Comparison of #artesunate–mefloquine and #artemether–lumefantrine fixed-dose combinations for #treatment of uncomplicated P. falciparum #malaria in #children younger than 5 yrs in sub-Saharan #Africa: … (Lancet ID., abstract)

[Source: The Lancet Infectious Diseases, full page: (LINK). Abstract, edited.]

Articles

Comparison of artesunate–mefloquine and artemether–lumefantrine fixed-dose combinations for treatment of uncomplicated Plasmodium falciparum malaria in children younger than 5 years in sub-Saharan Africa: a randomised, multicentre, phase 4 trial

Sodiomon B Sirima, MD, Bernhards Ogutu, MD, John P A Lusingu, MD, Ali Mtoro, MD, Zakayo Mrango, MD, Alphonse Ouedraogo, MD, Jean Baptiste Yaro, MD, Kevin Omondi Onyango, MBChB, Samwel Gesase, MD, Ernest Mnkande, MD, James Samwel Ngocho, MD, Isabelle Ackermann, MSc, François Aubin, MD, Joelle Vanraes, PharmD, Nathalie Strub, MD, Gwenaelle Carn, MS

Published Online: 15 July 2016 / Open Access / DOI: http://dx.doi.org/10.1016/S1473-3099(16)30020-2 / Open access funded by Department of Health UK

User License:  Creative Commons Attribution – NonCommercial – NoDerivs (CC BY-NC-ND 4.0)

© 2016 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND license. Published by Elsevier Ltd.

 

Summary

Background

WHO recommends combinations of an artemisinin derivative plus an antimalarial drug of longer half-life as treatment options for uncomplicated Plasmodium falciparum infection. In Africa, artemether–lumefantrine is the most widely used artemisinin-based combination therapy, whereas artesunate–mefloquine is used infrequently because of a perceived poor tolerance to mefloquine. WHO recommends reconsideration of the use of artesunate–mefloquine in Africa. We compared the efficacy and safety of fixed-dose artesunate–mefloquine with that of artemether–lumefantrine for treatment of children younger than 5 years with uncomplicated P falciparum malaria.

Methods

We did this multicentre, phase 4, open-label, non-inferiority trial in Burkina Faso, Kenya, and Tanzania. Children aged 6–59 months with uncomplicated malaria were randomly assigned (1:1), via a computer-generated randomisation list, to receive 3 days’ treatment with either one or two artesunate–mefloquine tablets (25 mg artesunate and 55 mg mefloquine) once a day or one or two artemether–lumefantrine tablets (20 mg artemether and 120 mg lumefantrine) twice a day. Parasitological assessments were done independently by two microscopists who were blinded to treatment allocation. The primary outcome was the PCR-corrected rate of adequate clinical and parasitological response (ACPR) at day 63 in the per-protocol population. Non-inferiority was shown if the lower limit of the 95% CI for the difference between groups was greater than −5%. Early vomiting was monitored and neuropsychiatric status assessed regularly during follow-up. This study is registered with ISRCTN, number ISRCTN17472707, and the Pan African Clinical Trials Registry, number PACTR201202000278282.

Findings

945 children were enrolled and randomised, 473 to artesunate–mefloquine and 472 to artemether–lumefantrine. The per-protocol population consisted of 407 children in each group. The PCR-corrected ACPR rate at day 63 was 90·9% (370 patients) in the artesunate–mefloquine group and 89·7% (365 patients) in the artemether–lumefantrine group (treatment difference 1·23%, 95% CI −2·84% to 5·29%). At 72 h after the start of treatment, no child had detectable parasitaemia and less than 6% had fever, with a similar number in each group (21 in the artesunate–mefloquine group vs 24 in the artemether–lumefantrine group). The safety profiles of artesunate–mefloquine and artemether–lumefantrine were similar, with low rates of early vomiting (71 [15·3%] of 463 patients in the artesunate–mefloquine group vs 79 [16·8%] of 471 patients in the artemether–lumefantrine group in any of the three dosing days), few neurological adverse events (ten [2·1%] of 468 vs five [1·1%] of 465), and no detectable psychiatric adverse events.

Interpretation

Artesunate–mefloquine is effective and safe, and an important treatment option, for children younger than 5 years with uncomplicated P falciparum malaria in Africa.

Funding

Agence Française de Développement, France; Department for International Development, UK; Dutch Ministry of Foreign Affairs, Netherlands; European and Developing Countries Clinical Trials Partnership; Fondation Arpe, Switzerland; Médecins Sans Frontières; Swiss Agency for Development and Cooperation, Switzerland.

Keywords: Research; Abstracts; Malaria; Artemisin.

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#Safety and #immunogenicity of #RTS,S/AS01 #malaria #vaccine in #infants and #children with #WHO stage 1 or 2 #HIV disease: a randomised, double-blind, controlled trial (Lancet ID., abstract)

[Source: The Lancet Infectious Diseases, full page: (LINK). Abstract, edited.]

Articles

Safety and immunogenicity of RTS,S/AS01 malaria vaccine in infants and children with WHO stage 1 or 2 HIV disease: a randomised, double-blind, controlled trial

Dr Lucas Otieno, MD, Martina Oneko, MD, Walter Otieno, PhD, Joseph Abuodha, MBChB, Emmanuel Owino, MSc, Chris Odero, PGD PH, Yolanda Guerra Mendoza, MD, Ben Andagalu, MSc, Norbert Awino, MSc, Karen Ivinson, BSc, Dirk Heerwegh, PhD, Nekoye Otsyula, MSc, Maria Oziemkowska, MPH, Effua Abigail Usuf, PhD, Allan Otieno, MD, Kephas Otieno, MPH, Didier Leboulleux, MD, Amanda Leach, MRCPCH, Janet Oyieko, MD, Laurence Slutsker, MD, Marc Lievens, MSc, Jessica Cowden, MD, Didier Lapierre, MD, Simon Kariuki, PhD, Bernhards Ogutu, PhD, Johan Vekemans, PhD, Mary J Hamel, MD

Published Online: 06 July 2016 / DOI: http://dx.doi.org/10.1016/S1473-3099(16)30161-X

© 2016 Elsevier Ltd. All rights reserved.

 

Summary

Background

Malaria remains a major global public health concern, especially in sub-Saharan Africa. The RTS,S/AS01 malaria candidate vaccine was reviewed by the European Medicines Agency and received a positive scientific opinion; WHO subsequently recommended pilot implementation in sub-Saharan African countries. Because malaria and HIV overlap geographically, HIV-infected children should be considered for RTS,S/AS01 vaccination. We therefore aimed to assess the safety of RTS,S/AS01 in HIV-infected children at two sites in western Kenya.

Methods

We did a randomised, double-blind, controlled trial at the clinical trial sites of the Kenya Medical Research Institute (KEMRI)–Walter Reed Army Institute of research in Kisumu and the KEMRI/US Centers for Disease Control and Prevention in Siaya. Eligible participants were infants and children aged from 6 weeks to 17 months with WHO stage 1 or 2 HIV disease (documented positive by DNA PCR), whether or not they were receiving antiretroviral therapy (ART). We randomly assigned participants (1:1) to receive three doses of either RTS,S/AS01 or rabies vaccine (both 0·5 mL per dose by intramuscular injection), given once per month at 0, 1, and 2 months. We did the treatment allocation using a web-based central randomisation system stratified by age (6 weeks–4 months, 5–17 months), and by baseline CD4% (<10, 10–14, 15–19, and ≥20). Data were obtained in an observer-blind manner, and the vaccine recipient, their parent or carer, the funder, and investigators responsible for the assessment of endpoints were all masked to treatment allocation (only staff responsible for the preparation and administration of the vaccines were aware of the assignment and these individuals played no other role in the study). We provided ART, even if the participants were not receiving ART before the study, and daily co-trimoxazole for prevention of opportunistic infections. The primary outcome was the occurrence of serious adverse events until 14 months after dose 1 of the vaccine, assessed in the intention-to-treat population. This trial was registered at ClinicalTrials.gov, number NCT01148459.

Findings

Between July 30, 2010, and May 24, 2013, we enrolled 200 children to our study and randomly assigned 99 to receive RTS,S/AS01 and 101 to receive rabies vaccine. 177 (89%) of the 200 children enrolled completed 14 months of follow-up. Serious adverse events were noted in 41 (41·4%, 95% CI 31·6–51·8) of 99 RTS,S/AS01 recipients and 37 (36·6%, 27·3–46·8) of 101 rabies-vaccine recipients (relative risk 1·1, 95% CI 0·8–1·6). 20 (20·2%, 95% CI 12·8–29·5) of 99 RTS,S/AS01 recipients and 12 (11·9%, 6·3–19·8) of 101 rabies-vaccine recipients had at least one serious adverse event within 30 days after vaccination, mainly pneumonia, febrile convulsions, and salmonella sepsis. Five (5·1%, 95% CI 1·7–11·4) of 99 RTS,S/AS01 recipients and four (4·0%, 1·1–9·8) of 101 rabies-vaccine recipients died, but no deaths were deemed related to vaccination. Mortality was associated with five cases of pneumonia (1% RTS,S/AS01 recipients vs 3% rabies-vaccine recipients), five cases of gastroenteritis (3% RTS,S/AS01 recipients vs 2% rabies-vaccine recipients), five cases of malnutrition (2% RTS,S/AS01 recipients vs 3% rabies-vaccine recipients), one case of sepsis (1% rabies-vaccine recipients), one case of Haemophilus influenza meningitis (1% rabies-vaccine recipients), and one case of tuberculosis (1% RTS,S/AS01 recipients).

Interpretation

RTS, S/AS01 was well tolerated when given to children with WHO clinical stage 1 or 2 HIV disease along with high antiretroviral and co-trimoxazole use. Children with HIV disease could be included in future RTS,S/AS01 vaccination programmes.

Funding

GlaxoSmithKline Biologicals SA and PATH Malaria Vaccine Initiative.

Keywords: Research; Abstracts; Malaria; Vaccines; HIV.

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#Efficacy of #topical #mosquito #repellent (#picaridin) plus long-lasting insecticidal nets versus long-lasting insecticidal nets alone for control of #malaria: a cluster randomised controlled trial (Lancet ID, abstract)

[Source: The Lancet Infectious Diseases, full page: (LINK). Abstract, edited.]

Articles

Efficacy of topical mosquito repellent (picaridin) plus long-lasting insecticidal nets versus long-lasting insecticidal nets alone for control of malaria: a cluster randomised controlled trial

Vincent Sluydts, PhD, Lies Durnez, PhD, Somony Heng, MD, Charlotte Gryseels, MSc, Lydie Canier, MSc, Saorin Kim, BSc, Karel Van Roey, MSc, Karen Kerkhof, MSc, Nimol Khim, PhD, Sokny Mao, MSc, Sambunny Uk, MSc, Siv Sovannaroth, MD, Prof Koen Peeters Grietens, PhD, Tho Sochantha, MD, Didier Menard, PhD, Prof Marc Coosemans, PhD

Published Online: 29 June 2016 / Open Access / Article has an altmetric score of 1 / DOI: http://dx.doi.org/10.1016/S1473-3099(16)30148-7  / Open access funded by Bill & Melinda Gates Foundation

© 2016 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY license. Published by Elsevier Ltd.

 

Summary

Background

Although effective topical repellents provide personal protection against malaria, whether mass use of topical repellents in addition to long-lasting insecticidal nets can contribute to a further decline of malaria is not known, particularly in areas where outdoor transmission occurs. We aimed to assess the epidemiological efficacy of a highly effective topical repellent in addition to long-lasting insecticidal nets in reducing malaria prevalence in this setting.

Methods

A cluster randomised controlled trial was done in the 117 most endemic villages in Ratanakiri province, Cambodia, to assess the efficacy of topical repellents in addition to long-lasting insecticidal nets in controlling malaria in a low-endemic setting. We did a pre-trial assessment of village accessibility and excluded four villages because of their inaccessibility during the rainy season. Another 25 villages were grouped because of their proximity to each other, resulting in 98 study clusters (comprising either a single village or multiple neighbouring villages). Clusters were randomly assigned (1:1) to either a control (long-lasting insecticidal nets) or intervention (long-lasting insecticidal nets plus topical repellent) study group after a restricted randomisation. All clusters received one long-lasting insecticidal net per individual, whereas those in the intervention group also received safe and effective topical repellents (picaridin KBR3023, SC Johnson, Racine, WI, USA), along with instruction and promotion of its daily use. Cross-sectional surveys of 65 randomly selected individuals per cluster were done at the beginning and end of the malaria transmission season in 2012 and 2013. The primary outcome was Plasmodium species-specific prevalence in participants obtained by real-time PCR, assessed in the intention-to-treat population. Complete safety analysis data will be published seperately; any ad-hoc adverse events are reported here. This trial is registered with ClinicalTrials.gov, number NCT01663831.

Findings

Of the 98 clusters that villages were split into, 49 were assigned to the control group and 49 were assigned to the intervention group. Despite having a successful distribution system, the daily use of repellents was suboptimum. No post-intervention differences in PCR plasmodium prevalence were observed between study groups in 2012 (4·91% in the control group vs 4·86% in the intervention group; adjusted odds ratio [aOR] 1·01 [95% CI 0·60–1·70]; p=0·975) or in 2013 (2·96% in the control group vs 3·85% in the intervention group; aOR 1·31 [0·81–2·11]; p=0·266). Similar results were obtained according to Plasmodium species (1·33% of participants in the intervention group vs 1·10% in the intervention group were infected with Plasmodium falciparum; aOR 0·83 [0·44–1·56]; p=0·561; and 1·85% in the control group vs 2·67% in the intervention group were infected with Plasmodium vivax; aOR 1·51 [0·88–2·57]; p=0·133). 41 adverse event notifications from nine villages were received, of which 33 were classified as adverse reactions (11 of these 33 were cases of repellent abuse through oral ingestion, either accidental or not). All participants with adverse reactions fully recovered and 17 were advised to permanently stop using the repellent.

Interpretation

Mass distribution of highly effective topical repellents in resource-sufficient conditions did not contribute to a further decline in malaria endemicity in a pre-elimination setting in the Greater Mekong subregion. Daily compliance and appropriate use of the repellents remains the main obstacle.

Funding

Bill & Melinda Gates Foundation.

Keywords: Research; Abstracts; Malaria; Insecticides.

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Single-step #biosynthesis and characterization of #silver #nanoparticles using #Zornia diphylla leaves: A potent eco-friendly tool against #malaria and #arbovirus vectors (J Photochem Photobiol B., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

J Photochem Photobiol B. 2016 Jun 11;161:482-489. doi: 10.1016/j.jphotobiol.2016.06.016. [Epub ahead of print]

Single-step biosynthesis and characterization of silver nanoparticles using Zornia diphylla leaves: A potent eco-friendly tool against malaria and arbovirus vectors.

Govindarajan M1, Rajeswary M2, Muthukumaran U2, Hoti SL3, Khater HF4, Benelli G5.

Author information: 1Unit of Vector Control, Phytochemistry and Nanotechnology, Department of Zoology, Annamalai University, Annamalainagar 608002, Tamil Nadu, India. Electronic address: drgovind1979@gmail.com. 2Unit of Vector Control, Phytochemistry and Nanotechnology, Department of Zoology, Annamalai University, Annamalainagar 608002, Tamil Nadu, India. 3Regional Medical Research Centre, Nehru Nagar, Belgaum 590010, Karnataka, India. 4Department of Parasitology, Faculty of Veterinary Medicine, Benha University, Moshtohor, Toukh 13736, Egypt. 5Insect Behavior Group, Department of Agriculture, Food and Environment, University of Pisa, via del Borghetto 80, 56124 Pisa, Italy. Electronic address: benelli.giovanni@gmail.com.

 

Abstract

Mosquitoes (Diptera: Culicidae) are vectors of important pathogens and parasites, including malaria, dengue, chikungunya, Japanese encephalitis, lymphatic filariasis and Zika virus. The application of synthetic insecticides causes development of resistance, biological magnification of toxic substances through the food chain, and adverse effects on the environment and human health. In this scenario, eco-friendly control tools of mosquito vectors are a priority. Here single-step fabrication of silver nanoparticles (AgNP) using a cheap aqueous leaf extract of Zornia diphylla as reducing and capping agent pf Ag+ ions has been carried out. Biosynthesized AgNP were characterized by UV-visible spectrophotometry, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDX) and X-ray diffraction analysis (XRD). The acute toxicity of Z. diphylla leaf extract and biosynthesized AgNP was evaluated against larvae of the malaria vector Anopheles subpictus, the dengue vector Aedes albopictus and the Japanese encephalitis vector Culex tritaeniorhynchus. Both the Z. diphylla leaf extract and Ag NP showed dose dependent larvicidal effect against all tested mosquito species. Compared to the leaf aqueous extract, biosynthesized Ag NP showed higher toxicity against An. subpictus, Ae. albopictus, and Cx. tritaeniorhynchus with LC50 values of 12.53, 13.42 and 14.61μg/ml, respectively. Biosynthesized Ag NP were found safer to non-target organisms Chironomus circumdatus, Anisops bouvieri and Gambusia affinis, with the respective LC50 values ranging from 613.11 to 6903.93μg/ml, if compared to target mosquitoes. Overall, our results highlight that Z. diphylla-fabricated Ag NP are a promising and eco-friendly tool against larval populations of mosquito vectors of medical and veterinary importance, with negligible toxicity against other non-target organisms.

Copyright © 2016 Elsevier B.V. All rights reserved.

KEYWORDS: Aedes albopictus; Anopheles subpictus; Culex tritaeniorhynchus; Nanomosquitocidals; Non-target effects; Plant-borne larvicides

PMID: 27318605 [PubMed – as supplied by publisher]

Keywords: Research; Abstracts; Larvicides; Aedes spp.

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Fractional third and fourth dose of #RTS,S/AS01 #malaria candidate #vaccine: a phase 2a controlled human malaria infection and #immunogenicity study (J Infect Dis., abstract)

[Source: The Journal of Infectious Diseases, full page: (LINK). Abstract, edited.]

Fractional third and fourth dose of RTS,S/AS01 malaria candidate vaccine: a phase 2a controlled human malaria infection and immunogenicity study

Jason A. Regules1,2, Susan B. Cicatelli1, Jason W. Bennett1, Kristopher M. Paolino1, Patrick S. Twomey1, James E. Moon1, April K. Kathcart1, Kevin D. Hauns1, Jack L. Komisar1, Aziz N. Qabar1, Silas A. Davidson1, Sheetij Dutta1, Matthew E. Griffith2, Charles D. Magee2, Mariusz Wojnarski1, Jeffrey R. Livezey1, Adrian T. Kress1, Paige E. Waterman1, Erik Jongert3, Ulrike Wille-Reece4, Wayne Volkmuth5, Daniel Emerling5, William H. Robinson5, Marc Lievens3, Danielle Morelle3, Cynthia K. Lee4, Bebi Yassin-Rajkumar4, Richard Weltzin4, Joe Cohen3, Robert M. Paris1, Norman C. Waters1, Ashley J. Birkett4, David C. Kaslow4, W. Ripley Ballou3, Christian F. Ockenhouse4 and Johan Vekemans3

Author Affiliations: 1Walter Reed Army Institute of Research, 503 Robert Grant Ave., Silver Spring, MD, 20910 USA  – 2Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, Maryland 20814, USA  – 3GSK Vaccines, 89 Rue de l’Institut, 1330 Rixensart, Belgium  – 4PATH-Malaria Vaccine Initiative, 2201 Westlake Avenue, Suite 200, Seattle, WA 98121 USA  – 5Atreca, 500 Saginaw Dr, Redwood City, CA 94063, USA

Correspondence to: Jason.a.regules.mil@mail.mil; Jason A Regules, MD, FACP; USAMRIID Frederick, MD 21702; Tel 1-240-357-5002; fax 1-301-619-2511

 

Abstract

Background. 

Three full doses of RTS,S/AS01 malaria vaccine provides partial protection against controlled human malaria infection (CHMI) and natural exposure. Immunization regimens including a delayed fractional third dose were assessed for potential increased protection against malaria and immunologic responses.

Methods. 

In a Phase IIa, controlled, open-label, study of healthy malaria-naïve adults, 16 subjects vaccinated with a 0, 1, 2-month full dose regimen (012M) and 30 subjects with a 0, 1, 7-month regimen including a fractional third dose (Fx017M) underwent CHMI three weeks after last dose. Plasmablast heavy and light chain immunoglobulin mRNA sequencing and antibody avidity were evaluated. Protection against repeat CHMI was evaluated post-8 months (Clinical Trials.gov: NCT01857869).

Results. 

26/30 subjects in the Fx017M group (vaccine efficacy [VE] 86·7% [95% CI: 66·8, 94·6]; p<0·0001), and 10/16 in the 012M group (VE 62·5% [95% CI: 29·4, 80·1]; p=0·0009) were protected against infection and protection differed between schedules (log rank p=0·040). The fractional dose boosting increased antibody somatic hypermutation and avidity, and sustained high protection upon re-challenge.

Discussion. 

A delayed third fractional vaccine dose improved immunogenicity and protection against infection. RTS,S/AS01 immunization regimen optimization may lead to improved approaches against malaria.

Published by Oxford University Press for the Infectious Diseases Society of America 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Keywords: Research; Abstracts; Malaria; Vaccines.

——

#Protection against #malaria at 1 year and #immune correlates following #PfSPZ #vaccination (Nature Med., abstract)

[Source: Nature Medicine, full page: (LINK). Abstract, edited.]

Nature Medicine | Article

Protection against malaria at 1 year and immune correlates following PfSPZ vaccination

Andrew S Ishizuka, Kirsten E Lyke, Adam DeZure, Andrea A Berry, Thomas L Richie, Floreliz H Mendoza, Mary E Enama, Ingelise J Gordon, Lee-Jah Chang, Uzma N Sarwar, Kathryn L Zephir, LaSonji A Holman, Eric R James, Peter F Billingsley, Anusha Gunasekera, Sumana Chakravarty, Anita Manoj, MingLin Li, Adam J Ruben, Tao Li, Abraham G Eappen, Richard E Stafford, Natasha K C, Tooba Murshedkar, Hope DeCederfelt  et al.

Nature Medicine 22, 614–623 (2016) doi:10.1038/nm.4110

Received 12 February 2016 – Accepted 15 April 2016 – Published online 09 May 2016 – Corrected online 18 May 2016 – Corrigendum (June, 2016)

 

Abstract

An attenuated Plasmodium falciparum (Pf) sporozoite (SPZ) vaccine, PfSPZ Vaccine, is highly protective against controlled human malaria infection (CHMI) 3 weeks after immunization, but the durability of protection is unknown. We assessed how vaccine dosage, regimen, and route of administration affected durable protection in malaria-naive adults. After four intravenous immunizations with 2.7 × 105 PfSPZ, 6/11 (55%) vaccinated subjects remained without parasitemia following CHMI 21 weeks after immunization. Five non-parasitemic subjects from this dosage group underwent repeat CHMI at 59 weeks, and none developed parasitemia. Although Pf-specific serum antibody levels correlated with protection up to 21–25 weeks after immunization, antibody levels waned substantially by 59 weeks. Pf-specific T cell responses also declined in blood by 59 weeks. To determine whether T cell responses in blood reflected responses in liver, we vaccinated nonhuman primates with PfSPZ Vaccine. Pf-specific interferon-γ-producing CD8 T cells were present at ~100-fold higher frequencies in liver than in blood. Our findings suggest that PfSPZ Vaccine conferred durable protection to malaria through long-lived tissue-resident T cells and that administration of higher doses may further enhance protection.

Subject terms: Malaria – Vaccines

Keywords: Research; Abstracts; Malaria; Vaccines.

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#Wolbachia #infections in natural #Anopheles populations affect egg laying and negatively correlate with #Plasmodium development (Nature Commun., abstract)

[Source: Nature Communications, full page: (LINK). Abstract, edited.]

Nature Communications / Article / Open

Wolbachia infections in natural Anopheles populations affect egg laying and negatively correlate with Plasmodium development

W. Robert Shaw, Perrine Marcenac, Lauren M. Childs, Caroline O. Buckee, Francesco Baldini, Simon P. Sawadogo, Roch K. Dabiré, Abdoulaye Diabaté & Flaminia Catteruccia

Nature Communications 7, Article number: 11772 – doi:10.1038/ncomms11772 – Received 16 January 2016 – Accepted 27 April 2016 – Published 31 May 2016

 

Abstract

The maternally inherited alpha-proteobacterium Wolbachia has been proposed as a tool to block transmission of devastating mosquito-borne infectious diseases like dengue and malaria. Here we study the reproductive manipulations induced by a recently identified Wolbachia strain that stably infects natural mosquito populations of a major malaria vector, Anopheles coluzzii, in Burkina Faso. We determine that these infections significantly accelerate egg laying but do not induce cytoplasmic incompatibility or sex-ratio distortion, two parasitic reproductive phenotypes that facilitate the spread of other Wolbachia strains within insect hosts. Analysis of 221 blood-fed A. coluzzii females collected from houses shows a negative correlation between the presence of Plasmodium parasites and Wolbachia infection. A mathematical model incorporating these results predicts that infection with these endosymbionts may reduce malaria prevalence in human populations. These data suggest that Wolbachia may be an important player in malaria transmission dynamics in Sub-Saharan Africa.

Subject terms: Biological sciences  – Ecology  – Microbiology  – Zoology

Keywords: Research; Abstracts; Wolbachia; Plasmodium spp.; Malaria.

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