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Viral Risk Factors
for DHF Pathogenesis
- Virus strain (genotype)
- Epidemic potential: viremia level, infectivity
- Virus serotype
- DHF risk is greatest for DEN-2, followed by DEN-3, DEN-4 and DEN-1
| Dengue hemorrhagic fever most often occurs in second infections
with dengue virus, but the phenomenon seems to be mostly restricted
to infections with certain dengue virus strains, or genotypes,
first identified in Southeast Asia. The potential for these
strains to produce DHF epidemics may be related to their ability
to produce greater concentrations of circulating virus in the
blood (level of viremia), or their ability to produce infection
in both the human and mosquito hosts. Cohort studies in Southeast
Asia have shown that secondary (repeat) infections in which
DEN-2 is the infective serotype have greater probability of
producing DHF than infections with other serotypes, followed
closely by DEN-3. The risk is less when the second infecting
virus is DEN-4 or DEN-1 (in that order). |
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