PO 8302 IMPACT OF TWO ANNUAL ROUNDS OF MASS DRUG ADMINISTRATION WITH DIHYDROARTEMISININ-PIPERAQUINE ON MALARIA TRANSMISSION IN A PROSPECTIVE COHORT STUDY

BackgroundMass drug administration (MDA) may reduce malaria transmission in low-transmission areas and interrupt transmission. The impact of MDA with dihydroartemisinin-piperaquine (DP) on malaria infection and clinical malaria was determined in a prospective cohort study in The Gambia.MethodsSingle annual MDA rounds with DP were done in 2014 and 2015 in a prospective cohort among residents aged >6 months in twelve villages in The Gambia at the start of the transmission season in June. Monthly blood samples for microscopy and PCR were collected during the transmission season from July to December, post MDA and once before MDA during the dry season in April. The incidence of infection and clinical malaria post-MDA were compared to 2013 and mixed effects logistic regression models assessed the efficacy and risk of re-infection post MDA.ResultsCoverage of 3 DP doses was 68.22% in 2014 and 65.60% in 2015. Compliance to 3 doses was high, 83.11% in 2014 and 85.93% in 2015. Incidence of infection in 2014 (2014: IR=0.23 PPY, 2013: IR=1.12 PPY, p<0.01) and clinical malaria in 2014 (2014: IR=0.08 PPY, 2013: IR=0.39: IRR=0.22, p<0.01) and 2015 (2015: IR=0.19, 2013:IR=0.38, IRR=0.50, p<0.01) was significantly lower after MDA compared to 2013. The incidence of clinical malaria remained higher in eastern Gambia compared to the western region. Subjects that took 3 DP doses had lower odds of infection in 2014 at 28 days (OR=0.61, 95% CI: 0.38–0.99) and 42 days (2014: OR=0.52, 95% CI: 0.29–0.89)ConclusionA single annual MDA round with DP temporarily reduced malaria infection and clinical disease during the transmission season and subjects that took 3 doses had lower risk of infection. However, several MDA rounds covering the entire transmission season and some targeting the human reservoir during the dry season, are needed to achieve a more marked sustained reduction of transmission.

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Mass Drug Administration With Dihydroartemisinin-piperaquine and Malaria Transmission Dynamics in The Gambia: A Prospective Cohort Study

Clinical Infectious Diseases ◽

10.1093/cid/ciy870 ◽

2018 ◽

Vol 69 (2) ◽

pp. 278-286 ◽

Cited By ~ 11

Author(s):

Julia Mwesigwa ◽

Jane Achan ◽

Muna Affara ◽

Miriam Wathuo ◽

Archibald Worwui ◽

...

Keyword(s):

Cohort Study ◽

Malaria Transmission ◽

Drug Administration ◽

Prospective Cohort Study ◽

Mass Drug Administration ◽

Prospective Cohort ◽

Dry Season ◽

Clinical Disease ◽

Infection Prevalence ◽

Low Transmission

Abstract Background Mass drug administration (MDA) may further reduce malaria transmission in low-transmission areas. The impact of MDA on the dynamics of malaria transmission was determined in a prospective cohort study. Methods Annual rounds of MDA with dihydroartemisinin-piperaquine (DP) were implemented were implemented in 2014 and 2015 in six village pairs before the malaria transmission season. Blood samples were collected from residents between July and December for microscopy and nested PCR. Incidence and prevalence of infection, clinical disease, and risk of malaria reinfection post-MDA were determined. Results Coverage of three DP doses was 68.2% (2014) and 65.6% (2015), compliance was greater than 80%. Incidence of infection was significantly lower in 2014 (incidence rate [IR] = 0.2 per person year [PPY]) than in 2013 (IR = 1.1 PPY; P < .01); monthly infection prevalence declined in the first three months post-MDA. Clinical malaria incidence was lower in 2014 (IR = 0.1 PPY) and 2015 (IR = 0.2 PPY) than in 2013 (IR = 0.4 PPY; P < .01), but remained higher in eastern Gambia. Individuals infected before MDA had a 2-fold higher odds of reinfection post-MDA (adjusted odds ratio = 2.5, 95% confidence interval 1.5–4.3; P < .01). Conclusions MDA reduced malaria infection and clinical disease during the first months. The reduction was maintained in low-transmission areas, but not in eastern Gambia. Annual MDA could be followed by focal MDA targeting individuals infected during the dry season. Repeated MDA rounds, some during the dry season over larger geographical areas, may result in a more marked and sustained decrease of malaria transmission.

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Sero-epidemiological evaluation of malaria transmission in The Gambia before and after mass drug administration

BMC Medicine ◽

10.1186/s12916-020-01785-6 ◽

2020 ◽

Vol 18 (1) ◽

Author(s):

Lindsey Wu ◽

Julia Mwesigwa ◽

Muna Affara ◽

Mamadou Bah ◽

Simon Correa ◽

...

Keyword(s):

Malaria Transmission ◽

Drug Administration ◽

Mass Drug Administration ◽

West Coast ◽

Malaria Infection ◽

The Gambia ◽

Antibody Responses ◽

The West ◽

Conversion Rates ◽

Antibody Levels

Abstract Background As The Gambia aims to achieve malaria elimination by 2030, serological assays are a useful surveillance tool to monitor trends in malaria incidence and evaluate community-based interventions. Methods Within a mass drug administration (MDA) study in The Gambia, where reduced malaria infection and clinical disease were observed after the intervention, a serological sub-study was conducted in four study villages. Spatio-temporal variation in transmission was measured with a panel of recombinant Pf antigens on a multiplexed bead-based assay. Village-level antibody levels were quantified as under-15 sero-prevalence, sero-conversion rates, and age-adjusted antibody acquisition rates. Antibody levels prior to MDA were assessed for association with persistent malaria infection after community chemoprophylaxis. Results Seasonal changes in antibodies to Etramp5.Ag1 were observed in children under 15 years in two transmission settings—the West Coast and Upper River Regions (4.32% and 31.30% Pf prevalence, respectively). At the end of the malaria season, short-lived antibody responses to Etramp5.Ag1, GEXP18, HSP40.Ag1, EBA175 RIII-V, and Rh2.2030 were lower amongst 1–15 year olds in the West Coast compared to the Upper River, reflecting known differences in transmission. Prior to MDA, individuals in the top 50th percentile of antibody levels had two-fold higher odds of clinical malaria during the transmission season, consistent with previous findings from the Malaria Transmission Dynamics Study, where individuals infected before the implementation of MDA had two-fold higher odds of re-infection post-MDA. Conclusions Serological markers can serve dual functions as indicators of malaria exposure and incidence. By monitoring age-specific sero-prevalence, the magnitude of age-stratified antibody levels, or identifying groups of individuals with above-average antibody responses, these antigens have the potential to complement conventional malaria surveillance tools. Further studies, particularly cluster randomised trials, can help establish standardised serological protocols to reliably measure transmission across endemic settings.

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Impact of Current Malaria Infection and Previous Malaria Exposure on the Clinical Profiles and Outcome of COVID-19 in a High Malaria Transmission Setting: A Prospective Cohort Study

SSRN Electronic Journal ◽

10.2139/ssrn.3844848 ◽

2021 ◽

Author(s):

Jane Achan ◽

Asadu Serwanga ◽

Humphrey Wanzira ◽

Tonny Kyagulanyi ◽

Anthony Nuwa ◽

...

Keyword(s):

Cohort Study ◽

Malaria Transmission ◽

Prospective Cohort Study ◽

Prospective Cohort ◽

Malaria Infection ◽

Transmission Setting ◽

Malaria Exposure ◽

Clinical Profiles

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A prospective cohort study to assess the micro-epidemiology of Plasmodium falciparum clinical malaria in Ilha Josina Machel (Manhiça, Mozambique)

Malaria Journal ◽

10.1186/s12936-016-1496-y ◽

2016 ◽

Vol 15 (1) ◽

Cited By ~ 9

Author(s):

Beatriz Galatas ◽

Caterina Guinovart ◽

Quique Bassat ◽

John J. Aponte ◽

Lídia Nhamússua ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Cohort Study ◽

Prospective Cohort Study ◽

Prospective Cohort ◽

Clinical Malaria

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Clinical malaria diagnosis in pregnancy in relation to early perinatal mother-to-child transmission of HIV: a prospective cohort study

HIV Medicine ◽

10.1111/hiv.12111 ◽

2013 ◽

Vol 15 (5) ◽

pp. 276-285 ◽

Cited By ~ 4

Author(s):

AE Ezeamama ◽

C Duggan ◽

KP Manji ◽

D Spiegelman ◽

E Hertzmark ◽

...

Keyword(s):

Cohort Study ◽

Prospective Cohort Study ◽

Prospective Cohort ◽

Malaria Diagnosis ◽

Clinical Malaria ◽

Mother To Child Transmission ◽

Child Transmission ◽

Mother To Child ◽

In Pregnancy

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A Cohort Study To Identify Risk Factors For Malaria In Burkinabe Children: Implications For Other High Burden High Impact Countries

10.21203/rs.3.rs-45492/v1 ◽

2020 ◽

Author(s):

Jean Baptiste Yaro ◽

Alphonse Ouedraogo ◽

Z Amidou Ouedraogo ◽

Amidou Diarra ◽

Malik Lankouande ◽

...

Keyword(s):

Risk Factors ◽

Cohort Study ◽

Burkina Faso ◽

Malaria Transmission ◽

Malaria Infection ◽

Economic Status ◽

Control Measures ◽

Previous Night ◽

Transmission Season ◽

Increased Risk

Abstract Background: Progress in controlling malaria has stalled in recent years. Today the malaria burden is increasingly concentrated in a few countries, including Burkina Faso, where malaria is not declining. We carried out a cohort study to identify risk factors for malaria infection in children in south-west Burkina Faso, an area with high insecticide-treated net (ITN) coverage and insecticide-resistant vectors.Methods: Incidence of malaria infection was measured in 252 children aged 5 to 15 years, using active and passive detection, during the 2017 transmission season, following clearance of infection. Demographic, socioeconomic, environmental and entomological risk factors, including use of ITNs and insecticide resistance were monitored. Results: During the six-month follow-up period, the overall incidence of Plasmodium falciparum infection, was 2.78 episodes per child (95% CI= 2.66-2.91) by microscopy, and 3.11 (95% CI= 2.95-3.28) by PCR. The entomological inoculation rate (EIR) was 80.4 infective bites per child over the six-month malaria transmission season. At baseline, 80.6% of children were reported as sleeping under an ITN the previous night, although at the last survey, 23.3% of nets were in poor condition and considered no longer protective. No association was found between the rate of P. falciparum infection and either EIR (Incidence Rate Ratio, IRR: 1.00, 95% CI: 1.00–1.00, p=0.08) or mortality in WHO tube tests when vectors were exposed to 0.05% deltamethrin (IRR: 1.05, 95% CI: 0.73–1.50, p=0.79). Travel history (IRR: 1.52, 95% CI: 1.45–1.59, p<0.001) and increasing socio-economic status were associated with an increased risk of P. falciparum infection (IRR: 1.05, 95% CI: 1.00–1.11, p=0.04).Conclusions: Malaria infection incidence remains overwhelmingly high in the study area. Our findings suggest that because of the exceptionally high levels of malaria transmission in the study area, malaria elimination cannot be achieved solely by mass deployment of ITNs and additional control measures are needed.

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Sero-epidemiological evaluation of malaria transmission in The Gambia before and after mass drug administration

10.1101/2020.04.09.20059774 ◽

2020 ◽

Author(s):

Lindsey Wu ◽

Julia Mwesigwa ◽

Muna Affara ◽

Mamadou Bah ◽

Simon Correa ◽

...

Keyword(s):

Drug Administration ◽

Mass Drug Administration ◽

West Coast ◽

Malaria Infection ◽

Malaria Incidence ◽

The Gambia ◽

Community Based Interventions ◽

The West ◽

Conversion Rates ◽

Antibody Levels

AbstractBackgroundAs The Gambia aims to achieve elimination by 2030, serological assays are a useful surveillance tool to monitor trends in malaria incidence and evaluate community-based interventions.MethodsWithin a mass drug administration (MDA) study in The Gambia, where reduced malaria infection and clinical disease were observed after the intervention, a serological sub-study was conducted in four study villages. Spatio-temporal variation in transmission was measured with a panel of recombinant Pf antigens on a multiplexed bead-based assay. Village-level antibody levels were quantified as under-15 sero-prevalence, sero-conversion rates, and age-adjusted antibody acquisition rates. Antibody levels prior to MDA were assessed for association with persistent malaria infection after community chemoprophylaxis.ResultsSeasonal changes in antibodies to Etramp5.Ag1 were observed in children under 15 in two transmission settings – the West Coast and Upper River Regions (4·32% and 31·30% Pf prevalence, respectively). At the end of the malaria season, short-lived antibody responses to Etramp5.Ag1, GEXP18, HSP40.Ag1, EBA175 RIII-V, and Rh2.2030 were lower amongst 1-15 year olds in the West Coast compared to the Upper River, reflecting known differences in transmission. Prior to MDA, individuals in the top 50th percentile of antibody levels had two-fold higher odds of clinical malaria during the transmission season, consistent with previous findings where individuals infected pre-MDA had 2-fold higher odds of re-infection post-MDA.ConclusionSerological markers can serve dual functions as indicators of malaria exposure and incidence. Further studies, particularly cluster randomised trials, can help establish standardised serological protocols to measure transmission across endemic settings.

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