barbara Navy Medical Entomology Research in by gegeshandong

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									 Navy Medical Entomology
Research in Southeast Asia



              LT Kathryn A. Barbara
         US Naval Medical Research Unit #2
                Jakarta, Indonesia

   DoD Pest Management Workshop, Feb 8-12, 2010
              Disclaimer
The opinions or assertions expressed herein
 are the private views of the authors and
 are not to be construed as representing
 those of the US Navy, the Department of
 Defense, or the Cambodia, Singapore, or
 Indonesia Ministry of Health.
  Effect of Land Use on Malaria
Vector Diversity and Distribution in
   Pursat Province, Cambodia



  K. A. Barbara, S. Rusmiarto, R. Pudiantari, A.
     Farzeli, I. Nurlaila, and S. Sovannaroth 2
 US Naval Research Unit No. 2 Jakarta, Indonesia
 2 The National Center for Parasitology, Entomology and Malaria Control,

 Phnom Penh, Cambodia
Effect of Land Use on Malaria Vector
Diversity and Distribution in Pursat
         Province, Cambodia
• Before 1970 over 73% of Cambodia was forest cover,
  currently 58% (70% primary forest in 1970, 3.1%
  currently)
• Rate of deforestation in Cambodia:
   – 1990-2005: 19.3% lost = 2,499,00 hectares (444,000 hectares
     primary forest)
   – Annual Change 2000-2005: 218,800 ha
• Deforestation in Cambodia is driven by
   –   agricultural development/expansion
   –   road construction
   –   mining
   –   hydropower development
   –   extensive commercial forest exploitation
Effect of Land Use on Malaria Vector
      Diversity and Distribution
• Conduct bionomics studies in areas bordering
  old forest growth and areas cleared of forest
  trees and reestablished as small agricultural
  areas
• Hypotheses:
  – Anopheles dirus will be the most abundant Anopheles
    spp. collected bordering the primary forest areas.
  – An. minimus (Theobald) will be the most abundant
    Anopheles spp. collected in the areas cleared for
    agricultural use.
  – An. dirus will be the main malaria vector in the forest
    sites; An. minimus will be the dominant malaria
    vector in the agriculture site.
Study Site
       Mosquito Collections
• Collections were conducted from October
  2008 to January 2009
• Indoor/outdoor, 12h human landing
  collections (1800-0600) over 8 days
• 8 houses served as permanent collection
  sites
• 22 nights (agricultural site), 23 nights
  (forest site)
         Agricultural




Forest
                                                Results
                                         Agricultural                           Forest


 Anopheles species            Indoor        Outdoor      HBR      Indoor (%)    Outdoor (%)   HBR       Total (%)
                                 (%)            (%)

An. barbirostris         254 (10.1)         263 (8.2)    2.94      74 (3.8)      135 (5.1)    1.14      726 (7.0)

An. dirus                585 (23.3)         795 (24.7)   7.84*    1234 (62.7)   1473 (55.9)   14.71*   4087 (39.6)

An. jamesi                    97 (3.9)      131 (4.1)    1.30       5 (0.3)          0        0.03      233 (2.3)

An. kochi                316 (12.6)         363 (11.3)   3.86      143 (7.3)     230 (8.7)    2.03     1052 (10.2)

An. maculatus            775 (30.9)        1016(31.5)    10.18*   413 (21.0)    590 (22.4)*   5.45*    2794 (27.0)*

An. minimus              278 (11.1)        444 (13.8)*   4.10      72 (3.7)      147 (5.6)*   1.19      941 (9.1)*

An. phillipinensis        123 (4.9)         112 (3.5)    1.34      19 (1.0)       37 (1.4)    0.30      291 (2.8)

An. tesselatus                15 (0.6)       5 (0.2)     0.06         0           1 (0.04)    0.01       21 (0.2)

An. vagus                     65 (2.6)       92 (2.9)    0.94       9 (0.5)       20 (0.8)    0.16      186 (1.8)

        Total                  2508           3221                   1969         2633*                   10331

 HBR = mosquitoes/human/12 hour collection period
 * Significance at p < 0.05
                 Discussion
• An. dirus HBR highest in FOREST
• An. maculatus HBR highest in AGRICULTURE
• An. minimus more prevalent in agriculture site
• An. dirus prevalent mosquito in both locations
  – Forest mosquitoes occasionally collected at forest
    fringes
  – Highly anthropophilic- our results show no significant
    difference between indoor and outdoor collections
  – Very difficult to control
                             ELISA Results
                              (Preliminary)
                                  Agriculture                                          Forest
       Species      Pv 210   Pf    Mixed       Mixed         EIR   Pv 210   Pf    Mixed           Mixed         EIR
                    or 247        (Pf + Pv)   (Pv210 +             or 247        (Pf + Pv)       (Pv210 +
                                               Pv247)                                             Pv247)

An. minimus s.l.    1        0    0           0          0.01      1        0    0           0              0.01

An. dirus s.l.*     2        4    1           2          0.05      0        0    0           0              0
An. philipinensis   0        0    0           0          0         0        0    0           0              0
An. tesellatus      0        0    0           0          0         0        0    0           0              0

An. vagus           0        0    0           0          0         0        0    0           0              0




  Pv = P. vivax
  Pf = P. falciparum
  •An. dirus collected from forest not yet tested
  •An. maculatus not yet tested
                     PCR Results
                 Anopheles minimus s.l.
                     (Preliminary)
         Percent of individuals identified morphologically as An. minimus
Site          An. minimus s.s.   An. harrisoni   An. aconitus   An. varuna   An. pampanai   Not identified
              (Species A)        (Species C)
Forest        60.91              0               14.09          1.82         1.82           7.73
Agriculture 50.96                0               13.84          20.68        0.27           9.18
ALL           52.84              0               13.89          16.21        0.63           9.27
                Conclusion
• Literature states deforestation may reduce the
  populations of An. dirus followed by invasion by
  other efficient vectors such as An. maculatus
  and An. minimus. Our data agrees with this and
  also suggests reestablishment of An. dirus in
  former forested areas.
• Species complex members demonstrate
  different behaviors, need to fully elucidate which
  members are present IN PROGRESS
• Correlate CSP+ data with species complex
  identification data IN PROGRESS
               Future Study
• Observe one complete year (wet and dry
  seasons) of anopheline population bionomics.
• Determine which vectors are most efficient and
  how habitat change will drive infection
• Correlate mosquito infection rates with human
  malaria prevalence in the two sites
• Larval surveillance compare with adult
  bionomics information

• Susceptibility of species complex members to
  current methods of control (insecticide treated
  bed nets, pesticides)
Control of Adult Mosquito Vectors
    on Military Installations in
 Singapore Using Mass Trapping
            Techniques

    K. A. Barbara1, A. Wilson2, L. C. Ng3,
         C. H. Tan3, and G. T. Brice1
           1US  Naval Medical Research Unit #2
              2Navy Region Center Singapore
         3Singapore National Environment Agency
  Navy Region Center Singapore
         Mass Trapping
• To determine the efficacy of a commercial
  mosquito trap (Mosquito Magnet Liberty Plus) in
  reducing prevalence of disease infected
  mosquito populations in a designated area
• Correlate trap catch with prevalence of infected
  mosquitoes and overall reduction in mosquito
  populations
• Determine the species composition and infection
  ratio of collected vectors
 Navy Region Center Singapore
        Mass Trapping
• 2 weeks CDC light trap “pre-treatment”
  surveillance (baseline)
• Trap line of 4 Mosquito Magnets in three
  areas with CDC light traps in control and
  treatment areas
• 6 week “treatment” period
• 2 weeks “post-treatment” surveillance
 Navy Region Center Singapore
        Mass Trapping
• Study initiated in January 2010
• Currently collecting data
• First field trial scheduled to be completed
  in March
• Second field trial to be conducted on
  Singapore Armed Forces training grounds
• FY11 funding requested to continue study
  on islands off the coast of Cambodia and
  Indonesia
      Future Studies NAMRU2
            Entomology
• FY10 Febrile Syndrome Surveillance in
  Cambodia (vector component)
• FY10/FY11 Mass Trapping on islands off
  Cambodia and Palau Seribu area near
  Jakarta
• FY12 Field collections of vectors to be
  tested using rapid dipstick testing being
  developed at WRAIR
      Acknowledgements
• The National Center for Parasitology,
  Entomology and Malaria Control, Phnom
  Penh, Cambodia
• National Environment Agency, Singapore
• Navy Region Center Singapore Public
  Works
• NAMRU2 entomology laboratory staff

								
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