Transmission potentials status of simulium damnosum and willingness to comply with Ivermectin Treatment in Imo River Basin, Nigeria

Abstract

Entomological, quantitative and qualitative data collection on willingness to comply with ivermectin treatment was conducted between May 2019 and March 2020 in Imo River Basin Nigeria. Simulium damnosum collected at Rivers Lolo and Ibii breeding sites by human-bait technique was assessed for transmission indices by standard methods. Structured questionnaires were used to ascertain compliance levels by communities (Umulolo and Amuro) and willingness to sustain the long-term ivermectin treatment. Entomologic indices (overall and specific for both sites) showed that infection, infective and parous rates were 0.7% (0.6% versus 0.7%), 0.0% (0.0% versus 0.0%), and 21.0% (22.3% versus 19.9%) respectively. Monthly biting rate (MBR) and monthly parous biting rate (MPBR) were 6,779.25 (3,291.75 versus 3,507.75) and 1,427.25 (770.0 versus 657.25) bites/person/month. Monthly transmission potentials (MTP) were zero indicative of no transmission. Of the 458 interviewed, 31.6% and 68.3% were males and females respectively. Among them, 66.8% were males and 67.4% were females treated before and 21 (14.5%) and 38 (121.1%) were high compliers. Sex did not affect the rate of compliance (p>0.05). Age group 25 years and above (74.3%) had been treated before with 21.3% high compliers among age groups. Analysis of data revealed that age significantly affected the intake of drug (p0.05). Suggested ways to improve compliance were documented and findings discussed in the context of possible onchocerciasis elimination.