Assessing bed net damage: comparisons of three measurement methods for estimating the size, shape, and distribution of holes on bed nets
Abstract Background Measuring the physical condition of long-lasting insecticidal nets (LLINs) under field conditions is of great importance for malaria control programmes to guide decisions on how frequently to replace LLINs. Current guidelines by the World Health Organization Pesticide Evaluation...
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ftdoajarticles:oai:doaj.org/article:7b83d16716fc44b1a764e83fa2ecffcc 2023-05-15T15:17:27+02:00 Assessing bed net damage: comparisons of three measurement methods for estimating the size, shape, and distribution of holes on bed nets Jodi L. Vanden Eng Don P. Mathanga Keren Landman Dyson Mwandama Anna A. Minta Monica Shah James Sutcliffe Joseph Chisaka Kim A. Lindblade Laura Steinhardt 2017-10-01T00:00:00Z https://doi.org/10.1186/s12936-017-2049-8 https://doaj.org/article/7b83d16716fc44b1a764e83fa2ecffcc EN eng BMC http://link.springer.com/article/10.1186/s12936-017-2049-8 https://doaj.org/toc/1475-2875 doi:10.1186/s12936-017-2049-8 1475-2875 https://doaj.org/article/7b83d16716fc44b1a764e83fa2ecffcc Malaria Journal, Vol 16, Iss 1, Pp 1-13 (2017) Bed net Physical durability Hole index Malaria Vector control Image analysis Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 article 2017 ftdoajarticles https://doi.org/10.1186/s12936-017-2049-8 2022-12-31T14:12:13Z Abstract Background Measuring the physical condition of long-lasting insecticidal nets (LLINs) under field conditions is of great importance for malaria control programmes to guide decisions on how frequently to replace LLINs. Current guidelines by the World Health Organization Pesticide Evaluation Scheme (WHOPES) propose a proportionate hole index (pHI) for assessing LLIN condition by counting the number of holes the size of a thumb, fist, head, and larger than a head. However, this method does not account for irregular hole shapes or exact hole sizes which could result in inaccurate decisions about when to replace LLINs. Methods LLINs were collected during a 2013 health facility-based malaria case control study in Machinga District, Malawi. To evaluate the accuracy of the pHI, the physical condition of 277 LLINs was estimated by the WHOPES method and then compared with two more thorough measurement methods: image analysis of digital photographs of each LLIN side; and for 10 nets, ruler measurements of the length, width, and location of each hole. Total hole counts and areas per net were estimated by each method, and detailed results of hole shapes and composite pictures of hole locations were generated using image analysis. Results The WHOPES method and image analysis resulted in similar estimates of total hole counts, each with a median of 10 (inter-quartile range (IQR) 4–24 and 4–23, respectively; p = 0.004); however, estimated hole areas were significantly larger using the WHOPES method (median 162 cm2, IQR 28–793) than image analysis (median 13 cm2, IQR 3–101; p < 0.0001). The WHOPES method classified fewer LLINs in ‘good condition’ compared to image analysis (42% vs 74%). The ruler method detected significantly more holes than image analysis did (p = 0.002) in 10 LLINs; however, total hole area was not significantly different (p = 0.16). Most holes were not circular but roughly 2–5 times longer in one direction. The lower quarter of LLIN sides was found to have the most holes. Conclusions The WHOPES ... Article in Journal/Newspaper Arctic Directory of Open Access Journals: DOAJ Articles Arctic Thumb ENVELOPE(-64.259,-64.259,-65.247,-65.247) Malaria Journal 16 1 |
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Directory of Open Access Journals: DOAJ Articles |
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ftdoajarticles |
language |
English |
topic |
Bed net Physical durability Hole index Malaria Vector control Image analysis Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 |
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Bed net Physical durability Hole index Malaria Vector control Image analysis Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 Jodi L. Vanden Eng Don P. Mathanga Keren Landman Dyson Mwandama Anna A. Minta Monica Shah James Sutcliffe Joseph Chisaka Kim A. Lindblade Laura Steinhardt Assessing bed net damage: comparisons of three measurement methods for estimating the size, shape, and distribution of holes on bed nets |
topic_facet |
Bed net Physical durability Hole index Malaria Vector control Image analysis Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 |
description |
Abstract Background Measuring the physical condition of long-lasting insecticidal nets (LLINs) under field conditions is of great importance for malaria control programmes to guide decisions on how frequently to replace LLINs. Current guidelines by the World Health Organization Pesticide Evaluation Scheme (WHOPES) propose a proportionate hole index (pHI) for assessing LLIN condition by counting the number of holes the size of a thumb, fist, head, and larger than a head. However, this method does not account for irregular hole shapes or exact hole sizes which could result in inaccurate decisions about when to replace LLINs. Methods LLINs were collected during a 2013 health facility-based malaria case control study in Machinga District, Malawi. To evaluate the accuracy of the pHI, the physical condition of 277 LLINs was estimated by the WHOPES method and then compared with two more thorough measurement methods: image analysis of digital photographs of each LLIN side; and for 10 nets, ruler measurements of the length, width, and location of each hole. Total hole counts and areas per net were estimated by each method, and detailed results of hole shapes and composite pictures of hole locations were generated using image analysis. Results The WHOPES method and image analysis resulted in similar estimates of total hole counts, each with a median of 10 (inter-quartile range (IQR) 4–24 and 4–23, respectively; p = 0.004); however, estimated hole areas were significantly larger using the WHOPES method (median 162 cm2, IQR 28–793) than image analysis (median 13 cm2, IQR 3–101; p < 0.0001). The WHOPES method classified fewer LLINs in ‘good condition’ compared to image analysis (42% vs 74%). The ruler method detected significantly more holes than image analysis did (p = 0.002) in 10 LLINs; however, total hole area was not significantly different (p = 0.16). Most holes were not circular but roughly 2–5 times longer in one direction. The lower quarter of LLIN sides was found to have the most holes. Conclusions The WHOPES ... |
format |
Article in Journal/Newspaper |
author |
Jodi L. Vanden Eng Don P. Mathanga Keren Landman Dyson Mwandama Anna A. Minta Monica Shah James Sutcliffe Joseph Chisaka Kim A. Lindblade Laura Steinhardt |
author_facet |
Jodi L. Vanden Eng Don P. Mathanga Keren Landman Dyson Mwandama Anna A. Minta Monica Shah James Sutcliffe Joseph Chisaka Kim A. Lindblade Laura Steinhardt |
author_sort |
Jodi L. Vanden Eng |
title |
Assessing bed net damage: comparisons of three measurement methods for estimating the size, shape, and distribution of holes on bed nets |
title_short |
Assessing bed net damage: comparisons of three measurement methods for estimating the size, shape, and distribution of holes on bed nets |
title_full |
Assessing bed net damage: comparisons of three measurement methods for estimating the size, shape, and distribution of holes on bed nets |
title_fullStr |
Assessing bed net damage: comparisons of three measurement methods for estimating the size, shape, and distribution of holes on bed nets |
title_full_unstemmed |
Assessing bed net damage: comparisons of three measurement methods for estimating the size, shape, and distribution of holes on bed nets |
title_sort |
assessing bed net damage: comparisons of three measurement methods for estimating the size, shape, and distribution of holes on bed nets |
publisher |
BMC |
publishDate |
2017 |
url |
https://doi.org/10.1186/s12936-017-2049-8 https://doaj.org/article/7b83d16716fc44b1a764e83fa2ecffcc |
long_lat |
ENVELOPE(-64.259,-64.259,-65.247,-65.247) |
geographic |
Arctic Thumb |
geographic_facet |
Arctic Thumb |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
Malaria Journal, Vol 16, Iss 1, Pp 1-13 (2017) |
op_relation |
http://link.springer.com/article/10.1186/s12936-017-2049-8 https://doaj.org/toc/1475-2875 doi:10.1186/s12936-017-2049-8 1475-2875 https://doaj.org/article/7b83d16716fc44b1a764e83fa2ecffcc |
op_doi |
https://doi.org/10.1186/s12936-017-2049-8 |
container_title |
Malaria Journal |
container_volume |
16 |
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1 |
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1766347689106079744 |