Aquatic habitats of the malaria vector, Anopheles funestus in rural south-eastern Tanzania
Background In rural south-eastern Tanzania, Anopheles funestus is a major malaria vector, and has been implicated in nearly 90% of all infective bites. Unfortunately, little is known about the natural ecological requirements and survival strategies of this mosquito species.
Methods Potential mosquito aquatic habitats were systematically searched along 1000 m transects from the centres of six villages in south-eastern Tanzania. All water bodies were geo-referenced, characterized and examined for presence of Anopheles larvae using standard 350mls dippers or 10L buckets. Larvae were collected for rearing, and the emergent adults identified to confirm habitats containing An. funestus.
Results One hundred and eleven (111) habitats were identified and assessed from the first five villages (all <300m altitude). Of these, 36 (32.4%) had An. funestus co-occurring with other mosquito species. Another 47 (42.3%) had other Anopheles species and/or culicines, but not An. funestus, and 28 (25.2%) had no mosquitoes. There were three main habitat types occupied by An. funestus, namely: a) small spring-fed pools with well-defined perimeters (36.1%), b) medium-sized natural ponds retaining water most of the year (16.7%), and c) slow-moving waters along river tributaries (47.2%). The habitats generally had clear waters with emergent surface vegetation, depths > 0.5m and distances < 100m from human dwellings. They were permanent or semi-permanent, retaining water most of the year. Water temperatures ranged from 25.2 to 28.8°C, pH from 6.5 to 6.7, turbidity from 26.6 to 54.8 NTU and total dissolved solids from 60.5 to 80.3 mg/L. In the sixth village (altitude >400m), very high densities of An. funestus were found along rivers with slow-moving clear waters and emergent vegetation.
Conclusion This study has documented the diversity and key characteristics of aquatic habitats of An. funestus across villages in south-eastern Tanzania, and will form an important basis for further studies to improve malaria control. The observations suggest that An. funestus habitats in the area can indeed be described as fixed, few and findable based on their unique characteristics. Future studies should investigate the potential of targeting these habitats with larviciding or larval source management to complement malaria control efforts in areas dominated by this vector species.
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Posted 15 Jun, 2020
On 23 Jun, 2020
On 13 Jun, 2020
On 12 Jun, 2020
On 11 Jun, 2020
On 11 Jun, 2020
On 08 Jun, 2020
On 05 Jun, 2020
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On 17 May, 2020
Received 12 May, 2020
Received 12 May, 2020
Received 06 May, 2020
On 15 Apr, 2020
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On 03 Apr, 2020
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Aquatic habitats of the malaria vector, Anopheles funestus in rural south-eastern Tanzania
Posted 15 Jun, 2020
On 23 Jun, 2020
On 13 Jun, 2020
On 12 Jun, 2020
On 11 Jun, 2020
On 11 Jun, 2020
On 08 Jun, 2020
On 05 Jun, 2020
On 04 Jun, 2020
On 04 Jun, 2020
On 17 May, 2020
Received 12 May, 2020
Received 12 May, 2020
Received 06 May, 2020
On 15 Apr, 2020
On 14 Apr, 2020
On 14 Apr, 2020
Invitations sent on 14 Apr, 2020
On 03 Apr, 2020
On 02 Apr, 2020
On 01 Apr, 2020
On 31 Mar, 2020
Background In rural south-eastern Tanzania, Anopheles funestus is a major malaria vector, and has been implicated in nearly 90% of all infective bites. Unfortunately, little is known about the natural ecological requirements and survival strategies of this mosquito species.
Methods Potential mosquito aquatic habitats were systematically searched along 1000 m transects from the centres of six villages in south-eastern Tanzania. All water bodies were geo-referenced, characterized and examined for presence of Anopheles larvae using standard 350mls dippers or 10L buckets. Larvae were collected for rearing, and the emergent adults identified to confirm habitats containing An. funestus.
Results One hundred and eleven (111) habitats were identified and assessed from the first five villages (all <300m altitude). Of these, 36 (32.4%) had An. funestus co-occurring with other mosquito species. Another 47 (42.3%) had other Anopheles species and/or culicines, but not An. funestus, and 28 (25.2%) had no mosquitoes. There were three main habitat types occupied by An. funestus, namely: a) small spring-fed pools with well-defined perimeters (36.1%), b) medium-sized natural ponds retaining water most of the year (16.7%), and c) slow-moving waters along river tributaries (47.2%). The habitats generally had clear waters with emergent surface vegetation, depths > 0.5m and distances < 100m from human dwellings. They were permanent or semi-permanent, retaining water most of the year. Water temperatures ranged from 25.2 to 28.8°C, pH from 6.5 to 6.7, turbidity from 26.6 to 54.8 NTU and total dissolved solids from 60.5 to 80.3 mg/L. In the sixth village (altitude >400m), very high densities of An. funestus were found along rivers with slow-moving clear waters and emergent vegetation.
Conclusion This study has documented the diversity and key characteristics of aquatic habitats of An. funestus across villages in south-eastern Tanzania, and will form an important basis for further studies to improve malaria control. The observations suggest that An. funestus habitats in the area can indeed be described as fixed, few and findable based on their unique characteristics. Future studies should investigate the potential of targeting these habitats with larviciding or larval source management to complement malaria control efforts in areas dominated by this vector species.
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Figure 5