Knowledge, attitudes and practice of communities of Wolaita, Southern Ethiopia about long-lasting insecticidal nets and evaluation of net fabric integrity and insecticidal activity

Optimal use of long-lasting insecticidal (LLINs) for malaria prevention depends on mass distribution, the users' perception and behaviour of local malaria vectors. This study was aimed at assessing knowledge, attitude and practice (KAP) of communities about LLINs and fabric integrities and insecticidal activities of nets under use in Wolaita zone, Sothern Ethiopia. Semi-structured interview questionnaires were used to collect data on KAP variables and WHO cone bioassay was used to test the insecticidal activity of sampled nets against an insectary colony of Anopheles arabiensis. Holes and repairs on surfaces of sample nets were counted and categorized following WHO guidelines to assess their fabric integrities. Chi-square (χ(2)) tests were used to verify associations between the demographic profiles of the respondents and their responses to KAP questionnaires. Out of a total of 770 household heads interviewed, 323 (42%) and 447 (58%) were males and females, respectively. The average family size in the surveyed households was 5.25 (±0.70 SE, range 1-12). The majority (81.1%) of the households owned at least one LLIN. The average numbers of LLINs being used and sleeping places in the households were 1.61 (0.04 SE, range 0-4) and 2.27(0.03 SE, range 1-6), respectively. Most of the respondents (n = 687; 89.2%) believed LLINs prevent malaria by killing or acting as physical barriers against mosquitoes. About 21 and 14% of the respondents considered children under five years and pregnant women as priority groups for sleeping under LLINs. Households use LLINs consistently throughout the year (86.4%) and tuck nets into bedding materials while sleeping (90.1%). Physical inspection of fabric integrity of sampled LLINs revealed holes ranging from size 1 (0.5-2 cm) to size 4 (> 25 cm) mostly on lower ("right/left") surfaces. Moreover, most surfaces of sampled LLINs caused 100% knockdown and mortality on insectary colonies of Anopheles arabiensis. The overall knowledge, attitude and practice about LLINs were satisfactory in the study areas. However, the family size net ratio must be narrowed and attention needs to be given to malaria vulnerable groups (children