow fever, dengue hemorrhagic fever. Weakening in blood vessels causing leakage
VHF are enveloped RNA viruses and are dependent on ______ as the natural reservoir and thus geographically restricted to areas where the host species lives
Vertebrate or insect host
What insect plays a major role in transmission of arboviruses?
Mosquitoes
What must be done when handling patients with VHF?
Barrier nursing techniques
What are the three major manifestations of VHF depending on arbovirus target?
CNS, major organs (esp liver), small blood vessels
VHF produce _____ resulting in inflammation leading to fever which involves small blood vessels and causes widespread tissue damage/necrosis
cellular necrosis
What is the tx for VHF?
No cure or tx, supportive therapy only option
_______ is caused by an enveloped icosohedral RNA flavivirus transmitted by mosquitoes, natural reservoir is monkeys and occurs in Africa, south and central america, and the carribean
Yellow fever
What are the acute symptoms of yellow fever?
headache, fever, chills, muscle aches, hepatitis, virus invades liver cells, kidney, spleen, LN, heart
What are symptoms of the secondary severe syndrome in yellow fever? (10-20% cases)
Nausea, uncontrollable hiccups, violent black vomit (due to inflammation of liver and blockage), jaundice, physical exhaustion, severe liver renal and brain damage. 60% mortality due to hemorrhage into GI
What is the tx for yellow fever?
No tx, can recover from acute stage, live attenuated vax avail that sometimes causes adverse reaction but recommended if traveling to high risk areas. 10 yr booster needed
What VHF is caused by an RNA flavivirus with 4 antigenic types, transmitted by mosquitoes, occurs in tropical and subtropical areas?
Dengue
After the 7 day incubation period what symptoms does dengue cause?
High fever, severe headache and back pain, SHARP JOINT AND MUSCLE PAINS, total body weakness (prostration). Recovery after one week
What happens if a patient is infected with a second viral type of dengue before recovery?
Dengue hemorrhagic fever
what happens in dengue hemorrhagic fever?
Massive internal bleeding, blood vomiting, black tar like stool, hemorrhaghic rash and bruising, death, antibodies from first infection fail to neutralize second infection and causes enhancement
How do you get lifetime immunity from dengue?
If you recover from the 2nd infection. No vac avail
What virus is caused by a ssRNA flaviviridae virus transmitted by the aedes mosquito but also sexually, blood borne, and congenitally?
Zika
What is the likely reservoir for zika?
Rhesus monkey in uganda
What happens after the 3-12 incubation of zika? (if patient isnt part of the 75-80% asymptomatic)
mild self limiting symptoms of sl fever, maculopapular rash, nonpurulent conjunctivitis, guillian barre possible
What happens in 13% of cases when congential zika develops?
Microcephaly, eye damage, congenital contractures, hypertonia
What vector borne bacteria can get into the lining of a blood vessel and replicate, and if not caught soon can spread rapidly and be terminal?
Rickettisa
The reservoir for epidemic typhus is ____ and endemic typhus is ______
Humans, rodents
____ is caused by Rickettsia rickettsi an extremely small intracellular bacteria transmitted to humans from a dog tick bite
Rocky mountain spotted fever
What is an issue with RMSF?
It is difficult to diagnose and hard to distinguish from typhus
What happens in the initial stage of rocky mountain spotted fever after the 7 day incubation? Along with headache, nausea, muscle aches, fever
Macular (small pink flat) rash
What happens in the late stage of rocky mountain spotted fever?
Papular (pimple like) rash or maculopapular
What can happen in 10% of RMSF cases?
CNS, splenomegaly, shock due to DIC, death
What is the tx for RMSF?
Antibiotics- successful if started at first suspicion
Rickettsia prowazekii causes ______
Typhus fever
The epidemic form of typhus fever is caused by ____ and the endemic form is caused by ______
head and body lice, fleas
What are symptoms of typhus fever after 7 day incubation?
Headache, high fever, maculopapular rash, mengioencephilitis, delerium, coma, death
Which has a higher mortality? RMSF or typhus?
Typhus - 60%
What is the treatment for typhus fever?
Abx. Rarely can be LN latent and reactivation can occur years later causing brill-zinsser disease
What gram - spirochete causes relapsing fever and what is it transmitted by?
Borrelia recurrentis, soft ticks, rodents reservoir, epidemic form caused by lice
What is the disease process of relapsing fever after 7 day incubation?
Headache, nausea, chills, joint pain, receding and reappearing high fever. (~3 days) will resolve (~7 days) and then get better slightly less severe until cleared with abx or fought off completely
What is the risk for pregnant women with relapsing fever?
Can infect fetus due to ability to breach placenta and result in complications or death
____ is caused by Borrelia burgdorferi and is transmitted by hard ticks (reservoir mice and deer)
Lyme disease
Lyme disease is progressive, what occurs in the first stage/early localized?
Flu like, bulls eye "erythema migrans" rash
What happens in stage 2 of lyme disease? (early disseminated 50%)
Multiple small ECMs and invasion of nervous system, joint pain, neuro and cardiac problems
What happens in the 3rd stage of lyme disease? (10%)
Major arthritis and altered mental capacity
What symptoms of lyme can last for years?
Arthritic
Lyme disease can infect the placenta of preg women and cause
Stillbirth
What is the tx for lyme?
Abx for a few weeks
How can you prevent lyme disease if bitten?
Immediate tick removal, takes an hour to transmit disease
_______ is caused by plasmodium falciparum and knowlesi, protozoal apicomplexans
Malaria
Malaria is transmitted by female anopheles mosquitos and also
Blood transfusion, organ transplants, congenitally, or through accidental needle stick
After the 7-30 day incubation of malaria, _______ enter liver cells and undergo biological development, _____ are released from the liver and infect RBCs
Sporozoite, merozoite
WHat hapens to RBCs in malaria?
They burst from merozoite replication and gametes are released into the blood for the next host, cyclic reinfection of RBCs occurs
Every 2-3 days in malaria when all infected cells burst, what are the symptoms?
Cold stage with chills and shiver, hot stage with high fever delerium headaches and muscle pains, sweating stage with intense sweats
What are severe complications of malaria?
Anemia, cerebral malaria leading to coma, jaundice, kidney failure, heart attack, death
What is the tx for malaria?
preventative Anti malarial drugs for travelers, drug combos for tx, incomplete immunity due to antigenic change so boosting is required. Relapses can happen for months or years
______ is caused by an elongated flagellate and results in african sleeping sickness and american chagas disease
Trypanosoma
How is trypanosoma transmitted?
Tsete fly (african sleeping sickness) or kissing bug (american chagas dz)
What is the tx for trypanosomiasis?
Meds but only effective in acute stage, antigenic change can happen during blood invasion. No vax
What are the actue symptoms of trypanosomiasis?
Chancre at bite site, swollen LN, psychological changes, wasting away
What are chronic symptoms of trypanosomiasis?
Heart damage and failure, coma, brain damage, GI damage, death
_____ is transmitted by Phlebotomus sandfly, dogs are reservoir
Leishmania
What are the two types of leishmania?
Visceral and cutaneous
What are symptoms of visceral leishmania?
Fever, swollen glands, enlarged organs (liver and spleen), progressive anemia, death (80-90%)
What are symptoms of cutaneous leishmania?
painless skin lesions (plaques nodules or ulcers)
Schistosomiasis is caused by _______ worms and flukes and is transmitted when someone is exposed to water contaminated with larvae from infected snails that can penetrate skin barrier
Schistosoma haematobium, japonicum, mansoni
Schistosoma reproduce where?
Liver where massive amounts of antigenic eggs are released into blood, some can lodge in bladder and cause infection and some can be passed in feces
What are symptoms of schistosoma?
Bladder infection, hepatomegaly, splenomegaly, intestinal hemorrhage, CNS lesions, systemic inflammatory response, granulomas
What is the treatment for schistosoma?
1-2 days of meds, third world often has no access
_____ is caused by wucheria bancfrofti and brugia and is transmitted by mosquitos that inject microfilaria into blood
Lymphatic filariasis
Lymphatic filariasis infect the lymphatic system and results in
Fever, rash, orchitis, swelling and inflammation of lymph, elephantitis
What is the inflammatory response in lymphatic filariasis due to?
symbiotic wohlbachia bacteria
How is lymphatic filariasis dx and tx?
Blood test, repeated tx to kill circulating worms, no successful tx for lymphedema
______ is a mild hemorrhagic disease caused by RNA virus arenaviridae transmitted through aerosol or direct content with rodent excrement, contaminated food, or blood transfer
Lassa fever
After the 5-10 days incubation of lassa was are the symptoms?
Persistent fever, chest and back pain, patchy blood filled hemorrhagic lesions of throat
What happens in severe lassa that can cause 20% mortality?
Disease rages for one week with profuse internal hemorrhaging and drop in BP
What is the tx for lassa?
Antivirals and prevention
_____ is cause by an enveloped RNA virus bunyaviridae transmitted by aerosolized mouse excrement in the US and americas
Hantavirus pulmonary syndrome
After the 1-5 week incubation of hantavirus what are the symptoms?
Fatigue, fever, muscle ache, resp distress and fluid on lungs (35% mortality)
What is the tx for hantavirus?
Supportive therapy, no vax avail
_____ and ____ are very similar hemorrhagic fevers caused by RNA virus filoviridae, native to africa where the reservoir is fruit bats
Ebola, marburg
How is ebola and marburg transmitted?
Contact with bodily fluids and secretions, enters MM and abrasions, nosocomial infection can also occur during outbreaks
Ebola has a mortality rate of ____ and marburgs is _____
90%, 25%
What are the symptoms of ebola and marburg?
Fever, headache, muscle and joint oain, fatigue, rash, red eyes, hiccups due to loss of control of diaphragm, internal and external bleeding and rash, DIC
What is the tx for ebola and marburg?
Supportive therapy, no prevention or vax avail
Q fever is caused by _____ a small intracellular bacterium that has no flagella, pili, or capsule
Coxiella burnetti
What is Q fever derived from?
Livestock are reservoir, occupational hazard for farmers, transmitted by inhalation unpasteurized milk and ticks
What are symptoms of Q fever?
fever, lung tissue lesions, atypical pnueumonia, chronic cough, severe symptoms are hepatitis, endocarditis, thrombocytopenia, and purapura
What is the treatment for q fever?
Antibiotics, lifelong immunity after recovery, vax avail for at risk humans and livestock but not in US
Anthrax is caused by _______ a gram + spore forming encapsulated bacteria present in soil as spores that infect wounds and MM
Bacillus anthracis
Anthrax is primarily a disease of
Animals that feed on grass
What are the many virulence factors of anthrax?
Antiphagocytic capsule, exotoxins, pore forming machinery, immune suppresive proteins, proteases
Anthrax can cause different disease manifestation depending on inoculation. What is caused if the spores infect a wound?
Cutaneous, painless eschar with necrotic black center, local LN invasion, septicemia (20% mortality)
What is caused if anthrax is transmitted by inhaling spores?
Alveolar macrophage invasion, cold like symptoms leading to resp distress and shock, woolsorters dz, edema and hemorrhage in thoracic cavity, 90% mortality if untreated
What is the tx for anthrax?
60 days abx, vaccine avail for military or high risk
The bubonic plague/black death is caused by ____ a gram - nonmotile encapsulated bacilli that bipolary stains
Yersinia pestis
How is black death transmitted?
Flea bites from fleas from rodents
What happens after the 2-6 incubation of the black death?
multiply in blood and causes LN invasion with large swollen pus filled LNs, swelling and hemorrhaging, 50% mortaliy
What are other severe complications of black death?
Septicemia, meninigitis, DIC, multi system invasion
What happens in bubonic plague invades resp system?
Pneumonic bronchopneumonia, bacilli in sputum, can be transmitted by resp drops and is almost 100% fatal
What is the tx for bubonic plague?
abx
_____ is caused by francisella tularensis, a gram - bacilli with lipid capsule that is transmitted by ticks with rodents (esp rabbits) are reservoir
Tularemia
Tularemia requires a low inoculum and results in what symptoms?
Dependent on portal of entry. Flu like symptoms, LN swelling, GI and liver invasions. tick bites result in skin ulcers and swollen LN, eye contact results in eye lesions, inhalation results in fever and pneumonia
Leptospirosis is caused by _____ a spirochete that can infect household pets, rodents, farm animals, colonizes kidneys and is excreted in urine
Leptospira interrogans
Humans acquire lepto from MM, thin skin in contact with urine contaminated water, and what results?
Blood vessel endothelium damage
What are the primary symptoms of lepto?
Flu like, conjuncitivitis, recovery in days to weeks
What are the symptoms of secondary lepto? (10%)
Infection and hemorrhagic dz involving organs, kidney failure- weils dz, aseptic meninges with CSF hemorrhage
Brucella species cause ______ in which domesticated animals are the reservoir and results in contagious abortion, contaminated animal products and fluids
Undulating fever
Infection of brucellosis occurs in local LN, thoracic ducts and then blood and results in what?
massive inflammatory response in bone marrow, flue like symptoms, undulating (on and off) fever, nigh sweats, body ache, 25% of cases get hepatomegaly, osteomyelitis, splenomegaly
Hydatid disease is caused by ____ a tiny tapeworm found in the intestines of dogs and foxes
Echinococcus granulosus
What do hydatid larvae do when they move through blood vessels?
Form fluid filled hydatid cysts especially in liver
What are symptoms of hydatid dz?
Difficult coordination, heart and breathing problems, obstructive jaundice, anaphylaxis
What is the tx for hydatid dz?
Surgery, PAIR tx, inoperable cases require life long drugs
Trichinosis is caused by _____ a roundworm and is transmitted by consuming undercooked meat products
Trichinella spiralis
What does trichonisis cause when infesting human intestines and moving through blood?
Hard cysts
What is the tx for trichinosis?
Surgery, anti parasitic for intestinal dz only, steroids and analgesics for muscle involvment
What are symptoms of trichinosis?
GI, fever, abd pain, preorbital edema, aching joints, petechial hemorrhage, sever complications are myocarditis and encephalitis
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