MalariaWorld journal最新文献

Introduction: The genetic diversity of Plasmodium falciparum correlates with its pathogenicity, therefore design of evidence-based intervention strategies to eradicate malaria requires genetic diversity surveillance. This study characterised the allelic frequencies and genetic diversity of P. falciparum parasites isolated from Awka, Nigeria.

Materials and methods: Genomic DNA was extracted from 177 P. falciparum isolates and the polymorphic regions of the msp2 and glurp genes were genotyped by nested polymerase chain reaction (PCR).

Results: Two msp2 alleles (3D7 and FC27) were analysed. The 3D7 (93.55%) msp2 allelic family was predominant in msp2 positivie isolates. Polyclonal msp2 infection was observed in 24 (38.71%) isolates. Twenty-one distinct msp2 alleles were detected, with fragment sizes ranging from 200 bp to 1200 bp. The 300 bp allelic fragment (26.83%) was predominant for the 3D7 allele, while the 400 bp allelic fragment (29.54%) was predominant for the FC27 allele. The multiplicity of infection (MoI) in msp2 was 2.03, and the expected Heterozygosity (He) was 0.34. Sixty-nine isolates (38.98%) were positive for the RII repeat region of the glurp gene. For the glurp gene, nine alleles were detected for fragment sizes ranging from 200 bp to 1150 bp, and the most prevalent allelic fragment was 200 bp (19%). The MoI and He for the glurp gene were 0.45 and 0.98, respectively.

Conclusions: The high level of polyclonal infections with P. falciparum parasites observed in this study indicates extensive genetic diversity in the study area. The data provide important baseline information that can be implemented in developing malaria control strategies and elimination in the study area and Nigeria.

For malaria control to be successful, experience has shown that success is more likely where all involved feel the attempt must not be allowed to fail, and that success can be the only acceptable outcome. Importantly, all those at the top must have such commitment, and, in particular, this should also include the funder, the source of finance of the attempt. That would be malaria control treated as a priority. If not treated as such, experience has shown the outcome of such attempts to be disappointing.

In the aftermath of the 2015 political crisis in Burundi, a humanitarian organisation, Maison Shalom, fled the country to Rwanda with tens of thousands of Burundians. In an attempt to assist their compatriots, a group of Burundians in the diaspora created the Académie Ubuntu and teamed with Maison Shalom to give online classes to the refugees. With courage and determination and despite the conditions in the refugee camp and the language barrier, 17 refugees successfully completed the 'Best Practices for Integrated Mosquito Management Virtual Training Programme', offered by the American Mosquito Control Association. These 17 refugees are determined to put these skills to work and perhaps start the very first mosquito abatement programme in Africa.

Overwhelmingly, contemporary malaria vector control equals the use of chemical pesticides (through insecticide-treated bednets or indoor residual spraying). Gradually, but surely, we have become enslaved to thinking that controlling malaria mosquitoes equals the use of chemical insecticides, and much of the vector control field today is dominated by scientists, lobbyists, chemical companies, funding agencies and (global) institutions that endlessly repeat this dogmatic belief. Although chemical control has undoubtedly saved millions of lives, which, morally speaking would immediately justify its continued use, it has many sides that may ultimately cost more lives than it saves. Not only the cyclical problems with insecticide resistance, but also our increased understanding of the human and environmental health impacts of these chemicals, continue to raise red flags. Furthermore, the millions of kilogrammes of annual bednet waste (polyethylene, polypropylene) and bednet packaging material cannot be ignored. In recent years, an abundance of evidence that the use of chemical pesticides is a prime cause for the global decline in insect biodiversity and abundance has surfaced. The rate at which this decline is happening is frightening and may sooner rather than later threaten food production on a global scale. Should we opt for saving lives in the short term by using chemicals and face devastating and irrevocable long-term consequences or become wise(r) in the way we control malaria mosquitoes?

For many years, the malaria community appears to have stumbled and fumbled along in its effort to control malaria with varying results that have often been ineffective. This article makes the suggestion the malaria community has appeared to avoid studying or applying methods that are acknowledged to have been successful in Palestine 100 years ago. The article further suggests such avoidance arose due to an anti-semitic minority element in the Palestine Arab leadership in the 1920s and '30s which sought to inflame the general Palestine Arab populace against the Jews (who had initiated the malaria control) by dishonestly explaining the Arab woes in Palestine had been caused by the Jews. The article asks the question if today's anti-semitism has perpetuated the '20s and '30s Palestine anti-semitism and has thereby continued to discourage the malaria community today from openly adopting the successful anti-malaria methods employed in Palestine 100 years ago.

Background: Malaria is a leading cause of mortality in children aged 5 years and below in Nigeria. Treatment guidelines stipulate among other recommendations, testing by microscopy or a rapid diagnostic test (RDT) before treatment. Non-adherence to these guidelines portends a challenge, especially among vulnerable under-five children. This study explored the factors influencing Nigerian public health workers' (HWs) adherence to these guidelines in under-five children.

Methods: A review of literature published between 2011- 2023 was conducted on Web of Science, Ovid Embase, Medline, Global Health, CAB Abstracts, Scopus, and Global Index Medicus. Data was extracted and analyzed under 4 themes: diagnosis, compliance with test results, use of recommended treatment, post-treatment counselling and severe malaria management.

Results: Nineteen (19) studies were included for review. Training and supervision, RDT and antimalarial availability, good knowledge of, and positive perception of RDTs promoted adherence to mRDT use. A lack of confidence in RDTs and age (≥ 40 years) fuelled presumptive treatment, especially among clinicians. mRDT and artemisinin-based combination therapy (ACT) stockouts dissuaded HWs from adhering to case management guidelines. Caregiver pressure for treatment was identified as a barrier to compliance with test results.

Conclusions: It is important to design context-specific strategies to improve adherence to guidelines for malaria case management, especially in under-five children. Training on the guidelines should be tailored, needs-based, and continuous, and HWs should be supportively supervised in implementing case management. Maintaining an adequate supply of quality-assured mRDTs and antimalarials can facilitate adherence to the guidelines.

Introduction: The cadherin G-protein coupled receptor BT-R₃ in the mosquito Anopheles gambiae is a single membrane-spanning α-helical (bitopic) protein that represents the most abundant and functionally diverse group of membrane proteins. Binding of the Cry4B toxin of Bacillus thuringiensis subsp. israelensis (Bti) to BT-R₃ triggers a Mg2+-dependent signalling pathway in the mosquito that involves stimulation of G protein α-subunit, which subsequently launches a coordinated signalling cascade involving Na⁺/K⁺-ATPase. Described in this study is the behaviour of the Cry4B purified active protein toxin in solution relative to its protoxin predecessor produced by Bti as well as identification of the region within BT-R₃ of An. gambiae to which the toxin binds.

Materials and methods: The relationship and behaviour of protoxin and toxin were ascertained in vitro by solubility studies in an alkaline environment like that of the mosquito larval midgut. To identify the specific toxin-binding site within BT-R₃, the full-length coding sequence of the bt-r3 gene was amplified and cloned in pENTR/D-TOTO and subcloned in pXINSECT-DEST38 resulting in recombinant pXINSECT-DEST38-bt-r3. Cytotoxicity was analysed using Trichoplusia ni High Five™ insect cells transfected with the pXINSECT-DEST38-bt-r3 plasmid rendering them susceptible to the Cry4B toxin. Truncation mutational analyses, receptor-toxin binding studies and live cell experiments were used to elucidate the toxin-binding site in BT-R₃.

Results: The N-terminal half of the Cry4B protoxin was cleaved releasing active Cry4B toxin. The nontoxic C-terminal portion was degraded into small peptide fragments. The receptor BT-R₃ contained a single toxin-binding site--a 106-amino acid polypeptide bounded by Ile1359 and Ser1464 (¹³⁵⁹IS¹⁴⁶⁴) localized in the 11th cadherin repeat of the receptor.

Conclusions: The structural features of the toxin-binding site are critical to the specificity, selectivity and affinity of the active toxin and for the design and development of novel Bti-based biopesticides.

Plasmodium vivax causes the vast majority of malaria cases in Brazil. The lifecycle of this parasite includes a latent stage in the liver, the hypnozoite. Reactivation of hypnozoites induces repeated relapses. We report a case of two relapses of vivax malaria in a teenage girl after conventional treatment with chloroquine and primaquine. Chloroquine prophylactic treatment for three months was prescribed with a favourable outcome of the case.

It is argued that reducing poverty is likely to alleviate malaria transmission and that the way to do this is by reducing inequality. The present capitalist system (as opposed to a straightforward market) tends to erode equality and promote profit over product. This may extend to the manufacture of bednets, bought by agencies rather than individual consumers, whose products may suffer from built in obsolescence. It is argued that better quality nets that can be re-impregnated locally are both desired and required. Derek Charlwood (aka Mzshensy#1) started his career as a medical entomologist in 1974 as a Research Assistant in the laboratory of the legendary Mick Gillies. By 2012 he had risen to become a Senior Research Assistant working for the Liverpool School of Tropical Medicine and so he is definitely ascending the career ladder. He has worked in numerous malaria endemic countries including Brazil, Papua New Guinea, Tanzania, Cambodia, São Tomé and Príncipe, Mozambique and Eritrea.