DOCSLIB.ORG

Pyrethroid and Carbamate Resistance in Anopheles Funestus Giles Along Lake Kariba in Southern Zambia

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Pyrethroid and Carbamate Resistance in Anopheles Funestus Giles Along Lake Kariba in Southern Zambia Am. J. Trop. Med. Hyg., 103(Suppl 2), 2020, pp. 90–97 doi:10.4269/ajtmh.19-0664 Copyright © 2020 by The American Society of Tropical Medicine and Hygiene Pyrethroid and Carbamate Resistance in Anopheles funestus Giles along Lake Kariba in Southern Zambia Javan Chanda,1* Kochelani Saili,1 Foustina Phiri,2 Jennifer C. Stevenson,3,4 Mulenga Mwenda,1 Sandra Chishimba,1 Conceptor Mulube,1 Brenda Mambwe,1 Christopher Lungu,1 Duncan Earle,1 Adam Bennett,5 Thomas P. Eisele,6 Mulakwa Kamuliwo,2 Richard W. Steketee,7 Joseph Keating,6 John M. Miller,1 and Chadwick H. Sikaala2,8 1PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia; 2National Malaria Elimination Centre, Zambia Ministry of Health, Lusaka, Zambia; 3Macha Research Trust, Choma, Zambia; 4W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; 5Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, California; 6Department of Tropical Medicine, Center for Applied Malaria Research and Evaluation, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana; 7PATH MACEPA, Seattle, Washington; 8SADC Malaria Elimination Eight Secretariat, Windhoek, Namibia Abstract. Whereas data on insecticide resistance and its underlying mechanisms exist for parts of Zambia, data remain limited in the southern part of the country. This study investigated the status of insecticide resistance, metabolic mechanisms, and parasite infection in Anopheles funestus along Lake Kariba in southern Zambia. Indoor-resting mos- quitoes were collected from 20 randomly selected houses within clusters where a mass drug administration trial was conducted and raised to F1 progeny. Non–blood-fed 2- to 5-day-old female An. funestus were exposed to WHO insecticide-impregnated papers with 0.05% deltamethrin, 0.1% bendiocarb, 0.25% pirimiphos-methyl, or 4% dichloro- diphenyl-trichloroethane (DDT). In separate assays, An. funestus were pre-exposed to piperonyl butoxide (PBO) to determine the presence of monooxygenases. Wild-caught An. funestus that had laid eggs for susceptibility assays were screened for circumsporozoite protein of Plasmodium falciparum by ELISA, and sibling species were identified by polymerase chain reaction. Anopheles funestus showed resistance to deltamethrin and bendiocarb but remained sus- ceptible to pirimiphos-methyl and DDT. The pre-exposure of An. funestus to PBO restored full susceptibility to delta- methrin but not to bendiocarb. The overall sporozoite infection rate in An. funestus populations was 5.8%. Detection of pyrethroid and carbamate resistance in An. funestus calls for increased insecticide resistance monitoring to guide planning and selection of effective insecticide resistance management strategies. To prevent the development of re- sistance and reduce the underlying vectorial capacity of mosquitoes in areas targeted for malaria elimination, an effective integrated vector management strategy is needed. INTRODUCTION these insecticides, pyrethroids, are the only insecticide class currently the WHO recommended for bednet impregnation Over the last 15 years, long-lasting insecticidal nets (LLINs), because of their effectiveness, low toxicity to humans, and high indoor residual spraying (IRS), intermittent preventive treat- excito-repellent effects on mosquitoes.8 A new-generation ment, prompt diagnosis, and treatment with artemisinin- mixture LLIN called Interceptor® G2 (BASF©, Ludwigshafen, based combination therapy have been scaled-up for malaria Germany) that combines chlorfenapyr (a pyrrole) and alphacy- control and elimination in sub-Saharan Africa, reducing malaria permethrin (a pyrethroid) has been developed by BASF© incidence by 22% and mortality by 29% between 2010 and fi 1 (Ludwigshafen, Germany) and prequali cations listed by the 2018. Equally in Zambia, malaria incidence declined by 5% 9 2 WHO but has yet to be rolled out widely. Entomological studies and mortality by 55% between 2010 and 2018. Most of the conducted in Zambia and Tanzania have demonstrated the gains reported in malaria reduction in sub-Saharan Africa impact of using either LLINs or IRS on reducing malaria vector are attributed to the rapid scale-up of vector control interven- abundance, infection rates, and malaria transmission.10–12 tions.3 However, the emergence of insecticide resistance in 4,5 Nonetheless, the effectiveness of LLINs and IRS depends on major malaria vectors puts these fragile gains at risk. high coverage within the community, mosquito susceptibility to In Zambia, Plasmodium falciparum account for 98% of all 2 insecticides used, and indoor-biting and resting behaviors of malaria cases reported at health facilities. Malaria trans- mosquitoes. mission is maintained by three major vectors: An. gambiae Long-lasting insecticidal nets and IRS exploit the biting and sensu stricto Giles, Anopheles arabiensis Paton, and Anoph- 6 resting behaviors of local malaria vectors to reduce malaria eles funestus sensu stricto Giles. To effectively control these transmission. Long-lasting insecticidal nets are designed to malaria vectors and reduce malaria transmission, the Ministry reduce human–vector contact by targeting night-biting of Health (MoH) through the National Malaria Control Pro- mosquitoes, whereas IRS aims to reduce the life span of gramme has scaled-up LLINs and IRS for malaria control and indoor-biting (endophagic) and indoor-resting (endophilic) elimination in the country. Operational vector control with mosquitoes.13 The endophagic and endophilic behavioral LLINs and IRS in Zambia depends on five classes of insecti- 7 characteristics of mosquitoes tend to expose them to insec- cides recommended by the WHO : pyrethroids, carbamates, ticides through contact with LLINs and or IRS.14 In addition, organophosphates, organochlorines, and neonicotinoids. Of the same insecticides used for public health are equally used in agriculture for pest control and usually end up contami- nating mosquito-breeding sites.15 In this regard, there has * Address correspondence to Javan Chanda, PATH Malaria Control and Elimination Partnership in Africa, Stand No. 11059, Mikwala been increased selection pressure on mosquito populations House, Off Brentwood Lane, Longacres, P.O. Box 32509, Lusaka that demonstrate either physiological or behavioral resistance 10101, Zambia. E-mail: [email protected] to different classes of insecticides. The common mechanisms 90 INSECTICIDE RESISTANCE IN AN. FUNESTUS IN SOUTHERN ZAMBIA 91 responsible for physiological resistance are metabolic de- sustainable for malaria vector control programs, the Global toxification and decreased target-site sensitivity.16 In meta- Plan for Insecticide Resistance Management encourages bolic detoxification, the insecticide is prevented from reaching continuous monitoring of insecticide resistance and identifi- the site of action in lethal concentration by detoxifying enzyme cation of resistance mechanisms in malaria major vector groups (P450s monooxygenases, glutathione s-transferases, populations.33 and esterases).16 By contrast, decreased target-site sensi- In the context of locally aggressive malaria control and tivity mechanism reduces the rate at which the insecticide elimination, this study provides updated information on An. binds to its target site (knockdown resistance [kdr], dieldrin funestus susceptibility status to the four classes of insecti- resistance [rdl], and acetylcholinesterase [ace.1]).16–18 The cides, underlying metabolic resistance mechanisms, and other mechanisms of resistance include penetration re- P. falciparum sporozoite infection rates in Southern Province, sistance which occurs as a result of cuticle thickening19 and Zambia. The results of this study also provide empirical evi- behavioral resistance where mosquitoes may evolve to avoid dence required to guide policy formulations and strategic insecticidal contact in malaria vectors.20,21 implementation of sustainable insecticide resistance man- Following a decade of scaling-up LLINs and IRS in Zambia, agement strategies aimed at reducing malaria transmission in major malaria vectors An. funestus s.s. and An. gambiae s.s. endemic areas of Southern Province. developed resistance to the dichloro-diphenyl-trichloroethane 22,23 (DDT) and pyrethroids. The detection of cross-resistance to MATERIALS AND METHODS pyrethroids and organochlorines in 2010 prompted the Zambian National Malaria Control Programme to change its policy, Study areas. The study was conducted in six study sites transitioning from using long-lasting DDT to short-lived car- where an MDA trial was being implemented in Southern bamates and organophosphates during the 2011 and 2012 Province, Zambia (Figure 1). Details of the trial setup are given IRS campaigns.23 Countrywide entomological monitoring elsewhere.27 Entomological collections of mosquitoes in the conducted between 2012 and 2013 revealed high resistance study sites were performed from April 2015 to May 2015. The to carbamates and pyrethroids in An. funestus s.s. and An. study sites were distributed along Lake Kariba in two districts, gambiae s.s. populations.24,25 As a result, in 2013, the National Siavonga and Sinazongwe. Mass distribution of pyrethroid- Malaria Control Programme stopped using carbamates and only LLINs, using PermaNet® 2.0 (Vestergaard Frandsen, Saint pyrethroids for IRS and adopted the organophosphate Francois, Switzerland) and Olyset Net®
Load more

Recommended publications
  • DRONES in INTERNATIONAL DEVELOPMENT Innovating the Supply Chain to Reach Patients in Remote Areas
    DRONES IN INTERNATIONAL DEVELOPMENT Innovating the Supply Chain to Reach Patients in Remote Areas AUTHORS: SCOTT DUBIN, ASHLEY GREVE, RYAN TRICHE DISCLAIMER: This activity was funded by the U.S. President's Emergency Plan for AIDS Relief, through the U.S. Agency for International Development. The views and opinions of authors expressed herein are our own and do not necessarily state or reflect those of the U.S. Government. TABLE OF CONTENTS INTRODUCTION 1 EXECUTIVE SUMMARY 2 KEY RECOMMENDATIONS FOR SUCCESS 2 SECTION I: PLANNING 9 ACTIVITY OVERVIEW AND OBJECTIVES 9 SELECTING THE RIGHT DRONE 11 INITIAL INVESTIGATIONS AND SCOPING VISITS 12 VALIDATION OF USE CASES 13 ACTIVITY DESIGN 14 CONTRACTING WITH DRONE SERVICE PROVIDERS 17 SECTION II: IMPLEMENTATION 19 FLIGHT OPERATIONS APPROVALS 19 COMMUNITY SENSITIZATION 20 START-UP 20 PHASE 1: JUNE-JULY 2019 21 PHASE 2: AUGUST-OCTOBER 2019 23 PHASE 3: NOVEMBER 2019-FEBRUARY 2020 23 STAKEHOLDER AND PARTNERSHIP MANAGEMENT 25 INCIDENT MANAGEMENT 27 SECTION III: ASSESSING AND COMMUNICATING VALUE 29 HEALTH IMPACT ANALYSIS 30 CARGO DATA 33 SAMPLE TURNAROUND TIME 34 SAMPLE COLLECTIONS 35 COMMUNICATING VALUE 36 COST CONSIDERATIONS 37 ACKNOWLEDGEMENTS 39 ANNEX 1. RESULTS FRAMEWORK 40 ANNEX 2. FLIGHT DATA REQUIREMENTS 42 ANNEX 3. UAV PROCUREMENT GUIDE 43 ANNEX 4. MEDICINE DELIVERIES MISSION NOTES 48 ANNEX 5. SAMPLE INITIAL SCOPE OF WORK FOR DRONE SERVICE PROVIDER 49 INTRODUCTION The USAID Global Health Supply Chain Program-Procurement and Supply Management (USAID GHSC- PSM) project works to ensure an uninterrupted supply of public health commodities. Through procurement and delivery of medicines and in-country technical assistance, the project strengthens health supply chains for HIV/AIDS, malaria, family planning, and maternal, newborn, and child health.
    [Show full text]
  • Schistosomiasis in Lake Malaŵi and the Potential Use of Indigenous Fish for Biological Control
    6 Schistosomiasis in Lake Malaŵi and the Potential Use of Indigenous Fish for Biological Control Jay R. Stauffer, Jr.1 and Henry Madsen2 1School of Forest Resources, Penn State University, University Park, PA 2DBL Centre for Health Research and Development, Faculty of Life Sciences, University of Copenhagen, Frederiksberg 1USA 2Denmark 1. Introduction Schistosomiasis is a parasitic disease of major public health importance in many countries in Africa, Asia, and South America, with an estimated 200 million people infected worldwide (World Health Organization, 2002). The disease is caused by trematodes of the genus Schistosoma that require specific freshwater snail species to complete their life cycles (Fig. 1). People contract schistosomiasis when they come in contact with water containing the infective larval stage (cercariae) of the trematode. Fig. 1. Life cycle of schistosomes (Source: CDC/Alexander J. da Silva, PhD/Melanie Moser) www.intechopen.com 120 Schistosomiasis Schistosome transmission, Schistosoma haematobium, is a major public health concern in the Cape Maclear area of Lake Malaŵi (Fig. 2), because the disease poses a great problem for local people and reduces revenue from tourism. Until the mid-1980’s, the open shores of Lake Malaŵi were considered free from human schistosomes (Evans, 1975; Stauffer et al., 1997); thus, only within relatively protected areas of the lake or tributaries would transmission take place. These areas were suitable habitat of intermediate host snail, Bulinus globosus. During mid-1980’s, reports indicated that transmission also occurred along open shorelines. It is now evident that in the southern part of the lake, especially Cape Maclear on Nankumba Peninsula, transmission occurs along exposed shorelines with sandy sediment devoid of aquatic plants via another intermediate host, Bulinus nyassanus (Madsen et al., 2001, 2004).
    [Show full text]
  • Impact of Indoor Residual Spraying with Lambda-Cyhalothrin On
    Am. J. Trop. Med. Hyg., 86(6), 2012, pp. 997–1004 doi:10.4269/ajtmh.2012.11-0621 Copyright © 2012 by The American Society of Tropical Medicine and Hygiene Impact of Indoor Residual Spraying with Lambda-Cyhalothrin on Malaria Parasitemia and Anemia Prevalence among Children Less than Five Years of Age in an Area of Intense, Year-Round Transmission in Malawi Jacek Skarbinski,* Dyson Mwandama, Adam Wolkon, Madalitso Luka, James Jafali, Alison Smith, Themba Mzilahowa, John Gimnig, Carl Campbell, John Chiphwanya, Doreen Ali, and Don P. Mathanga Malaria Branch, and Entomology Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia; Malaria Alert Centre, and Department of Community Health, College of Medicine, Blantyre, Malawi; Center for Tropical and Global Emerging Diseases, University of Georgia, Athens, Georgia; National Malaria Control Programme, Ministry of Health, Lilongwe, Malawi Abstract. Little is known about the impact of indoor residual spraying (IRS) in areas with intense malaria transmis- sion such as sub-Saharan Africa. In Malawi, IRS with lambda-cyhalothrin has been applied annually in an area of intense year-long transmission since 2007. We evaluated the impact of IRS on parasitemia and anemia prevalence in children less than five years of age by using a cross-sectional household survey conducted in 2009, six months after the second IRS spray round. We measured malaria parasitemia and anemia (hemoglobin level < 11 g/dL) in 899 children less than five years of age and used binomial regression to assess the impact of IRS by comparing children living in a household sprayed with IRS (direct IRS) with those in a household not sprayed with IRS, but in an IRS area (indirect IRS) and those living in a household not sprayed with IRS and not in an IRS area (no IRS).
    [Show full text]
  • The Structure of Sexual Networks and the Spread of HIV in Sub-Saharan Africa: Evidence from Likoma Island (Malawi)
    The structure of sexual networks and the spread of HIV in Sub-Saharan Africa: evidence from Likoma island (Malawi) Stéphane Helleringer Hans-Peter Kohler Department of Sociology Population Studies Center University of Pennsylvania It is widely believed that the HIV epidemic in Sub-Saharan Africa (SSA) is driven by transmission during unprotected heterosexual intercourse. In particular, infection with HIV in SSA is thought to be fueled by repeated contacts with sex workers or other highly sexually active group, and subsequently diffused to the general population through links of marriage or other stable types of partnerships. Such a theoretical model of sexual mixing has informed many policy simulations of interventions to stem the spread of the disease (see Oster 2005). However, empirical evidence for this diffusion process (i.e. from a group of highly active individuals to a low activity “periphery”) is somewhat scarce as epidemiological studies have generally reported weaker than expected relations between measures of such sexual behavior and risk/prevalence of HIV infection. At the individual level, differences in the rate of sexual partner acquisition only marginally predict an increased risk of infection for both prevalent (e.g. Gregson et al. 2002) and incident cases (e.g. Quigley et al. 2000). Similarly, at the population level, several comparative studies of the factors of HIV infection have found that differences in the prevalence of risky behaviors (high rate of partner change, contacts with sex workers etc.) could not explain the “uneven spread” of HIV across regions of SSA (Boerma et al. 2003). These discrepancies between indicators of sexual activity and prevalence/risk of HIV have been primarily attributed to two factors: reporting bias and differential mortality of HIV- infected individuals.
    [Show full text]
  • The Spatial Spread of HIV in Malawi: an Individual-Based Mathematical Model
    medRxiv preprint doi: https://doi.org/10.1101/2020.12.23.20248757; this version posted March 16, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-NC-ND 4.0 International license . The spatial spread of HIV in Malawi: An individual-based mathematical model Running head: The spatial spread of HIV in Malawi Janne ESTILL1,2, Wingston NG’AMBI3, Liudmila ROZANOVA1, Olivia KEISER1 1Institute of Global Health, University of Geneva, Geneva, Switzerland 2Institute of Mathematical Statistics and Actuarial Science, University of Bern, Bern, Switzerland 3College of Medicine, Health Economics and Policy Unit, University of Malawi, Lilongwe, Malawi Abstract 250 words, main text 3499 words, 1 table, 4 figures, and a Supplemental Digital Content file with 4 supplementary tables and 1 supplementary figure. Correspondence to: Janne Estill University of Geneva, Institute of Global Health 9 Chemin des Mines, 1202 Geneva, Switzerland [email protected] +41 (0)31 631 88 18 This work was supported by the Swiss National Science Foundation (grant 163878). 1 NOTE: This preprint reports new research that has not been certified by peer review and should not be used to guide clinical practice. medRxiv preprint doi: https://doi.org/10.1101/2020.12.23.20248757; this version posted March 16, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.
    [Show full text]
  • Nkwichi Lodge, on the Mozambique Side, Where We Would Spend Our First Two Nights
    By Peter Browne. Published in Condé Nast Traveller 10th September 2012. KAFUE NATIONAL PARK, ZAMBIA Zambia and Malawi are a wild new twist on the classic bush-to-beach double- hit. Peter Browne revisits the southern Africa of his childhood and finds he is still in frontier territory in a vast and empty Africa. In bed on my first night in Zambia, blanketed by warm, sweet-scented air, I could hear the intermittent roars of lion and the baritone laughter of hippo. At dawn I watched the first rays of sunlight lick the grassland; all around me, puku and lechwe antelope grazed on the vast flood plains, ears twitching, the horizon a silver shimmy of mist. Kafue National Park is Zambia's largest and least-visited protected area. Although it has existed since 1950, there is very little infrastructure in the park: successive governments have never had the resources or inclination to invest in such high- class concerns as wildlife management. Surrounded by far more profitable big- game hunting reserves, the government-owned park has until recently remained one of Africa's most intriguing forgotten wildernesses. This is real wild-frontier stuff, especially in the north, where the Busanga flood plains emerge from the water for just three months of the year, exposing immense, open grasslands - an utterly pristine region unexplored and unknown, vast and unfathomable. Pictured: the plains of Kafue National Park, Zambia Michel Figuet BUSANGA PLAINS As I set off on the first game drive with my guide, John D Muleka, the heat of the sun was already dissipating the rosewater shades of dawn; soon any subtleties in the landscape would be lost to the pin-sharp clarity of southern Africa's late- September light; by noon the temperature would reach 38˚C or 40˚C.
    [Show full text]
  • A Planning Survey of the Northern Region, Malawi
    A PLANNING SURVEY OF THE NORTHERN REGION, MALAWI Leo de Haan Jan de Jong Jan Sterkenburg Department of Geography of Developing Countries University of Utrecht, The Netherlands February, 1975 INTRODUCTION This regional planning survey of the Northern Region has been written at the request of the Town Planning Department of the Ministry of Works and Supplies. Initially, it was intended to restrict the sur- vey to the physical aspects of planning, the aspects of settlements, services, service centres and infrastructure in particular. Under an agreement between the Town Planning Department and the University of Utrecht, the authors were assigned the task of surveying the existing pattern of resources of the Northern Region of Malawi with a view to making recommendations for the improved Organisation of physical de- velopment through plans and policies aimed at securing greater co- ordination of development effort, at strengthening and relationalizing infrastructural services, at identifying rural-urban relationships and generally at providing a basic framework for integral planning of the region's land uses. Regional physical planning is, however, closely related to the economie and social development of an area. For the Northern Region agriculture is the basis of the economy and the source of employment for more than 90 % of its population. Consequently, aspects of physi- cal planning cannot be dealt with without paying adequate attention to the agricultural sector, the existing constraints for raising productivity and the attempts of the Malawi government to improve this sector. An expanding agricultural sector earns foreign exchange, provides food for the non-agricultural population, and may increase rural incomes and provide a growing market for manufactured products.
    [Show full text]
  • Pyrethroid Resistance in Southern African Anopheles Funestus Extends to Likoma Island in Lake Malawi RH Hunt1,2, M Edwardes3, M Coetzee1,2*
    Hunt et al. Parasites & Vectors 2010, 3:122 http://www.parasitesandvectors.com/content/3/1/122 RESEARCH Open Access Pyrethroid resistance in southern African Anopheles funestus extends to Likoma Island in Lake Malawi RH Hunt1,2, M Edwardes3, M Coetzee1,2* Abstract Background: A mosquito survey was carried out on the island of Likoma in Lake Malawi with a view to collecting baseline data to determine the feasibility of implementing an integrated malaria vector control programme. No vector control interventions are currently being applied on the island apart from the sporadic use of treated and untreated bed nets. Results: Large numbers of Anopheles funestus were found resting inside houses. WHO susceptibility tests were carried out on wild caught females and 1-5 day old F-1 female progeny. Wild caught females were tested on deltamethrin (77.8% mortality) and bendiocarb (56.4% mortality). Female progeny were tested on deltamethrin (41.4% mortality), permethrin (40.4%), bendiocarb (52.5%), propoxur (7.4%), malathion, fenitrothion, DDT, dieldrin (all 100%) and pirimiphos-methyl (98.9%). The malaria parasite rate was 4.9%. A small number of Anopheles arabiensis were also collected. Conclusion: This locality is 1,500 km north of the currently known distribution of pyrethroid resistant An. funestus in southern Africa. The susceptibility results mirror those found in southern Mozambique and South African populations, but are markedly different to An. funestus populations in Uganda, indicating that the Malawi resistance has spread from the south. Background parasite rate in An. funestus was 5.4% and the mosquitoes Anopheles funestus is the major malaria vector in south- were found to be resistant to both pyrethroids and ern Africa.
    [Show full text]
  • Stability of Mbuna Species Populations in Lake Malawi
    Journal of Environmental Science and Engineering B 1 (2012) 543-555 Formerly part of Journal of Environmental Science and Engineering, ISSN 1934-8932 D DAVID PUBLISHING Stability of Mbuna Species Populations in Lake Malawi Lucious G. Kanyumba1, Wisdom J. Changadeya1, Aggrey J.D. Ambali2, Leonard A. Kamwanja3 and Emmanuel 4 K.W. Kaunda 1. Department of Biology, University of Malawi, Zomba 280, Malawi 2. NEPAD Planning and Coordinating Agency, Pretoria 0184, South Africa 3. University Office, University of Malawi, Zomba 278, Malawi 4. Department of Aquaculture and Fisheries Science, University of Malawi, Lilongwe 219, Malawi Received: April 21, 2011 / Accepted: November 11, 2011 / Published: April 20, 2012. Abstract: The first comprehensive study of abundance, richness and distribution of Mbuna in Lake Malawi was carried out in the 1980s. The present study examined changes of species richness and abundance of Mbuna with time. Most sites demarcated during the 1980s survey were explored in order to determine changes in abundance and composition of Mbuna over a period of more than 20 years. Chi-square analysis revealed significant difference (p < 0.05) in abundance of Mbuna between 1983 and 2005 with the exception of Chinyankhwazi and Chinyamwezi where the difference was not significant (p > 0.05). Cluster analysis showed changes in species composition between 1983 and 2005 in various sites. Generally, there were more species lost in a given area than new species observed in 2005. Decline in Mbuna species richness might have been caused by siltation, harvesting of Mbuna for food and ornamental fish trade while new species were mostly introduced through translocation from one part of the lake to another.
    [Show full text]
  • An Epidemiological Profile of Malaria and Its Control in Malawi
    An Epidemiological Profile of Malaria and its Control in Malawi Report prepared for National Malaria Control Programme By The INFORM Project & Malaria Alert Centre March 2014 Contacts INFORM Project Public Health Department, KEMRI-Wellcome Trust Collaborative Programme P.O.Box 43640 00100 Nairobi, Kenya [email protected] [email protected] Malaria Alert Centre University of Malawi College of Medicine, Private Bag Blantyre, Malawi [email protected] Suggested citation Emelda A Okiro, Abdisalan M Noor, Josephine Malinga, Bernard Mitto, Clara W Mundia, Don Mathanga, Themba Mzilahowa & Robert W Snow (2013). An epidemiological profile of malaria and its control in Malawi. A report prepared for the Ministry of Health, the Roll Back Malaria Partnership and the Department for International Development, UK. March, 2014 i Acknowledgments The authors are indebted to the following individuals from the INFORM Project, KEMRI- Wellcome Trust programme in Kenya: Ngiang-Bakwin Kandala, Caroline Kabaria, Viola Otieno, Damaris Kinyoki, Jonesmus Mutua, Punam Amratia, Boniface Makone and Stella Kasura; Catherine Linard for assistance on modelling human population settlement; and Muriel Bastien, Marie Sarah Villemin Partow, Reynald Erard and Christian Pethas-Magilad of the World Health Organization (WHO) archives in Geneva. We would also like to extend a special acknowledgement to Lawrence Kazembe and Adam Bennett, both of whom have provided valuable insights and sustained enthusiasm around risk mapping and its applications for health planning in Malawi. We are also grateful to Malcolm Molyneux, Monica Olewe and Peter Troell who provided comments on an earlier draft of the report. And finally the important feedback and contribributions made by the National Malaria Control Programme, notably Drs Doreen Ali, Misheck Luhanga and John Zoya and Wilfred Dodoli of the World Health Organization, Country Office.
    [Show full text]
  • The Emergence of Insecticide Resistance in Central Mozambique
    Abilio et al. Malaria Journal 2011, 10:110 http://www.malariajournal.com/content/10/1/110 RESEARCH Open Access The emergence of insecticide resistance in central Mozambique and potential threat to the successful indoor residual spraying malaria control programme Ana P Abilio1, Immo Kleinschmidt2, Andrea M Rehman2, Nelson Cuamba1, Varsha Ramdeen3, David S Mthembu3, Sarel Coetzer3, Rajendra Maharaj3, Craig S Wilding4, Andrew Steven4, Marlize Coleman4, Janet Hemingway4 and Michael Coleman4* Abstract Background: Malaria vector control by indoor residual spraying was reinitiated in 2006 with DDT in Zambézia province, Mozambique. In 2007, these efforts were strengthened by the President’s Malaria Initiative. This manuscript reports on the monitoring and evaluation of this programme as carried out by the Malaria Decision Support Project. Methods: Mosquitoes were captured daily through a series of 114 window exit traps located at 19 sentinel sites, identified to species and analysed for sporozoites. Anopheles mosquitoes were collected resting indoors and tested for insecticide resistance following the standard WHO protocol. Annual cross sectional household parasite surveys were carried out to monitor the impact of the control programme on prevalence of Plasmodium falciparum in children aged 1 to 15 years. Results: A total of 3,769 and 2,853 Anopheles gambiae s.l. and Anopheles funestus, respectively, were captured from window exit traps throughout the period. In 2010 resistance to the pyrethroids lambda-cyhalothrin and permethrin and the carbamate, bendiocarb was detected in An. funestus. In 2006, the sporozoite rate in An. gambiae s.s. was 4% and this reduced to 1% over 4 rounds of spraying. The sporozoite rate for An.
    [Show full text]
  • Swarms of the Malaria Vector Anopheles Funestus in Tanzania Emmanuel W
    Kaindoa et al. Malar J (2019) 18:29 https://doi.org/10.1186/s12936-019-2660-y Malaria Journal RESEARCH Open Access Swarms of the malaria vector Anopheles funestus in Tanzania Emmanuel W. Kaindoa1,2* , Halfan S. Ngowo1, Alex J. Limwagu1, Magellan Tchouakui3, Emmanuel Hape1, Said Abbasi1, Japhet Kihonda1, Arnold S. Mmbando1, Rukiyah M. Njalambaha1, Gustav Mkandawile1, Hamis Bwanary1, Maureen Coetzee4,5 and Fredros O. Okumu1,2,6 Abstract Background: Anopheles funestus mosquitoes currently contribute more than 85% of ongoing malaria transmission events in south-eastern Tanzania, even though they occur in lower densities than other vectors, such as Anopheles arabiensis. Unfortunately, the species ecology is minimally understood, partly because of difculties in laboratory colonization. This study describes the frst observations of An. funestus swarms in Tanzania, possibly heralding new opportunities for control. Method: Using systematic searches by community-based volunteers and expert entomologists, An. funestus swarms were identifed in two villages in Ulanga and Kilombero districts in south-eastern Tanzania, starting June 2018. Swarms were characterized by size, height, start- and end-times, presence of copulation and associated environmen- tal features. Samples of male mosquitoes from the swarms were examined for sexual maturity by observing genitalia rotation, species identity using polymerase chain reaction and wing sizes. Results: 581 An. funestus (98.1% males (n 570) and 1.9% (n 11) females) and 9 Anopheles gambiae sensu lato (s.l.) males were sampled using sweep nets from= the 81 confrmed= swarms in two villages (Ikwambi in Kilombero district and Tulizamoyo in Ulanga district). Six copulation events were observed in the swarms.
    [Show full text]