viral arthropathies Flashcards
arthralgia
pain in the joints
arthritis
inflammation of the joint with the presence of inflammatory cells
arthropathy
something wrong with the joint that may or may not be arthritis
arthritogenic
something that tends to cause arthritis
monoarthritis
a single joint infected
oligoarthritis
2 or 3 joints affected
polyarthritis
lots of joints affected
migratory arthritis
one joint is affected and then resolves, pain moves onto another joint
differential diagnosis of joint pain
bacterial, viral, postinfectious, crystal arthropathy, rheumatological diseases, osteoarthritis, trauma
viruses commonly causing arthropathy
arboviruses
rubella virus
parvovirus
viruses that rarely cause arthropathy
hepatitis viruses and HIV
herpesvirus
enteroviruses
adenoviruses
arboviruses
arthropod borne viruses
transmitted via arthropod vector, usually mosquito
- flavivirus (RNA)
- alphavirus (RNA)
flavivirus
yellow fever virus (viscerotropic)
eg. dengue, zika, neuurotopric (encephalic) viruses
dengue
most common flavivirus infection worldwide
zika
caused an epidemic in south and central america
neurotropic flavivirus
tend to cause infection of the CNS
australia neurotropic viruses
murray valley encephalitis
kunjin virus
non australian flaviviruses
japanese encephalitis virus
west nile virus
st louis encephalitis virus
alphaviruses
arthritogenic - ross river - barmah forest virus - chikungunya neurotropic - western equine encephalitis virus - eastern equine encephalitis virus - venezuelan equine encephalitis virus - mayaro (arthritogenic)
dengue virus transmitted by
aedes aegypti
also aedes albopictus
dengue infects
maintained in human populations
can infect non human primates
dengue seotypes
4 serotypes which co circulate
dengue incubation period
3-14 days after mosquito bite
clincal manifestations of dengue
fever
headache, eye pain, myalgia, arthralgia
rash, usually 2-5 days after symptom onset
GI symptoms
dengue lab resullts
abnormal LFTs, low platelets
serology for diagnosis - NS1 antigen and IgM and IgG antibodies
nucleic acid testing (PCR) also works for diagnosis
severe dengue
formerly dengue haemorrhagic fever and dengue shock syndrome
more common in secondary than primary dengue infection
plasma leakage, heamorrhage, shock
critical period 3-7 days after symptom onset
dengue treatment
supportive care only
careful fluid management in severe dengue
vaccine development hampered by antibody dependant enhancement
Zika transmitted by
Ae. aegypti, Ae. albopictus
Zika incubation period
2 - 14 days
clinical manifestations of Zika
similar to dengue but milder
50-75% of infections are asymptomatic
conjunctivitus is common in symptomatic infection
lab diagnosis of zika
serology for igM and IgG antibodies
definitive diagnosis can be difficult due to cross reactivity with other flaviviruses
nucleic acid testing
treatment of zika
supportive care only
person to person transmission in Zika
sexual and vertical transmission possible
neurotropism of zika
microcephaly and other neurological abnormalities from intrauterine infection
causes guillain barre syndrome
ross river and barmah forest viruses
most common causes of viral polyarthritis in australia
regular epidemics with a geographical focus
distributed throughout australia, also found in melanesia
multiple mosquito vectors
infection is enzootic in native macropods (kangaroos, wallabies), can also infect horses, livestock, other wild animals
incubation period for ross river and barmah forest
3-21 days
clinical manifestationss of ross river and barmah forest viruses
arthralgia
fatigue
rash
fever and myalgia
arthralgia in ross river and barmah forest viruses
athralgia is usually symmetrical, affects wrists, knees, ankles, MCP/IP joints of the hands
may persist for 3-6 months
lab diagnosis for ross river and barmah forest
serology for IgM and IgG
nucleic acid testing
treatment for ross rver and barmah frest
supportive care only
chikungunya virus vectors
prmary vectors are Ae. aegypti and Ae. albopictus
chikungunya virus incubation period
incubation period 1-14
chikungunya virus clinical manifestations
fever
arthralga
rash
headache, myagla, GI symptoms
althralgia in chickungunya vrus
usually 2-3 days after fever onset, similar distribution to other alphaviruses
can be debilitating, gradually mproves over 3-18 months
lab diagnosis of chikungunya
serology for IgM and IgG
nucleic acd testing
treatment for chikungunya
supportive care only
rubella caussed by
rubella virus (RNA)
rubella incubation period
14-18 days
rubella tranmission
person to person via large respiratory droplets
clinical manifestations in children of rubella
often mild or asymptomatic
distinctive rash spreads from face to trunk and extremities within 24 hours, lasts 3-8 days
low grade fever and lymphadenopathy pay precede the rash
clinical manifestations of rubella in adults
rarely asymptomatic
prodrome with fever and lymphadenopathy more pronounced, followed by rash
arthralgia reported in 70% of adult women, concurrent with rash
- may persist for 1-2 months
- knees, wrists, fingers most frequently involved
lab diagnosis of rubella
serology IgM and IgG anitbodies
nucleic acid testing (PCR)
treatment for rubella
supportive care only
rubella in pregnancy
transplacental infection may occur
greatest risk in first trimester, minimal after 20 weeks gestation
intrauterine infection may lead to fetal loss or congental rubella syndrome
congenital rubella syndrome
hearing loss
intellectual impairment
cardiac abnormalities
cataracts
rubella precautions in pregnancy
testing for rubella immunity routinely recommended in pregnancy; post-pregnancy booster if IgG is low
post exposure prophylaxis in pregnancy has not been shown to be beneficial
confirmed cases managed by maternal-fetal medicine
parvovirus
parvovirus B19
small DNA virus with global dictribution, first isolated in australia
causes another childhood exanthem ‘fifth disease’
50% infected by age 15
transmission person to person by large respiratory droplets
incubation period 1-2 weeks
clinical manifestations of parvovirus
25% asymptomatic
50% have mild, non-specific illness (fever, myalgia, coryza, headache)
25% present with erythema infectiosum or arthralgia
erythema infectosum
usually seen in children
erythematous malar rash with circumoral pallor (slapped cheek syndrome) follows 2-5 days after prodrome
generalised rash follows
athralgia in parvovirus
mainly adults, especially women
affects hands, wrists, knees, feet symmetrically
usually lasts three weeks
generalised rash in 75% of cases
other manifestations of parvovirus
aplastic crisis in haematological disorders
chronic haemolysis in immunocompromised patients
lab diagnosis of parvovirus
serology for IgM and IgG antibodies
nucleic acid testing (PCR)
parvovirus treatment
supportive care only
no vaccine or post exposure prophylaxis exists
parvovirus in pregnancy
transplacental infection may occur
may lead to fetal loss or fetal hydrops
- parvovirus is cytotoxic too fetal red blood cell precursors
greatest risk prior to 20 weeks
confirmed infection in pregnancy managed by maternal-fetal medicine
- fetal blood transfusion may be used to treat fetal hydrops
pathogenesis of viral arthropathy
not well understood
not simply viral replication in the joints
at least partially immune mediated
virus has occasionally been cultured from joint aspirates
- viral antigens and nucleic acid detected more commonly
- viral inclusions have been seen in joint macrophages
immune complex deposition thought to contribute to joint symptoms and rash
qualities of viral anthropathies
usually symmetrical
affect wrists, knees, hands, feet,
often accompanies by rash and/or fever
