Barriers against and strategies for malaria control during the COVID-19 pandemic in low- and middle-income countries: a systematic review

Examining Public Sector Availability and Supply Chain Management Practices for Malaria Commodities: Findings From Northern Nigeria

BACKGROUND

Nigeria accounts for substantial proportions of global malaria infections and deaths, with children aged younger than 5 years being the most affected group. This suggests that access to lifesaving malaria interventions could be suboptimal, especially at public health facilities where most rural dwellers seek health care. We conducted this study to ascertain if public health facilities have the commodities and the robust supply chain management (SCM) system required to deliver malaria interventions to children younger than 5 years.

METHOD

We conducted a cross-sectional survey in 1,858 health facilities across 7 states in Nigeria. Using structured questionnaires, we assessed the availability of selected malaria commodities required by children aged younger than 5 years. We also interviewed health workers to evaluate other core SCM activities.

RESULT

More than 50% of health facilities in 5 states were stocked out of malaria rapid diagnostic tests (mRDTs), and stock-out rates for artemisinin-based combination therapies (ACTs) were over 50% for almost all assessed ACTs across all states. The percentage of health facilities that received malaria commodities within the recommended lead time was below average across most states (71%). States with a higher percentage of health workers who were aware of and placed orders following the national reporting timeline and those that delivered commodities to the last mile predominantly through third-party logistics service providers tended to have higher availability of mRDTs and artemether/lumefantrine combinations. The top 2 logistics challenges were insecurity and inadequate funding.

CONCLUSION

The availability of lifesaving malaria commodities across the health facilities visited was suboptimal, possibly due to several SCM challenges. The results from this study underscore the urgent need to implement effective interventions to address the observed gaps. This will contribute to reducing malaria morbidity and mortality among children aged younger than 5 years in Nigeria.

Identifying childhood malaria hotspots and risk factors in a Nigerian city using geostatistical modelling approach

Malaria ranks high among prevalent and ravaging infectious diseases in sub-Saharan Africa (SSA). The negative impacts, disease burden, and risk are higher among children and pregnant women as part of the most vulnerable groups to malaria in Nigeria. However, the burden of malaria is not even in space and time. This study explores the spatial variability of malaria prevalence among children under five years (U5) in medium-sized rapidly growing city of Akure, Nigeria using model-based geostatistical modeling (MBG) technique to predict U5 malaria burden at a 100 × 100 m grid, while the parameter estimation was done using Monte Carlo maximum likelihood method. The non-spatial logistic regression model shows that U5 malaria prevalence is significantly influenced by the usage of insecticide-treated nets-ITNs, window protection, and water source. Furthermore, the MBG model shows predicted U5 malaria prevalence in Akure is greater than 35% at certain locations while we were able to ascertain places with U5 prevalence > 10% (i.e. hotspots) using exceedance probability modelling which is a vital tool for policy development. The map provides place-based evidence on the spatial variation of U5 malaria in Akure, and direction on where intensified interventions are crucial for the reduction of U5 malaria burden and improvement of urban health in Akure, Nigeria.

A Comparative Study of Genetic Diversity and Multiplicity of Infection in Uncomplicated Plasmodium falciparum Infections in Selected Regions of Pre-Elimination and High Transmission Settings Using MSP1 and MSP2 Genes

BACKGROUND

Understanding the genetic structure of P. falciparum population in different regions is pivotal to malaria elimination. Genetic diversity and the multiplicity of infection are indicators used for measuring malaria endemicity across different transmission settings. Therefore, this study characterized P. falciparum infections from selected areas constituting pre-elimination and high transmission settings in South Africa and Nigeria, respectively.

METHODS

Parasite genomic DNA was extracted from 129 participants with uncomplicated P. falciparum infections. Isolates were collected from 78 participants in South Africa (southern Africa) and 51 in Nigeria (western Africa). Allelic typing of the msp1 and msp2 genes was carried out using nested PCR.

RESULTS

In msp1, the K1 allele (39.7%) was the most common allele among the South African isolates, while the RO33 allele (90.2%) was the most common allele among the Nigerian isolates. In the msp2 gene, FC27 and IC3D7 showed almost the same percentage distribution (44.9% and 43.6%) in the South African isolates, whereas FC27 had the highest percentage distribution (60.8%) in the Nigerian isolates. The msp2 gene showed highly distinctive genotypes, indicating high genetic diversity in the South African isolates, whereas msp1 showed high genetic diversity in the Nigerian isolates. The RO33 allelic family displayed an inverse relationship with participants' age in the Nigerian isolates. The overall multiplicity of infection (MOI) was significantly higher in Nigeria (2.87) than in South Africa (2.44) (p < 0.000 *). In addition, heterozygosity was moderately higher in South Africa (1.46) than in Nigeria (1.13).

CONCLUSIONS

The high genetic diversity and MOI in P. falciparum that were observed in this study could provide surveillance data, on the basis of which appropriate control strategies should be adopted.

The problem of antimalarial resistance and its implications for drug discovery

INTRODUCTION

Malaria remains a devastating infectious disease with hundreds of thousands of casualties each year. Antimalarial drug resistance has been a threat to malaria control and elimination for many decades and is still of concern today. Despite the continued effectiveness of current first-line treatments, namely artemisinin-based combination therapies, the emergence of drug-resistant parasites in Southeast Asia and even more alarmingly the occurrence of resistance mutations in Africa is of great concern and requires immediate attention.

AREAS COVERED

A comprehensive overview of the mechanisms underlying the acquisition of drug resistance in Plasmodium falciparum is given. Understanding these processes provides valuable insights that can be harnessed for the development and selection of novel antimalarials with reduced resistance potential. Additionally, strategies to mitigate resistance to antimalarial compounds on the short term by using approved drugs are discussed.

EXPERT OPINION

While employing strategies that utilize already approved drugs may offer a prompt and cost-effective approach to counter antimalarial drug resistance, it is crucial to recognize that only continuous efforts into the development of novel antimalarial drugs can ensure the successful treatment of malaria in the future. Incorporating resistance propensity assessment during this developmental process will increase the likelihood of effective and enduring malaria treatments.

Mosquito-borne diseases in India over the past 50 years and their Global Public Health Implications: A Systematic Review

Mosquito-borne diseases (MBDs) pose a significant public health concern globally, and India, with its unique eco-sociodemographic characteristics, is particularly vulnerable to these diseases. This comprehensive review aims to provide an in-depth overview of MBDs in India, emphasizing their impact and potential implications for global health. The article explores distribution, epidemiology, control or elimination, and economic burden of the prevalent diseases such as malaria, dengue, chikungunya, Japanese encephalitis, and lymphatic filariasis, which collectively contribute to millions of cases annually. It sheds light on their profound effects on morbidity, mortality, and socioeconomic burdens and the potential for international transmission through travel and trade. The challenges and perspectives associated with controlling mosquito populations are highlighted, underscoring the importance of effective public health communication for prevention and early detection. The potential for these diseases to spread beyond national borders is recognized, necessitating a holistic approach to address the challenge. A comprehensive literature search was conducted, covering the past five decades (1972-2022), utilizing databases such as Web of Science, PubMed, and Google Scholar, in addition to in-person library consultations. The literature review analyzed 4,082 articles initially identified through various databases. After screening and eligibility assessment, 252 articles were included for analysis. The review focused on malaria, dengue, chikungunya, Japanese encephalitis, and lymphatic filariasis. The included studies focused on MBDs occurrence in India, while those conducted outside India, lacking statistical analysis, or published before 1970 were excluded. This review provides valuable insights into the status of MBDs in India and underscores the need for concerted efforts to combat these diseases on both national and global scales through consilience.

Health workers' adherence to the malaria test, treat and track strategy during the COVID-19 pandemic in malaria high transmission area in Eastern Uganda

BACKGROUND

Coronavirus disease 2019 (COVID-19) pandemic affected malaria control activities in sub-Saharan Africa (SSA) resulting in 690,000 excess deaths in the year 2021. The authors hypothesized that COVID-19 affected the World Health Organization (WHO) Test, Treat and Track (T3) strategy that has been implemented in Uganda since 2010. In this study, health worker's adherence to the T3 strategy during COVID-19 pandemic in Eastern Uganda was studied by assessing their knowledge, skills and practices.

METHODS

A cross-sectional study utilizing mixed quantitative and qualitative data collections methods was conducted at Mbale Regional Referral Hospital in Eastern Uganda between November and December in 2020. Data were captured on demographics, knowledge, skills and practices for both health workers (HWs) and patients. Quantitative data were analysed using STATA 15.0 and reported as descriptive statistics, proportions and statistical associations. Moreover, qualitative data were collected via key informant interviews (KII) among purposively sampled study participants and analysed thematically using NVIVO software. Ethical approval was obtained prior to the study.

RESULTS

A total of 436 study participants, of whom 103/436 (24%) and 333/436 (76%) were HWs and patients, respectively were studied. Among the HWs with mean age of 34 years (SD = 8.8 years), 81/103 (79%) had good practices, most 63/103 (61%) had good knowledge, and only 11/103 (10.7%) had good skills. Specifically, on the cadres, the laboratory personnel 19/103 (18%) had good knowledge 14/19 (74%) OR: 2.0 (95% CI 0.7-6) and were highly skilled OR: 4.6 (95% CI 1.2-18.1; P < 0.0150) compared to other cadres, respectively. Among the patients whose age ranged 3 months to 80 years (mean 17.8 years) and females 177/333 (53%); a majority 257/333 (77%) were tested, of whom 139/333 (42%) tested positive. Out of the positive cases, 115/333 (35%) were treated and tracked. About 75/333 (23%) were not tested but treated for malaria. Of the 168/239 (70.3%) patients tested, 115/168 (68.5%) were positive and treated, P = 0.0001. The KII revealed low level of In-service training, overwhelming number of patients and stock-out of supplies as a key factor for poor HW adherence to T3 strategy.

CONCLUSIONS

During COVID-19 pandemic period HWs adherence to T3 initiative was low as 27% malaria patients did not receive treatment.

Antimalarial Agents Targeting Plasmodium falciparum Carbonic Anhydrase: Towards Artesunate Hybrid Compounds with Dual Mechanism of Action

Malaria continues to be a major public health challenge worldwide and, as part of the global effort toward malaria eradication, plasmodium carbonic anhydrases (CAs) have recently been proposed as potential targets for malaria treatment. In this study, a series of eight hybrid compounds combining the Artesunate core with a sulfonamide moiety were synthesized and evaluated for their inhibition potency against the widely expressed human (h) CAs I, II and the isoform from P. falciparum (PfCA). All derivatives demonstrated high inhibition potency against PfCA, achieving a KI value in the sub-nanomolar range (0.35 nM). Two Compounds showed a selectivity index of 4.1 and 3.1, respectively, against this protozoan isoform compared to hCA II. Three Derivatives showed no cytotoxic effects on human gingival fibroblasts at 50 μM with a high killing rate against both P. falciparum and P. knowlesi strains with IC50 in the sub-nanomolar range, providing a wide therapeutic window. Our findings suggest that these compounds may serve as promising leads for developing new antimalarial drugs and warrant further investigation, including activity against antimalarial-resistant strains, mode of action studies, and in vivo efficacy assessment in preclinical mouse models of malaria.

Design, synthesis and antiplasmodial evaluation of new amide-, carbamate-, and ureido-type harmicines

Malaria, one of the oldest parasitic diseases, remains a global health threat, and the increasing resistance of the malaria parasite to current antimalarials is forcing the discovery of new, effective drugs. Harmicines, hybrid compounds in which harmine/β-carboline alkaloids and cinnamic acid derivatives are linked via an amide bond or a triazole ring, represent new antiplasmodial agents. In this work, we used a multiple linear regression technique to build a linear quantitative structure-activity relationship (QSAR) model, based on a group of 40 previously prepared amide-type (AT) harmicines and their antiplasmodial activities against erythrocytic stage of chloroquine-sensitive strain of P. falciparum (Pf3D7). After analysing the QSAR model, new harmicines were designed and synthesized: six amide-type, eleven carbamate-type and two ureido-type harmicines at the N-9 position of the β-carboline core. Subsequently, we evaluated the antiplasmodial activity of the new harmicines against the erythrocytic and hepatic stages of the Plasmodium life cycle in vitro and their antiproliferative activity against HepG2 cells. UT harmicine (E)-1-(2-(7-methoxy-1-methyl-9H-pyrido[3,4-b]indol-9-yl)ethyl)-3-(3-(3-(trifluoromethyl)phenyl)allyl)urea at the N-9 position of the β-carboline ring exhibited pronounced antiplasmodial activity against both the erythrocytic and the hepatic stages of the Plasmodium life cycle, accompanied by good selectivity towards Plasmodium.

Mass distribution campaign of long-lasting insecticidal nets (LLINs) during the COVID-19 pandemic in Uganda: lessons learned

BACKGROUND

Uganda implemented its third mass campaign to distribute long-lasting insecticidal nets (LLINs) in 2020 during the COVID-19 pandemic. This context necessitated modification of implementation guidelines. The mass campaign's objective was to ensure that at least 85% of the targeted population had access to LLINs.

METHODS

Revised implementation guidelines were followed while conducting the LLIN distribution campaign. Lessons learned were captured from documented activities and reports.

RESULTS

A total of 27,789,044 mosquito nets were distributed in 11,287,392 households, with an average of 5.1 persons per household. Household coverage of the LLIN distribution was 94.1%. The 2020/2021 campaign design was modified to follow COVID-19 Standard Operating Procedures (SOPs). These included using Personal Protective Equipment (PPE), e-platforms for training and briefing meetings, electronic data management systems and door-to-door household registration and distribution of LLINs.

CONCLUSIONS

Campaign modifications due to the COVID-19 pandemic were effective in implementing mass distribution of LLINs despite the disruptions and restrictions. The campaign's net coverage far exceeded its objective. Electronic data management was critical in monitoring and reporting distribution activities.