Ticks, Mites, Fleas etc etc. Flashcards
What 3 main diseases are spread by body lice?
Louse Borne Epidemic Typhus
Trench Fever
Louse Borne Relapsing Fever (Epidemic Relapsing Fever)
What bacteria causes Louse Borne Epidemic Typhus
Rickettsia Powazekii
(Typhus Allen likes Polish People)
What bacteria causes Trench Fever?
Bartonella Quintana (Bartonella had a quinciñera)
What bacteria causes Louse Borne Relapsing fever?
Borrelia Recurrentis
What two main diseases are spread by fleas?
Plague
Murine Typhus
What main diseases are spread by hard ticks?
Lyme Disease
Rocky Mountain Spotted Fever
What bacteria is responsible for Lyme Disease
Borelia Burgdorferi
What main diseases are spread by soft ticks?
Tick Borne Relapsing Fever
What bacteria causes Tick Borne Relapsing Fever?
Borelia Duttoni
What mite causes Scabies?
Sarcopetes Scabiei
What is spread by Chigger Mites?
Scrub Typhus
What is the bacteria that causes Scrub Typhus?
Orientia Tsutsugamushi
What flea is associated with Plague and Murine Typhus?
Xenopsylla - Tropical Rat Flea
What is Kyasanur forest disease (KFD)
An Arbovirus spread through HARD TICKS that occurs in India, assocaited with agricultural development and deforestation
Have high suspicion of disease when you have an increase in monkey deaths in your area (reservoir/Host)
What is Tick Paralysis?
Transient paralysis that can occur from multi-day exposure to toxic tick saliva
Recovery is swift once tick is removed
Often mistaken for Polio
How can you control Hard Ticks?
Tick insecticides (acaricides)
PPE and long sleeves
Treatment of infested areas
Cut long grass where applicable
intermittent Ivermectin
What is the clinical relevance of Soft Ticks
Spread Tick Borne Relapsing Fever
Vector of African Swine Fever Virus (this just affects pigs, but has important economic effects)
What spp. of Soft tick is responsible for Tick Borne Relapsing Fever?
Ornithodoros sp
How is TBRF spread?
Organism is Borrelia Duttonii.
Borrelia is in Coxal fluid of the tick
When the tick leaks coxal fluid this can enter into the site of the bite or other skin abrasions –> infection
Which ticks cause a painful bite?
Soft Ticks
How does Scabies infection spread?
Human to human
Contact necessary
What are the risk factors of scabies infection?
Overcrowding
Bed sharing
Poor hygeine
How does Scabies infection present?
Generalised rash (not an indicator that this is where the ticks are in the skin)
Tunnelling/burrowing, especially between fingers and around wrists
How do you managed uncomplicated scabies?
5% permethrin topical application - given to the whole family, must be applied to the entire body
How can you remove Scabies Mites from clothing/bedding/ housing
Temephos insecticides
Wash and iron clothing/bedding
How do you manage systemic scabies (e.g Norweigian Scabies?)
Ivermectin
Which two medically relevant things are spread by mites?
Scabies
Scrub Typhus
What mite is responsible for Scrub Typhus
Chigger mite (larva and nymph)
What bacteria causes Scrub Typhus
Orientia Tsutsugamushi
Where could you find Scrub Typhus infections?
Asia
Which form of developing larva of a Chigger mite feeds on humans, potentially spreading Scrub Typhus
Larval form only!!!!!
How does Scrub Typhus present?
Eschar at bite site
Name the 3 common Borrelial infections
Louse Borne Relapsing Fever
Tick Borne Relapsing Fever
Lyme Disease
What is the vector of Louse Borne Relapsing Fever?
Louse
Pediculus Homanus
What is the vector of Tick Borne Relapsing Fever?
Soft Ticks (Ioxdodies)
What is the Vector of Lyme Disease?
Hard Tick
What kind of organism/bacteria are Borrelia?
Spirochetes
How should you diagnose Spirochete Borrelial infections?
Blood Microscopy
Darkfield Microscopy
PCR
**serology not helpful
What is a risk factor when treating Spirochete infection?
Jarisch-Herxheimer reaction
**this is an immune mediated response that occurs from spirochete death
- Risk increases with higher spirochete loads; LBRF > TBRF
- causes fever and blood pressure tank
- Mortality of 3-4%
What is the differntial of Relapsing Fever (Tick Borne or Louse Borne)
Malaria
Typhus fever
Typhoid
Meningococcal Septicaemia
Meningitis
Hepatitis
Dengue and other Arboviruses
Leptospirosis
VHFs
What is the pathophysiology of Relapsing Fevers?
Spirochetes enter into the blood (either through Body Louse or through Soft Tick)
Spirochetes like the reticuloendothelial system –> travel to the liver, spleen and CNS
While they travel they cause vascular endothelial damage –> vasculitis like picture and low platelets
Disease severity corresponds to the degree of spirochetes in the blood
What is the incubation of Relapsing Fevers?
4-8 days
How do relapsing fevers present?
HIGH FEVER BIG SPLEEN BIG LIVER BIT CONFUSED
Fever, headache, myalgia, arthralgia
Neuropsyhiatric features, confusion, meningism
Bleeding and platelet dysfxn (can present like a VHF or a haemorrhagic arbovirus)
How many relapses occur in Louse Borne Relapsing Fever?
Usually <3
How many relapses occur in Tick Borne Relapsing Fever
Loads, some people have about 12
Which bacteria is responsible for Louse Borne Relapsing Fever?
Borella Recurrentis
Where in the world is Louse Borne Relapsing Fever most common?
Ethiopia is the only place in the world where it is currently Endemic
There is an outbreak in Sudan at the moment
How is LBRF spread?
Crushing of Pediculus humanus louse
Which Relapsing fever is more likely to cause jaundice and hepatomegaly?
LBRF
What is the CFR of LBRF?
Up to 70%
How do you manage LBRF?
Doxycycline stat ± ceftriaxone if CNS invovlement
How can you prevent LBRF
Assocaited with body lice = assocaited with overcrowding and poor hygiene
Frequent washing of clothes and changing of bedding
Permethrin sprays
PEP of doxycycline in areas of high risk or outbreak
What bacteria is responsible for causing TBRF?
Borellia Duttonii
Where can you find TBRF?
East and Central Africa
NOT found in the west
Which Relapsing Fever has animal reservoirs?
TBRF
How is TBRF spread?
Coxal fluid or saliva from soft ticks
what is the CFR of TBRF?
10% —> significantly worse in pregnant women
How do you manage TBRF?
Doxyclycine (usually treatment is given for up to 10 days to manage the frequent relapses; this is not the case in LBRF)
±
Ceftriaxone if CNS involvement
Hw does TBRF present?
Hihg fever, painful joints
Recurring fever of 3 days, 7 day break, 3 day fever, 7 day break etc.
FEVER is followed by FLUSHING
How can you prevent TBRF?
Improve housing
Sweep floors (soft ticks drop to the floor after they’ve have a quick lil scran of your blood)
What three typhus fevers are in the rickettsial family?
Louse Borne Typhus Fever
Scrub Typhus
Murine Typhus
What bacteria and vector cause Epidemic Typhus
Louse Borne Epidemic Typhus spread by Pediculus Homanus
Rickettsia Prowazekii
What bacteria and vector cause Scrub Typhus?
Chigger Mite
Orentia Tsutsugamushi
What bacteria and vector cause Murine Typhus?
Flea borne typhus
Rickettsia Typhi
What bacteria and vector Cause Trench Fever?
Pediculus Humanus Louse
Bartonella Quintana
Which two diseases are spread by fleas?
Plague
Murine Typhus
±Tapeworms (Dypylidium Caninum)
Which flea is responsible for spreding Murine Typhus and Plague?
Xenopsylla (Tropical Rat flea)
What species are the hosts for Xenopsylla fleas?
Rattus Norvegicus
Rattus rattus
What bacteria causes Murine Typhus (fleaborn typhus)?
Rickettsia Typhi (mooseri)
Where might you find Murine Typhus?
Ports (found globally)
How does Murine Typhus present?
Fever, transient rash, headache, backache
How should you control flea-spread illnesses?
- Kill the fleas (first - before the rats otherwise you can rapidly spread the disease because the fleas just find a new host!)
- Residual spraying
- treat all dwellings
- Insecticides
- Resin insecticide strips on container - Kill the rats
- Rodenticides
- Methyl Bromide Gas
how do rickettsial infections present?
Fever and rash
± other symptoms
What is the vector of Louse Borne Typhus?
Pediculus Hominus (feacal spread)
What bacteria causes Louse Borne Typhus
Rickettsia Prowazekki
What is the presentation of Louse Borne (epidemic) Typhus?
Fever, conjunctival injection, headache, central macular rash
How can you diagnose Epidemic Typhus?
Weil Felix Serology
PCR
**rickettsia is an intracellular organism meaning culture is very challenging
** recall all the epidemic rickettsial/borrelial illnesses are caused by body lice
How do you manage Epidemic Typhus?
Supportive Care
Tetracycline 500mg QID
What causes Scrub Typhus?
Chigger Mite
Orentia Tsutsugamushi
Which stage of the chigger mite bites people, potentially spreading Scrub Typhus?
Larva only
Where does Scrub typhus occur?
South East Asia
Australia
How does Scrub Typhus present?
Eschar at site of bite, usually over sites of tight clothing (waistbands, sock tops)
Rash (trunk with palmar sparing)
Fever, hepatosplenomealy
Hearing Loss
How do you manage Scrub Typhus?
Doxycyline ± Chloramphenical