Work Package 7: New tools for monitoring heterogeneities in vector species composition and behaviour, and their potential impact on control measures

University of Rome CNRFP Logo IFIKARA HEALTH INSTITUTE UNIVERSITY OF GLASGOW

 

WP7 GroupWork Package leader: Dr Alessandra della Torre. la Sapienza, University of Rome, 

Objectives:

Apply knowledge of vector behavioural traits and population structure to inform the successful implementation of integrated vector management by

 

 Task

 Progress/Plans

 

Develop and evaluate an Electric-Grid Tent Trap (EG-TT) for sampling outdoor feeding

A robust new Electric Grid Trap has been developed which  represents a promising new method for sampling host seeking mosquitoes, and providing reliable estimates of key vector behaviours such as the time of biting and proportion that occurs outdoors. The exposure-free method of assessing biting rates on humans, reduces the risks associated with the current gold standard of Human Landing Catches.

NT

CP

Develop and evaluate Sticky Resting-Boxes (SRB) to sample resting mosquitoes

Two models of Mosquito Adhesive Resting Trap (i.e. the Sticky Resting Box, SRB, and the Sticky Resting Buckets, SBu) have been developed and tested in Tanzania and Burkina Faso.  Adhesive Resting Traps represent “passive” collection approaches, which can continuously collect mosquitoes over time, without human intervention, thus providing estimates of relative densities of resting mosquitoes during an entire week.  DNA extracted from mosquitoes collected in these traps is amenable to analysis.

NT

CP

Assess the impact of urbanization on vector behaviour and population

In order to analyse the population structure of An. gambiae s.s. M and S-molecular forms over time and to determine whether ecological changes associated with recent urbanization have had an impact on the genetic structure of the local malaria vector populations in Burkina Faso, twenty years of historical collections of Anopheles mosquitoes collected from Oubritenga province have been catalogued. These are now being analysed using neutral markers distributed throughout the genome.

NT

Assess the impact of vector control practices on mosquito behaviour and population structure

Mosquito vector behaviour with respect to the degree of outdoor biting and resting, and human blood index, is being intensively monitored at 4 sites in Kilombero valley (wet season and dry season) over a 5 yr period in which the coverage of LLIN is expected to reach near 100%. Combining this data with historical data collected before the mass LLIN distribution campaign (2007-09), analysis will be conducted to test for shifts in key mosquito feeding and resting behaviours in response to changes in the coverage of control measures. A total of 235 households have been sampled since the start of the study.

 

Model the impact of behavioural heterogeneities on efficacy of alternative vector control interventions

Data collected in this WP will enable the development of more generalised predictive models to guide decision-making about the most effective control tools for targeting vector populations with different behaviours.  This activity will begin in the final year of the projects

 

 

Publications & Outcomes

N.J. Govella, D.F. Maliti, A.T. Mlwale, J.P. Masallu, N. Mirzai, P.C.D. Johnson, H.M. Ferguson, G.F. Killeen. An improved mosquito electrocuting trap that safely reproduces epidemiologically relevant metrics of mosquito human-feeding behaviours as determined by human landing catch. Malaria Journal 2016 15:465

Mafalda Viana, Angela Hughes, Jason Matthiopoulos, Hilary Ranson and Heather M. Ferguson. Delayed mortality effects cust the malaria transmission potential of insecticide resistant mosquitoes. PNAS vol. 113 no. 32, 8975-8980

D.V. Maliti, C.D. Marsden, B.J. Main, N.J. Govella, Y. Yamasaki, T.C. Collier, K. Kreppel, J.C. Chiu, G.C. Lanzaro, H.M. Ferguson, Y.  Lee. Investigating associations between biting time in the malaria vector Anopheles arabiensis Patton and single nucleotide polymorphisms in circadian clock genes: support for sub-structure among An. arabiensis in the Kilombero valley of Tanzania. Malaria Journal 2016 15:76

Bryson A. Ndenga, Nicholas L. Mulaya, Sandra K. Musaki, Joan N. Shiroko, Stefan Dongus and Ulrike Fillinger. Malaria vectors and their blood‑meal sources in an area of high bed net ownership in the western Kenya highlands. Malaria Journal 2016 15:76

K. Kreppel; P.C.D Johnson; N. J. Govella; M. Pombi; D. Maliti and H.M. Ferguson. Comparative evaluation of the Sticky-Resting-Box-Trap, the standardised resting-bucket-trap and indoor aspiration for sampling malaria vectors. Parasites & Vectors 2015, 8:462

M. Pombi; W. M. Guelbeogo; M. Calzetta; S. N’Fale; V. Petrarca; V. La Gioia and A. della Torre. Evaluation of a protocol for remote identification of mosquito vector species reveals BG-Sentinel trap as an efficient tool for Anopheles gambiae outdoor collection in Burkina Faso. Malaria Journal (2015) 14:161

M. Pombi; W. M. Guelbeogo; K. Kreppel; M. Calzetta; A. Traoré; A. Sanou; H. Ranson; H. M. Ferguson; S. N’Fale and A. della Torre. The Sticky Resting Box, a new tool for studying resting behaviour of Afrotropical malaria vectors. Parasites & Vectors 2014, 7:247