Protocol > Research Study
de Wit MBK, Rao B, Lassovski M, Ouabo A, Badjo C, et al.
2018 July 1
Primary Objective: To measure the prevalence of molecular markers of SP resistant malaria in North and South Kivu, DRC.
Sulfadoxine/pyrimethamine (SP) forms the backbone of most malaria chemoprevention programmes in high endemicity settings, including intermittent preventative therapy in pregnancy and infants (IPTp and IPTi respectively) as well as seasonal malaria chemoprevention (SMC). P. falciparum parasite resistance to SP threatens recent triumphs preventing malaria infection in the most vulnerable risk groups. WHO guidance is that chemoprevention using SP may not be implemented when prevalence of the dhps K540E gene denoting SP resistance are greater than 50%. Simple, robust polymerase chain reaction (PCR) - based methods for molecular surveillance of resistance to SP have the potential to indicate whether SP-based chemoprevention programmes would be effective in areas where surveillance was conducted, but also to identify early stages of emerging resistance in order to advocate for alternative chemoprevention strategies.
A minimum of 750 samples will be collected per province. Three sites per province will provide 250 samples assuming an estimated prevalence of 50% prevalence of dhps K540E gene with 95% confidence and 5% precision. This is also sufficient for robust estimation of the prevalence of dhps 581, an alternative critical marker. This sample size is calculated to estimate regional prevalence, i.e. for both South Kivu and North Kivu, and hence this study requires samples from multiple MSF sites (including from different MSF Operating Centre missions) e.g. Baraka, Kimbi and Lulingu amongst others in South Kivu and Mweso, Rutsuru and Walikale in North Kivu with a minimum total of 750 per province. If estimating specific prevalence in only one limited site, a large sample size would be required.
Sulfadoxine/pyrimethamine (SP) forms the backbone of most malaria chemoprevention programmes in high endemicity settings, including intermittent preventative therapy in pregnancy and infants (IPTp and IPTi respectively) as well as seasonal malaria chemoprevention (SMC). P. falciparum parasite resistance to SP threatens recent triumphs preventing malaria infection in the most vulnerable risk groups. WHO guidance is that chemoprevention using SP may not be implemented when prevalence of the dhps K540E gene denoting SP resistance are greater than 50%. Simple, robust polymerase chain reaction (PCR) - based methods for molecular surveillance of resistance to SP have the potential to indicate whether SP-based chemoprevention programmes would be effective in areas where surveillance was conducted, but also to identify early stages of emerging resistance in order to advocate for alternative chemoprevention strategies.
A minimum of 750 samples will be collected per province. Three sites per province will provide 250 samples assuming an estimated prevalence of 50% prevalence of dhps K540E gene with 95% confidence and 5% precision. This is also sufficient for robust estimation of the prevalence of dhps 581, an alternative critical marker. This sample size is calculated to estimate regional prevalence, i.e. for both South Kivu and North Kivu, and hence this study requires samples from multiple MSF sites (including from different MSF Operating Centre missions) e.g. Baraka, Kimbi and Lulingu amongst others in South Kivu and Mweso, Rutsuru and Walikale in North Kivu with a minimum total of 750 per province. If estimating specific prevalence in only one limited site, a large sample size would be required.
Conference Material > Abstract
Truelove SA, Hedge S, Kostandova N, Niehaus L, Rao B, et al.
MSF Scientific Days International 2021: Research. 2021 May 18
INTRODUCTION
Since the emergence of the COVID-19 pandemic, concerns have arisen regarding the potential impact of outbreaks affecting Rohingya refugees living in the Kutupalong-Balukhali refugee camps in Bangladesh. Early modeling work projected substantial outbreaks of SARS-CoV-2 virus were likely within the camps. However only 435 laboratory-confirmed cases and 10 deaths were reported from 14 May 2020 through 19 March 2021. While these official numbers imply spread of SARS-CoV-2 has been controlled, other data are contradictory, highlighting a population unwilling to seek care or be tested. Surveys from slums in India and Bangladesh suggest seroprevalence rates of 45% and 75%. Here we use multiple data sources to evaluate whether SARS-CoV-2 outbreaks may in fact have been larger than previously thought among Rohingya refugees in the Kutupalong-Balukhali camps.
METHODS
We used a mixed-methods approach to analyze SARSCoV-2 transmission in the Kutupalong-Balukhali refugee camps using multiple datasets. We developed a probabilistic inference framework to assess support for three hypotheses of how variability in care seeking and testing might alter the interpretation of official case and testing data. We estimated weekly numbers of infections among the Rohingya refugees using official reported case and testing data, data on acute respiratory infections (ARI) from WHO’s Emergency Warning and Response System, probability of SARS-CoV-2 PCR test among ARI cases at MSF health centres, and data from a serological survey conducted in Dhaka. Separately, we assessed compatibility with suspected COVID-19 among deaths identified through an International Organization for Migration (IOM) mortality survey among the Rohingya during April–July 2020. We compare these deaths to the inference model results to identify consistency between sources and methods.
ETHICS
This study fulfilled the exemption criteria set by the MSF Ethics Review Board (ERB) for a posteriori analyses of routinely collected clinical data and thus did not require MSF ERB review. It was conducted with permission from Dr Kiran Jobanputra, Operational Centre Amsterdam, MSF.
RESULTS
Under our probability framework, each hypothesis suggests a substantial outbreak occurred, though size and timing vary substantially. Under hypotheses accounting for declines in willingness to seek care, the data suggest a large outbreak occurred in spring 2020, with up to 400,000 infections, or 47% of the population, and 390 deaths occurring during April-December 2020. These findings were consistent in both timing and magnitude of the outbreak estimated separately from deaths identified by the IOM survey, including 47 unreported deaths consistent with suspected COVID-19 and up to 370 suspected COVID-19 deaths after adjusting for sampling. These deaths coincided temporally with spikes in reported cases and test-positivity rates during June 2020 and with increased contact during Ramadan.
CONCLUSIONS
Despite the low numbers of reported cases and deaths, we suggest an early large-scale outbreak is consistent with the reported data, with the outbreak remaining unobserved because of reduced care-seeking behavior and low infection severity among this population. Current data do not permit precise estimation of incidence, but results do suggest substantial unrecognized transmission of SARS-CoV-2 within the camps. However, confirmation will await more conclusive evidence from serological testing.
CONFLICTS OF INTEREST
None declared.
Since the emergence of the COVID-19 pandemic, concerns have arisen regarding the potential impact of outbreaks affecting Rohingya refugees living in the Kutupalong-Balukhali refugee camps in Bangladesh. Early modeling work projected substantial outbreaks of SARS-CoV-2 virus were likely within the camps. However only 435 laboratory-confirmed cases and 10 deaths were reported from 14 May 2020 through 19 March 2021. While these official numbers imply spread of SARS-CoV-2 has been controlled, other data are contradictory, highlighting a population unwilling to seek care or be tested. Surveys from slums in India and Bangladesh suggest seroprevalence rates of 45% and 75%. Here we use multiple data sources to evaluate whether SARS-CoV-2 outbreaks may in fact have been larger than previously thought among Rohingya refugees in the Kutupalong-Balukhali camps.
METHODS
We used a mixed-methods approach to analyze SARSCoV-2 transmission in the Kutupalong-Balukhali refugee camps using multiple datasets. We developed a probabilistic inference framework to assess support for three hypotheses of how variability in care seeking and testing might alter the interpretation of official case and testing data. We estimated weekly numbers of infections among the Rohingya refugees using official reported case and testing data, data on acute respiratory infections (ARI) from WHO’s Emergency Warning and Response System, probability of SARS-CoV-2 PCR test among ARI cases at MSF health centres, and data from a serological survey conducted in Dhaka. Separately, we assessed compatibility with suspected COVID-19 among deaths identified through an International Organization for Migration (IOM) mortality survey among the Rohingya during April–July 2020. We compare these deaths to the inference model results to identify consistency between sources and methods.
ETHICS
This study fulfilled the exemption criteria set by the MSF Ethics Review Board (ERB) for a posteriori analyses of routinely collected clinical data and thus did not require MSF ERB review. It was conducted with permission from Dr Kiran Jobanputra, Operational Centre Amsterdam, MSF.
RESULTS
Under our probability framework, each hypothesis suggests a substantial outbreak occurred, though size and timing vary substantially. Under hypotheses accounting for declines in willingness to seek care, the data suggest a large outbreak occurred in spring 2020, with up to 400,000 infections, or 47% of the population, and 390 deaths occurring during April-December 2020. These findings were consistent in both timing and magnitude of the outbreak estimated separately from deaths identified by the IOM survey, including 47 unreported deaths consistent with suspected COVID-19 and up to 370 suspected COVID-19 deaths after adjusting for sampling. These deaths coincided temporally with spikes in reported cases and test-positivity rates during June 2020 and with increased contact during Ramadan.
CONCLUSIONS
Despite the low numbers of reported cases and deaths, we suggest an early large-scale outbreak is consistent with the reported data, with the outbreak remaining unobserved because of reduced care-seeking behavior and low infection severity among this population. Current data do not permit precise estimation of incidence, but results do suggest substantial unrecognized transmission of SARS-CoV-2 within the camps. However, confirmation will await more conclusive evidence from serological testing.
CONFLICTS OF INTEREST
None declared.
Journal Article > LetterFull Text
Lancet. 2022 July 2; Volume 400 (Issue 10345); 23.; DOI:10.1016/S0140-6736(22)01187-4
Abbara A, Rao B, Titanji BK, Boum Y, Zumla A
Lancet. 2022 July 2; Volume 400 (Issue 10345); 23.; DOI:10.1016/S0140-6736(22)01187-4
Journal Article > ResearchFull Text
Malar J. 2024 May 15; Volume 23 (Issue 1); 146.; DOI:10.1186/s12936-024-04968-1
Robinson E, Ouabo A, Rose L, van Braak F, Vyncke J, et al.
Malar J. 2024 May 15; Volume 23 (Issue 1); 146.; DOI:10.1186/s12936-024-04968-1
BACKGROUND
In 2020, during the COVID-19 pandemic, Médecins Sans Frontières (MSF) initiated three cycles of dihydroartemisin-piperaquine (DHA-PQ) mass drug administration (MDA) for children aged three months to 15 years within Bossangoa sub-prefecture, Central African Republic. Coverage, clinical impact, and community members perspectives were evaluated to inform the use of MDAs in humanitarian emergencies.
METHODS
A household survey was undertaken after the MDA focusing on participation, recent illness among eligible children, and household satisfaction. Using routine surveillance data, the reduction during the MDA period compared to the same period of preceding two years in consultations, malaria diagnoses, malaria rapid diagnostic test (RDT) positivity in three MSF community healthcare facilities (HFs), and the reduction in severe malaria admissions at the regional hospital were estimated. Twenty-seven focus groups discussions (FGDs) with community members were conducted.
RESULTS
Overall coverage based on the MDA card or verbal report was 94.3% (95% confidence interval (CI): 86.3–97.8%). Among participants of the household survey, 2.6% (95% CI 1.6–40.3%) of round 3 MDA participants experienced illness in the preceding four weeks compared to 30.6% (95% CI 22.1–40.8%) of MDA non-participants. One community HF experienced a 54.5% (95% CI 50.8–57.9) reduction in consultations, a 73.7% (95% CI 70.5–76.5) reduction in malaria diagnoses, and 42.9% (95% CI 36.0–49.0) reduction in the proportion of positive RDTs among children under five. A second community HF experienced an increase in consultations (+ 15.1% (− 23.3 to 7.5)) and stable malaria diagnoses (4.2% (3.9–11.6)). A third community HF experienced an increase in consultations (+ 41.1% (95% CI 51.2–31.8) and malaria diagnoses (+ 37.3% (95% CI 47.4–27.9)). There were a 25.2% (95% CI 2.0–42.8) reduction in hospital admissions with severe malaria among children under five from the MDA area. FGDs revealed community members perceived less illness among children because of the MDA, as well as fewer hospitalizations. Other indirect benefits such as reduced household expenditure on healthcare were also described.
CONCLUSION
The MDA achieved high coverage and community acceptance. While some positive health impact was observed, it was resource intensive, particularly in this rural context. The priority for malaria control in humanitarian contexts should remain diagnosis and treatment. MDA may be additional tool where the context supports its implementation.
In 2020, during the COVID-19 pandemic, Médecins Sans Frontières (MSF) initiated three cycles of dihydroartemisin-piperaquine (DHA-PQ) mass drug administration (MDA) for children aged three months to 15 years within Bossangoa sub-prefecture, Central African Republic. Coverage, clinical impact, and community members perspectives were evaluated to inform the use of MDAs in humanitarian emergencies.
METHODS
A household survey was undertaken after the MDA focusing on participation, recent illness among eligible children, and household satisfaction. Using routine surveillance data, the reduction during the MDA period compared to the same period of preceding two years in consultations, malaria diagnoses, malaria rapid diagnostic test (RDT) positivity in three MSF community healthcare facilities (HFs), and the reduction in severe malaria admissions at the regional hospital were estimated. Twenty-seven focus groups discussions (FGDs) with community members were conducted.
RESULTS
Overall coverage based on the MDA card or verbal report was 94.3% (95% confidence interval (CI): 86.3–97.8%). Among participants of the household survey, 2.6% (95% CI 1.6–40.3%) of round 3 MDA participants experienced illness in the preceding four weeks compared to 30.6% (95% CI 22.1–40.8%) of MDA non-participants. One community HF experienced a 54.5% (95% CI 50.8–57.9) reduction in consultations, a 73.7% (95% CI 70.5–76.5) reduction in malaria diagnoses, and 42.9% (95% CI 36.0–49.0) reduction in the proportion of positive RDTs among children under five. A second community HF experienced an increase in consultations (+ 15.1% (− 23.3 to 7.5)) and stable malaria diagnoses (4.2% (3.9–11.6)). A third community HF experienced an increase in consultations (+ 41.1% (95% CI 51.2–31.8) and malaria diagnoses (+ 37.3% (95% CI 47.4–27.9)). There were a 25.2% (95% CI 2.0–42.8) reduction in hospital admissions with severe malaria among children under five from the MDA area. FGDs revealed community members perceived less illness among children because of the MDA, as well as fewer hospitalizations. Other indirect benefits such as reduced household expenditure on healthcare were also described.
CONCLUSION
The MDA achieved high coverage and community acceptance. While some positive health impact was observed, it was resource intensive, particularly in this rural context. The priority for malaria control in humanitarian contexts should remain diagnosis and treatment. MDA may be additional tool where the context supports its implementation.
Journal Article > ResearchFull Text
Malar J. 2018 August 29; Volume 17 (Issue 1); 312.; DOI:10.1186/s12936-018-2460-9
Hellewell J, Walker PGT, Ghani AC, Rao B, Churcher TS
Malar J. 2018 August 29; Volume 17 (Issue 1); 312.; DOI:10.1186/s12936-018-2460-9
BACKGROUND
The number of clinical cases of malaria is often recorded in resource constrained or conflict settings as a proxy for disease burden. Interpreting case count data in areas of humanitarian need is challenging due to uncertainties in population size caused by security concerns, resource constraints and population movement. Malaria prevalence in women visiting ante-natal care (ANC) clinics has the potential to be an easier and more accurate metric for malaria surveillance that is unbiased by population size if malaria testing is routinely conducted irrespective of symptoms.
METHODS
A suite of distributed lag non-linear models was fitted to clinical incidence time-series data in children under 5 years and ANC prevalence data from health centres run by Médecins Sans Frontières in the Democratic Republic of Congo, which implement routine intermittent screening and treatment alongside intermittent preventative treatment in pregnancy. These statistical models enable the temporal relationship between the two metrics to be disentangled.
RESULTS
There was a strong relationship between the ANC prevalence and clinical incidence suggesting that both can be used to describe current malaria endemicity. There was no evidence that ANC prevalence could predict future clinical incidence, though a change in clinical incidence was shown to influence ANC prevalence up to 3 months into the future.
CONCLUSIONS
The results indicate that ANC prevalence may be a suitable metric for retrospective evaluations of the impact of malaria interventions and is a useful method for evaluating long-term malaria trends in resource constrained settings.
The number of clinical cases of malaria is often recorded in resource constrained or conflict settings as a proxy for disease burden. Interpreting case count data in areas of humanitarian need is challenging due to uncertainties in population size caused by security concerns, resource constraints and population movement. Malaria prevalence in women visiting ante-natal care (ANC) clinics has the potential to be an easier and more accurate metric for malaria surveillance that is unbiased by population size if malaria testing is routinely conducted irrespective of symptoms.
METHODS
A suite of distributed lag non-linear models was fitted to clinical incidence time-series data in children under 5 years and ANC prevalence data from health centres run by Médecins Sans Frontières in the Democratic Republic of Congo, which implement routine intermittent screening and treatment alongside intermittent preventative treatment in pregnancy. These statistical models enable the temporal relationship between the two metrics to be disentangled.
RESULTS
There was a strong relationship between the ANC prevalence and clinical incidence suggesting that both can be used to describe current malaria endemicity. There was no evidence that ANC prevalence could predict future clinical incidence, though a change in clinical incidence was shown to influence ANC prevalence up to 3 months into the future.
CONCLUSIONS
The results indicate that ANC prevalence may be a suitable metric for retrospective evaluations of the impact of malaria interventions and is a useful method for evaluating long-term malaria trends in resource constrained settings.
Conference Material > Abstract
Sadique S, Lin YD, Walker SA, Rao B, du Cros PAK, et al.
MSF Scientific Days International 2022. 2022 May 9; DOI:10.57740/s2se-8951
INTRODUCTION
The crowded conditions within camps for refugees and internally displaced people create risk environments for unmitigated transmission of SARS-CoV-2. Within one such setting, Cox’s Bazar, Bangladesh, MSF distributed face masks in July-August 2020 for use by people living in eight camps to reduce transmission risks. However, uptake of face masks within camp populations and the factors influencing use are not well understood.
METHODS
We conducted a multi-level triangulation mixed-methods study in March 2021 in Cox’s Bazar. Field observations were undertaken in public spaces in four camps, noting individuals’ facemask use (appropriate versus not), use of other types of face covering (e.g., headscarf), and gender. We also analysed photographs posted on Twitter during March 2021 that were geotagged in the Cox’s Bazar area, posted with a specific keyword, or posted by connected accounts and tweets. Photographs were also categorised by facemask/headscarf use and gender. Finally, we conducted 32 in-depth interviews to understand perceptions and barriers around mask use. Qualitative data were analysed thematically using NVivo.
ETHICS
This study was approved by the Office of the Civil Surgeon, Cox’s Bazar, Bangladesh and by the MSF Ethics Review Board.
RESULTS
We made 3,152 public observations. Only 190/3,152 (6%) were using a mask appropriately. Men were more likely to be seen using any visible standard facemask appropriately than women (odds ratio, OR, 1.5, 95% confidence interval 1.1-2.2, p-value 0.037). Most women were observed wearing headscarves that precluded observing if masks were worn underneath. The content of 20 tweets were analysed. One photograph showed one person wearing a mask correctly; in 17 photographs individuals wore no face covering and in 2 wore scarves. Qualitative data suggested participants were aware of the importance of mask use but highlighted several reasons for not wearing them, including the fear of being insulted for wearing a mask due to the association between mask use and having Covid-19; a view that they were unnecessary because there was little Covid-19 in the camps; experiences of physical difficulties or discomfort whilst wearing masks; and a belief that wearing facemasks was unnecessary because “life or death is up to Allah”. Participants highlighted the current shortage of masks in the camps as well as adverse consequences of insufficient masks, and requested further distribution.
CONCLUSION
These findings suggest low adherence to recommendations around mask use in this camp setting. Multiple strategies need to be considered, including better distribution strategies and improved messaging and engagement with religious and community leaders to increase facemask use in settings such as Cox’s Bazar.
CONFLICTS OF INTEREST
None declared.
The crowded conditions within camps for refugees and internally displaced people create risk environments for unmitigated transmission of SARS-CoV-2. Within one such setting, Cox’s Bazar, Bangladesh, MSF distributed face masks in July-August 2020 for use by people living in eight camps to reduce transmission risks. However, uptake of face masks within camp populations and the factors influencing use are not well understood.
METHODS
We conducted a multi-level triangulation mixed-methods study in March 2021 in Cox’s Bazar. Field observations were undertaken in public spaces in four camps, noting individuals’ facemask use (appropriate versus not), use of other types of face covering (e.g., headscarf), and gender. We also analysed photographs posted on Twitter during March 2021 that were geotagged in the Cox’s Bazar area, posted with a specific keyword, or posted by connected accounts and tweets. Photographs were also categorised by facemask/headscarf use and gender. Finally, we conducted 32 in-depth interviews to understand perceptions and barriers around mask use. Qualitative data were analysed thematically using NVivo.
ETHICS
This study was approved by the Office of the Civil Surgeon, Cox’s Bazar, Bangladesh and by the MSF Ethics Review Board.
RESULTS
We made 3,152 public observations. Only 190/3,152 (6%) were using a mask appropriately. Men were more likely to be seen using any visible standard facemask appropriately than women (odds ratio, OR, 1.5, 95% confidence interval 1.1-2.2, p-value 0.037). Most women were observed wearing headscarves that precluded observing if masks were worn underneath. The content of 20 tweets were analysed. One photograph showed one person wearing a mask correctly; in 17 photographs individuals wore no face covering and in 2 wore scarves. Qualitative data suggested participants were aware of the importance of mask use but highlighted several reasons for not wearing them, including the fear of being insulted for wearing a mask due to the association between mask use and having Covid-19; a view that they were unnecessary because there was little Covid-19 in the camps; experiences of physical difficulties or discomfort whilst wearing masks; and a belief that wearing facemasks was unnecessary because “life or death is up to Allah”. Participants highlighted the current shortage of masks in the camps as well as adverse consequences of insufficient masks, and requested further distribution.
CONCLUSION
These findings suggest low adherence to recommendations around mask use in this camp setting. Multiple strategies need to be considered, including better distribution strategies and improved messaging and engagement with religious and community leaders to increase facemask use in settings such as Cox’s Bazar.
CONFLICTS OF INTEREST
None declared.
Journal Article > ResearchFull Text
Malar J. 2019 December 18; Volume 18 (Issue 1); 430.; DOI:10.1186/s12936-019-3057-7
van Lenthe M, van der Meulen R, Lassovsky M, Ouabo A, Bakula E, et al.
Malar J. 2019 December 18; Volume 18 (Issue 1); 430.; DOI:10.1186/s12936-019-3057-7
BACKGROUND
Sulfadoxine–pyrimethamine (SP) is a cornerstone of malaria chemoprophylaxis and is considered for programmes in the Democratic Republic of Congo (DRC). However, SP efficacy is threatened by drug resistance, that is conferred by mutations in the dhfr and dhps genes. The World Health Organization has specified that intermittent preventive treatment for infants (IPTi) with SP should be implemented only if the prevalence of the dhps K540E mutation is under 50%. There are limited current data on the prevalence of resistance-conferring mutations available from Eastern DRC. The current study aimed to address this knowledge gap.
METHODS
Dried blood-spot samples were collected from clinically suspected malaria patients [outpatient department (OPD)] and pregnant women attending antenatal care (ANC) in four sites in North and South Kivu, DRC. Quantitative PCR (qPCR) was performed on samples from individuals with positive and with negative rapid diagnostic test (RDT) results. Dhps K450E and A581G and dhfr I164L were assessed by nested PCR followed by allele-specific primer extension and detection by multiplex bead-based assays.
RESULTS
Across populations, Plasmodium falciparum parasite prevalence was 47.9% (1160/2421) by RDT and 71.7 (1763/2421) by qPCR. Median parasite density measured by qPCR in RDT-negative qPCR-positive samples was very low with a median of 2.3 parasites/µL (IQR 0.5–25.2). Resistance genotyping was successfully performed in RDT-positive samples and RDT-negative/qPCR-positive samples with success rates of 86.2% (937/1086) and 55.5% (361/651), respectively. The presence of dhps K540E was high across sites (50.3–87.9%), with strong evidence for differences between sites (p < 0.001). Dhps A581G mutants were less prevalent (12.7–47.2%). The dhfr I164L mutation was found in one sample.
CONCLUSIONS
The prevalence of the SP resistance marker dhps K540E exceeds 50% in all four study sites in North and South Kivu, DRC. K540E mutations regularly co-occurred with mutations in dhps A581G but not with the dhfr I164L mutation. The current results do not support implementation of IPTi with SP in the study area.
Sulfadoxine–pyrimethamine (SP) is a cornerstone of malaria chemoprophylaxis and is considered for programmes in the Democratic Republic of Congo (DRC). However, SP efficacy is threatened by drug resistance, that is conferred by mutations in the dhfr and dhps genes. The World Health Organization has specified that intermittent preventive treatment for infants (IPTi) with SP should be implemented only if the prevalence of the dhps K540E mutation is under 50%. There are limited current data on the prevalence of resistance-conferring mutations available from Eastern DRC. The current study aimed to address this knowledge gap.
METHODS
Dried blood-spot samples were collected from clinically suspected malaria patients [outpatient department (OPD)] and pregnant women attending antenatal care (ANC) in four sites in North and South Kivu, DRC. Quantitative PCR (qPCR) was performed on samples from individuals with positive and with negative rapid diagnostic test (RDT) results. Dhps K450E and A581G and dhfr I164L were assessed by nested PCR followed by allele-specific primer extension and detection by multiplex bead-based assays.
RESULTS
Across populations, Plasmodium falciparum parasite prevalence was 47.9% (1160/2421) by RDT and 71.7 (1763/2421) by qPCR. Median parasite density measured by qPCR in RDT-negative qPCR-positive samples was very low with a median of 2.3 parasites/µL (IQR 0.5–25.2). Resistance genotyping was successfully performed in RDT-positive samples and RDT-negative/qPCR-positive samples with success rates of 86.2% (937/1086) and 55.5% (361/651), respectively. The presence of dhps K540E was high across sites (50.3–87.9%), with strong evidence for differences between sites (p < 0.001). Dhps A581G mutants were less prevalent (12.7–47.2%). The dhfr I164L mutation was found in one sample.
CONCLUSIONS
The prevalence of the SP resistance marker dhps K540E exceeds 50% in all four study sites in North and South Kivu, DRC. K540E mutations regularly co-occurred with mutations in dhps A581G but not with the dhfr I164L mutation. The current results do not support implementation of IPTi with SP in the study area.
Conference Material > Poster
Hinh J, Chan G, du Cros PAK, Walker SA, Graham SM, et al.
MSF Scientific Days International 2022. 2022 May 9; DOI:10.57740/3r4d-b715
Conference Material > Slide Presentation
Sadique S, Lin YD, Walker SA, Rao B, du Cros PAK, et al.
MSF Scientific Days International 2022. 2022 May 10; DOI:10.57740/54qw-5453
Conference Material > Slide Presentation
Tremblay LL, Wardley T, Tesfay B, Galban-Horcajo F, West KP, et al.
MSF Scientific Day International 2023. 2023 June 7; DOI:10.57740/9wsa-v278