Department of Nursing

MOSQUITOCIDAL EFFECTS OF ORALLY ADMINISTERED IVERMECTIN AGAINST ANOPHELES GAMBIAE SENSU STRICTO

2024-02-21T09:18:29Z

MOSQUITOCIDAL EFFECTS OF ORALLY ADMINISTERED IVERMECTIN AGAINST ANOPHELES GAMBIAE SENSU STRICTO TUWEI, JEPKEMBOI MERCY Introduction: The progress towards malaria elimination has relatively stagnated since 2015 attributed in part to the over reliance on insecticide-based vector control methods and ensuing selective pressure that has led to increased insensitivity of vectors to insecticides and behavioral changes that contribute to the persistence of malaria transmission. New and improved vector control approaches are needed to supplement existing tools. Endectocides and ivermectin is one such tool. This current study was undertaken to evaluate the mosquitocidal effect of different ivermectin oral regimens on Anopheles gambiae s.s mosquitoes with the aim of gathering evidence on most advantageous dose regimen for mass drug administration campaigns for malaria vector control. Methods: A Phase II open-label randomised controlled trial was carried out as part of the Broad One-Health Endectocide-based Malaria initiative in Africa project (BOHEMIA). Sixteen healthy human subjects were recruited from Ngerenya village (Kilifi) and randomized into three groups: 1) single dose 400mcg/Kg; 2) 300mcg/Kg given once a day for three consecutive days; and 3) control (no treatment). Participants were enrolled in four permuted cohorts of four participants each (3 participants were assigned to an ivermectin-treatment and 1 to control). Participants were followed up for 28 days during which blood was withdrawn at different time’s points (Day 0+4hrs, D7, D10, D14, D21, and D28) and fed to mosquitoes to assess mosquitocidal effect post-treatment. Mosquito blood feeding was done by direct membrane feeding assay (DMFA), where a total of 150 insectary reared female An. gambiae s.s Kilifi strain (2-5 days old) were fed on each participant blood collected at the different timepoints. After blood feeding mosquitoes were kept under standard insectary conditions and monitored for daily survival for 28 days. Data was analyzed with STATA Version 17 software using Kaplan Meier curves for survival curve estimation, log rank test for a statistical comparison and Cox proportional hazard regressions to show the variability in the drug effect. Results: Ivermectin at a dose of 400mcg/kg given once was effective for 21 days (HR=1.80 (1.46-2.23), p<0.0001) while 300mcg/kg given thrice taking 28 days (HR=2.53 (2.06-3.10), P<0.0001). Mosquitoes fed on 400mcg/kg blood at 0+4hrs (HR=22.14 (17.07-28.72), p<0.0001) to day 7 (HR=4.56 (3.8-5.45), p<0.0001) post treatment and 300mcg/kg blood at 0+4hrs (HR=8.72 (7.25-10.49), p<0.0001) was unlikely to survive for more than 10 days. Overall, the median mosquito survival time was 17 and 23 days for ivermectin 400mcg/kg and 300mcg/kg respectively. Conclusion: Single high dose ivermectin 400mcg/kg was more hazardous to mosquitoes than 300mcg/kg given thrice. Sustained mosquitocidal effect was observed for both doses for a period of 21 days’ post treatment. Ivermectin 400mcg/kg is a good candidate for MDA against malaria vectors. The dose regime provides adequate mosquitocidal effect for 21 days. Furthermore, 400mcg/Kg is already approved for human use in countries with stringent regulatory approvals (SRA) and is likely to be more feasible to administer in an MDA campaign ensuring higher levels of compliance compared to a 3-day regimen. Keywords: Malaria, An. gambiae s.s, ivermectin, endectocide, direct membrane feeding assay, randomised controlled trial, Kilifi Introduction: The progress towards malaria elimination has relatively stagnated since 2015 attributed in part to the over reliance on insecticide-based vector control methods and ensuing selective pressure that has led to increased insensitivity of vectors to insecticides and behavioral changes that contribute to the persistence of malaria transmission. New and improved vector control approaches are needed to supplement existing tools. Endectocides and ivermectin is one such tool. This current study was undertaken to evaluate the mosquitocidal effect of different ivermectin oral regimens on Anopheles gambiae s.s mosquitoes with the aim of gathering evidence on most advantageous dose regimen for mass drug administration campaigns for malaria vector control. Methods: A Phase II open-label randomised controlled trial was carried out as part of the Broad One-Health Endectocide-based Malaria initiative in Africa project (BOHEMIA). Sixteen healthy human subjects were recruited from Ngerenya village (Kilifi) and randomized into three groups: 1) single dose 400mcg/Kg; 2) 300mcg/Kg given once a day for three consecutive days; and 3) control (no treatment). Participants were enrolled in four permuted cohorts of four participants each (3 participants were assigned to an ivermectin-treatment and 1 to control). Participants were followed up for 28 days during which blood was withdrawn at different time’s points (Day 0+4hrs, D7, D10, D14, D21, and D28) and fed to mosquitoes to assess mosquitocidal effect post-treatment. Mosquito blood feeding was done by direct membrane feeding assay (DMFA), where a total of 150 insectary reared female An. gambiae s.s Kilifi strain (2-5 days old) were fed on each participant blood collected at the different timepoints. After blood feeding mosquitoes were kept under standard insectary conditions and monitored for daily survival for 28 days. Data was analyzed with STATA Version 17 software using Kaplan Meier curves for survival curve estimation, log rank test for a statistical comparison and Cox proportional hazard regressions to show the variability in the drug effect. Results: Ivermectin at a dose of 400mcg/kg given once was effective for 21 days (HR=1.80 (1.46-2.23), p<0.0001) while 300mcg/kg given thrice taking 28 days (HR=2.53 (2.06-3.10), P<0.0001). Mosquitoes fed on 400mcg/kg blood at 0+4hrs (HR=22.14 (17.07-28.72), p<0.0001) to day 7 (HR=4.56 (3.8-5.45), p<0.0001) post treatment and 300mcg/kg blood at 0+4hrs (HR=8.72 (7.25-10.49), p<0.0001) was unlikely to survive for more than 10 days. Overall, the median mosquito survival time was 17 and 23 days for ivermectin 400mcg/kg and 300mcg/kg respectively. Conclusion: Single high dose ivermectin 400mcg/kg was more hazardous to mosquitoes than 300mcg/kg given thrice. Sustained mosquitocidal effect was observed for both doses for a period of 21 days’ post treatment. Ivermectin 400mcg/kg is a good candidate for MDA against malaria vectors. The dose regime provides adequate mosquitocidal effect for 21 days. Furthermore, 400mcg/Kg is already approved for human use in countries with stringent regulatory approvals (SRA) and is likely to be more feasible to administer in an MDA campaign ensuring higher levels of compliance compared to a 3-day regimen. Keywords: Malaria, An. gambiae s.s, ivermectin, endectocide, direct membrane feeding assay, randomised controlled trial, Kilifi

EXPLORING INTRODUCTIONS AND SPREAD OF HUMAN CORONAVIRUSES IN KILIFI, COASTAL KENYA, BY ANALYSIS OF EPIDEMIOLOGICAL AND MOLECULAR SEQUENCE DATA, 2015-2016

2022-02-10T06:21:24Z

EXPLORING INTRODUCTIONS AND SPREAD OF HUMAN CORONAVIRUSES IN KILIFI, COASTAL KENYA, BY ANALYSIS OF EPIDEMIOLOGICAL AND MOLECULAR SEQUENCE DATA, 2015-2016 ABIDHA, AKINYI CAROL Human coronaviruses (HCoV) OC43 and NL63 are globally endemic viruses that contribute to mild and severe respiratory tract infections. These two have been previously observed to be the most prevalent HCoV strains in childhood acute respiratory illness surveillance studies in Kenya. However, their molecular epidemiology including the pathways of introduction and spread are not well understood. This study reports on the origins and spread of HCoV-OC43 and NL63 detected at the Kenyan Coast by integrating molecular and epidemiological data. Archived HCoV positive nasopharyngeal samples (n=169) collected between December 2015 and June 2016 in Coastal Kenya, Kilifi, were sequenced and analyzed. These samples were from either hospitalized <5-year olds or individuals across all age groups attending the 9 peripheral Health Centres across Kilifi Health and Demographic Surveillance System. They were identified as HCoV-NL63 or OC43 positive by a multiplex real time RT-PCR diagnostic assay targeting the RNA dependent RNA polymerase gene. Extracted viral RNA was reverse transcribed, PCR amplified and sequenced in the Spike protein-encoding gene. Resultant sequences were assembled and phylogenetically analyzed. A total of 77/3314 (2.3%) and 92/3314 (2.8%) samples tested positive for HCoV-NL63 and OC43 respectively. Of these, 31 (2.3kb) NL63 and 40 (3.5kb) OC43 positives were successfully sequenced. Four NL63 and Three OC43 genetic variants were identified based on the nucleotide differences and clustering on the global phylogeny. The NL63 and OC43 strains did not cluster by Health Centre except at the global level. Two Kilifi variants of NL63 were not found elsewhere globally. Majority of NL63 and OC43 identified variants were identical in spike sequence across Health Centres. HCoV-OC43 vi and NL63 incidence appeared to be out of phase in temporal occurrence. Low HCoVNL63 virus titers appeared to be the main reason for its failed spike gene amplifications. The HCoV-NL63 and OC43 that circulated in Kilifi over the six months appeared to represent multiple variant importations. This makes it possible for HCoV-OC43 and NL63 to persist locally. Sharing of the variants across Health Centres suggests a rapid virus spread and extensive mixing of the Kilifi HDSS population. This warrants continuous surveillance of endemic HCoVs with a pandemic potential Human coronaviruses (HCoV) OC43 and NL63 are globally endemic viruses that contribute to mild and severe respiratory tract infections. These two have been previously observed to be the most prevalent HCoV strains in childhood acute respiratory illness surveillance studies in Kenya. However, their molecular epidemiology including the pathways of introduction and spread are not well understood. This study reports on the origins and spread of HCoV-OC43 and NL63 detected at the Kenyan Coast by integrating molecular and epidemiological data. Archived HCoV positive nasopharyngeal samples (n=169) collected between December 2015 and June 2016 in Coastal Kenya, Kilifi, were sequenced and analyzed. These samples were from either hospitalized <5-year olds or individuals across all age groups attending the 9 peripheral Health Centres across Kilifi Health and Demographic Surveillance System. They were identified as HCoV-NL63 or OC43 positive by a multiplex real time RT-PCR diagnostic assay targeting the RNA dependent RNA polymerase gene. Extracted viral RNA was reverse transcribed, PCR amplified and sequenced in the Spike protein-encoding gene. Resultant sequences were assembled and phylogenetically analyzed. A total of 77/3314 (2.3%) and 92/3314 (2.8%) samples tested positive for HCoV-NL63 and OC43 respectively. Of these, 31 (2.3kb) NL63 and 40 (3.5kb) OC43 positives were successfully sequenced. Four NL63 and Three OC43 genetic variants were identified based on the nucleotide differences and clustering on the global phylogeny. The NL63 and OC43 strains did not cluster by Health Centre except at the global level. Two Kilifi variants of NL63 were not found elsewhere globally. Majority of NL63 and OC43 identified variants were identical in spike sequence across Health Centres. HCoV-OC43 vi and NL63 incidence appeared to be out of phase in temporal occurrence. Low HCoVNL63 virus titers appeared to be the main reason for its failed spike gene amplifications. The HCoV-NL63 and OC43 that circulated in Kilifi over the six months appeared to represent multiple variant importations. This makes it possible for HCoV-OC43 and NL63 to persist locally. Sharing of the variants across Health Centres suggests a rapid virus spread and extensive mixing of the Kilifi HDSS population. This warrants continuous surveillance of endemic HCoVs with a pandemic potential

CONCOMITANT HEROIN USE AMONG RECIPIENTS OF MEDICALLY (METHADONE) ASSISTED THERAPY ENROLLED IN MALINDI SUB-COUNTY HOSPITAL

2022-02-10T06:21:11Z

CONCOMITANT HEROIN USE AMONG RECIPIENTS OF MEDICALLY (METHADONE) ASSISTED THERAPY ENROLLED IN MALINDI SUB-COUNTY HOSPITAL HMED, AZRAA MAHMOUD Concomitant Heroine Use (CHU) negatively impacts the success of Medically (Methadone) Assisted Therapy (MAT) against substance abuse among addicts. We aimed to assess the prevalence, risks factors and context of CHU among MAT recipients at the Malindi Sub- County Hospital. A mixed methods design involving quantitative and qualitative methods was used. A convenient cross sectional sample of persons who used drugs (PWUDs) and on MAT were recruited. Quantitative work involved interviewer administered questionnaires among PWUDS (N=156), whilst qualitative work included focused group discussions (FGDs, N=2) amongst care providers (N=24). CHU was determined based on a rapid urine drug test from urine samples. Of the 156 participants, 38 (24%) were female, median age 35 years. Overall CHU was 30.1% (95% confidence interval (CI): 23.0-38.0); 31.3% (37/118) among men and 26.3% (10/38) among women (p=0.6). Self-reported heroine-use in the last month was 27.1% for men, and21.1% for women (p=0.5). In multivariate regression, adjusted for age, gender, and education, sex work in the previous 3 months (Adjusted odds ratio (aOR): 5.3 (95% CI: 1.5-18.9), and history of defaulting (aOR: 3.0 (95%CI: 1.4-6.7) were strongly associated with CHU. While clinic and support staff had the impression that CHU was low, three out of ten MAT clients in Malindi used heroine concomitantly. Perceived challenges included poor psychosocial counseling adherence and lack of enough resources. Care providers suggested systematic education strategies to empower PWUDs towards harm reduction, including abstinence to CHU. High levels (30%) of CHU were observed amongst PWUDs on the Methadone programme in this setting. CHU continues across MAT attendees despite, the perception that CHU gradually reduces. Sex work and defaulting were strongly associated with CHU, therefore vi interventions aimed at addressing the two and customized package of care to improve MAT adherence will further help reduce CHU. Keywords: Concomitant Heroin Use, Sex Work, Defa Concomitant Heroine Use (CHU) negatively impacts the success of Medically (Methadone) Assisted Therapy (MAT) against substance abuse among addicts. We aimed to assess the prevalence, risks factors and context of CHU among MAT recipients at the Malindi Sub- County Hospital. A mixed methods design involving quantitative and qualitative methods was used. A convenient cross sectional sample of persons who used drugs (PWUDs) and on MAT were recruited. Quantitative work involved interviewer administered questionnaires among PWUDS (N=156), whilst qualitative work included focused group discussions (FGDs, N=2) amongst care providers (N=24). CHU was determined based on a rapid urine drug test from urine samples. Of the 156 participants, 38 (24%) were female, median age 35 years. Overall CHU was 30.1% (95% confidence interval (CI): 23.0-38.0); 31.3% (37/118) among men and 26.3% (10/38) among women (p=0.6). Self-reported heroine-use in the last month was 27.1% for men, and21.1% for women (p=0.5). In multivariate regression, adjusted for age, gender, and education, sex work in the previous 3 months (Adjusted odds ratio (aOR): 5.3 (95% CI: 1.5-18.9), and history of defaulting (aOR: 3.0 (95%CI: 1.4-6.7) were strongly associated with CHU. While clinic and support staff had the impression that CHU was low, three out of ten MAT clients in Malindi used heroine concomitantly. Perceived challenges included poor psychosocial counseling adherence and lack of enough resources. Care providers suggested systematic education strategies to empower PWUDs towards harm reduction, including abstinence to CHU. High levels (30%) of CHU were observed amongst PWUDs on the Methadone programme in this setting. CHU continues across MAT attendees despite, the perception that CHU gradually reduces. Sex work and defaulting were strongly associated with CHU, therefore vi interventions aimed at addressing the two and customized package of care to improve MAT adherence will further help reduce CHU. Keywords: Concomitant Heroin Use, Sex Work, Defa