Category Archives: Publications

Does it matter if the county next to you does vector control? YES!

ABSTRACT: Vector-borne disease transmission is often typified by highly focal transmission and influenced by movement of hosts and vectors across different scales. The ecological and environmental conditions (including those created by humans through vector control programmes) that result in metapopulation dynamics remain poorly understood. The development of control strategies that would most effectively limit outbreaks given such dynamics is particularly urgent given the recent epidemics of dengue, chikungunya and Zika viruses. We developed a stochastic, spatial model of vectorborne disease transmission, allowing for movement of hosts between patches. Our model is applicable to arbovirus transmission by Aedes aegypti in urban settings and was parametrized to capture Zika virus transmission in particular. Using simulations, we investigated the extent to which two aspects of vector control strategies are affected by human commuting patterns: the extent of coordination and cooperation between neighbouring communities. We find that transmission intensity is highest at intermediate levels of host movement. The extent to which coordination of control activities among neighbouring patches decreases the prevalence of infection is affected by both how frequently humans commute and the proportion of neighbouring patches that commits to vector surveillance and control activities. At high levels of host movement, patches that do not contribute to vector control may act as sources of infection in the landscape, yet have comparable levels of prevalence as patches that do cooperate. This result suggests that real cooperation among neighbours will be critical to the development of effective pro-active strategies for vector-borne disease control in today’s commuter-linked communities.

Read the full article: Stone CM, Schwab SR, Fonseca DM and Fefferman NH 2017 Human movement, cooperation and the effectiveness of coordinated vector control strategies. J. R. Soc. Interface 14: 20170336. http://dx.doi.org/10.1098/rsif.2017.0336c

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Surveillance with Stable Isotopes

ABSTRACT

Stocking pen-raised northern bobwhite (Colinus virginianus) into habitats inhabited by wild bobwhite is a widespread practice, yet no technique other than marking exists to distinguish between these birds when they are harvested or recaptured. We assessed the potential of stable isotope analysis of primary feather tissue to distinguish between wild and pen-raised bobwhite. We obtained 104 feather samples from 3 game farms and 3 hunters in New Jersey, USA, collected between 1998 and 2006. We analyzed all samples for isotopes of carbon13C/12C, nitrogen15N/14N, sulfur34S/32S, and a preliminary sample for hydrogen2H/1H. Combinations of isotopic ratios of carbon, nitrogen, and sulfur yielded unique patterns for the 2 groups, enabling us to form a significant function that discriminated between these groups 100% of the time. The function was influenced most by the isotopic ratios of nitrogen and carbon. We were unable to discriminate between age classes or sex within groups, but could discriminate among farms and between years for the one farm where we had 2 years of samples. In our pilot study, stable isotope analysis of primary feather tissue was a reliable technique for distinguishing wild and pen-raised bobwhite for 12–14 months following postjuvenal or postnuptial feather molt. Summer stocking, feeding stations, or long-term survival of pen-raised birds would reduce the efficacy of this technique, depending upon the definition of a wild population. © 2017 The Wildlife Society.

Castelli P and L Reed 2017 Use of stable isotopes to distinguish wild from pen-raised Northern Bobwhite. Wildlife Society Bulletin. http://onlinelibrary.wiley.com/doi/10.1002/wsb.746/full

More News from the Center

  • CVB has just received approval to initiate a search for the long desired microbiology position. More to follow.
  • The Faraji and Gaugler paper “Experimental host preference of diapause and non-diapause induced Culex pipiens pipiens” published this year in Parasites & Vectors is designated as “highly accessed” by the journal.
    • From the abstract and conclusions: “To determine the effect of diapause on the innate host preference of Cx. p. pipiens emerging from winter hibernation, we conducted host-choice experiments using bird and mammal hosts….We provide new information about the innate host preference of Cx. p. pipiens emerging from diapause in temperate habitats where winter survival is crucial for disease transmission cycles. Although we showed that Cx. p. pipiens prefers an avian to a mammalian host, nearly 20 % of emerging mosquitoes in the spring could feed on mammals. Changes in host preferences may also contain valuable clues about transmission dynamics and subsequent timely interventions by vector control and public health practitioners.”
  • CVB members Isik Unlu (Mercer Co.) and Greg Williams (Hudson Co.) were granted adjunct professor status by the Rutgers Department of Entomology.
Isik

Isik Unlu from Mercer County Mosquito Control

Greg Williams from Hudson County Mosquito Control

Greg Williams from Hudson County Mosquito Control