Rickettsia and Related Diseases

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Titi pipi

Cards (51)

How does Epidemic Typhus spread?
Through louse feces or blood into wounds
What are the transmission methods for Murine Typhus?
Direct contact via fleas
Inhalation of feces or dust
How are Rickettsial diseases primarily spread?
By arthropods such as ticks and fleas
How does O. tsutsugamushi transmit from one host to another?
Transovarian transmission (from adult to egg)
What could be the possible cause of this skin condition?
Allergic reaction
Viral or bacterial infection
Skin irritation
How long after exposure do symptoms of Murine Typhus typically start?
After 1-2 weeks
In which regions is Epidemic Typhus mainly found?
Africa and South America
How can Q fever be contracted?
By inhaling dust or aerosols from urine or milk
What organism causes Epidemic Typhus?
$R. prowazekii$
What type of skin condition is shown in the image?
The image shows a skin condition with red spots or bumps on the skin.
How should this skin condition be treated?
Topical creams or ointments
Oral antihistamines
Avoiding irritants
Seeking medical advice
What happens to engorged larvae in the life cycle of O. tsutsugamushi?
They transform into nymphs and adults
What is the animal source of Murine Typhus?
Rodents
What is the normal food source for the larva (chigger) of O. tsutsugamushi?
Small mammals or ground-feeding birds
What is the significance of the rash in Murine Typhus cases?
It occurs in over half of cases
When may Brill-Zinsser disease occur?
Years after recovery from typhus
What conditions are often associated with Epidemic Typhus?
High population density and poor hygiene
What are the larvae of O. tsutsugamushi called?
Chiggers
What is the effect of early treatment with doxycycline for Epidemic Typhus?
Leads to rapid recovery
What is the purpose of Dip-S-ticks in Scrub typhus diagnosis?
They offer quick bedside detection
What do ELISA, PCR, and immunofluorescence provide in Scrub typhus diagnosis?
Accurate antibody or DNA detection
What type of infection is Murine Typhus?
Flea-borne bacterial infection
Where do nymphs and adults of O. tsutsugamushi live?
Free in soil
What bacteria causes Scrub Typhus?
tsutsugamushi
What are the key features of the different life stages of O. tsutsugamushi shown in the image?
Larva (chigger): Feeds on small mammals or ground-feeding birds
Engorged larva: Enlarged after feeding
Nymph & Adult: Free-living in the soil
What are the limitations of the Weil-Felix test?
It has low sensitivity and specificity
What are the potential complications if this skin condition is left untreated?
Worsening of symptoms
Spread of infection
Scarring or discoloration of the skin
Secondary skin infections
Why are humans considered accidental hosts for the larva (chigger) of O. tsutsugamushi?
Humans are not the normal food source for the larva
What tests are involved in diagnosing Scrub typhus?
Rapid immunochromatographic flow assays
Dip-S-ticks
Weil-Felix test
ELISA
PCR
Indirect immuno-peroxidase
Immunofluorescence
Cultivation on L929 cells
What do rapid immunochromatographic flow assays detect?
IgM/IgG antibodies
What are the common symptoms of Murine Typhus?
Headache
Muscle pain
Cough
Rash (in over half of cases)
If you wanted to observe the detailed surface features of a cell, which type of microscope would you use?
Scanning electron microscope
What is the life cycle of O. tsutsugamushi?
Adults transmit bacteria to eggs via transovarial transmission
Eggs develop into larvae (chiggers)
Larvae feed on small animals or humans
Engorged larvae transform into nymphs and adults in soil
What is Brill-Zinsser disease?
A mild, latent reactivation of typhus
What type of infection is Epidemic Typhus?
Louse-borne infection
What does the Weil-Felix test use for diagnosis?
Cross-reactivity with Proteus OX-K
How is Murine typhus transmitted?
By fleas from rodents
What is the significance of humans in the life cycle of O. tsutsugamushi?
They serve as temporary feeding hosts
What transmits Indian tick typhus?
Ticks from animals
What type of cells are used for cultivation in laboratories for Scrub typhus?
L929 cells