Viruses I - Dengue, Enterovirus Flashcards
Dengue
- Genome Envelop
- Dengue Symptoms
- DSS brief pathophysiology,
DHF symptoms, clinical signs
ssRNA, Yes
- Fever, pain behind ears
- joint pain, muscle, rash;
- deterioration: ab pain, liver enlargement
- DSS - SHOCK; DHF - Hemorrhage
- severe bleeding, plasma leakage due to increased vascular permeability
- PPE, non blanching rash
- liver damage
- CNS impaired consciousness;
- hypotension, weak pulse pressure - Shock
- ascites due to plasma accumulation;
- sudden drop in temperature;
Dengue blood test signs [2]
which painkiller to give
management
Thrombocytopenia - low platelets
Hematocrit increase due to plasma leaking
Give paracetamol instead of NSAIDs
- NSAIDs bleeding;
- for fever too;
Plasma fluid infusion
- recover loss;
Dengue immunology pathophysiology + enhancement
Virus replicates in mononuclear phagocytes (monocytes, macrophages, histiocytes, Kupffer cells (specialized macrophages in liver))
Their circulation allows for viraemia; can PCR
IgM first
IgG - this one leads to enhancement after initial cross-reactivity protection
but if IgG drops then enhancement gone;
Maternal IgG first 6 months
2nd infection
- Non-neutralizing antibody (infection-enhancing antibody) form complex
- FC activate phagocytes - internalize into phagocytes
- standard immunoflow; C3 cleave, anaphylatoxin complement activation
- hence babies 1st bite can be DSS already
Lab Diagnosis of Dengue
IgM IgG ELISA
NS1 antigen ELISA
2 DDx and special symptoms for them
Chikungunya
- arthritis inflamed joints
- fever, rash, arthralgia
Zika
- same dengue features + CONJUNCTIVITS
- Like rubella: congenital problem of microcephaly
- ICC: peripheral // grey-white matter interface;
Zika Cx [3]
Microcephaly, ICC
Guillain–Barré syndrome
- polyneuropathy; peripheral neuropathy; Type II HS ab damage to schwann cells;
- linked to campylobacter pylori; Herpes 5 CMV, Zika; Herpes 3 Varicella, 4 EBV,
Enterovirus
- genome, envelop
- route of infection!
ssRNA, NO
- insensitive to detergents;
- Fecal Oral
- from GIT tract to BLOOD - viraemia - then target organs;
Note virus isolation is not useful for diagnosis but for monitoring
- too slow;
- swabs and csf;
okie
Enterovirus serology and PCR
Not used cos of cross-reactivity
PCR used
Enterovirus management and vaccines
Symptomatic (i think)
No antiviral for them
- Vaccine ‘only’ is POLIO; have all 3 serotypes
IPV (Salk) and OPV (Sabin)
- IM - inactivated - IgG - can infect
- Oral - Live attenuated - IgA at GUT - no carrier
Enterovirus species and stuffs [3]
Cosackie A and B
- both have encephalitis
- A more epithelial - herpangina, HFMD
- B more muscular
Enterovirus 71 - HFMD, childhood rash (erythema)
- common!
Echovirus
