Dr Jennifer StevensonLimonty Simubali

Dr Doug Norris

Macha, Choma – 1 site of southern Africa International Center of Excellence for Malaria Research (ICEMR

Collaboration with Johns Hopkins Bloomberg School of Public Health

Combined and complimentary studies on malaria epidemiology, vector biology and parasite genetics/genomics

ICEMR Vector Biology

◦ Basic vector biology/bionomics

◦ Vector behavior

◦ Response to interventions

◦ Vector genetics

◦ Insecticide resistance

parasitemia

gametocytemia

antibodies anemia

insecticide

treated nets

anopheline

vectors

ecological

risk factorsknowledge

and practices

CDC light traps - current

Pyrethrum spray catches

Human landing catches

Larval surveys

Mosquitoes are identified using guides based on their physical appearance

Identities are confirmed using molecular techniques – PCR

The source of the bloodmeal is indentified using PCR

Infection status is determined using ELISA

0

2

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6

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Mean no. Anopheles per trap per night

Cross-sectional

Longitudinal

April 2012 - March 2013Total different households visited: 125Total traps set 267Total female Anopheles caught 847Mean catch per trap 3.17

175 anophelines

caught in one house, 70% arabiensis

=Household with

Anopheles

=Household without

Anopheles

Morphological identification

n=981An. gambiae

An. squamosus

An. coustani

An. rufipes

An. longipalpis

An. pretoriensis

An. funestus

An.longipalpis

An. dureni

Molecular identification

n= 103 An. arabiensis

An. coustani

An. leesoni

An. longipalpis

An. parensis

An. pretoriensis

An. quadriannulaus

An. rufipes

ITS2 = 300 bp

ITS2 = 350 bp

ITS2 = 450 bp

ITS2 = 300 bp

Colonies of An.arabiensis, original collections from Macha area

Used for

◦ bioassays – testing effectiveness of control measures e.g. nets, indoor spraying

◦ studying mosquito behaviour in the lab

◦ training

◦ supply for other insectaries

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January –March 2012Locality Species Insecticide Mean

Mortality

Macha An. arabiensisDeltamethrin

(F1)100% (27)

Namwala

An. rivulorum

Deltamethrin(Field and F1)

100 % (n=126)

DDT(Field and F1)

100 % (n=113)

Bendiocarb( F1)

100 % (n=78)

An. arabiensis

Deltamethrin (Field)

100 % (n=4)

Deltamethrin(F1)

80% (n=10)

Namwalinda An. arabiensisDeltamethrin

(F1)100 % (n=27)

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An. arabiensis colony: 100% mortality

F1 field mosquitoes: 88% mortality

Norris L & Norris D, Malaria Journal 2011, 10:254

LLIN efficacy

Collection of 19 nets from 16 households. Nets were

2 year old deltamethrin LLINs

Norris L & Norris D, Malaria Journal 2011, 10:254

Household ID

very small holes(<1 cm)

small holes(1-5 cm)

medium holes(5-15 cm)

large holes(15-30 cm)

very large holes (>30 cm)

HH1-H2 2 1

HH3-H5 2 1

HH3-H8 3

HH4-H5 7 1

HH5-H1 1

HH6-H2 4 3

HH12-H3

HH13-H2

HH16-H2

HH19-H7 10 2

HH55-H8 2 5 2 2

HH58-H1 2 1

HH70-H4 15 10 1

HH75-H4

HH75-H5

HH79-H1 9 2 4

HH81-H1 1

HH90-H1 1 1

HH90-H2 1

Indoor vs outdoor feeding

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2

4

6

8

10

12

Dec07 Jan08 Feb08 Mar08 Apr08 Dec08 Jan09 Feb09 Mar09 Apr09

Seasonality of An. arabiensis Caught by HLC Pairs during the

2007-2008 and 2008-2009 Rainy Seasons

Paired indoor and outdoor HLCs were conducted

2008 - 130 inside, 279 outside

2009 - 61 inside, 96 outside

HLCs outside

caught

roughly 1.7 x

as many as

indoors

An. arabiensis caught by HLC Pairs December to April

Indoor vs outdoor, Biting Times

2008 Season

2009 SeasonOutdoor Biting Indoor Biting

Outdoor Biting Indoor Biting

• Overall 14% of HLC collections occurred before 10pm

Entomological surveillance and behavioural studies as part of national activities aimed to make southern Zambia malaria-free

Further evaluation of effectiveness of nets and IRS

Training and support for external projects for molecular assays

Refurbishment of insectary to house a standard global reference strain

Construction of a new insectary for locally caught colonies

Proposal of development of a malaria sphere

Large insect-proof greenhouses

Mosquitoes released inside or

colonies maintained inside

Used to study:◦ behaviour of mosquitoes

◦ effect of interventions

The community of Choma

ICEMR Team

MRT Team

Funding: MRT& The Johns Hopkins Malaria Research Institute, NIH ICEMR Program