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1.
Microbiol Spectr ; : e0382022, 2023 Sep 12.
Article in English | MEDLINE | ID: mdl-37698406

ABSTRACT

Our overall understanding of the developmental biology of malaria parasites has been greatly enhanced by recent advances in transcriptomic analysis. However, most of these investigations rely on laboratory strains (LS) that were adapted into in vitro culture many years ago, and the transcriptomes of clinical isolates (CI) circulating in human populations have not been assessed. In this study, RNA-seq was used to compare the global transcriptome of mid-stage gametocytes derived from three short-term cultured CI, with gametocytes derived from the NF54 reference laboratory strain. The core transcriptome appeared to be consistent between CI- and LS-derived gametocyte preparations, but some important differences were also observed. A majority of gametocyte-specific genes (43/53) appear to have relatively higher expression in CI-derived gametocytes than in LS-derived gametocytes, but a K-means clustering analysis showed that genes involved in flagellum- and microtubule-based processes (movement/motility) were more abundant in both groups, albeit with some differences between them. In addition, gametocytes from one CI described as CI group II gametocytes (CI:GGII) showed gene expression variation in the form of reduced gametocyte-specific gene expression compared to the other two CI-derived gametocytes (CI gametocyte group I, CI:GGI), although the mixed developmental stages used in our study is a potential confounder, only partially mitigated by the inclusion of multiple replicates for each CI. Overall, our study suggests that there may be subtle differences in the gene expression profiles of mid-stage gametocytes from CI relative to the NF54 reference strain of Plasmodium falciparum. Thus, it is necessary to deploy gametocyte-producing clinical parasite isolates to fully understand the diversity of gene expression strategies that may occur during the sequestered development of parasite sexual stages. IMPORTANCE Maturing gametocytes of Plasmodium falciparum are known to sequester away from peripheral circulation into the bone marrow until they are mature. Blocking gametocyte sequestration can prevent malaria transmission from humans to mosquitoes, but most studies aim to understand gametocyte development utilizing long-term adapted laboratory lines instead of clinical isolates. This is a particular issue for our understanding of the sexual stages, which are known to decrease rapidly during adaptation to long-term culture, meaning that many LS are unable to produce transmissible gametocytes. Using RNA-seq, we investigated the global transcriptome of mid-stage gametocytes derived from three clinical isolates and a reference strain (NF54). This identified important differences in gene expression profiles between immature gametocytes of CI and the NF54 reference strain of P. falciparum, suggesting increased investment in gametocytogenesis in clinical isolates. Our transcriptomic data highlight the use of clinical isolates in studying the morphological, cellular features and molecular biology of gametocytes.

2.
Malar J ; 22(1): 271, 2023 Sep 14.
Article in English | MEDLINE | ID: mdl-37710288

ABSTRACT

BACKGROUND: The routine surveillance of asymptomatic malaria using nucleic acid-based amplification tests is essential in obtaining reliable data that would inform malaria policy formulation and the implementation of appropriate control measures. METHODS: In this study, the prevalence rate and the dynamics of Plasmodium species among asymptomatic children (n = 1697) under 5 years from 30 communities within the Hohoe municipality in Ghana were determined. RESULTS AND DISCUSSION: The observed prevalence of Plasmodium parasite infection by polymerase chain reaction (PCR) was 33.6% (571/1697), which was significantly higher compared to that obtained by microscopy [26.6% (451/1697)] (P < 0.0001). Based on species-specific analysis by nested PCR, Plasmodium falciparum infection [33.6% (570/1697)] was dominant, with Plasmodium malariae, Plasmodium ovale and Plasmodium vivax infections accounting for 0.1% (1/1697), 0.0% (0/1697), and 0.0% (0/1697), respectively. The prevalence of P. falciparum infection among the 30 communities ranged from 0.0 to 82.5%. Following artesunate-amodiaquine (AS + AQ, 25 mg/kg) treatment of a sub-population of the participants (n = 184), there was a substantial reduction in Plasmodium parasite prevalence by 100% and 79.2% on day 7 based on microscopy and nested PCR analysis, respectively. However, there was an increase in parasite prevalence from day 14 to day 42, with a subsequent decline on day 70 by both microscopy and nested PCR. For parasite clearance rate analysis, we found a significant proportion of the participants harbouring residual Plasmodium parasites or parasite genomic DNA on day 1 [65.0% (13/20)], day 2 [65.0% (13/20)] and day 3 [60.0% (12/20)] after initiating treatment. Of note, gametocyte carriage among participants was low before and after treatment. CONCLUSION: Taken together, the results indicate that a significant number of individuals could harbour residual Plasmodium parasites or parasite genomic DNA after treatment. The study demonstrates the importance of routine surveillance of asymptomatic malaria using sensitive nucleic acid-based amplification techniques.


Subject(s)
Artemisinins , Malaria, Falciparum , Malaria , Nucleic Acids , Child , Humans , Ghana/epidemiology , Malaria/drug therapy , Malaria/epidemiology , Artemisinins/therapeutic use , Malaria, Falciparum/drug therapy , Malaria, Falciparum/epidemiology , Plasmodium malariae
3.
PLoS One ; 18(9): e0291808, 2023.
Article in English | MEDLINE | ID: mdl-37729176

ABSTRACT

INTRODUCTION: The Coronavirus disease 2019 (COVID-19) burden, coupled with unprecedented control measures including physical distancing, travel bans, and lockdowns of cities, implemented to stop the spread of the virus, have undoubtedly far-reaching aftereffects on other diseases. In low and middle-income countries (LMICs), a particular worry is the potential impact on Human Immunodeficiency Virus (HIV) and Tuberculosis (TB), as a consequence of possible disruption to health services and limiting access to needed life-saving health care. In Ghana, there is a paucity of information regarding the impact of COVID-19 on disease control, particularly TB and HIV control. This study sought to contribute to bridging this knowledge gap. METHOD: The study involved the analysis of secondary data obtained from the District Health Information Management System-2 (DHIMS-2) database of Ghana Health Service, from 2016 to 2020. Data were analysed using an interrupted time-series regression approach to estimate the impact of COVID-19 on TB case notification, HIV testing, and Antiretroviral Therapy (ART) initiations, using March 2020 as the event period. RESULTS: The study showed that during the COVID-19 pandemic period, there was an abrupt decline of 20.5% (955CI: 16.0%, 24.5%) in TB case notifications in April and 32.7% (95%CI: 28.8%, 39.1%) in May 2020, with a median monthly decline of 21.4% from April-December 2020. A cumulative loss of 2,128 (20%; 95%CI: 13.3%, 26.7%) TB cases was observed nationwide as of December 2020. There was also a 40.3% decrease in people presenting for HIV tests in the first month of COVID-19 (April 2020) and a cumulative loss of 262620 (26.5%) HIV tests as of December 2020 attributable to the COVID-19 pandemic. ART initiations increased by 39.2% in the first month and thereafter decreased by an average of 10% per month from May to September 2020. Cumulatively, 443 (1.9%) more of the people living with HIV initiated ART during the pandemic period, however, this was not statistically significant. CONCLUSION: This study demonstrated that the COVID-19 pandemic negatively impacted TB case notifications and HIV testing and counselling services, However, ART initiation was generally not impacted during the first year of the pandemic. Proactive approaches aimed at actively finding the thousands of individuals with TB who were missed in 2020 and increasing HIV testing and counselling and subsequent treatment initiations should be prioritised.


Subject(s)
COVID-19 , HIV Infections , Humans , HIV , Pandemics , Ghana/epidemiology , Interrupted Time Series Analysis , COVID-19/epidemiology , Communicable Disease Control , HIV Infections/drug therapy , HIV Infections/epidemiology
4.
Parasite Epidemiol Control ; 19: e00276, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36263093

ABSTRACT

Background: Over 90% of severe malaria (SM) cases occur in African children. Parenteral artesunate is currently the recommended treatment for SM. Studies of parasite clearance in paediatric SM cases are needed for assessment of therapeutic outcomes but are lacking in Africa. Methods: Severe malaria patients were recruited in the children's emergency ward at Ho Teaching Hospital, Ghana, in 2018. Blood samples were taken upon admission, every 24 h for 3 days and 1 week after treatment, and DNA extracted. Parasitaemia and parasite densities were performed by microscopy at enrolment and the follow-up days wherever possible. Relative parasite density was measured at each timepoint by duplex qPCR and parameters of parasite clearance estimated. Results: Of 25 evaluable SM patients, clearance of qPCR-detectable parasites occurred within 48 h for 17 patients, but three out of the remaining eight were still qPCR-positive on day 3. Increased time to parasite clearance was seen in children ≥5 years old, those with lower haemoglobin levels and those with a high number of previous malaria diagnoses, but these associations were not statistically significant. Conclusion: We examined parasite clearance dynamics among paediatric cases of SM. Our observations suggest that daily sampling for qPCR estimation of P. falciparum peripheral density is a useful method for assessing treatment response in hospitalised SM cases. The study demonstrated varied parasite clearance response, thus illuminating the complex nature of the mechanism in this important patient group, and further investigations utilizing larger sample sizes are needed to confirm our findings.

5.
Pharmacol Res Perspect ; 10(4): e00987, 2022 08.
Article in English | MEDLINE | ID: mdl-35855566

ABSTRACT

The assessment in real-life conditions of the safety and efficacy of new antimalarial drugs is of greatest interest. This study aimed to monitor and evaluate both clinical and biological safety of pyronaridine-artesunate (PA) in real-life conditions in Burkina Faso's health system. This was a single-arm, open-label study, where patients attending Nanoro health facilities with uncomplicated malaria were consented to be part of a cohort event monitoring (CEM). At inclusion (day-0), PA was administered orally once a day for 3 days. Patients spontaneous reported any clinical adverse events (AEs) occurring within 28 days following the treatment. Additionally, the study focused on AEs of special interest (AESI), namely clinical signs related to hepatotoxicity and increased alanine aminotransferase (ALT) and aspartate aminotransferase (AST). A nested subset of patients with blood sample collection at day-0 and day-7 were monitored to investigate the effect of PA on biochemistry parameters. From September 2017 to October 2018, 2786 patients were treated with PA. About 97.8% (2720/2786) of patients did not report any AE. The most commonly reported events were respiratory, thoracic, and mediastinal disorders (8.3 per 1000), infections and infestations (7.9 per 1000), and gastrointestinal disorders (7.2 per 1000). No clinical or biological hepatotoxicity event related to PA was reported during the follow-up. Changes in biochemistry parameters remained within laboratory reference ranges. The study showed that PA is a well-tolerated drug and should be considered as a good option by malaria control programs in countries where existing first-line antimalarial drugs are continuously threatened by the emergence of drug resistance.


Subject(s)
Antimalarials , Artemisinins , Chemical and Drug Induced Liver Injury , Drug-Related Side Effects and Adverse Reactions , Malaria , Antimalarials/adverse effects , Artemisinins/adverse effects , Artesunate , Burkina Faso/epidemiology , Chemical and Drug Induced Liver Injury/epidemiology , Chemical and Drug Induced Liver Injury/etiology , Drug Combinations , Drug-Related Side Effects and Adverse Reactions/drug therapy , Humans , Malaria/chemically induced , Malaria/drug therapy , Naphthyridines , Rural Health
6.
AIDS Behav ; 26(8): 2653-2663, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35122579

ABSTRACT

In Ghana, HIV status disclosure to partners is voluntary. This study sought to determine the factors associated with HIV status disclosure to partners among antiretroviral therapy (ART) clients in the Upper East Region. A matched case-control study (1:1) was carried out in nine ART sites in the Upper East region in which 100 ART sexually active clients who had not disclosed their status to their partners were compared with 100 ART sexually ART clients who had disclosed their status to their partners. To each of the 200 study participants, a structured questionnaire was administered to elicit relevant responses. Discordant pair analysis was done with Mantel-Haenszel matched test to determine associations between variables. The study found persons with informal education more likely to disclose HIV status, whereas persons living apart or not having children with a partner were less likely to disclose their status to their sexual partners. On the other hand, active involvement or participation in ART-related services were more likely going to impact HIV status disclosure. Early initiation of ART, while adherence to ART services and the use of treatment monitors were less associated with disclosure. Active participation in ART related services such as prompt initiation of ART following diagnosis, adherence promotion, and treatment monitoring should be encouraged to promote HIV status disclosure among sexual partners.


Subject(s)
HIV Infections , Case-Control Studies , Child , Cross-Sectional Studies , Disclosure , Ghana/epidemiology , HIV Infections/drug therapy , HIV Infections/epidemiology , Humans , Sexual Partners , Truth Disclosure
7.
Arch Dis Child ; 107(7): 644-649, 2022 07.
Article in English | MEDLINE | ID: mdl-34969670

ABSTRACT

The World Health Organization (WHO) has a mandate to promote maternal and child health and welfare through support to governments in the form of technical assistance, standards, epidemiological and statistical services, promoting teaching and training of healthcare professionals and providing direct aid in emergencies. The Strategic and Technical Advisory Group of Experts (STAGE) for maternal, newborn, child and adolescent health and nutrition (MNCAHN) was established in 2020 to advise the Director-General of WHO on issues relating to MNCAHN. STAGE comprises individuals from multiple low-income and middle-income and high-income countries, has representatives from many professional disciplines and with diverse experience and interests.Progress in MNCAHN requires improvements in quality of services, equity of access and the evolution of services as technical guidance, community needs and epidemiology changes. Knowledge translation of WHO guidance and other guidelines is an important part of this. Countries need effective and responsive structures for adaptation and implementation of evidence-based interventions, strategies to improve guideline uptake, education and training and mechanisms to monitor quality and safety. This paper summarises STAGE's recommendations on how to improve knowledge translation in MNCAHN. They include support for national and regional technical advisory groups and subnational committees that coordinate maternal and child health; support for national plans for MNCAHN and their implementation and monitoring; the production of a small number of consolidated MNCAHN guidelines to promote integrated and holistic care; education and quality improvement strategies to support guidelines uptake; monitoring of gaps in knowledge translation and operational research in MNCAHN.


Subject(s)
Adolescent Health , Maternal Health Services , Adolescent , Child , Family , Female , Humans , Infant, Newborn , Nutritional Status , Pregnancy , Translational Science, Biomedical , World Health Organization
8.
Pan Afr Med J ; 39(Suppl 1): 8, 2021.
Article in English | MEDLINE | ID: mdl-34548900

ABSTRACT

INTRODUCTION: we examined the epidemiology, clinical and demographic characteristics of intussusception in Ghanaian infants. METHODS: active sentinel surveillance for pediatric intussusception was conducted at Komfo Anokye Teaching Hospital in Kumasi and Korle Bu Teaching Hospital in Accra. From March 2012 to December 2016, infants < 1 year of age who met the Brighton Collaboration level 1 diagnostic criteria for intussusception were enrolled. Data were collected through parental interviews and medical records abstraction. RESULTS: a total of 378 children < 1 year of age were enrolled. Median age at onset of intussusception was 27 weeks; only 12 cases (1%) occurred in infants < 12 weeks while most occurred in infants aged 22-34 weeks. Median time from symptom onset until referral to a tertiary hospital was 2 days (IQR: 1-4 days). Overall, 35% of infants were treated by enema, 33% had surgical reduction and 32% required surgical reduction and bowel resection. Median length of hospital stay was 5 days (IQR: 3-8 days) with most patients (95%) discharged home. Eleven (3%) infants died. Infants undergoing enema reduction were more likely than those treated surgically to present for treatment sooner after symptom onset (median 1 vs 3 days; p < 0.0001) and have shorter hospital stays (median 3 vs 7 days; p < 0.001). CONCLUSION: Ghanaian infants had a relatively low case fatality rate due to intussusception, with a substantial proportion of cases treated non-surgically. Early presentation for treatment, possibly enhanced by community-based health education programs and health information from various media platforms during the study period might contribute to both the low fatality rate and high number of successful non-surgical treatments in this population.


Subject(s)
Enema/methods , Hospitalization/statistics & numerical data , Intussusception/epidemiology , Female , Ghana/epidemiology , Hospitals, Teaching , Humans , Infant , Infant, Newborn , Intussusception/diagnosis , Intussusception/therapy , Length of Stay/statistics & numerical data , Male , Sentinel Surveillance , Tertiary Care Centers , Time Factors , Time-to-Treatment , Watchful Waiting
9.
Lancet ; 397(10287): 1782-1783, 2021 05 15.
Article in English | MEDLINE | ID: mdl-33964224
11.
Malar J ; 20(1): 18, 2021 Jan 06.
Article in English | MEDLINE | ID: mdl-33407454

ABSTRACT

BACKGROUND: Accurate measurement of anti-malarial drug concentrations in therapeutic efficacy studies is essential to distinguish between inadequate drug exposure and anti-malarial drug resistance, and to inform optimal anti-malarial dosing in key target population groups. METHODS: A sensitive and selective LC-MS/MS method was developed and validated for the simultaneous determination of amodiaquine and its active metabolite, desethylamodiaquine, and used to describe their pharmacokinetic parameters in Ghanaian patients with uncomplicated falciparum malaria treated with the fixed-dose combination, artesunate-amodiaquine. RESULTS: The day-28 genotype-adjusted adequate clinical and parasitological response rate in 308 patients studied was > 97% by both intention-to-treat and per-protocol analysis. After excluding 64 patients with quantifiable amodiaquine concentrations pre-treatment and 17 with too few quantifiable concentrations, the pharmacokinetic analysis included 227 patients (9 infants, 127 aged 1-4 years, 91 aged ≥ 5 years). Increased median day-3 amodiaquine concentrations were associated with a lower risk of treatment failure [HR 0.87 (95% CI 0.78-0.98), p = 0.021]. Amodiaquine exposure (median AUC0-∞) was significantly higher in infants (4201 ng h/mL) and children aged 1-5 years (1994 ng h/mL) compared to older children and adults (875 ng h/mL, p = 0.001), even though infants received a lower mg/kg amodiaquine dose (median 25.3 versus 33.8 mg/kg in older patients). Desethylamodiaquine AUC0-∞ was not significantly associated with age. No significant safety concerns were identified. CONCLUSIONS: Efficacy of artesunate-amodiaquine at currently recommended dosage regimens was high across all age groups. Reassuringly, amodiaquine and desethylamodiaquine exposure was not reduced in underweight-for-age young children or those with high parasitaemia, two of the most vulnerable target populations. A larger pharmacokinetic study with close monitoring of safety, including full blood counts and liver function tests, is needed to confirm the higher amodiaquine exposure in infants, understand any safety implications and assess whether dose optimization in this vulnerable, understudied population is needed.


Subject(s)
Amodiaquine/analogs & derivatives , Amodiaquine/pharmacokinetics , Antimalarials/pharmacokinetics , Malaria, Falciparum/prevention & control , Adolescent , Adult , Aged , Aged, 80 and over , Amodiaquine/administration & dosage , Artemisinins/administration & dosage , Child , Child, Preschool , Chromatography, Liquid/methods , Drug Combinations , Female , Ghana , Humans , Infant , Malaria, Falciparum/parasitology , Male , Middle Aged , Tandem Mass Spectrometry/methods , Young Adult
12.
Vaccine ; 38(31): 4820-4828, 2020 06 26.
Article in English | MEDLINE | ID: mdl-32513513

ABSTRACT

BACKGROUND: Rotavirus incidence remains relatively high in low-income countries (LICs) compared to high-income countries (HICs) after vaccine introduction. Ghana introduced monovalent rotavirus vaccine in April 2012 and despite the high coverage, vaccine performance has been modest compared to developed countries. The predictors of low vaccine effectiveness in LICs are poorly understood, and the drivers of subnational heterogeneity in rotavirus vaccine impact are unknown. METHODS: We used mathematical models to investigate variations in rotavirus incidence in children <5 years old in Ghana. We fit models to surveillance and case-control data from three different hospitals: Korle-Bu Teaching Hospital in Accra, Komfo Anokye Teaching Hospital in Kumasi, and War Memorial Hospital in Navrongo. The models were fitted to both pre- and post-vaccine data to estimate parameters describing the transmission rate, waning of maternal immunity, and vaccine response rate. RESULTS: The seasonal pattern and age distribution of rotavirus cases varied among the three study sites in Ghana. Our model was able to capture the spatio-temporal variations in rotavirus incidence across the three sites and showed good agreement with the age distribution of observed cases. The rotavirus transmission rate was highest in Accra and lowest in Navrongo, while the estimated duration of maternal immunity was longer (~5 months) in Accra and Kumasi and shorter (~3 months) in Navrongo. The proportion of infants who responded to the vaccine was estimated to be high in Accra and Kumasi and low in Navrongo. CONCLUSIONS: Rotavirus vaccine impact varies within Ghana. A low vaccine response rate was estimated for Navrongo, where rotavirus is highly seasonal and incidence limited to a few months of the year. Our findings highlight the need to further explore the relationship between rotavirus seasonality, maternal immunity, and vaccine response rate to determine how they influence vaccine effectiveness and to develop strategies to improve vaccine impact.


Subject(s)
Rotavirus Infections , Rotavirus Vaccines , Rotavirus , Child , Child, Preschool , Ghana/epidemiology , Humans , Infant , Rotavirus Infections/epidemiology , Rotavirus Infections/prevention & control , Vaccination
13.
Article in English | MEDLINE | ID: mdl-32312783

ABSTRACT

Dihydroartemisinin-piperaquine has shown excellent efficacy and tolerability in malaria treatment. However, concerns have been raised of potentially harmful cardiotoxic effects associated with piperaquine. The population pharmacokinetics and cardiac effects of piperaquine were evaluated in 1,000 patients, mostly children enrolled in a multicenter trial from 10 sites in Africa. A linear relationship described the QTc-prolonging effect of piperaquine, estimating a 5.90-ms mean QTc prolongation per 100-ng/ml increase in piperaquine concentration. The effect of piperaquine on absolute QTc interval estimated a mean maximum QTc interval of 456 ms (50% effective concentration of 209 ng/ml). Simulations from the pharmacokinetic-pharmacodynamic models predicted 1.98 to 2.46% risk of having QTc prolongation of >60 ms in all treatment settings. Although piperaquine administration resulted in QTc prolongation, no cardiovascular adverse events were found in these patients. Thus, the use of dihydroartemisinin-piperaquine should not be limited by this concern. (This study has been registered at ClinicalTrials.gov under identifier NCT02199951.).


Subject(s)
Antimalarials , Malaria, Falciparum , Malaria , Quinolines , Africa , Antimalarials/adverse effects , Child , Humans , Malaria/drug therapy , Malaria, Falciparum/drug therapy , Quinolines/adverse effects
14.
Am J Trop Med Hyg ; 102(2s): 3-24, 2020 02.
Article in English | MEDLINE | ID: mdl-31971144

ABSTRACT

In the context of stalling progress against malaria, resistance of mosquitoes to insecticides, and residual transmission, mass drug administration (MDA) of ivermectin, an endectocide used for neglected tropical diseases (NTDs), has emerged as a promising complementary vector control method. Ivermectin reduces the life span of Anopheles mosquitoes that feed on treated humans and/or livestock, potentially decreasing malaria parasite transmission when administered at the community level. Following the publication by WHO of the preferred product characteristics for endectocides as vector control tools, this roadmap provides a comprehensive view of processes needed to make ivermectin available as a vector control tool by 2024 with a completely novel mechanism of action. The roadmap covers various aspects, which include 1) the definition of optimal dosage/regimens for ivermectin MDA in both humans and livestock, 2) the risk of resistance to the drug and environmental impact, 3) ethical issues, 4) political and community engagement, 5) translation of evidence into policy, and 6) operational aspects of large-scale deployment of the drug, all in the context of a drug given as a prevention tool acting at the community level. The roadmap reflects the insights of a multidisciplinary group of global health experts who worked together to elucidate the path to inclusion of ivermectin in the toolbox against malaria, to address residual transmission, counteract insecticide resistance, and contribute to the end of this deadly disease.


Subject(s)
Antiparasitic Agents/pharmacology , Insecticides/pharmacology , Ivermectin/pharmacology , Malaria/prevention & control , Mosquito Vectors/drug effects , Africa , Animals , Antiparasitic Agents/therapeutic use , Endemic Diseases/prevention & control , Humans , Insecticides/therapeutic use , Ivermectin/therapeutic use , Lethal Dose 50 , Malaria/drug therapy , Malaria/transmission , Mass Drug Administration , Safety , Spain , World Health Organization
15.
Am J Trop Med Hyg ; 101(6): 1434-1441, 2019 12.
Article in English | MEDLINE | ID: mdl-31595867

ABSTRACT

In addition to the direct effect of insecticide-treated nets (ITNs), there has been evidence for spatial indirect effects. Spatial analyses in cluster randomized trials (CRTs) are rare, but a large-scale CRT from 1993 was one of the first to conduct a spatial analysis of ITNs in CRTs. We revisit these data by applying a broader range of contemporary spatial methods to further explore spatial spillover. We conducted three analyses: 1) exploratory spatial analysis, considering spatial patterns and spillover in the data; 2) spatial modeling, estimating the intervention effect considering spatial effects; and 3) analysis of distance-based spillover and interaction with the intervention, characterizing the functional distance over which the spillover effect was present. There were consistent indications of spatial patterns from the exploratory analysis. Bed nets were associated with a 17% reduction in all-cause mortality for children aged 6-59 months, and the intervention estimate remained robust when allowing for the spatial structure of the data. There was strong evidence of a spatial spillover effect: for every additional 100 m that a control household was from an intervention household (and vice versa), the standardized mortality ratio (SMR) increased by 1.7% (SMR 1.017, 95% credible interval 1.006-1.026). Despite evidence of a spatial spillover effect, the conclusions of the trial remain unaffected by spatial model specifications. Use of ITNs was clearly beneficial for individuals, and there was compelling evidence that they provide an indirect benefit to individuals living nearby. This article demonstrates the extra utility that spatial methods can provide when analyzing a CRT.


Subject(s)
Insecticide-Treated Bednets , Insecticides/pharmacology , Mortality , Permethrin/pharmacology , Spatial Analysis , Child, Preschool , Data Interpretation, Statistical , Humans , Infant , Mosquito Control/methods
18.
Patient Prefer Adherence ; 13: 371-380, 2019.
Article in English | MEDLINE | ID: mdl-30880921

ABSTRACT

PURPOSE: In 2005, Burkina Faso changed its first-line treatment for uncomplicated malaria from chloroquine to artemisinin-based combination therapies (ACTs). Patient adherence to ACTs regimen is a keystone to achieve the expected therapeutic outcome and prevent the emergence and spread of parasite resistance. Eleven years after the introduction of ACTs in the health system, this study aimed to measure adherence level of patients in rural settlement and investigate the determinants of nonadherence. PATIENTS AND METHODS: The study was carried out at public peripheral health facilities from May 2017 to August 2017 in Nanoro health district, Burkina Faso. An electronic semi-structured questionnaire was used for data collection from patients with an ACT prescription at their medical consultation exit visit and during home visit at day 5±2. Adherence level was measured through self-report and pill counts. Logistic regression was performed to identify factors for nonadherence. RESULTS: The analysis was conducted on 199 outpatients who received ACT as prescription. About 92.5% of ACT prescriptions included artemether-lumefantrine tablets. Adherence level was measured in 97.0% of included patients at day 5±2. Of these, 86.0% were classified as "complete adherent" and 14.0% as "nonadherent". In univariate analysis, patients/caregivers who considered that affordability of ACTs was easy seemed to be less adherent to the treatment regimen (OR: 0.26; 95% CI: 0.07-0.70). In univariate and multivariable analyses, patients/caregivers who did not receive advices from health care workers (HCWs) were more likely to be nonadherent to the prescribed ACTs (adjusted OR: 3.21; 95% CI: 1.13-9.12). CONCLUSION: This study demonstrates that majority of those who get an ACT prescription comply with the recommended regimen. This emphasizes that in rural settings where ACTs are provided free of charge or at a subsidized price, patient adherence to ACTs is high, thus minimizing the risk of subtherapeutic concentrations of the drug in blood which is known to increase resistance and susceptibility to new infections. Therefore, to address the problem of patient nonadherence, strategy to strengthen communication between HCWs and patients should be given greater consideration.

19.
Front Immunol ; 10: 136, 2019.
Article in English | MEDLINE | ID: mdl-30804940

ABSTRACT

Malaria infections remain a serious global health problem in the world, particularly among children and pregnant women in Sub-Saharan Africa. Moreover, malaria control and elimination is hampered by rapid development of resistance by the parasite and the vector to commonly used antimalarial drugs and insecticides, respectively. Therefore, vaccine-based strategies are sorely needed, including those designed to interrupt disease transmission. However, a prerequisite for such a vaccine strategy is the understanding of both the human and vector immune responses to parasite developmental stages involved in parasite transmission in both man and mosquito. Here, we review the naturally acquired humoral and cellular responses to sexual stages of the parasite while in the human host and the Anopheles vector. In addition, updates on current anti-gametocyte, anti-gamete, and anti-mosquito transmission blocking vaccines are given. We conclude with our views on some important future directions of research into P. falciparum sexual stage immunity relevant to the search for the most appropriate transmission-blocking vaccine.


Subject(s)
Host-Parasite Interactions/immunology , Life Cycle Stages , Malaria Vaccines , Mosquito Vectors/immunology , Plasmodium falciparum , Animals , Antigens, Protozoan/immunology , Humans , Plasmodium falciparum/growth & development , Plasmodium falciparum/immunology , Plasmodium falciparum/pathogenicity
20.
BMC Nutr ; 5: 40, 2019.
Article in English | MEDLINE | ID: mdl-32153953

ABSTRACT

BACKGROUND: Anaemia among pregnant women and post-partum mothers is a public health challenge in Ghana, especially in the Volta Region. While literature abounds on anaemia among pregnant women, the same cannot be said for anaemia among post-partum mothers in the region. This study, therefore, examined the prevalence and associated risk factors of anaemia among women attending antenatal care and post-natal care. METHODS: This descriptive cross-sectional survey recruited 409 pregnant women and 194 post-natal mothers attending antenatal and post-natal care, at the Hohoe Municipal Hospital. Background characteristics were collected using a semi-structured questionnaire, blood samples were analysed for the presence of anaemia and malaria parasitaemia and folders were reviewed for estimated blood loss. RESULTS: We found the prevalence of anaemia among pregnant women and post-partum mothers to be 33 and 16% respectively. Higher malaria parasitaemia (2%) was found in pregnant women compared with postpartum mothers (1%). We found that 4% of post-partum mothers had abnormal blood loss (301mls-500mls) whereas 5% of them had postpartum haemorrhage (>500mls) during child birth. A univariate logistics regression of anaemia status on some risk factors in pregnant women showed no significant association between anaemia and any of the risk factors. Among post-partum mothers, only mothers' age was statistically significant in the univariate analysis [COR = 0.27 (95% CI:0.103, 0.72);0.008]. Mothers aged 20-29 were 73% less likely to be anaemic. CONCLUSION: The prevalence of anaemia among pregnant women found in this study points to a situation of moderate public health problem according to WHO cut-off values for the public health significance of anaemia. Strategies should therefore be put in place to encourage thorough health education and promotion programmes among both pregnant and post-partum women.

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