She’s a femme fatale: low-density larval development produces good disease vectors
Mem. Inst. Oswaldo Cruz
; 109(8): 1070-1077, 12/2014. tab, graf
Article
in English
| LILACS
| ID: lil-732600
Responsible library:
BR1.1
ABSTRACT
Two hypotheses for how conditions for larval mosquitoes affect vectorial capacity make opposite predictions about the relationship of adult size and frequency of infection with vector-borne pathogens. Competition among larvae produces small adult females. The competition-susceptibility hypothesis postulates that small females are more susceptible to infection and predicts frequency of infection should decrease with size. The competition-longevity hypothesis postulates that small females have lower longevity and lower probability of becoming competent to transmit the pathogen and thus predicts frequency of infection should increase with size. We tested these hypotheses for Aedes aegypti in Rio de Janeiro, Brazil, during a dengue outbreak. In the laboratory, longevity increases with size, then decreases at the largest sizes. For field-collected females, generalised linear mixed model comparisons showed that a model with a linear increase of frequency of dengue with size produced the best Akaike’s information criterion with a correction for small sample sizes (AICc). Consensus prediction of three competing models indicated that frequency of infection increases monotonically with female size, consistent with the competition-longevity hypothesis. Site frequency of infection was not significantly related to site mean size of females. Thus, our data indicate that uncrowded, low competition conditions for larvae produce the females that are most likely to be important vectors of dengue. More generally, ecological conditions, particularly crowding and intraspecific competition among larvae, are likely to affect vector-borne pathogen transmission in nature, in this case via effects on longevity of resulting adults. Heterogeneity among individual vectors in likelihood of infection is a generally important outcome of ecological conditions impacting vectors as larvae.
Full text:
Available
Collection:
International databases
Health context:
SDG3 - Health and Well-Being
/
Neglected Diseases
Health problem:
Target 3.3: End transmission of communicable diseases
/
Target 3.9: Reduce the amount of deaths produced by dangerous chemicals and the pollution of the air, water and soil
/
Dengue
Database:
LILACS
Main subject:
Aedes
/
Dengue
/
Body Size
/
Epidemics
/
Insect Vectors
Type of study:
Prognostic study
Limits:
Animals
Country/Region as subject:
South America
/
Brazil
Language:
English
Journal:
Mem. Inst. Oswaldo Cruz
Journal subject:
Tropical Medicine
/
Parasitology
Year:
2014
Document type:
Article
/
Project document
Affiliation country:
United States
Institution/Affiliation country:
Illinois State University/US