Arboviruses
Chikungunya, Dengue and Zika viruses are arboviral infections transmitted by the bite of the Aedes mosquitoes (A. aegypti, A. albopictus and A. africanus). A high index of suspicion is necessary in endemic areas (Africa, South America and Asia) and a travel history is important, as the patient may be unaware of being bitten. Fever occurs after short incubation periods, followed by rash and varying degrees of systemic symptoms. Joint involvement may be less common in children but may be difficult to distinguish from juvenile idiopathic arthritis (JIA). Treatment is symptomatic. Vaccines are not yet available.
|
VIRUS |
CHIKUNGUNYA |
DENGUE |
ZIKA |
|
Cause |
Single stranded RNA alphavirus. |
Dengue flavivirus. |
Zika flavivirus. |
|
Transmission |
Vector: Aedes aegypti, A. albopictus. |
Vector: Aedes aegypti, A. albopictus. |
Vector: Aedes aegypti, A. albopictus, A. africanus Non Vector: Congenital, Perinatal, Sexual. |
|
History |
Endemic area, travel, contact may be present. |
Endemic areas. Travel History. |
Endemic areas. Travel History. |
|
Clinical Presentation |
Incubation period 2-5 days. |
Incubation period. 4-10 days. |
Incubation period 3–10 days. 80% cases asymptomatic. Self-limiting. |
|
Fever |
High Grade >= 39 °C. |
High Grade >= 39 °C. |
Low Grade <= 38°C. |
|
Rash |
Macular, macular papular on limbs. Diffuse pigmented, bullous lesions described in children. |
Macular papular, Haemorrhagic. |
Maculopapular, pruritic – starts proximally with distal spread. |
|
Joint Presentation |
Painful swollen joints, tenosynovitis, predilection for distal small joints. Chronic Persistent Arthritis. |
Arthralgia, transient synovitis, Macrophage activation syndrome. |
Arthralgia. |
|
Other symptoms |
Headache, Conjunctivitis, Myalgia, Lymphadenopathy, Neuropathy, GIT symptoms. |
Severe headache, retro orbital pain, myalgia, lymphadenopathy, GIT symptoms. Severe: Bleeding dyscrasia, shock. |
Conjunctivitis, myalgia, headache. Meningitis, Guillaine Barre in adults. |
|
Laboratory Tests |
Full blood count (FBC) may show lymphopaenia, thrombocytopaenia. |
Marked cytopenia (all cell lines). |
FBC often normal or mild changes. |
|
|
Inflammatory markers: ESR and CRP may be normal. |
ESR/CRP may be normal. |
ESR/CRP normal or slightly raised. |
|
Diagnosis |
Serology IgM + > 4 days (in acute phase), IgG positive > 2 weeks of onset (be aware of cross reactivity). |
Serology IgM + > 4 days (in acute phase), IgG positive > 2 weeks of onset (be aware of cross reactivity). |
Serological testing not recommended due to cross reactivity with other flaviviruses. |
|
|
Reverse Transcriptase PCR + during acute phase (in first week of illness). |
Reverse Transcriptase PCR + during acute phase (in first week of illness). |
Reverse Transcriptase PCR on serum and urine in acute phase < 14 days from onset of symptoms. |
|
|
Synovial biopsy may demonstrate virus. |
Isolating virus: Immunofluorescence biopsy/ post mortem specimens. |
|
|
Treatment |
Supportive (i.e., fluids, analgesia, non-steroidal anti inflammatory drugs - NSAIDS). |
Supportive. Avoid NSAIDS as may exacerbate haemorrhage. |
Supportive. Avoid NSAID’s until Dengue excluded. |
Further Information is available from the Centre of Disease Control and Prevention
Further reading:
- Ritz N, Hufnagel M, Gerardin P. Chikungunya in children. Pediatric Infectious Disease Journal: July 2015 - Volume 34 - Issue 7 - p 789–791 doi: 0.1097/INF.0000000000000716
- Binoy J. Paul and Shajit Sadanand. Chikungunya: a re-emerging epidemic? Rheumatol Ther (2018). https://doi.org/10.1007/s40744-018-0121-7
- Plourde AR, Bloch EM. A Literature Review of Zika Virus. Emerg Infect Dis. 2016;22(7):1185-1192. https://dx.doi.org/10.3201/eid2207.151990
- Elling R, Henneke P, More C. Dengue Fever in children. Where are we now ? Pediatric Infectious Disease Journal: 2013: 32(9):1020-1022. doi: 10.1097/INF.0b013e31829fd0e9
