Jimmy Opigo - Academia.edu (original) (raw)

Papers by Jimmy Opigo

Gates open research, Jan 30, 2023

Background: The World Health Organization (WHO) recommends seasonal malaria chemoprevention (SMC)... more Background: The World Health Organization (WHO) recommends seasonal malaria chemoprevention (SMC) with sulfadoxinepyrimethamine and amodiaquine for children aged 3 to 59 months, living in areas where malaria transmission is highly seasonal. However, due to widespread prevalence of resistance markers, SMC has not been implemented at scale in East and Southern Africa. An initial study in Uganda showed that SMC with SPAQ was feasible, acceptable, and protective against malaria in eligible children in Karamoja region. Nonetheless, exploration of alternative regimens is warranted since parasite resistance threats persist. Objective: The study aims to test the effectiveness of SMC with DP or SPAQ (DP-SMC & SPAQ-SMC), chemoprevention efficacy as well as the safety and tolerability of DP compared to that of SPAQ among 3-59 months old children in Karamoja region, an area of Uganda where malaria transmission is highly seasonal. Methods: A Type II hybrid effectiveness-implementation study design consisting of four components: 1) a cluster randomized controlled trial (cRCT) using passive surveillance to establish confirmed malaria cases in children using both SPAQ and DP; 2a) a prospective cohort study to determine the chemoprevention efficacy of SPAQ and DP (if SPAQ or Open Peer Review Approval Status AWAITING PEER REVIEW Any reports and responses or comments on the article can be found at the end of the article.

Malaria Journal

Background Until recently, due to widespread prevalence of molecular markers associated with sulf... more Background Until recently, due to widespread prevalence of molecular markers associated with sulfadoxine-pyrimethamine (SP) and amodiaquine (AQ) resistance in east and southern Africa, seasonal malaria chemoprevention (SMC) has not been used at scale in this region. This study assessed the protective effectiveness of monthly administration of SP + AQ (SPAQ) to children aged 3–59 months in Karamoja sub-region, Uganda, where parasite resistance is assumed to be high and malaria transmission is seasonal. Methods A two-arm quasi-experimental, open-label prospective non-randomized control trial (nRCT) was conducted in three districts. In two intervention districts, 85,000 children aged 3–59 months were targeted to receive monthly courses of SMC using SPAQ during the peak transmission season (May to September) 2021. A third district served as a control, where SMC was not implemented. Communities with comparable malaria attack rates were selected from the three districts, and households wi...

Malaria Journal

Background In 2020–2021, long-lasting insecticidal nets (LLINs) were distributed nationwide in Ug... more Background In 2020–2021, long-lasting insecticidal nets (LLINs) were distributed nationwide in Uganda during the COVID-19 pandemic. A cross-sectional survey was conducted in 12 districts to evaluate the impact of the campaign 1–5 months after LLIN distribution. Methods During April–May 2021, households were randomly selected from target areas (1–7 villages) surrounding 12 government-run health facilities established as Malaria Reference Centres; at least 50 households were enrolled per cluster. Outcomes included household ownership of LLINs distributed through the universal coverage campaign (UCC) (at least one UCC LLIN), adequate coverage of UCC LLINs (at least one UCC LLIN per 2 residents), and use of LLINs (resident slept under a LLIN the previous night). Multivariate logistic regression models were used to identify household- and individual-level factors associated with outcomes, controlling for clustering around health facilities. Results In total, 634 households, with 3342 res...

The American Journal of Tropical Medicine and Hygiene

ABSTRACT. Malaria is the leading cause of disease burden in sub-Saharan Africa. In 2010, the East... more ABSTRACT. Malaria is the leading cause of disease burden in sub-Saharan Africa. In 2010, the East Africa International Center of Excellence for Malaria Research, also known as the Program for Resistance, Immunology, Surveillance, and Modeling of Malaria (PRISM), was established to provide a comprehensive approach to malaria surveillance in Uganda. We instituted cohort studies and a robust malaria and entomological surveillance network at selected public health facilities that have provided a platform for monitoring trends in malaria morbidity and mortality, tracking the impact of malaria control interventions (indoor residual spraying of insecticide [IRS], use of long-lasting insecticidal nets [LLINs], and case management with artemisinin-based combination therapies [ACTs]), as well as monitoring of antimalarial drug and insecticide resistance. PRISM studies have informed Uganda’s malaria treatment policies, guided selection of LLINs for national distribution campaigns, and revealed...

Malaria Journal

Background Malaria is a major cause of morbidity and mortality globally, especially in sub-Sahara... more Background Malaria is a major cause of morbidity and mortality globally, especially in sub-Saharan Africa. Widespread resistance to pyrethroids threatens the gains achieved by vector control. To counter resistance to pyrethroids, third-generation indoor residual spraying (3GIRS) products have been developed. This study details the results of a multi-country cost and cost-effectiveness analysis of indoor residual spraying (IRS) programmes using Actellic®300CS, a 3GIRS product with pirimiphos-methyl, in sub-Saharan Africa in 2017 added to standard malaria control interventions including insecticide-treated bed nets versus standard malaria control interventions alone. Methods An economic evaluation of 3GIRS using Actellic®300CS in a broad range of sub-Saharan African settings was conducted using a variety of primary data collection and evidence synthesis methods. Four IRS programmes in Ghana, Mali, Uganda, and Zambia were included in the effectiveness analysis. Cost data come from six ...

Current Research in Parasitology & Vector-Borne Diseases

Additional file 3: The patient exit interview questionnaire. The questionnaire was transformed in... more Additional file 3: The patient exit interview questionnaire. The questionnaire was transformed into an electonic version enabling collection of data using tablets.

Additional file 4: A tabular presentation of data used to determine the weights to consider when ... more Additional file 4: A tabular presentation of data used to determine the weights to consider when adjusting sampled facilities to match the population distribution of facilities. For the final analysis weights presented in Table 1 were considered.

Additional file 1: Table S1. Summary of key indicators among hospitalized children at Tororo hosp... more Additional file 1: Table S1. Summary of key indicators among hospitalized children at Tororo hospital: 2012 to 2019.

PLOS ONE, 2020

Background Plasmodium falciparum histidine-rich protein 2 (HRP2)-based rapid diagnostic tests (RD... more Background Plasmodium falciparum histidine-rich protein 2 (HRP2)-based rapid diagnostic tests (RDTs) are exclusively recommended for malaria diagnosis in Uganda; however, their functionality can be affected by parasite-related factors that have not been investigated in field settings. Methods Using a cross-sectional design, we analysed 219 RDT-/microscopy+ and 140 RDT+/microscopy+ dried blood spots obtained from symptomatic children aged 2–10 years from 48 districts in Uganda between 2017 and 2019. We aimed to investigate parasite-related factors contributing to false RDT results by molecular characterization of parasite isolates. ArcGIS software was used to map the geographical distribution of parasites. Statistical analysis was performed using chi-square or Fisher’s exact tests, with P ≤ 0.05 indicating significance. Odds ratios (ORs) were used to assess associations, while logistic regression was performed to explore possible factors associated with false RDT results. Results The...

Additional file 3: Figure S3. Sporozoite infection rates by sub region. a P. falciparum sporozoit... more Additional file 3: Figure S3. Sporozoite infection rates by sub region. a P. falciparum sporozoite infection rate in An. gambiae (s.s.). b Combined sporozoite infection rate for P. vivax, P. ovale and P. malariae in An. gambiae (s.s.). c P. falciparum sporozoite infection rate in An. funestus (s.s.). d Combined sporozoite infection rate for P. vivax, P. ovale and P. malariae in An. funestus (s.s.).

Additional file 2: Figure S2. Phylogenetic tree constructed from mitochondrial cox1 gene sequence... more Additional file 2: Figure S2. Phylogenetic tree constructed from mitochondrial cox1 gene sequence of the unknown mosquito samples (in red boxes) were compared with known sequences of major anopheline vectors from the NCBI database. A mid-rooted phylogenetic tree was plotted using PHYML (Maximum Likelihood relationship) algorithm, following multiple sequence alignment by MUSCLE. The black dots are the tree nodes which represent a common ancestor. The figures show the branch length which represents the amount of change in-terms of mutations that has occurred with time between members.

Additional file 1. Climatic data processing.

SPIRIT 2013 Checklist: standard protocol items: recommendations for interventional trials. (DOC 1... more SPIRIT 2013 Checklist: standard protocol items: recommendations for interventional trials. (DOC 123 kb)

European Journal of Clinical Medicine

Background: As COVID-19 disease surges across much of the world, researchers in different setting... more Background: As COVID-19 disease surges across much of the world, researchers in different settings have a unique opportunity to address the various research priorities that have been identified. The challenges that containment and mitigation strategies present for research, especially in resource limited settings, could be significant and negatively impact the essential contribution of these settings to COVID-19 research. Objectives: To describe experiences of conducting research during this pandemic, discuss challenges faced and present strategies implemented to address these challenges Methods: Malaria Consortium recently initiated an observational case series study to assess the magnitude and clinical consequences of co-infection of COVID-19, malaria, and other common infections. This study is being conducted in eight COVID-19 treatment centres in Uganda. Qualitative methods including observations and interviews were utilized to document experiences and mitigating strategies for ...

Background:Declines in malaria burden in Uganda have slowed. Modelling predicts that indoor resid... more Background:Declines in malaria burden in Uganda have slowed. Modelling predicts that indoor residual spraying (IRS) and mass drug administration (MDA), when co-timed, have synergistic impact. This study investigated additional protective impact of population-based MDA on malaria prevalence, if any, when added to IRS, as compared with IRS alone and with standard of care (SOC).Methods:The 32-month prospective controlled community trial enrolled an open cohort of residents (46,765 individuals, 1st enumeration and 52,133, 4th enumeration) in Katakwi District in northeastern Uganda. Consented participants were assigned to three arms based on residential subcounty: MDA+IRS, IRS, and SOC (insecticide treated bednets and case management). IRS with pirimiphos methyl and MDA with dihydroartemisinin- piperaquine were delivered in 4 co-timed campaign-style rounds 8 months apart. The primary endpoint was population prevalence of malaria, estimated by 6 cross-sectional surveys, starting at baseli...

ABSTRACTLong Lasting Insecticidal Nets (LLINs) supplemented with the synergist piperonyl butoxide... more ABSTRACTLong Lasting Insecticidal Nets (LLINs) supplemented with the synergist piperonyl butoxide have been developed in response to growing pyrethroid resistance however their durability in the field remains poorly described. A pragmatic cluster-randomised trial was embedded into Uganda’s 2017-2018 distribution to compare the durability of LLINs with and without PBOA total of 104 clusters were included with each receiving one of four LLIN products, two with pyrethroid+PBO (Olyset Plus and PermaNet 3.0) and two pyrethroid-only (Olyset Net and PermaNet 2.0). Nets were sampled at baseline, 12, and 25 months post-distribution to assess physical condition, chemical content, and bioefficacy. Physical condition was quantified using proportionate Hole Index and chemical content measured using high-performance liquid chromatography. Bioefficacy was assessed with three-minute WHO Cone and Wireball assays using pyrethroid-resistant An. gambiae, with 1hr knockdown and 24hr mortality recorded.T...

Additional file 5: Table S1. Resistance and polytene chromosome allele frequencies in Anopheles g... more Additional file 5: Table S1. Resistance and polytene chromosome allele frequencies in Anopheles gambiae (s.s.) analysed as a function of sub-region using a generalized linear model.

Gates open research, Jan 30, 2023

Background: The World Health Organization (WHO) recommends seasonal malaria chemoprevention (SMC)... more Background: The World Health Organization (WHO) recommends seasonal malaria chemoprevention (SMC) with sulfadoxinepyrimethamine and amodiaquine for children aged 3 to 59 months, living in areas where malaria transmission is highly seasonal. However, due to widespread prevalence of resistance markers, SMC has not been implemented at scale in East and Southern Africa. An initial study in Uganda showed that SMC with SPAQ was feasible, acceptable, and protective against malaria in eligible children in Karamoja region. Nonetheless, exploration of alternative regimens is warranted since parasite resistance threats persist. Objective: The study aims to test the effectiveness of SMC with DP or SPAQ (DP-SMC & SPAQ-SMC), chemoprevention efficacy as well as the safety and tolerability of DP compared to that of SPAQ among 3-59 months old children in Karamoja region, an area of Uganda where malaria transmission is highly seasonal. Methods: A Type II hybrid effectiveness-implementation study design consisting of four components: 1) a cluster randomized controlled trial (cRCT) using passive surveillance to establish confirmed malaria cases in children using both SPAQ and DP; 2a) a prospective cohort study to determine the chemoprevention efficacy of SPAQ and DP (if SPAQ or Open Peer Review Approval Status AWAITING PEER REVIEW Any reports and responses or comments on the article can be found at the end of the article.

Malaria Journal

Background Until recently, due to widespread prevalence of molecular markers associated with sulf... more Background Until recently, due to widespread prevalence of molecular markers associated with sulfadoxine-pyrimethamine (SP) and amodiaquine (AQ) resistance in east and southern Africa, seasonal malaria chemoprevention (SMC) has not been used at scale in this region. This study assessed the protective effectiveness of monthly administration of SP + AQ (SPAQ) to children aged 3–59 months in Karamoja sub-region, Uganda, where parasite resistance is assumed to be high and malaria transmission is seasonal. Methods A two-arm quasi-experimental, open-label prospective non-randomized control trial (nRCT) was conducted in three districts. In two intervention districts, 85,000 children aged 3–59 months were targeted to receive monthly courses of SMC using SPAQ during the peak transmission season (May to September) 2021. A third district served as a control, where SMC was not implemented. Communities with comparable malaria attack rates were selected from the three districts, and households wi...

Malaria Journal

Background In 2020–2021, long-lasting insecticidal nets (LLINs) were distributed nationwide in Ug... more Background In 2020–2021, long-lasting insecticidal nets (LLINs) were distributed nationwide in Uganda during the COVID-19 pandemic. A cross-sectional survey was conducted in 12 districts to evaluate the impact of the campaign 1–5 months after LLIN distribution. Methods During April–May 2021, households were randomly selected from target areas (1–7 villages) surrounding 12 government-run health facilities established as Malaria Reference Centres; at least 50 households were enrolled per cluster. Outcomes included household ownership of LLINs distributed through the universal coverage campaign (UCC) (at least one UCC LLIN), adequate coverage of UCC LLINs (at least one UCC LLIN per 2 residents), and use of LLINs (resident slept under a LLIN the previous night). Multivariate logistic regression models were used to identify household- and individual-level factors associated with outcomes, controlling for clustering around health facilities. Results In total, 634 households, with 3342 res...

The American Journal of Tropical Medicine and Hygiene

ABSTRACT. Malaria is the leading cause of disease burden in sub-Saharan Africa. In 2010, the East... more ABSTRACT. Malaria is the leading cause of disease burden in sub-Saharan Africa. In 2010, the East Africa International Center of Excellence for Malaria Research, also known as the Program for Resistance, Immunology, Surveillance, and Modeling of Malaria (PRISM), was established to provide a comprehensive approach to malaria surveillance in Uganda. We instituted cohort studies and a robust malaria and entomological surveillance network at selected public health facilities that have provided a platform for monitoring trends in malaria morbidity and mortality, tracking the impact of malaria control interventions (indoor residual spraying of insecticide [IRS], use of long-lasting insecticidal nets [LLINs], and case management with artemisinin-based combination therapies [ACTs]), as well as monitoring of antimalarial drug and insecticide resistance. PRISM studies have informed Uganda’s malaria treatment policies, guided selection of LLINs for national distribution campaigns, and revealed...

Malaria Journal

Background Malaria is a major cause of morbidity and mortality globally, especially in sub-Sahara... more Background Malaria is a major cause of morbidity and mortality globally, especially in sub-Saharan Africa. Widespread resistance to pyrethroids threatens the gains achieved by vector control. To counter resistance to pyrethroids, third-generation indoor residual spraying (3GIRS) products have been developed. This study details the results of a multi-country cost and cost-effectiveness analysis of indoor residual spraying (IRS) programmes using Actellic®300CS, a 3GIRS product with pirimiphos-methyl, in sub-Saharan Africa in 2017 added to standard malaria control interventions including insecticide-treated bed nets versus standard malaria control interventions alone. Methods An economic evaluation of 3GIRS using Actellic®300CS in a broad range of sub-Saharan African settings was conducted using a variety of primary data collection and evidence synthesis methods. Four IRS programmes in Ghana, Mali, Uganda, and Zambia were included in the effectiveness analysis. Cost data come from six ...

Current Research in Parasitology & Vector-Borne Diseases

Additional file 3: The patient exit interview questionnaire. The questionnaire was transformed in... more Additional file 3: The patient exit interview questionnaire. The questionnaire was transformed into an electonic version enabling collection of data using tablets.

Additional file 4: A tabular presentation of data used to determine the weights to consider when ... more Additional file 4: A tabular presentation of data used to determine the weights to consider when adjusting sampled facilities to match the population distribution of facilities. For the final analysis weights presented in Table 1 were considered.

Additional file 1: Table S1. Summary of key indicators among hospitalized children at Tororo hosp... more Additional file 1: Table S1. Summary of key indicators among hospitalized children at Tororo hospital: 2012 to 2019.

PLOS ONE, 2020

Background Plasmodium falciparum histidine-rich protein 2 (HRP2)-based rapid diagnostic tests (RD... more Background Plasmodium falciparum histidine-rich protein 2 (HRP2)-based rapid diagnostic tests (RDTs) are exclusively recommended for malaria diagnosis in Uganda; however, their functionality can be affected by parasite-related factors that have not been investigated in field settings. Methods Using a cross-sectional design, we analysed 219 RDT-/microscopy+ and 140 RDT+/microscopy+ dried blood spots obtained from symptomatic children aged 2–10 years from 48 districts in Uganda between 2017 and 2019. We aimed to investigate parasite-related factors contributing to false RDT results by molecular characterization of parasite isolates. ArcGIS software was used to map the geographical distribution of parasites. Statistical analysis was performed using chi-square or Fisher’s exact tests, with P ≤ 0.05 indicating significance. Odds ratios (ORs) were used to assess associations, while logistic regression was performed to explore possible factors associated with false RDT results. Results The...

Additional file 3: Figure S3. Sporozoite infection rates by sub region. a P. falciparum sporozoit... more Additional file 3: Figure S3. Sporozoite infection rates by sub region. a P. falciparum sporozoite infection rate in An. gambiae (s.s.). b Combined sporozoite infection rate for P. vivax, P. ovale and P. malariae in An. gambiae (s.s.). c P. falciparum sporozoite infection rate in An. funestus (s.s.). d Combined sporozoite infection rate for P. vivax, P. ovale and P. malariae in An. funestus (s.s.).

Additional file 2: Figure S2. Phylogenetic tree constructed from mitochondrial cox1 gene sequence... more Additional file 2: Figure S2. Phylogenetic tree constructed from mitochondrial cox1 gene sequence of the unknown mosquito samples (in red boxes) were compared with known sequences of major anopheline vectors from the NCBI database. A mid-rooted phylogenetic tree was plotted using PHYML (Maximum Likelihood relationship) algorithm, following multiple sequence alignment by MUSCLE. The black dots are the tree nodes which represent a common ancestor. The figures show the branch length which represents the amount of change in-terms of mutations that has occurred with time between members.

Additional file 1. Climatic data processing.

SPIRIT 2013 Checklist: standard protocol items: recommendations for interventional trials. (DOC 1... more SPIRIT 2013 Checklist: standard protocol items: recommendations for interventional trials. (DOC 123 kb)

European Journal of Clinical Medicine

Background: As COVID-19 disease surges across much of the world, researchers in different setting... more Background: As COVID-19 disease surges across much of the world, researchers in different settings have a unique opportunity to address the various research priorities that have been identified. The challenges that containment and mitigation strategies present for research, especially in resource limited settings, could be significant and negatively impact the essential contribution of these settings to COVID-19 research. Objectives: To describe experiences of conducting research during this pandemic, discuss challenges faced and present strategies implemented to address these challenges Methods: Malaria Consortium recently initiated an observational case series study to assess the magnitude and clinical consequences of co-infection of COVID-19, malaria, and other common infections. This study is being conducted in eight COVID-19 treatment centres in Uganda. Qualitative methods including observations and interviews were utilized to document experiences and mitigating strategies for ...

Background:Declines in malaria burden in Uganda have slowed. Modelling predicts that indoor resid... more Background:Declines in malaria burden in Uganda have slowed. Modelling predicts that indoor residual spraying (IRS) and mass drug administration (MDA), when co-timed, have synergistic impact. This study investigated additional protective impact of population-based MDA on malaria prevalence, if any, when added to IRS, as compared with IRS alone and with standard of care (SOC).Methods:The 32-month prospective controlled community trial enrolled an open cohort of residents (46,765 individuals, 1st enumeration and 52,133, 4th enumeration) in Katakwi District in northeastern Uganda. Consented participants were assigned to three arms based on residential subcounty: MDA+IRS, IRS, and SOC (insecticide treated bednets and case management). IRS with pirimiphos methyl and MDA with dihydroartemisinin- piperaquine were delivered in 4 co-timed campaign-style rounds 8 months apart. The primary endpoint was population prevalence of malaria, estimated by 6 cross-sectional surveys, starting at baseli...

ABSTRACTLong Lasting Insecticidal Nets (LLINs) supplemented with the synergist piperonyl butoxide... more ABSTRACTLong Lasting Insecticidal Nets (LLINs) supplemented with the synergist piperonyl butoxide have been developed in response to growing pyrethroid resistance however their durability in the field remains poorly described. A pragmatic cluster-randomised trial was embedded into Uganda’s 2017-2018 distribution to compare the durability of LLINs with and without PBOA total of 104 clusters were included with each receiving one of four LLIN products, two with pyrethroid+PBO (Olyset Plus and PermaNet 3.0) and two pyrethroid-only (Olyset Net and PermaNet 2.0). Nets were sampled at baseline, 12, and 25 months post-distribution to assess physical condition, chemical content, and bioefficacy. Physical condition was quantified using proportionate Hole Index and chemical content measured using high-performance liquid chromatography. Bioefficacy was assessed with three-minute WHO Cone and Wireball assays using pyrethroid-resistant An. gambiae, with 1hr knockdown and 24hr mortality recorded.T...

Additional file 5: Table S1. Resistance and polytene chromosome allele frequencies in Anopheles g... more Additional file 5: Table S1. Resistance and polytene chromosome allele frequencies in Anopheles gambiae (s.s.) analysed as a function of sub-region using a generalized linear model.