| dc.creator |
Musa, Jeremiah John |
|
| dc.date |
2020-11-18T08:56:46Z |
|
| dc.date |
2020-11-18T08:56:46Z |
|
| dc.date |
2020-03 |
|
| dc.date.accessioned |
2022-10-25T09:19:09Z |
|
| dc.date.available |
2022-10-25T09:19:09Z |
|
| dc.identifier |
https://dspace.nm-aist.ac.tz/handle/20.500.12479/1008 |
|
| dc.identifier.uri |
http://hdl.handle.net/123456789/94791 |
|
| dc.description |
A Dissertation Submitted in Partial Fulfilment of the Requirements for the Degree of
Master of Science in Public Health Research of the Nelson Mandela African Institution of
Science and Technology |
|
| dc.description |
Long Lasting Insecticidal Nets (LLINs) are the most sustainable and effective malaria control tool
currently available. Global targets are for ≥80% of the population living in malaria endemic areas
to have access to and use a LLIN. However, current access to LLINs in endemic areas is 56% due
to system inefficiencies and budget limitations. Thus, cost-effective approaches to maximize
access of effective LLINs in endemic areas are required. This study evaluated whether LLINs that
had been stored for more than five years under manufacturer recommended conditions may be
optimally effective against Anopheles mosquitoes, to inform malaria control programs and
governments on the periods over which LLINs may be stored between distributions, in an effort
to maximise use of available LLINs. Standard World Health Organization (WHO) bioassays (cone
and tunnel tests) were used to evaluate the bio-efficacy and wash resistance of Olyset
®
and
DawaPlus
®
2.0
(rebranded Tsara
®
Soft) LLINs after five years of storage at 25
C - 33.4C and
40%-100% relative humidity. In addition, a small scale Ifakara Ambient Chamber test (I-ACT)
was conducted to compare bio-efficacy of one long stored LLIN to one new LLIN of the same
brand, unwashed and washed. Long-lasting insecticidal nets were evaluated using laboratory
reared fully susceptible Anopheles gambiae sensu stricto (s.s) (Ifakara str
ain) and pyrethroid
resistant Anopheles arabiensis (Kingani strain). After five years of storage, both unwashed and
washed Olyset
®
and DawaPlus
®
2.0
LLINs passed WHO efficacy criteria on Knockdown (KD60)
≥95%, 24-h
r mortality ≥ 80% and ≥90% blood-feeding inhibition as per conducted WHO
bioassays against susceptible An. gambiae s.s. The DawaPlus
®
2.0 LLINs also passed combined
WHO bio-assay criteria against resistant An. arabiensis. Confirmatory I-ACT test using whole
nets demonstrated that long stored LLINs showed similar efficacy to new LLINs on both feeding
inhibition and mortality endpoints against susceptible and resistant strains. Therefore, even after
long storage of around 5 years, both Olyset
®
and DawaPlus
®
2.0 remain efficacious against
susceptible Anopheles mosquitoes at optimal storage range of 25
C - 33.4C and 40%-100%
relative humidity measured by standard WHO methods. DawaPlus
®
2.0 remained efficacious
against pyrethroid-resistant strain. |
|
| dc.format |
application/pdf |
|
| dc.language |
en |
|
| dc.publisher |
NM-AIST |
|
| dc.rights |
Attribution-NonCommercial-ShareAlike 4.0 International |
|
| dc.rights |
http://creativecommons.org/licenses/by-nc-sa/4.0/ |
|
| dc.subject |
Long storage nets |
|
| dc.subject |
Long lasting insecticidal nets |
|
| dc.title |
Bio-efficacy evaluation of long-lasting insecticidal nets after five years of storage: implications for malaria control programmes |
|
| dc.type |
Thesis |
|