Dengue research published by Professor Simmons

4 June

veski innovation fellow Professor Cameron Simmons is continuing his dengue research in Vietnam and Australia.

Most recently, he and his colleagues have published 'Host and viral features of human dengue cases shape the population of infected and infectious Aedes aegypti mosquitoes' in the Proceedings of the National Academy of Sciences of the United States of America (PNAS).

The following is an abstract from the paper:

Dengue is the most prevalent arboviral disease of humans. The host and virus variables associated with dengue virus (DENV) transmission from symptomatic dengue cases (n = 208) to Aedes aegypti mosquitoes during 407 independent exposure events was defined. The 50% mosquito infectious dose for each of DENV-1–4 ranged from 6.29 to 7.52 log10 RNA copies/mL of plasma. Increasing day of illness, declining viremia, and rising antibody titers were independently associated with reduced risk of DENV transmission. High early DENV plasma viremia levels in patients were a marker of the duration of human infectiousness, and blood meals containing high concentrations of DENV were positively associated with the prevalence of infectious mosquitoes 14 d after blood feeding. Ambulatory dengue cases had lower viremia levels compared with hospitalized dengue cases but nonetheless at levels predicted to be infectious to mosquitoes. These data define serotype-specific viremia levels that vaccines or drugs must inhibit to prevent DENV transmission.

The above pictures of an Aedes aegypti mosquito imbibing a human blood meal accompanied the paper. Blood is visible in the lumen of the needle in front of the withdrawn sheath.  Nguyet Minh Nguyen et al. identified the 50% mosquito infectious dose of dengue virus for Aedes aegypti mosquitoes via direct mosquito biting experiments on adult dengue cases.  High dengue virus levels in human blood were predictive of the duration of human infectiousness and the likelihood of mosquitoes being infectious 2 weeks after taking a blood meal.  The results identify important virological thresholds for dengue virus transmission to Aedes aegypti mosquitoes.

Images courtesy of Nicholas Fernandez (Fact & Fiction Films).

What's On

S M T W T F S
 
 
 
1
 
2
 
3
 
4
 
5
 
6
 
7
 
8
 
9
 
10
 
11
 
12
 
13
 
14
 
15
 
16
 
17
 
18
 
19
 
20
 
21
 
22
 
23
 
24
 
25
 
26
 
27
 
28
 
29
 
30