Assessing the effect of seasonal malaria chemoprevention on malaria burden among children under 5 years in Burkina Faso

The monthly trends of malaria cases in children under 5 years of age in Guinea: comparative analysis between a seasonal malaria chemoprevention (SMC) and a non-SMC health district

BACKGROUND

The Republic of Guinea, where malaria represents the leading cause of morbidity and mortality among children, the seasonal malaria chemoprevention (SMC) is deployed only in areas with very seasonal modes of transmission. It should target children at the highest risk of serious illness. The objective of the study was to prevent uncomplicated and serious cases of malaria in the target population. This study aimed to analyse the monthly trends in malaria-related morbidity among children under the age of 5 in Guinea.

METHODS

This was a quasi-experimental study with routine data from the National Health Information System (SNIS). The two districts Mamou (the SMC intervention site) and Kindia (the control site) were selected to compare the monthly trends in malaria cases among children under the age of 5, from July to October, covering the years from 2015 to 2020. The statistical analysis used interrupted time series to estimate the effects of the SMC.

RESULTS

The SMC programme contributed to a significant average reduction in the number of malaria cases of 225 cases per month in the intervention district (95% CI - 362 to - 88; p = 0.002), compared to the control district. However, the study also revealed that the effect of SMC varied between cycles, presenting different monthly malaria cases.

CONCLUSION

The SMC contributed to a significant reduction in malaria cases among children under the age of 5 in the health district of Mamou from 2018 to 2020. However, this reduction varied by monthly SMC cycle. This study suggests extending the SMC in other areas with high perennial seasonal transmission respecting the World Health Organization SMC eligibility criteria, as a strategy in the dynamic of reducing malaria cases in children under the age of 5 in Guinea.

Impact of seasonal malaria chemoprevention based on the number of medicines doses received on malaria burden among children aged 3-59 months in Nigeria: A propensity score-matched analysis

BACKGROUND

Seasonal malaria chemoprevention using sulfadoxine-pyrimethamine plus amodiaquine (sulfadoxine-pyrimethamine plus amodiaquine on Day 1 and amodiaquine on both Day 2 and Day 3) is delivered to children aged 3-59 months in areas of highly season malaria transmission. While the overall population-level impact of seasonal malaria chemoprevention on malaria control has been documented in various countries and time periods, there is no clear evidence regarding seasonal malaria chemoprevention impact based on the number of medicine doses children receive in one cycle in routine programmatic conditions.

METHODS

Data were extracted from Nigeria's routinely collected seasonal malaria chemoprevention end-of-round coverage surveys (2021, 2022). We matched seasonal malaria chemoprevention-targeted children who received specific numbers of seasonal malaria chemoprevention medicines with those who did not receive any doses of seasonal malaria chemoprevention medicines (non-sulfadoxine-pyrimethamine plus amodiaquine) using multiple sets of propensity score matches. We performed multilevel logistic regression for each matched group to evaluate the association between the number of doses of seasonal malaria chemoprevention medicines and monthly confirmed malaria cases (caregiver-reported malaria infection diagnosed by rapid diagnostic test at a health facility following the penultimate cycle of seasonal malaria chemoprevention).

RESULTS

Among 21,621 SMC-targeted children, 9.7% received non-sulfadoxine-pyrimethamine plus amodiaquine, 0.5% received only Day 1 sulfadoxine-pyrimethamine plus amodiaquine, 1.0% received Day 1 sulfadoxine-pyrimethamine plus amodiaquine and either Day 2 amodiaquine or Day 3 amodiaquine (sulfadoxine-pyrimethamine plus amodiaquine + amodiaquine), and 88.8% received Day 1 sulfadoxine-pyrimethamine plus amodiaquine and both Day 2 and Day 3 amodiaquine (sulfadoxine-pyrimethamine plus amodiaquine + amodiaquine + amodiaquine). Children receiving only Day 1 sulfadoxine-pyrimethamine plus amodiaquine did not have significant lower odds of rapid diagnostic tests-confirmed malaria than those receiving non-sulfadoxine-pyrimethamine plus amodiaquine (OR 0.77, 0.42-1.42). However, children receiving sulfadoxine-pyrimethamine plus amodiaquine + amodiaquine had significantly lower odds of rapid diagnostic tests-confirmed malaria than those receiving non-sulfadoxine-pyrimethamine plus amodiaquine (OR 0.42, 95% CI 0.28-0.63). Similarly, children receiving sulfadoxine-pyrimethamine plus amodiaquine + amodiaquine + amodiaquine also had significantly lower odds of rapid diagnostic test-confirmed malaria than those receiving non-sulfadoxine-pyrimethamine plus amodiaquine (OR 0.54, 95% CI 0.47-0.62).

CONCLUSION

Adherence to at least one daily dose of amodiaquine administration following receipt of Day 1 sulfadoxine-pyrimethamine plus amodiaquine by eligible children is crucial to ensure the effectiveness of seasonal malaria chemoprevention. This demonstrates the importance of enhancing caregiver awareness regarding the importance of amodiaquine and identifying barriers toward amodiaquine administration at the community level.

Malaria prevention in children: an update

PURPOSE OF REVIEW

Malaria cases and deaths decreased from 2000 to 2015 but remain increased since 2019. Several new developments and strategies could help reverse this trend. The purpose of this review is to discuss new World Health Organization (WHO) guidelines and recent research on malaria prevention in children.

RECENT FINDINGS

Fifteen countries have now rolled out seasonal malaria chemoprophylaxis (SMC) in children at highest risk for severe malaria, and new WHO recommendations provide more flexibility for SMC implementation in terms of target age groups, geographic region, and number of cycles. Recent studies confirm that malaria burden in school aged children, and their contribution to transmission, is high. New guidelines permit expanded chemoprevention options for these children. Two vaccines have been approved for use in malaria endemic countries, RTS,S/AS01 E and R21/Matrix-M. Additionally, pyrethroid-chlorfenapyr bed nets are being deployed to combat resistant mosquitoes.

SUMMARY

While challenges remain in malaria control towards elimination, new guidelines and recently approved vaccines offer hope. Monitoring for continued vaccine and chemoprevention effectiveness, and for possible epidemiologic shifts in severe malaria presentation and deaths as additional prevention efforts roll out will be paramount.

A Bayesian spatio-temporal framework to assess the effect of seasonal malaria chemoprevention on children under 5 years in Cameroon from 2016 to 2021 using routine data

BACKGROUND

Malaria affects millions of Cameroonian children under 5 years of age living in the North and Far North regions. These regions bear the greatest burden, particularly for children under 5 years of age. To reduce the burden of disease in these regions, Cameroon adopted the Seasonal Malaria Chemoprevention (SMC) in 2016 and has implemented it each year since its adoption. However, no previous studies have systematically assessed the effects of this intervention in Cameroon. It is important to understand its effect and whether its implementation could be improved. This study aimed to assess the effect of SMC in Cameroon during the period 2016-2021 on malaria morbidity in children under 5 years of age using routine data.

METHODS

Data on malaria cases were extracted from the Cameroon Health Monitoring Information System (HMIS) from January 1, 2011, to December 31, 2021. Health facilities report these data monthly on a single platform, the District Health Information System version 2 (DHIS2). Thus, a controlled interrupted time-series model in a Bayesian framework was used to evaluate the effects of the SMC on malaria morbidity.

RESULTS

SMC implementation was associated with a reduction in the incidence of uncomplicated malaria cases during the high-transmission periods from 2016 to 2021. Regarding the incidence of severe malaria during the high-transmission period, a reduction was found over the period 2016-2019. The highest reduction was registered during the second year of implementation in 2017:15% (95% Credible Interval, 10-19) of uncomplicated malaria cases and 51% (47-54) of confirmed severe malaria cases.

CONCLUSION

The addition of SMC to the malaria intervention package in Cameroon decreased the incidence of uncomplicated and severe malaria among children under 5 years of age. Based on these findings, this study supports the wide implementation of SMC to reduce the malaria burden in Cameroon as well as the use of routine malaria data to monitor the efficiency of the strategy in a timely manner.

Malariometric Indices in the Context of Seasonal Malaria Chemoprevention in Children Aged 1.5 to 12 Years during the Period of High Malaria Transmission in the Suburban Area of Banfora, Burkina Faso

Continuous monitoring of malaria epidemiology is needed in malaria-endemic settings to inform malaria control and elimination strategies. This study aimed to compare the malariometric indices between the under-fives and school-age children. We surveyed children aged 1.5 to 12 years for plasmodia carriage with the aim of including them in a longitudinal follow-up cohort. The survey took place from 7-11 September 2020 in a southwest area of Burkina Faso. Clinical and demographic data including malaria control measures were collected. A finger prick blood sample was taken for haemoglobin testing, and blood smears and dried blood spot preparation. The malariometric indices were calculated and compared between school-age children and those under the age of five. Multiple logistic regression was fitted to assess the association between malaria parasite carriage and age categories. Based on the PCR results, the parasite prevalence was 21.4% in the under-fives versus 44.2% in school-age children (p-value < 0.0001), with a pooled prevalence of 32.7% (CI = [28.8, 36.8]). The gametocyte prevalence was also significantly higher in school-age children (11.9%) compared to the under-fives (3.7%). Adjusted for covariates, school-age children were 2.9 times (IC = [2.0, 4.2]) more likely to carry the asexual parasite, compared to the under-fives. Malaria was moderate and stable endemic in this area and school-age children play a key role in the spread of the disease. The WHO conditional recommendation for intermittent preventive treatment of malaria in school-aged children living in malaria-endemic settings with moderate to high perennial or seasonal transmission should be implemented.

Seasonal malaria chemoprevention in Africa and China's upgraded role as a contributor: a scoping review

BACKGROUND

Children under five are the vulnerable population most at risk of being infected with Plasmodium parasites, especially in the Sahel region. Seasonal malaria chemoprevention (SMC) recommended by World Health Organization (WHO), has proven to be a highly effective intervention to prevent malaria. Given more deaths reported during the COVID-19 pandemic than in previous years due to the disruptions to essential medical services, it is, therefore, necessary to seek a more coordinated and integrated approach to increasing the pace, coverage and resilience of SMC. Towards this end, fully leverage the resources of major players in the global fight against malaria, such as China could accelerate the SMC process in Africa.

METHODS

We searched PubMed, MEDLINE, Web of Science, and Embase for research articles and the Institutional Repository for Information Sharing of WHO for reports on SMC. We used gap analysis to investigate the challenges and gaps of SMC since COVID-19. Through the above methods to explore China's prospective contribution to SMC.

RESULTS

A total of 68 research articles and reports were found. Through gap analysis, we found that despite the delays in the SMC campaign, 11.8 million children received SMC in 2020. However, there remained some challenges: (1) a shortage of fully covered monthly courses; (2) lack of adherence to the second and third doses of amodiaquine; (3) four courses of SMC are not sufficient to cover the entire malaria transmission season in areas where the peak transmission lasts longer; (4) additional interventions are needed to consolidate SMC efforts. China was certified malaria-free by WHO in 2021, and its experience and expertise in malaria elimination can be shared with high-burden countries. With the potential to join the multilateral cooperation in SMC, including the supply of quality-assured health commodities, know-how transfer and experience sharing, China is expected to contribute to the ongoing scale-up of SMC.

CONCLUSIONS

A combination of necessary preventive and curative activities may prove beneficial both for targeted populations and for health system strengthening in the long run. More actions are entailed to promote the partnership and China can be one of the main contributors with various roles.

Impact of high human genetic diversity in Africa on immunogenicity and efficacy of RTS,S/AS01 vaccine

In modern medicine, vaccination is one of the most effective public health strategies to prevent infectious diseases. Indisputably, vaccines have saved millions of lives by reducing the burden of many serious infections such as polio, tuberculosis, measles, pneumonia, and tetanus. Despite the recent recommendation by the World Health Organization (WHO) to roll out RTS,S/AS01, this malaria vaccine still faces major challenges of variability in its efficacy partly due to high genetic variation in humans and malaria parasites. Immune responses to malaria vary between individuals and populations. Human genetic variation in immune system genes is the probable cause for this heterogeneity. In this review, we will focus on human genetic factors that determine variable responses to vaccination and how variation in immune system genes affect the immunogenicity and efficacy of the RTS,S/AS01 vaccine.

National-scale simulation of human movement in a spatially coupled individual-based model of malaria in Burkina Faso

Malaria due to the Plasmodium falciparum parasite remains a threat to human health despite eradication efforts and the development of anti-malarial treatments, such as artemisinin combination therapies. Human movement and migration have been linked to the propagation of malaria on national scales, highlighting the need for the incorporation of human movement in modeling efforts. Spatially couped individual-based models have been used to study how anti-malarial resistance evolves and spreads in response to drug policy changes; however, as the spatial scale of the model increases, the challenges associated with modeling of movement also increase. In this paper we discuss the development, calibration, and validation of a movement model in the context of a national-scale, spatial, individual-based model used to study the evolution of drug resistance in the malaria parasite.

Surveillance des effets indésirables lors des campagnes de la chimioprévention du paludisme saisonnier chez les enfants de 3-59 mois au Burkina Faso

INTRODUCTION

Seasonal malaria chemoprevention (SMC) by mass administration of sulfadoxine pyrimethamine + amodiaquine (SPAQ) reduces the burden of malaria in children aged 3-59 months. The occurrence of adverse drug reaction (ADR) may affect the success of this intervention. There are few studies of SMC adverse event surveillance in sub-Saharan Africa, particularly in Burkina Faso, a highly endemic country. Our main objective was to characterize the ADRs reported during SMC campaigns in Burkina Faso. Secondly, we evaluated the performance of the pharmacovigilance integrated into the SMC program in order to support safe administration of SMC.

METHOD

This was a retrospective descriptive study of SMC individual case safety reports recorded in VigiBase® in Burkina Faso from 2014 to 2021. We used the P-method for the analysis of preventable serious adverse drug reactions and WHO criteria for assessing the performance of pharmacovigilance integrated into the SMC program.

RESULTS

A total of 1,105 SMC individual case safety reports were registered in VigiBase® for 23,311,453 doses of SPAQ given between 2014 and 2021. No pharmacovigilance signal was detected. The number of serious cases was 101, of which 23 (22.8%) were preventable. In 38.1% of children, the occurrence of ADRs led to discontinuation of SMC treatment. Vomiting was the most frequently reported adverse drug reaction (48.0%). The proportion of children whose treatment was discontinued due to vomiting was 42.7%, while the proportion of treatment discontinuation for other ADRs was 32.8% (p = 0.01). The SMC program contributed at 46.2% to the national pharmacovigilance database. The reporting rate was 0.03 per 1,000 exposed children in 2021. The median completeness score of the ICSRs was 0.7 (IQR: 0.5-0.7), and the median time to register the ICSRs in VigiBase® was 204 (IQR: 143-333) days.

CONCLUSIONS

Post-drug administration vomiting may interfere with the purpose of SMC. Measures to manage this adverse drug reaction should be taken to improve the success of the SMC program. Based on the information on reporting time and reporting rate, spontaneous reporting should be supported by active surveillance, including cohort event monitoring, in Burkina Faso.

Factors Influencing Second and Third Dose Observance during Seasonal Malaria Chemoprevention (SMC): A Quantitative Study in Burkina Faso, Mali and Niger

This study aims to evaluate the factors influencing the adherence to the 2nd and 3rd doses of Amodiaquine (AQ) during seasonal malaria chemoprevention (SMC) in Burkina Faso, Mali, and Niger. Overall, 3132 people were interviewed during surveys between 2019 and 2020 in 15 health districts. In Burkina Faso, Mali, and Niger, the proportions of non-adherence were 4.15%, 5.60%, and 13.30%, respectively, for the 2nd dose and 3.98%, 5.60% and 14.39% for the 3rd dose. The main cause of non-adherence to the 2nd and 3rd doses was other illnesses in 28.5% and 29.78%, respectively, in Burkina Faso, 5.35% and 5.35% in Mali and 1.6% and 0.75% in Niger. It was followed by vomiting in 12.24% and 10.63% for Burkina and 2.45% and 3.78% in Niger. The last cause was refusal in 6.12% and 4.25% in Burkina, 33.9% and 15.25% in Mali and 0.8% and 1.51% in Niger. Non-adherence of doses related to parents was primarily due to their absence in 28.5% and 27.65% in Burkina, 16.07% and 16.07% in Mali and 7.37% and 6.06% in Niger. Traveling was the second cause related to parents in 12.24% and 12.76% in Burkina, 19.64% and 19.64% in Mali and 0.81% and 0.75% in Niger. Non-adherence related to community distributors was mainly due to missing the doses in 4.08% and 4.25% in Burkina, 23.21% and 23.21% in Mali, 77.04% and 76.51% in Niger. Our study reported very small proportions of non-adherence to 2nd and 3rd doses of SMC and identified the main causes of non-adherence. These findings will provide helpful information for policymakers and public health authorities to improve adherence to SMC