Administrative practices of health professionals and use of artesunate-amodiaquine by community members for treating uncomplicated malaria in southern Ghana: implications for artemisinin-based combination therapy deployment

Evaluation of packaging, labels, and some physicochemical properties of herbal antimalarial products on the Ghanaian market

Introduction

Malaria is a parasitic disease that is endemic in tropical areas and can be life-threatening. There has been a decrease in the prevalence of malaria in Ghana but the burden of the disease is still high in the country. Many Ghanaians depend on herbal products for malaria treatment. This study aimed to survey and evaluate commercial herbal antimalarials in the Volta Region of Ghana.

Methods

A survey of finished herbal antimalarials was done at herbal shops, pharmacies, and over-the-counter medicine seller shops. Products available on shelves were purchased and their details were recorded, after which they were examined using a visual inspection tool. The density, pH, and extract weight per dose of each sample were also determined.

Results

Thirty-four liquid formulations (A-1-34) containing 1-9 different herbs were found. The majority of the product labels had errors in consumer age classifications. Unconventional ways of stating doses were found on two products (A-13, "tot"; A-19, cupful). Six products did not have dosing devices. No duration of treatment was indicated on 24 products. Dose errors were found on A-14 and A-22. Samples A-17 and A-28 did not have registration or batch numbers. Product A-28 did not have its herbs listed on it and was indicated for persons aged 3-8 years at a dose of 45 mL. The relative density range for the products was 0.997-1.015. From the pH investigation, no product was extremely erosive; however, 10 samples were deemed erosive (pH, 3.0-3.99), whereas 24 were minimally erosive (pH, ≥4.0). The extract weight per dose volume (20-90 mL) was 0.048-1.766 g, indicating that unit dose capsules or tablets could be formulated from the products.

Conclusion

The findings clearly show that Ghanaian authorities responsible for regulating herbal products must enforce guidelines for the formulation, label details, and sale of antimalarial products. Additionally, the unpleasant taste of liquid herbal mixtures can affect patient compliance and dosing convenience; therefore, it is recommended that oral solid dosage forms of herbal antimalarials are produced as alternatives to the liquid mixtures.

In Vitro Assessment of Antiplasmodial Activity and Cytotoxicity of Polyalthia longifolia Leaf Extracts on Plasmodium falciparum Strain NF54

Background

Malaria is one of the most important life-threatening infectious diseases in the tropics. In spite of the effectiveness of artemisinin-based combination therapy, reports on reduced sensitivity of the parasite to artemisinin in Cambodia and Thailand warrants screening for new potential antimalarial drugs for future use. Ghanaian herbalists claim that Polyalthia longifolia has antimalarial activity. Therefore, antiplasmodial activity, cytotoxic effects, and antioxidant and phytochemical properties of P. longifolia leaf extract were investigated in this study.

Methodology/Principal Findings

Aqueous, 70% hydroethanolic and ethyl acetate leaf extracts were prepared using standard procedures. Antiplasmodial activity was assessed in vitro by using chloroquine-sensitive malaria parasite strain NF54. The SYBR® Green and tetrazolium-based calorimetric assays were used to measure parasite growth inhibition and cytotoxicity, respectively, after extract treatment. Total antioxidant activity was evaluated using a free radical scavenging assay. Results obtained showed that extracts protected red blood cells against Plasmodium falciparum mediated damage. Fifty percent inhibitory concentration (IC₅₀) values were 24.0±1.08 μg/ml, 22.5±0.12 μg/ml, and 9.5±0.69 μg/ml for aqueous, hydroethanolic, and ethyl acetate extracts, respectively. Flavonoids, tannins, and saponins were present in the hydroethanolic extract, whereas only the latter was observed in the aqueous extract. Aqueous and hydroethanolic extracts showed stronger antioxidant activities compared to the ethyl acetate extract.

Conclusions/Significance

The extracts of P. longifolia have antiplasmodial properties and low toxicities to human red blood cells. The extracts could be developed as useful alternatives to antimalarial drugs. These results support claims of the herbalists that decoctions of P. longifolia are useful antimalarial agents.

Activity of Herbal Medicines on Plasmodium falciparum Gametocytes: Implications for Malaria Transmission in Ghana

Background

Malaria still remains a major health issue in Ghana despite the introduction of Artemisinin-based combination therapy (ACT) coupled with other preventative measures such as the use of insecticide treated nets (ITNs). The global quest for eradication of malaria has heightened the interest of identifying drugs that target the sexual stage of the parasite, referred to as transmission-blocking drugs. This study aimed at assessing the efficacy and gametocydal effects of some commonly used herbal malaria products in Ghana.

Methodology/Principal Findings

After identifying herbal anti-malarial products frequently purchased on the Ghanaian market, ten of them were selected and lyophilized. In vitro drug sensitivity testing of different concentrations of the herbal products was carried out on asexual and in vitro generated gametocytes of the 3D7 strain of Plasmodium falciparum. The efficacies of the products were assessed by microscopy. Cultures containing low dose of RT also produced the least number of late stage gametocytes. Two of the herbal products CM and RT inhibited the growth of late stage gametocytes by > 80% at 100 μg/ml whilst KG was the most inhibitory to early stage gametocytes at that same concentration. However at 1 μg/ml, only YF significantly inhibited the survival of late stage gametocytes although at that same concentration YF barely inhibited the survival of early stage gametocytes.

Conclusions/Significance

Herbal product RT (Aloe schweinfurthii, Khaya senegalensis, Piliostigma thonningii and Cassia siamea) demonstrated properties of a highly efficacious gametocydal product. Low dose of herbal product RT exhibited the highest gametocydal activity and at 100 μg/ml, RT exhibited >80% inhibition of late stage gametocytes. However inhibition of asexual stage parasite by RT was not optimal. Improving the asexual inhibition of RT could convert RT into an ideal antimalarial herbal product. We also found that generally C. sanguinolenta containing herbal products exhibited gametocydal activity in addition to high asexual efficacy. Herbal products with high gametocydal activity can help in the fight to reduce malaria transmission.

Transmission indices and microfilariae prevalence in human population prior to mass drug administration with ivermectin and albendazole in the Gomoa District of Ghana

BACKGROUND

The Lymphatic Filariasis Elimination Programme in Ghana involves annual mass drug administration (MDA) of ivermectin and albendazole to persons living in endemic areas. This is repeated annually for 4-6 years to span across the reproductive lifespan of adult worms. In order to stimulate participation of community members in the MDA programme, this study was carried out to understand local views on transmission, management and prevention of the disease. The study also presents baseline transmission indices and microfilariae prevalence in the human population in eight endemic communities of coastal Ghana prior to the MDA.

METHODS

A descriptive survey was carried out to explore perceptions on causes, treatment and prevention of lymphatic filariasis. Perceptions on community participation in disease control programmes were also assessed. After participants were selected by cluster sampling and 100 μl of blood sampled from each individual and examined for mf microfilariae. A similar volume of blood was used to determine the presence of circulating filarial antigen. Mosquitoes were collected simultaneously at all sites by human landing catches for 4 days per month over a six-month period. All Anopheles mosquitoes were dissected and examined for the larval stages of the parasite following which molecular identification of both vector and parasite was done.

RESULTS

Eight hundred and four persons were interviewed, of which 284 (32.9%; CI 31.1-34.5) acknowledged elephantiasis and hydrocoele as health related issues in the communities. Thirty-three people (3.8%; CI 2.1-5.5) thought sleeping under bed net could help prevent elephantiasis. Microfilariae prevalence was 4.6% (43/941) whiles 8.7% (75/861) were positive for circulating filarial antigen. A total of 17,784 mosquitoes were collected, majority (55.8%) of which were Anopheles followed by Culex species (40%). Monthly biting rates ranged between 311 and 6116 bites/person for all the eight communities together. Annual transmission potential values for An. gambiae s.s. and An. funestus were 311.35 and 153.50 respectively.

CONCLUSION

Even though the highest mf density among inhabitants was recorded in a community that had the lowest Anopheles density with Culex species constituting 95% of all mosquitoes collected, Anopheles gambiae s.s. and An. funestus remained the main vectors.

Women's access and provider practices for the case management of malaria during pregnancy: a systematic review and meta-analysis

BACKGROUND

WHO recommends prompt diagnosis and quinine plus clindamycin for treatment of uncomplicated malaria in the first trimester and artemisinin-based combination therapies in subsequent trimesters. We undertook a systematic review of women's access to and healthcare provider adherence to WHO case management policy for malaria in pregnant women.

METHODS AND FINDINGS

We searched the Malaria in Pregnancy Library, the Global Health Database, and the International Network for the Rational Use of Drugs Bibliography from 1 January 2006 to 3 April 2014, without language restriction. Data were appraised for quality and content. Frequencies of women's and healthcare providers' practices were explored using narrative synthesis and random effect meta-analysis. Barriers to women's access and providers' adherence to policy were explored by content analysis using NVivo. Determinants of women's access and providers' case management practices were extracted and compared across studies. We did not perform a meta-ethnography. Thirty-seven studies were included, conducted in Africa (30), Asia (4), Yemen (1), and Brazil (2). One- to three-quarters of women reported malaria episodes during pregnancy, of whom treatment was sought by >85%. Barriers to access among women included poor knowledge of drug safety, prohibitive costs, and self-treatment practices, used by 5%-40% of women. Determinants of women's treatment-seeking behaviour were education and previous experience of miscarriage and antenatal care. Healthcare provider reliance on clinical diagnosis and poor adherence to treatment policy, especially in first versus other trimesters (28%, 95% CI 14%-47%, versus 72%, 95% CI 39%-91%, p = 0.02), was consistently reported. Prescribing practices were driven by concerns over side effects and drug safety, patient preference, drug availability, and cost. Determinants of provider practices were access to training and facility type (public versus private). Findings were limited by the availability, quality, scope, and methodological inconsistencies of the included studies.

CONCLUSIONS

A systematic assessment of the extent of substandard case management practices of malaria in pregnancy is required, as well as quality improvement interventions that reach all providers administering antimalarial drugs in the community. Pregnant women need access to information on which anti-malarial drugs are safe to use at different stages of pregnancy. Please see later in the article for the Editors' Summary.

A SYBR Green 1-based in vitro test of susceptibility of Ghanaian Plasmodium falciparum clinical isolates to a panel of anti-malarial drugs

BACKGROUND

Based on report of declining efficacy of chloroquine, Ghana shifted to the use of artemisinin-based combination therapy (ACT) in 2005 as the first-line anti-malarial drug. Since then, there has not been any major evaluation of the efficacy of anti-malarial drugs in Ghana in vitro. The sensitivity of Ghanaian Plasmodium falciparum isolates to anti-malarial drugs was, therefore, assessed and the data compared with that obtained prior to the change in the malaria treatment policy.

METHODS

A SYBR Green 1 fluorescent-based in vitro drug sensitivity assay was used to assess the susceptibility of clinical isolates of P. falciparum to a panel of 12 anti-malarial drugs in three distinct eco-epidemiological zones in Ghana. The isolates were obtained from children visiting health facilities in sentinel sites located in Hohoe, Navrongo and Cape Coast municipalities. The concentration of anti-malarial drug inhibiting parasite growth by 50% (IC50) for each drug was estimated using the online program, ICEstimator.

RESULTS

Pooled results from all the sentinel sites indicated geometric mean IC50 values of 1.60, 3.80, 4.00, 4.56, 5.20, 6.11, 10.12, 28.32, 31.56, 93.60, 107.20, and 8952.50 nM for atovaquone, artesunate, dihydroartemisin, artemether, lumefantrine, amodiaquine, mefloquine, piperaquine, chloroquine, tafenoquine, quinine, and doxycycline, respectively. With reference to the literature threshold value indicative of resistance, the parasites showed resistance to all the test drugs except the artemisinin derivatives, atovaquone and to a lesser extent, lumefantrine. There was nearly a two-fold decrease in the IC50 value determined for chloroquine in this study compared to that determined in 2004 (57.56 nM). This observation is important, since it suggests a significant improvement in the efficacy of chloroquine, probably as a direct consequence of reduced drug pressure after cessation of its use. Compared to that measured prior to the change in treatment policy, significant elevation of artesunate IC50 value was observed. The results also suggest the existence of possible cross-resistance among some of the test drugs.

CONCLUSION

Ghanaian P. falciparum isolates, to some extent, have become susceptible to chloroquine in vitro, however the increasing trend in artesunate IC50 value observed should be of concern. Continuous monitoring of ACT in Ghana is recommended.

Plasmodium falciparum isolates from southern Ghana exhibit polymorphisms in the SERCA-type PfATPase6 though sensitive to artesunate in vitro

BACKGROUND

In 2005, Ghana replaced chloroquine with artemisinin-based combination therapy as the first-line treatment for uncomplicated malaria. The aim of this work was to determine for the first time, polymorphisms in the putative pfATPase6 and pftctp, pfmdr1, pfcrt genes in Ghanaian isolates, particularly at a time when there is no report on artemisinin resistance in malaria parasites from Ghana. The sensitivity of parasite isolates to anti-malaria drugs were also evaluated for a possible association with polymorphisms in these genes.

METHODS

The prevalence of point mutations in the above Plasmodium falciparum genes were assessed from filter-paper blood blot samples by DNA sequencing. In vitro drug sensitivity test was carried out on some of the blood samples from volunteers visiting hospitals/clinics in southern Ghana using a modified version of the standard WHO Mark III micro-test.

RESULTS

All successfully tested parasite isolates were sensitive to artesunate; while 19.4%, 29.0% and 51.6% were resistant to quinine, amodiaquine and chloroquine respectively. The geometric mean of IC50 value for artesunate was 0.73 nM (95% CI, 0.38-1.08), amodiaquine 30.69 nM (95% CI, 14.18-47.20) and chloroquine 58.73 nM (95% CI, 38.08-79.38). Twenty point mutations were observed in pfATPase6 gene, with no L263E and S769N. All mutations found were low in frequency, except D639G which was observed in about half of the isolates but was not associated with artesunate response (p = 0.42). The pftctp gene is highly conserved as no mutation was observed, while CVIET which is chloroquine-resistant genotype at codon 72-76 of the pfcrt gene was identified in about half of the isolates; this was consistent with chloroquine IC50 values (p = 0.001). Mutations were present in pfmdr1 gene but were not associated with artemisinin response (p = 1.00).

CONCLUSION

The pfATPase6 gene is highly polymorphic with D639G appearing to be fixed in Ghanaian isolates. These may just be spontaneous mutations as all parasite isolates that were tested displayed satisfactory in vitro response to artesunate. However, there is no improvement in susceptibility of the parasites to chloroquine five years after its proscription.