Infectious diseases Flashcards
What is the pathogenesis of HSV infection?
What are the clinical manifestations of HSV?
Oral facial infection: gingivostomatitis and pharyngitis (most common clinical manifestation of HSV1 infection), herpes labialis (most common clinical manifestation of reactivation of HSV 1 infection): vesicular lesions on an erythematous base of oral mucosa commonly referred to as cold sores
Genital herpes: recurrence of genital herpes common but less severe and shorter duration
CNS infection: HSV encephalitis (neonates: HSV1/HSV2, in adults –> nearly all causes are HSV1), HSV meningitis (HSV2), Bells palsy
Ocular infection: HSV keratitis (chemosis, conjunctivitis and characteristic dendritic lesions of cornea), chorioretinitis, acute retinal necrosis
Cutaneous manifestation: herpetic whitlow (HSV infection of the finger –> complication of primary oral or genital herpes by inoculation of virus through a break in skin barrier), herpes gladiatorum (face, neck and arms), eczema herpeticum (atopic dermatitis patients are at risk), erythema multiforme
Visceral infections: HSV proctitis, HSV esophagitis, HSV hepatitis (both HSV1 and HSV2. Lab findings: leukopenia, coagulopathy, elevated serum aminotransferase level and bilirubin), HSV pneumonitis (uncommon except in immunocompromised patients): results from direct extension of herpetic tracheobronchitis into lung parenchyma
What are the biochemical tests for HSV?
What is medical treatment for HSV infection?
What are the general features of varicella zoster virus?
What is the pathogenesis of VZV?
Primary and reactivation
What are the SS of chickenpox?
What are the SS of shingles?
What is the biochemical tests for VZV?
What is treatment for varicella and herpes zoster (shingles)
What is the treatment for complicated VZV infection?
What are the complications of chickenpox?
What are the complications of shingles?
What is the prevention of VZV?
What is the triad of infectious mononucleosis, route of transmission?
what is the ddx of infectious mononucleosis
What is the pathogenesis of infectious mononucleosis?
What general features and PE for infectious mononucleosis?
What biochemical tests for infectious mononucleosis and results
CBC with DC: leukocytosis with lymphocyte predominance
Peripheral blood smear: lymphocytosis, atypical lymphocytosis (defined as atypical lymphocyte >10% of total lymphocytes. Atypical cells are primarily mature CD8+ CTL that have been antigenically activated
LFT: may show hepatitis pattern
Heterophile antibodies (monospot test): latex agglutination assay using horse RBC as substrate for heterophile antibodies to agglutinate
EBV specific antibodies: EBV VCA IgM (most valuable), EBNA (nuclear antigen)
EBV DNA PCR
What is the general management of infectious mononucleosis?
What are the complications of infectious mononucleosis?
What is the pathogenesis of mumps?
What specific symptom of mumps?
What biochemical test for mumos:
CBC with DC
Serology: IgM in serum confirms acute infection
RT-PCR
Viral culture
What is complications of mumps infection?
What is prevention of mumps?
What is mode of transmission, incubation period and infectious period of measles?
What are the RF of measles infection?
- Children too young to be vaccinated
- Individuals without vaccination
- Individuals without a 2nd dose of vaccination
- Individuals with vaccination but failed to elicit a protective immune response (very small
fraction of those immunized) - Travelers to areas where measles is endemic or contact with ill person arriving from those countries
What is the pathogenesis of infection of measles?
Infection occurs in upper respiratory tract epithelium
Viral replication in upper respiratory tract epithelial cells and LNs leads to primary viremia in
around 2 – 3 days
Subsequent dissemination to distal reticuloendothelial sites such as spleen leads to secondary
viremia in around 5 – 7 days
* Secondary viremia leads to spread to respiratory tract and other organs
What is clinical course of measles?
What Ix for measles?
What treatment for measles?
What are the complications of measles?
When is vaccination for measles done?
What is the general features of rubella
mode of transmission
incubation period and infecitous period
What are the SS for rubella?
What Ix and tx for rubella?
What are the complications of rubella>
How to diagnose maternal rubella
Management of women with possible exposure to rubella virus
dx of congenital rubella infection after delivery
How to prevent rubella?
What are the regions affected by enteric fever
What transmission and reservoir?
What bacteria causes enteric fever?
What is the clinical course of enteric fever
What SS?
Complications
What tests for suspicion of enteric fever?
What is management of enteric fever?
What is the prevention of typhoid/paratyphoid fever?
What is ricketssia
what mode of transmission and incubation period?
What is the geographical distribution of rickettsial illness?
What is the rickettsia and orientia species categorized into?
What is the pathogenesis of rickettsial illness?
Bacteria are transmitted via arthropod saliva during bite
* Bacteria multiply and penetrate skin at site of arthropod bite
* Primary target cells are vascular endothelial cells except for Orientia tsutsugamushi and Rickettsia akari which infects monocytes
* Replication in endothelial cells of small blood vessels causes vasculitis and local hemorrhage and certain species cause local skin necrosis (eschar) at exposure site
* Regional lymphadenopathy is common in infection with Orientia tsutsugamushi and some members of spotted fever group
What is SS of ricketssial illness?
What is SS of rocky mountain spotted fever (rickettsial)?
What is SS of Meditteranean spotted fever (rickettsial)?
- Classic triad variably present
- Presents with rash that may be macular, maculopapular or purpuric
- Presence of inoculation eschar at tick bite sites
- Associated laboratory features include thrombocytopenia, hyponatremia and abnormal
LFT
What is SS of epidemic typhus (rickettsial)?
- Classic triad variably present
- Presents with macular or petechial rash that spread centrifugally
o Centrifugal spread meaning lesions first arise on trunk and spread gradually towards the wrist and ankles - Neurological symptoms are common and range from confusion, seizure to coma
- Inoculation eschar is typically NOT present at sites
- Associated laboratory features include thrombocytopenia and abnormal LFT
What is SS of murine typhus (rickettsial)?
- Classic triad occurs in 15% of cases
- Presents with macular or petechial rash that spread centrifugally
o Centrifugal spread meaning lesions first arise on trunk and spread gradually towards the wrist and ankles - Inoculation eschar is typically NOT present at sites
- Associated laboratory features include anemia, thrombocytopenia, hyponatremia and
abnormal LFT
What is SS of scrub typhus (rickettsial)?
- Classic triad variably present
- Presents with rash in 30% of cases and is macular, transient and pale
- Distinct feature includes eschar in 50% of cases and may be multiple and associated localized lymphadenopathy
- Neurological symptoms may be present ranging from slight intellectual blunting to delirium and coma
- Associated laboratory features include anemia, thrombocytopenia, hyponatremia and abnormal LFT
What tests for rickettsia?
What treatment for rickettsia?
What is the micbio of dengue virus?
What is the pathogenesis of dengue fever?
What is the clinical manifestation of dengue fever?
What are the 3 categories of symptomatic dengue virus infection and description based on WHO 1997 (outdated)?
What are the 3 categories of symptomatic dengue virus infection and description based on WHO 2009 ?
How to confirm dx of dengue fever?
Early phase of illness
* Detection of virus by cell culture
* Detection of viral nucleic acid by nucleic acid amplification tests
* Detection of viral antigens by ELISA
End of acute phase of illness
* Detection of antibodies by serology
What biochemical tests done for dengue fever?
What are the virus types causing malaria?
What conditions protect against malaria?
5 Different types of plasmodium species
* Plasmodium falciparum (most common and severe)
o Most prevalent malaria parasite on the African continent and responsible for most malaria-related deaths globally
* Plasmodium vivax
o Dominant malaria parasite in most countries outside of sub-Saharan Africa
* Plasmodium malariae
* Plasmodium ovale
* Plasmodium knowlesi
Conditions that protects against malaria
* G6PD deficiency
* Thalassemia
* Hemoglobinopathies (Hb S/C/SC/E/F)
What is the region, transmission and incubation period for malaria?
What is the life cycle of plasmodium species in human hosts?
What is the classical SS for malaria?
What are the SS of severe malaria?
What biochemical tests for malaria?
What is the treatment of uncomplicated malaria?
What is the treatment for complicated malaria?
What is done for prevention of malaria?
