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Keven JB, Vinit R, Katusele M, Reimer LJ, Zimmerman PA, Karl S, Walker ED. Genetic differentiation and bottleneck effects in the malaria vectors Anopheles farauti and Anopheles punctulatus after an LLIN-based vector control program in Papua New Guinea. Ecol Evol 2024; 14:e10917. [PMID: 38371856 PMCID: PMC10869881 DOI: 10.1002/ece3.10917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 01/09/2024] [Accepted: 01/15/2024] [Indexed: 02/20/2024] Open
Abstract
Implementation of long-lasting insecticide-treated net (LLIN) programs to control human malaria transmission leads to substantial reductions in the abundance of Anopheles mosquitoes, but the impact on the population genetic structure of the malaria vectors is poorly known, nor has it been investigated in Papua New Guinea, where malaria is highly endemic and where several species of Anopheles have vector roles. Here, we applied Wright's F-statistic, analysis of molecular variance, Bayesian structure analysis, and discriminant analysis of principle components to microsatellite genotype data to analyze the population genetic structure of Anopheles farauti between and within the northern and southern lowland plains and of Anopheles punctulatus within the northern plain of Papua New Guinea after such a program. Bottleneck effects in the two malaria vectors were analyzed using Luikart and Cornuet's tests of heterozygosity. A large, panmictic population of An. punctulatus pre-LLIN program diverged into two subregional populations corresponding to Madang and East Sepik provinces post-LLIN distribution and experienced a genetic bottleneck during this process. By contrast, the An. farauti population existed as two regional populations isolated by mountain ranges pre-LLIN, a genetic structure that persisted after the distribution of LLINs with no further geographic differentiation nor evidence of a genetic bottleneck. These findings show the differential response of populations of different vector species to interventions, which has implications for program sustainability and gene flow.
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Affiliation(s)
- John B. Keven
- Department of Population Health and Disease Prevention, Program in Public HealthUniversity of California‐IrvineIrvineCaliforniaUSA
- Department of EntomologyMichigan State UniversityEast LansingMichiganUSA
- Department of Microbiology and Molecular GeneticsMichigan State UniversityEast LansingMichiganUSA
- Vector‐borne Diseases UnitPapua New Guinea Institute of Medical ResearchMadangMadang ProvincePapua New Guinea
| | - Rebecca Vinit
- Vector‐borne Diseases UnitPapua New Guinea Institute of Medical ResearchMadangMadang ProvincePapua New Guinea
| | - Michelle Katusele
- Vector‐borne Diseases UnitPapua New Guinea Institute of Medical ResearchMadangMadang ProvincePapua New Guinea
| | - Lisa J. Reimer
- Department of Vector BiologyLiverpool School of Tropical MedicineLiverpoolUK
| | - Peter A. Zimmerman
- Center for Global Health and Diseases, Pathology DepartmentCase Western Reserve UniversityClevelandOhioUSA
| | - Stephan Karl
- Vector‐borne Diseases UnitPapua New Guinea Institute of Medical ResearchMadangMadang ProvincePapua New Guinea
- Australian Institute of Tropical Health and MedicineJames Cook UniversityCairnsQueenslandAustralia
| | - Edward D. Walker
- Department of EntomologyMichigan State UniversityEast LansingMichiganUSA
- Department of Microbiology and Molecular GeneticsMichigan State UniversityEast LansingMichiganUSA
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Cleary E, Hetzel MW, Clements ACA. A review of malaria epidemiology and control in Papua New Guinea 1900 to 2021: Progress made and future directions. FRONTIERS IN EPIDEMIOLOGY 2022; 2:980795. [PMID: 38455277 PMCID: PMC10910954 DOI: 10.3389/fepid.2022.980795] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 09/29/2022] [Indexed: 03/09/2024]
Abstract
The research and control of malaria has a long history in Papua New Guinea, sometimes resulting in substantial changes to the distribution of infection and transmission dynamics in the country. There have been four major periods of malaria control in PNG, with the current control programme having commenced in 2004. Each previous control programme was successful in reducing malaria burden in the country, but multiple factors led to programme failures and eventual breakdown. A comprehensive review of the literature dating from 1900 to 2021 was undertaken to summarize control strategies, epidemiology, vector ecology and environmental drivers of malaria transmission in PNG. Evaluations of historical control programs reveal poor planning and communication, and difficulty in sustaining financial investment once malaria burden had decreased as common themes in the breakdown of previous programs. Success of current and future malaria control programs in PNG is contingent on adequate planning and management of control programs, effective communication and engagement with at-risk populations, and cohesive targeted approaches to sub-national and national control and elimination.
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Affiliation(s)
- Eimear Cleary
- Research School of Population Health, Australian National University, Canberra, ACT, Australia
- WorldPop, School of Geography and Environmental Science, University of Southampton, Southampton, United Kingdom
| | - Manuel W. Hetzel
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Archie C. A. Clements
- Curtin University, Perth, WA, Australia
- Telethon Kids Institute, Perth, WA, Australia
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Holzschuh A, Gruenberg M, Hofmann NE, Wampfler R, Kiniboro B, Robinson LJ, Mueller I, Felger I, White MT. Co-infection of the four major Plasmodium species: Effects on densities and gametocyte carriage. PLoS Negl Trop Dis 2022; 16:e0010760. [PMID: 36099312 PMCID: PMC9506632 DOI: 10.1371/journal.pntd.0010760] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 09/23/2022] [Accepted: 08/22/2022] [Indexed: 11/19/2022] Open
Abstract
Background Co-infection of the four major species of human malaria parasite Plasmodium falciparum (Pf), P. vivax (Pv), P. malariae (Pm), and P. ovale sp. (Po) is regularly observed, but there is limited understanding of between-species interactions. In particular, little is known about the effects of multiple Plasmodium species co-infections on gametocyte production. Methods We developed molecular assays for detecting asexual and gametocyte stages of Pf, Pv, Pm, and Po. This is the first description of molecular diagnostics for Pm and Po gametocytes. These assays were implemented in a unique epidemiological setting in Papua New Guinea with sympatric transmission of all four Plasmodium species permitting a comprehensive investigation of species interactions. Findings The observed frequency of Pf-Pv co-infection for asexual parasites (14.7%) was higher than expected from individual prevalence rates (23.8%Pf x 47.4%Pv = 11.3%). The observed frequency of co-infection with Pf and Pv gametocytes (4.6%) was higher than expected from individual prevalence rates (13.1%Pf x 28.2%Pv = 3.7%). The excess risk of co-infection was 1.38 (95% confidence interval (CI): 1.09, 1.67) for all parasites and 1.37 (95% CI: 0.95, 1.79) for gametocytes. This excess co-infection risk was partially attributable to malaria infections clustering in some villages. Pf-Pv-Pm triple infections were four times more frequent than expected by chance alone, which could not be fully explained by infections clustering in highly exposed individuals. The effect of co-infection on parasite density was analyzed by systematic comparison of all pairwise interactions. This revealed a significant 6.57-fold increase of Pm density when co-infected with Pf. Pm gametocytemia also increased with Pf co-infection. Conclusions Heterogeneity in exposure to mosquitoes is a key epidemiological driver of Plasmodium co-infection. Among the four co-circulating parasites, Pm benefitted most from co-infection with other species. Beyond this, no general prevailing pattern of suppression or facilitation was identified in pairwise analysis of gametocytemia and parasitemia of the four species. Trial registration This trial is registered with ClinicalTrials.gov, Trial ID: NCT02143934. The majority of malaria research focuses on the Plasmodium falciparum and P. vivax parasite species, due to their large public health burden. The epidemiology of P. malariae and P. ovale parasites has been comparatively neglected, due to a lack of research tools, most notably diagnostics. We present new molecular diagnostic assays for detecting P. malariae and P. ovale gametocytes, the sexual stage of the malaria parasite transmitted to mosquitoes. These assays were applied to samples collected in Papua New Guinea, a rare region with high transmission of the four major malaria parasite species. Patterns of co-infections were characterized accounting for interactions between pairs and triples of parasites. Heterogeneity in exposure to mosquito bites was identified as a key driver of patterns of co-infection. The effect of co-infection on parasite density was analyzed by systematic comparison of all pairwise interactions. The most significant within-host interaction of parasites was the large increase in P. malariae parasite density due to co-infection with P. falciparum. This finding was replicated for P. malariae gametocytes (but did not attain statistical significance due to low sample numbers) suggesting that co-infection provides a key transmission advantage to P. malariae.
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Affiliation(s)
- Aurel Holzschuh
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Maria Gruenberg
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Natalie E. Hofmann
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Rahel Wampfler
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Benson Kiniboro
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang and Maprik, Papua New Guinea
| | - Leanne J. Robinson
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang and Maprik, Papua New Guinea
- Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
- University of Melbourne, Melbourne, Australia
| | - Ivo Mueller
- Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
- University of Melbourne, Melbourne, Australia
| | - Ingrid Felger
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- * E-mail: (IF); (MTW)
| | - Michael T. White
- Institut Pasteur, Université de Paris Cité, G5 Épidémiologie et Analyse des Maladies Infectieuses, Département de Santé Globale, Paris, France
- * E-mail: (IF); (MTW)
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Loeffel M, Ross A. The relative impact of interventions on sympatric Plasmodium vivax and Plasmodium falciparum malaria: A systematic review. PLoS Negl Trop Dis 2022; 16:e0010541. [PMID: 35767578 PMCID: PMC9242512 DOI: 10.1371/journal.pntd.0010541] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Accepted: 05/27/2022] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND In areas with both Plasmodium vivax and Plasmodium falciparum malaria, interventions can reduce the burden of both species but the impact may vary due to their different biology. Knowing the expected relative impact on the two species over time for vector- and drug-based interventions, and the factors affecting this, could help plan and evaluate intervention strategies. METHODS For three interventions (treated bed nets (ITN), mass drug administration (MDA) and indoor residual spraying (IRS)), we identified studies providing information on the proportion of clinical illness and patent infections attributed to P. vivax over time using a literature search. The change in the proportion of malaria attributed to P. vivax up to two years since implementation was estimated using logistic regression accounting for clustering with random effects. Potential factors (intervention type, coverage, relapse pattern, transmission intensity, seasonality, initial proportion of P. vivax and round of intervention) were assessed. RESULTS In total there were 55 studies found that led to 72 series of time-points for clinical case data and 69 series for patent infection data. The main reason of study exclusion was insufficient information on interventions. There was considerable variation in the proportion of malaria attributed to P. vivax over time by study and location for all of the interventions. Overall, there was an increase apart from MDA in the short-term. The potential factors could not be ruled in or out. Although not consistently significant, coverage, transmission intensity and relapse pattern are possible factors that explain some of the variation found. CONCLUSION While there are reports of an increase in the proportion of malaria due to P. vivax following interventions in the long-term, there was substantial variation for the shorter time-scales considered in this study (up to 24 months for IRS and ITN, and up to six months for MDA). The large variability points to the need for the monitoring of both species after an intervention. Studies should report intervention timing and characteristics to allow inclusion in systematic reviews.
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Affiliation(s)
- Melanie Loeffel
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Amanda Ross
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
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5
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Gumbo A, Topazian HM, Mwanza A, Mitchell CL, Puerto-Meredith S, Njiko R, Kayange M, Mwalilino D, Mvula B, Tegha G, Mvalo T, Hoffman I, Juliano JJ. Occurrence and Distribution of Nonfalciparum Malaria Parasite Species Among Adolescents and Adults in Malawi. J Infect Dis 2022; 225:257-268. [PMID: 34244739 PMCID: PMC8763954 DOI: 10.1093/infdis/jiab353] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 07/08/2021] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Plasmodium falciparum malaria dominates throughout sub-Saharan Africa, but the prevalence of Plasmodium malariae, Plasmodium ovale spp., and Plasmodium vivax increasingly contribute to infection in countries that control malaria using P. falciparum-specific diagnostic and treatment strategies. METHODS We performed quantitative polymerase chain reaction (qPCR) on 2987 dried blood spots from the 2015-2016 Malawi Demographic and Health Survey to identify presence and distribution of nonfalciparum infection. Bivariate models were used to determine species-specific associations with demographic and environmental risk factors. RESULTS Nonfalciparum infections had broad spatial distributions. Weighted prevalence was 0.025 (SE, 0.004) for P. malariae, 0.097 (SE, 0.008) for P. ovale spp., and 0.001 (SE, 0.0005) for P. vivax. Most infections (85.6%) had low-density parasitemias ≤ 10 parasites/µL, and 66.7% of P. malariae, 34.6% of P. ovale spp., and 40.0% of P. vivax infections were coinfected with P. falciparum. Risk factors for P. malariae were like those known for P. falciparum; however, there were few risk factors recognized for P. ovale spp. and P. vivax, perhaps due to the potential for relapsing episodes. CONCLUSIONS The prevalence of any nonfalciparum infection was 11.7%, with infections distributed across Malawi. Continued monitoring of Plasmodium spp. becomes critical as nonfalciparum infections become important sources of ongoing transmission.
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Affiliation(s)
- Austin Gumbo
- National Malaria Control Programme, Malawi Ministry of Health, Lilongwe, Malawi
| | - Hillary M Topazian
- Department of Epidemiology, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Alexis Mwanza
- Department of Epidemiology, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Cedar L Mitchell
- Department of Epidemiology, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Sydney Puerto-Meredith
- Department of Epidemiology, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Ruth Njiko
- University of North Carolina Project-Malawi, Lilongwe, Malawi
| | - Michael Kayange
- National Malaria Control Programme, Malawi Ministry of Health, Lilongwe, Malawi
| | - David Mwalilino
- National HIV Reference Laboratory, Malawi Ministry of Health, Lilongwe, Malawi
| | - Bernard Mvula
- National HIV Reference Laboratory, Malawi Ministry of Health, Lilongwe, Malawi
| | - Gerald Tegha
- University of North Carolina Project-Malawi, Lilongwe, Malawi
| | - Tisungane Mvalo
- University of North Carolina Project-Malawi, Lilongwe, Malawi
- Department of Pediatrics, School of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Irving Hoffman
- University of North Carolina Project-Malawi, Lilongwe, Malawi
- Institute for Global Health and Infectious Diseases, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Jonathan J Juliano
- Division of Infectious Diseases, School of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA
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6
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Keven JB, Katusele M, Vinit R, Rodríguez-Rodríguez D, Hetzel MW, Robinson LJ, Laman M, Karl S, Walker ED. Vector composition, abundance, biting patterns and malaria transmission intensity in Madang, Papua New Guinea: assessment after 7 years of an LLIN-based malaria control programme. Malar J 2022; 21:7. [PMID: 34983530 PMCID: PMC8729043 DOI: 10.1186/s12936-021-04030-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 12/17/2021] [Indexed: 11/18/2022] Open
Abstract
Background A malaria control programme based on distribution of long-lasting insecticidal bed nets (LLINs) and artemisinin combination therapy began in Papua New Guinea in 2009. After implementation of the programme, substantial reductions in vector abundance and malaria transmission intensity occurred. The research reported here investigated whether these reductions remained after seven years of sustained effort. Methods All-night (18:00 to 06:00) mosquito collections were conducted using human landing catches and barrier screen methods in four villages of Madang Province between September 2016 and March 2017. Anopheles species identification and sporozoite infection with Plasmodium vivax and Plasmodium falciparum were determined with molecular methods. Vector composition was expressed as the relative proportion of different species in villages, and vector abundance was quantified as the number of mosquitoes per barrier screen-night and per person-night. Transmission intensity was quantified as the number of sporozoite-infective vector bites per person-night. Results Five Anopheles species were present, but vector composition varied greatly among villages. Anopheles koliensis, a strongly anthropophilic species was the most prevalent in Bulal, Matukar and Wasab villages, constituting 63.7–73.8% of all Anopheles, but in Megiar Anopheles farauti was the most prevalent species (97.6%). Vector abundance varied among villages (ranging from 2.8 to 72.3 Anopheles per screen-night and 2.2–31.1 Anopheles per person-night), and spatially within villages. Malaria transmission intensity varied among the villages, with values ranging from 0.03 to 0.5 infective Anopheles bites per person-night. Most (54.1–75.1%) of the Anopheles bites occurred outdoors, with a substantial proportion (25.5–50.8%) occurring before 22:00. Conclusion The estimates of vector abundance and transmission intensity in the current study were comparable to or higher than estimates in the same villages in 2010–2012, indicating impeded programme effectiveness. Outdoor and early biting behaviours of vectors are some of the likely explanatory factors. Heterogeneity in vector composition, abundance and distribution among and within villages challenge malaria control programmes and must be considered when planning them. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-021-04030-4.
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Affiliation(s)
- John B Keven
- Department of Entomology, Michigan State University, East Lansing, MI, USA. .,Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA. .,Papua New Guinea Institute of Medical Research, Vector-Borne Diseases Unit, Madang, Papua New Guinea.
| | - Michelle Katusele
- Papua New Guinea Institute of Medical Research, Vector-Borne Diseases Unit, Madang, Papua New Guinea
| | - Rebecca Vinit
- Papua New Guinea Institute of Medical Research, Vector-Borne Diseases Unit, Madang, Papua New Guinea
| | | | - Manuel W Hetzel
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Leanne J Robinson
- Papua New Guinea Institute of Medical Research, Vector-Borne Diseases Unit, Madang, Papua New Guinea.,Burnet Institute, Melbourne, VIC, Australia.,Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Moses Laman
- Papua New Guinea Institute of Medical Research, Vector-Borne Diseases Unit, Madang, Papua New Guinea
| | - Stephan Karl
- Papua New Guinea Institute of Medical Research, Vector-Borne Diseases Unit, Madang, Papua New Guinea.,Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD, Australia
| | - Edward D Walker
- Department of Entomology, Michigan State University, East Lansing, MI, USA.,Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA
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Seidahmed O, Jamea S, Kurumop S, Timbi D, Makita L, Ahmed M, Freeman T, Pomat W, Hetzel MW. Stratification of malaria incidence in Papua New Guinea (2011-2019): Contribution towards a sub-national control policy. PLOS GLOBAL PUBLIC HEALTH 2022; 2:e0000747. [PMID: 36962582 PMCID: PMC10022348 DOI: 10.1371/journal.pgph.0000747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 10/20/2022] [Indexed: 11/22/2022]
Abstract
Malaria risk in Papua New Guinea (PNG) is highly heterogeneous, between and within geographical regions, which is operationally challenging for control. To enhance targeting of malaria interventions in PNG, we investigated risk factors and stratified malaria incidence at the level of health facility catchment areas. Catchment areas and populations of 808 health facilities were delineated using a travel-time accessibility approach and linked to reported malaria cases (2011-2019). Zonal statistics tools were used to calculate average altitude and air temperature in catchment areas before they were spatially joined with incidence rates. In addition, empirical Bayesian kriging (EBK) was employed to interpolate incidence risk strata across PNG. Malaria annual incidence rates are, on average, 186.3 per 1000 population in catchment areas up to 600 m, dropped to 98.8 at (800-1400) m, and to 24.1 cases above 1400 m altitude. In areas above the two altitudinal thresholds 600m and 1400m, the average annual temperature drops below 22°C and 17°C, respectively. EBK models show very low- to low-risk strata (<100 cases per 1000) in the Highlands, National Capital District and Bougainville. In contrast, patches of high-risk (>200 per 1000) strata are modelled mainly in Momase and Islands Regions. Besides, strata with moderate risk (100-200) predominate throughout the coastal areas. While 35.7% of the PNG population (estimated 3.33 million in 2019) lives in places at high or moderate risk of malaria, 52.2% (estimated 4.88 million) resides in very low-risk areas. In five provinces, relatively large proportions of populations (> 50%) inhabit high-risk areas: New Ireland, East and West New Britain, Sandaun and Milne Bay. Incidence maps show a contrast in malaria risk between coastal and inland areas influenced by altitude. However, the risk is highly variable in low-lying areas. Malaria interventions should be guided by sub-national risk levels in PNG.
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Affiliation(s)
- Osama Seidahmed
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
- University of Basel, Basel, Switzerland
| | - Sharon Jamea
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Serah Kurumop
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Diana Timbi
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Leo Makita
- National Department of Health, Port Moresby, Papua New Guinea
| | - Munir Ahmed
- Rotarians Against Malaria, Port Moresby, Papua New Guinea
| | - Tim Freeman
- Rotarians Against Malaria, Port Moresby, Papua New Guinea
| | - William Pomat
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Manuel W Hetzel
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
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8
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Keven JB, Katusele M, Vinit R, Rodríguez-Rodríguez D, Hetzel MW, Robinson LJ, Laman M, Karl S, Foran DR, Walker ED. Nonrandom Selection and Multiple Blood Feeding of Human Hosts by Anopheles Vectors: Implications for Malaria Transmission in Papua New Guinea. Am J Trop Med Hyg 2021; 105:1747-1758. [PMID: 34583342 PMCID: PMC8641310 DOI: 10.4269/ajtmh.21-0210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 07/21/2021] [Indexed: 11/07/2022] Open
Abstract
Nonrandom selection and multiple blood feeding of human hosts by Anopheles mosquitoes may exacerbate malaria transmission. Both patterns of blood feeding and their relationship to malaria epidemiology were investigated in Anopheles vectors in Papua New Guinea (PNG). Blood samples from humans and mosquito blood meals were collected in villages and human genetic profiles ("fingerprints") were analyzed by genotyping 23 microsatellites and a sex-specific marker. Frequency of blood meals acquired from different humans, identified by unique genetic profiles, was fitted to Poisson and negative binomial distributions to test for nonrandom patterns of host selection. Blood meals with more than one genetic profiles were classified as mosquitoes that fed on multiple humans. The age of a person bitten by a mosquito was determined by matching the blood-meal genetic profile to the villagers' genetic profiles. Malaria infection in humans was determined by PCR test of blood samples. The results show nonrandom distribution of blood feeding among humans, with biased selection toward males and individuals aged 15-30 years. Prevalence of Plasmodium falciparum infection was higher in this age group, suggesting males in this age range could be super-spreaders of malaria parasites. The proportion of mosquitoes that fed on multiple humans ranged from 6% to 13% among villages. The patterns of host utilization observed here can amplify transmission and contribute to the persistence of malaria in PNG despite efforts to suppress it with insecticidal bed nets. Excessive feeding on males aged 15-30 years underscores the importance of targeted interventions focusing on this demographic group.
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Affiliation(s)
- John B. Keven
- Department of Microbiology and Molecular Genetics, and Department of Entomology, Michigan State University, East Lansing, Michigan
- Vector-borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Michelle Katusele
- Vector-borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Rebecca Vinit
- Vector-borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Daniela Rodríguez-Rodríguez
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- Department of Epidemiology and Public Health, University of Basel, Basel, Switzerland
| | - Manuel W. Hetzel
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- Department of Epidemiology and Public Health, University of Basel, Basel, Switzerland
| | - Leanne J. Robinson
- Vector-borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
- Vector-Borne Diseases and Tropical Public Health Group, Burnet Institute, Melbourne, Victoria, Australia
- Division of Population Health and Immunity, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
| | - Moses Laman
- Vector-borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Stephan Karl
- Vector-borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
| | - David R. Foran
- School of Criminal Justice and Department of Integrative Biology, Michigan State University, Michigan
| | - Edward D. Walker
- Department of Microbiology and Molecular Genetics, and Department of Entomology, Michigan State University, East Lansing, Michigan
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9
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Millat-Martínez P, Gabong R, Balanza N, Luana S, Sanz S, Raulo S, Elizah A, Wali C, Paivu B, Dalmas J, Tabie S, Karl S, Laman M, Pomat W, Mitjà O, Baro B, Bassat Q. Coverage, determinants of use and repurposing of long-lasting insecticidal nets two years after a mass distribution in Lihir Islands, Papua New Guinea: a cross-sectional study. Malar J 2021; 20:336. [PMID: 34348727 PMCID: PMC8336363 DOI: 10.1186/s12936-021-03867-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 07/27/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Universal coverage with long-lasting insecticidal nets (LLINs) is an essential component of malaria control programmes. Three-yearly mass distribution of LLINs in Papua New Guinea (PNG) has been successful in reducing infection transmission since 2009, but malaria prevalence ramped up from 2015 onwards. Although LLIN universal coverage is mostly achieved during these campaigns, it may not be related with net use over time. Uses given to LLINs and non-compliance of this strategy were evaluated. METHODS A knowledge, attitude and practice (KAP) cross-sectional study was conducted in Lihir Islands, PNG, 2-2.5 years after the last LLIN mass distribution campaign. Data on bed net ownership, use and maintenance behaviour was collected using a household questionnaire administered by trained community volunteers. Logistic regression models were used to identify factors associated with owning at least one LLIN and sleeping under a LLIN the previous night. RESULTS Among 2694 households surveyed, 27.4 % (95 % CI: 25.8-29.2) owned at least one LLIN and 8.7 % (95 % CI: 7.6-9.8) had an adequate LLIN coverage (at least one LLIN for every two people). Out of 13,595 individuals in the surveyed households, 13.6 % (95 % CI: 13.0--4.2) reported having slept under a LLIN the preceding night. Determinants for sleeping under LLIN included living in a household with adequate LLIN coverage [adjusted OR (aOR) = 5.82 (95 % CI: 3.23-10.49)], household heads knowledge about LLINs [aOR = 16.44 (95 % CI: 8.29-32.58)], and female gender [aOR = 1.92 (95 % CI: 1.53-2.40)] (all p-values < 0.001). LLIN use decreased with older age [aOR = 0.29 (95 % CI: 0.21-0.40) for ≥ 15 year-olds, aOR = 0.38 (95 % CI: 0.27-0.55) for 5-14 year-olds] compared to < 5 year-olds (p-value < 0.001). Knowledge on the use of LLIN was good in 37.0 % of the household heads. Repurposed nets were reported serving as fishing nets (30.4 %), fruits and seedlings protection (26.6 %), covering up food (19.0 %) and bed linen (11.5 %). CONCLUSIONS Two years after mass distribution, LLIN coverage and use in Lihir Islands is extremely low. Three yearly distribution campaigns may not suffice to maintain an acceptable LLIN coverage unless knowledge on maintenance and use is promoted trough educational campaigns.
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Affiliation(s)
- Pere Millat-Martínez
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Spain. .,Lihir Malaria Elimination Programme (LMEP), Lihir Island, Papua New Guinea.
| | - Rebecca Gabong
- Lihir Malaria Elimination Programme (LMEP), Lihir Island, Papua New Guinea
| | - Núria Balanza
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Spain
| | - Sakaia Luana
- Lihir Malaria Elimination Programme (LMEP), Lihir Island, Papua New Guinea
| | - Sergi Sanz
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.,Consorcio de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain.,Department of Basic Clinical Practice, Faculty of Medicine, Universitat de Barcelona, Barcelona, Spain
| | - Silvia Raulo
- Lihir Malaria Elimination Programme (LMEP), Lihir Island, Papua New Guinea
| | - Arthur Elizah
- Lihir Malaria Elimination Programme (LMEP), Lihir Island, Papua New Guinea
| | - Chilaka Wali
- Lihir Malaria Elimination Programme (LMEP), Lihir Island, Papua New Guinea
| | - Benjamin Paivu
- Lihir Malaria Elimination Programme (LMEP), Lihir Island, Papua New Guinea
| | - Julian Dalmas
- Lihir Malaria Elimination Programme (LMEP), Lihir Island, Papua New Guinea
| | - Samson Tabie
- Lihir Malaria Elimination Programme (LMEP), Lihir Island, Papua New Guinea
| | - Stephan Karl
- Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, Australia.,Papua New Guinea Institute of Medical Research, Goroka/Madang, Papua New Guinea
| | - Moses Laman
- Papua New Guinea Institute of Medical Research, Goroka/Madang, Papua New Guinea
| | - William Pomat
- Papua New Guinea Institute of Medical Research, Goroka/Madang, Papua New Guinea
| | - Oriol Mitjà
- Fight AIDS and Infectious Diseases Foundation, Badalona, Spain.,Infectious Disease Department, Hospital Universitari Germans Trias i Pujol, Badalona, Spain.,Department of Clinical Sciences, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain.,Lihir Medical Centre, International SOS, Lihir Island, Papua New Guinea
| | - Bàrbara Baro
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Spain
| | - Quique Bassat
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.,Consorcio de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain.,ICREA, Pg. Lluís Companys 23, 08010, Barcelona, Spain.,Pediatrics Department, Hospital Sant Joan de Déu, Universitat de Barcelona, Esplugues, Barcelona, Spain.,Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
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10
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Hii J, Hustedt J, Bangs MJ. Residual Malaria Transmission in Select Countries of Asia-Pacific Region: Old Wine in a New Barrel. J Infect Dis 2021; 223:S111-S142. [PMID: 33906222 PMCID: PMC8079134 DOI: 10.1093/infdis/jiab004] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Background Despite substantial reductions in malaria burden and improvement in case management, malaria remains a major public health challenge in the Asia-Pacific region. Residual malaria transmission (RMT) is the fraction of total transmission that persists after achievement of full operational coverage with effective insecticide-treated bed nets (ITNs)/long-lasting insecticidal nets (LLINs) and/or indoor residual spray interventions. There is a critical need to standardize and share best practices for entomological, anthropological, and product development investigative protocols to meet the challenges of RMT and elimination goals. Methods A systematic review was conducted to describe when and where RMT is occurring, while specifically targeting ownership and usage of ITN/LLINs, indoor residual spray application, insecticide susceptibility of vectors, and human and vector biting behavior, with a focus on nighttime activities. Results Sixty-six publications from 1995 to present met the inclusion criteria for closer review. Associations between local vector control coverage and use with behaviors of human and mosquito vectors varied by locality and circumstance. Consequently, the magnitude of RMT is insufficiently studied and analyzed with sparse estimates of individual exposure in communities, insufficient or incomplete observations of ITN/LLIN use, and the local human population movement into and from high-risk areas. Conclusions This review identified significant gaps or deficiencies that require urgent attention, namely, developing standardized procedures and methods to estimate risk exposure beyond the peridomestic setting, analytical approaches to measure key human-vector interactions, and seasonal location-specific agricultural or forest use calendars, and establishing the collection of longitudinal human and vector data close in time and location.
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Affiliation(s)
- Jeffrey Hii
- Malaria Consortium Asia, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland, Australia
| | | | - Michael J Bangs
- Public Health and Malaria Control Department, PT Freeport Indonesia, International SOS, Jl. Kertajasa, Kuala Kencana, Papua, Indonesia.,Department of Entomology, Faculty of Agriculture, Kasertart University, Bangkok, Thailand
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11
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Myers-Hansen JL, Abuaku B, Oyebola MK, Mensah BA, Ahorlu C, Wilson MD, Awandare G, Koram KA, Ngwa AA, Ghansah A. Assessment of antimalarial drug resistant markers in asymptomatic Plasmodium falciparum infections after 4 years of indoor residual spraying in Northern Ghana. PLoS One 2020; 15:e0233478. [PMID: 33284800 PMCID: PMC7721464 DOI: 10.1371/journal.pone.0233478] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 08/18/2020] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Drug resistance remains a concern for malaria control and elimination. The effect of interventions on its prevalence needs to be monitored to pre-empt further selection. We assessed the prevalence of Plasmodium falciparum gene mutations associated with resistance to the antimalarial drugs: sulfadoxine-pyrimethamine (SP), chloroquine (CQ) and artemisinin combination therapy (ACTs) after the scale-up of a vector control activity that reduced transmission. METHODS A total of 400 P. falciparum isolates from children under five years were genotyped for seventeen single nucleotide polymorphisms (SNPs) in pfcrt, pfmdr1, pfdhfr, pfdhps and pfk13 genes using polymerase chain reaction (PCR) and high resolution melting (HRM) analysis. These included 80 isolates, each randomly selected from cross-sectional surveys of asymptomatic infections across 2010 (baseline), 2011, 2012, 2013 (midline: post-IRS) and 2014 (endline: post-IRS) during the peak transmission season, when IRS intervention was rolled out in Bunkpurugu Yunyoo (BY) District, Ghana. The proportions of isolates with drug resistant alleles were assessed over this period. RESULTS There were significant decreases in the prevalence of pfdhfr- I51R59N108 haplotype from 2010 to 2014, while the decline in pfdhfr/pfdhps- I51R59N108G437 during the same period was not significant. The prevalence of lumefantrine (LM), mefloquine (MQ) and amodiaquine (AQ) resistance-associated haplotypes pfmdr1-N86F184D1246 and pfmdr1-Y86Y184Y1246 showed decreasing trends (z = -2.86, P = 0.004 and z = -2.71, P = 0.007, respectively). Each of pfcrt-T76 and pfmdr1-Y86 mutant alleles also showed a declining trend in the asymptomatic reservoir, after the IRS rollout in 2014 (z = -2.87, P = 0.004 and z = -2.65, P = 0.008, respectively). Similarly, Pyrimethamine resistance mediating polymorphisms pfdhfr-N108, pfdhfr-I51 and pfdhfr-R59 also declined (z = -2.03, P = 0.042, z = -3.54, P<0.001 and z = -4.63, P<0.001, respectively), but not the sulphadoxine resistance mediating pfdhps-G437 and pfdhps-F436 (z = -0.36, P = 0.715 and z = 0.41, P = 0.684, respectively). No mutant pfk13-Y580 were detected during the study period. CONCLUSION The study demonstrated declining trends in the prevalence of drug resistant mutations in asymptomatic P. falciparum infections following transmission reduction after an enhanced IRS intervention in Northern Ghana.
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Affiliation(s)
| | - Benjamin Abuaku
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Muyiwa K. Oyebola
- West African Center for Cell Biology of Infectious Pathogens, University of Ghana, Legon, Ghana
| | - Benedicta A. Mensah
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Collins Ahorlu
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Michael D. Wilson
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Gordon Awandare
- West African Center for Cell Biology of Infectious Pathogens, University of Ghana, Legon, Ghana
| | - Kwadwo A. Koram
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | | | - Anita Ghansah
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
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12
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Kattenberg JH, Razook Z, Keo R, Koepfli C, Jennison C, Lautu-Gumal D, Fola AA, Ome-Kaius M, Barnadas C, Siba P, Felger I, Kazura J, Mueller I, Robinson LJ, Barry AE. Monitoring Plasmodium falciparum and Plasmodium vivax using microsatellite markers indicates limited changes in population structure after substantial transmission decline in Papua New Guinea. Mol Ecol 2020; 29:4525-4541. [PMID: 32985031 PMCID: PMC10008436 DOI: 10.1111/mec.15654] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 07/27/2020] [Indexed: 02/01/2023]
Abstract
Monitoring the genetic structure of pathogen populations may be an economical and sensitive approach to quantify the impact of control on transmission dynamics, highlighting the need for a better understanding of changes in population genetic parameters as transmission declines. Here we describe the first population genetic analysis of two major human malaria parasites, Plasmodium falciparum (Pf) and Plasmodium vivax (Pv), following nationwide distribution of long-lasting insecticide-treated nets (LLINs) in Papua New Guinea (PNG). Parasite isolates from pre- (2005-2006) and post-LLIN (2010-2014) were genotyped using microsatellite markers. Despite parasite prevalence declining substantially (East Sepik Province: Pf = 54.9%-8.5%, Pv = 35.7%-5.6%, Madang Province: Pf = 38.0%-9.0%, Pv: 31.8%-19.7%), genetically diverse and intermixing parasite populations remained. Pf diversity declined modestly post-LLIN relative to pre-LLIN (East Sepik: Rs = 7.1-6.4, HE = 0.77-0.71; Madang: Rs = 8.2-6.1, HE = 0.79-0.71). Unexpectedly, population structure present in pre-LLIN populations was lost post-LLIN, suggesting that more frequent human movement between provinces may have contributed to higher gene flow. Pv prevalence initially declined but increased again in one province, yet diversity remained high throughout the study period (East Sepik: Rs = 11.4-9.3, HE = 0.83-0.80; Madang: Rs = 12.2-14.5, HE = 0.85-0.88). Although genetic differentiation values increased between provinces over time, no significant population structure was observed at any time point. For both species, a decline in multiple infections and increasing clonal transmission and significant multilocus linkage disequilibrium post-LLIN were positive indicators of impact on the parasite population using microsatellite markers. These parameters may be useful adjuncts to traditional epidemiological tools in the early stages of transmission reduction.
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Affiliation(s)
- Johanna Helena Kattenberg
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Yagaum, Papua New Guinea
| | - Zahra Razook
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
| | - Raksmei Keo
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
| | - Cristian Koepfli
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Charlie Jennison
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Dulcie Lautu-Gumal
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Yagaum, Papua New Guinea.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Abebe A Fola
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Maria Ome-Kaius
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Yagaum, Papua New Guinea.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Céline Barnadas
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Yagaum, Papua New Guinea.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Peter Siba
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Ingrid Felger
- Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - James Kazura
- Centre for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA
| | - Ivo Mueller
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia.,Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
| | - Leanne J Robinson
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Yagaum, Papua New Guinea.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia.,Disease Elimination, Burnet Institute, Melbourne, VIC, Australia
| | - Alyssa E Barry
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
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13
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Decreased bioefficacy of long-lasting insecticidal nets and the resurgence of malaria in Papua New Guinea. Nat Commun 2020; 11:3646. [PMID: 32686679 PMCID: PMC7371689 DOI: 10.1038/s41467-020-17456-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 06/30/2020] [Indexed: 11/17/2022] Open
Abstract
Papua New Guinea (PNG) has the highest malaria transmission outside of Africa. Long-lasting insecticidal nets (LLINs) are believed to have helped to reduce average malaria prevalence in PNG from 16% in 2008 to 1% in 2014. Since 2015 malaria in PNG has resurged significantly. Here, we present observations documenting decreased bioefficacy of unused LLINs with manufacturing dates between 2013 and 2019 collected from villages and LLIN distributors in PNG. Specifically, we show that of n = 167 tested LLINs manufactured after 2013, only 17% are fulfilling the required World Health Organisation bioefficacy standards of ≥ 80% 24 h mortality or ≥ 95% 60 min knockdown in bioassays with pyrethroid susceptible Anopheles farauti mosquitoes. In contrast, all (100%, n = 25) LLINs with manufacturing dates prior to 2013 are meeting these bioefficacy standards. These results suggest that decreased bioefficacy of LLINs is contributing to the malaria resurgence in PNG and increased scrutiny of LLIN quality is warranted. Malaria prevalence in Papua New Guinea has risen in recent years after almost a decade of decline. In this study, the authors demonstrate that long-lasting insecticidal nets used in the country that were manufactured since 2013 have significantly reduced bioefficacy.
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14
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Kattenberg JH, Gumal DL, Ome-Kaius M, Kiniboro B, Philip M, Jally S, Kasian B, Sambale N, Siba PM, Karl S, Barry AE, Felger I, Kazura JW, Mueller I, Robinson LJ. The epidemiology of Plasmodium falciparum and Plasmodium vivax in East Sepik Province, Papua New Guinea, pre- and post-implementation of national malaria control efforts. Malar J 2020; 19:198. [PMID: 32503607 PMCID: PMC7275396 DOI: 10.1186/s12936-020-03265-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 05/20/2020] [Indexed: 02/07/2023] Open
Abstract
Background In the past decade, national malaria control efforts in Papua New Guinea (PNG) have received renewed support, facilitating nationwide distribution of free long-lasting insecticidal nets (LLINs), as well as improvements in access to parasite-confirmed diagnosis and effective artemisinin-combination therapy in 2011–2012. Methods To study the effects of these intensified control efforts on the epidemiology and transmission of Plasmodium falciparum and Plasmodium vivax infections and investigate risk factors at the individual and household level, two cross-sectional surveys were conducted in the East Sepik Province of PNG; one in 2005, before the scale-up of national campaigns and one in late 2012-early 2013, after 2 rounds of LLIN distribution (2008 and 2011–2012). Differences between studies were investigated using Chi square (χ2), Fischer’s exact tests and Student’s t-test. Multivariable logistic regression models were built to investigate factors associated with infection at the individual and household level. Results The prevalence of P. falciparum and P. vivax in surveyed communities decreased from 55% (2005) to 9% (2013) and 36% to 6%, respectively. The mean multiplicity of infection (MOI) decreased from 1.8 to 1.6 for P. falciparum (p = 0.08) and from 2.2 to 1.4 for P. vivax (p < 0.001). Alongside these reductions, a shift towards a more uniform distribution of infections and illness across age groups was observed but there was greater heterogeneity across the study area and within the study villages. Microscopy positive infections and clinical cases in the household were associated with high rate infection households (> 50% of household members with Plasmodium infection). Conclusion After the scale-up of malaria control interventions in PNG between 2008 and 2012, there was a substantial reduction in P. falciparum and P. vivax infection rates in the studies villages in East Sepik Province. Understanding the extent of local heterogeneity in malaria transmission and the driving factors is critical to identify and implement targeted control strategies to ensure the ongoing success of malaria control in PNG and inform the development of tools required to achieve elimination. In household-based interventions, diagnostics with a sensitivity similar to (expert) microscopy could be used to identify and target high rate households.
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Affiliation(s)
- Johanna H Kattenberg
- Vector Borne Disease Unit, Papua New Guinea Institute of Medical Research, PO Box 378, Madang, 511, MP, Papua New Guinea.,Division of Population Health and Immunity, Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia.,Department of Biomedical Sciences, Institute of Tropical Medicine, Malariology Unit, Nationalestraat 155, 2000, Antwerp, Belgium
| | - Dulcie L Gumal
- Vector Borne Disease Unit, Papua New Guinea Institute of Medical Research, PO Box 378, Madang, 511, MP, Papua New Guinea.,Disease Elimination Program, Vector-borne Diseases and Tropical Public Health Group, Burnet Institute, 85 Commercial Rd, Melbourne, VIC, 3004, Australia
| | - Maria Ome-Kaius
- Vector Borne Disease Unit, Papua New Guinea Institute of Medical Research, PO Box 378, Madang, 511, MP, Papua New Guinea.,Division of Population Health and Immunity, Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia
| | - Benson Kiniboro
- Vector Borne Disease Unit, Papua New Guinea Institute of Medical Research, PO Box 378, Madang, 511, MP, Papua New Guinea
| | - Matthew Philip
- Vector Borne Disease Unit, Papua New Guinea Institute of Medical Research, PO Box 378, Madang, 511, MP, Papua New Guinea
| | - Shadrach Jally
- Vector Borne Disease Unit, Papua New Guinea Institute of Medical Research, PO Box 378, Madang, 511, MP, Papua New Guinea
| | - Bernadine Kasian
- Vector Borne Disease Unit, Papua New Guinea Institute of Medical Research, PO Box 378, Madang, 511, MP, Papua New Guinea
| | - Naomi Sambale
- Vector Borne Disease Unit, Papua New Guinea Institute of Medical Research, PO Box 378, Madang, 511, MP, Papua New Guinea
| | - Peter M Siba
- Vector Borne Disease Unit, Papua New Guinea Institute of Medical Research, PO Box 378, Madang, 511, MP, Papua New Guinea
| | - Stephan Karl
- Vector Borne Disease Unit, Papua New Guinea Institute of Medical Research, PO Box 378, Madang, 511, MP, Papua New Guinea.,Division of Population Health and Immunity, Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia
| | - Alyssa E Barry
- Division of Population Health and Immunity, Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia.,Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia.,School of Medicine, Deakin University, Geelong and Burnet Institute, Melbourne, VIC, Australia
| | - Ingrid Felger
- Medical Parasitology and Infection Biology, Swiss Tropical & Public Health Institute, Socinstrasse 57, 4051, Basel, Switzerland
| | - James W Kazura
- Center for Global Health and Diseases, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH, 44106, USA
| | - Ivo Mueller
- Division of Population Health and Immunity, Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia.,Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia.,Department of Parasites and Insect Vectors, Malaria Parasites and Hosts Unit, Pasteur Institute, 25-28 rue du Docteur-Roux, 75724, Paris Cedex 15, France
| | - Leanne J Robinson
- Vector Borne Disease Unit, Papua New Guinea Institute of Medical Research, PO Box 378, Madang, 511, MP, Papua New Guinea. .,Division of Population Health and Immunity, Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia. .,Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia. .,Disease Elimination Program, Vector-borne Diseases and Tropical Public Health Group, Burnet Institute, 85 Commercial Rd, Melbourne, VIC, 3004, Australia.
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15
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Rodriguez-Rodriguez D, Maraga S, Lorry L, Robinson LJ, Siba PM, Mueller I, Pulford J, Ross A, Hetzel MW. Repeated mosquito net distributions, improved treatment, and trends in malaria cases in sentinel health facilities in Papua New Guinea. Malar J 2019; 18:364. [PMID: 31718659 PMCID: PMC6852945 DOI: 10.1186/s12936-019-2993-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 11/04/2019] [Indexed: 11/16/2022] Open
Abstract
Background Long-lasting insecticidal nets (LLIN), improved diagnosis and artemisinin-based combination therapy (ACT) have reduced malaria prevalence in Papua New Guinea since 2008. Yet, national incidence trends are inconclusive due to confounding effects of the scale-up of rapid diagnostic tests, and inconsistencies in routine reporting. Methods Malaria trends and their association with LLIN and ACT roll-out between 2010 and 2014 in seven sentinel health facilities were analysed. The analysis included 35,329 fever patients. Intervention effects were estimated using regression models. Results Malaria incidence initially ranged from 20 to 115/1000 population; subsequent trends varied by site. Overall, LLIN distributions had a cumulative effect, reducing the number of malaria cases with each round (incidence rate ratio ranging from 0.12 to 0.53 in five sites). No significant reduction was associated with ACT introduction. Plasmodium falciparum remained the dominant parasite in all sentinel health facilities. Resurgence occurred in one site in which a shift to early and outdoor biting of anophelines had previously been documented. Conclusions LLINs, but not ACT, were associated with reductions of malaria cases in a range of settings, but sustainability of the gains appear to depend on local factors. Malaria programmes covering diverse transmission settings such as Papua New Guinea must consider local heterogeneity when choosing interventions and ensure continuous monitoring of trends.
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Affiliation(s)
- Daniela Rodriguez-Rodriguez
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland.,Papua New Guinea Institute of Medical Research, Goroka and Madang, Papua New Guinea
| | - Seri Maraga
- Papua New Guinea Institute of Medical Research, Goroka and Madang, Papua New Guinea
| | - Lina Lorry
- Papua New Guinea Institute of Medical Research, Goroka and Madang, Papua New Guinea
| | - Leanne J Robinson
- Papua New Guinea Institute of Medical Research, Goroka and Madang, Papua New Guinea.,Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Burnet Institute, Melbourne, Australia
| | - Peter M Siba
- Papua New Guinea Institute of Medical Research, Goroka and Madang, Papua New Guinea
| | - Ivo Mueller
- Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Institut Pasteur, Paris, France
| | | | - Amanda Ross
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Manuel W Hetzel
- Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
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16
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Carias LL, Dechavanne S, Nicolete VC, Sreng S, Suon S, Amaratunga C, Fairhurst RM, Dechavanne C, Barnes S, Witkowski B, Popovici J, Roesch C, Chen E, Ferreira MU, Tolia NH, Adams JH, King CL. Identification and Characterization of Functional Human Monoclonal Antibodies to Plasmodium vivax Duffy-Binding Protein. THE JOURNAL OF IMMUNOLOGY 2019; 202:2648-2660. [PMID: 30944159 DOI: 10.4049/jimmunol.1801631] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 02/22/2019] [Indexed: 01/25/2023]
Abstract
Plasmodium vivax invasion of reticulocytes relies on distinct receptor-ligand interactions between the parasite and host erythrocytes. Engagement of the highly polymorphic domain II of the P. vivax Duffy-binding protein (DBPII) with the erythrocyte's Duffy Ag receptor for chemokines (DARC) is essential. Some P. vivax-exposed individuals acquired Abs to DBPII that block DBPII-DARC interaction and inhibit P. vivax reticulocyte invasion, and Ab levels correlate with protection against P. vivax malaria. To better understand the functional characteristics and fine specificity of protective human Abs to DBPII, we sorted single DBPII-specific IgG+ memory B cells from three individuals with high blocking activity to DBPII. We identified 12 DBPII-specific human mAbs from distinct lineages that blocked DBPII-DARC binding. All mAbs were P. vivax strain transcending and targeted known binding motifs of DBPII with DARC. Eleven mAbs competed with each other for binding, indicating recognition of the same or overlapping epitopes. Naturally acquired blocking Abs to DBPII from individuals with high levels residing in different P. vivax-endemic areas worldwide competed with mAbs, suggesting broadly shared recognition sites. We also found that mAbs inhibited P. vivax entry into reticulocytes in vitro. These findings suggest that IgG+ memory B cell activity in individuals with P. vivax strain-transcending Abs to DBPII display a limited clonal response with inhibitory blocking directed against a distinct region of the molecule.
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Affiliation(s)
- Lenore L Carias
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH 44106
| | - Sebastien Dechavanne
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH 44106
| | - Vanessa C Nicolete
- Department of Parasitology, University of Sao Paulo, 05508-000 Sao Paulo, Brazil
| | - Sokunthea Sreng
- National Center for Parasitology, Entomology and Malaria Control, 12101 Phnom Penh, Cambodia
| | - Seila Suon
- National Center for Parasitology, Entomology and Malaria Control, 12101 Phnom Penh, Cambodia
| | - Chanaki Amaratunga
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Rick M Fairhurst
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Celia Dechavanne
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH 44106.,UMR 261-Mother and Child Facing Tropical Infections, French National Research Institute for Development, Paris Descartes University, 75006 Paris, France
| | - Samantha Barnes
- Center for Global Health and Infectious Diseases Research, Department of Global Health, University of South Florida, Tampa, FL 33612
| | - Benoit Witkowski
- Malaria Unit, Pasteur Institute in Cambodia, 12201 Phnom Penh, Cambodia
| | - Jean Popovici
- Malaria Unit, Pasteur Institute in Cambodia, 12201 Phnom Penh, Cambodia
| | - Camille Roesch
- Malaria Unit, Pasteur Institute in Cambodia, 12201 Phnom Penh, Cambodia
| | - Edwin Chen
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110.,Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110
| | - Marcelo U Ferreira
- Department of Parasitology, University of Sao Paulo, 05508-000 Sao Paulo, Brazil
| | - Niraj H Tolia
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110.,Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892; and
| | - John H Adams
- Center for Global Health and Infectious Diseases Research, Department of Global Health, University of South Florida, Tampa, FL 33612
| | - Christopher L King
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH 44106; .,Cleveland VA Medical Center, Cleveland, OH 44106
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17
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Keven JB, Katusele M, Vinit R, Koimbu G, Vincent N, Thomsen EK, Karl S, Reimer LJ, Walker ED. Species abundance, composition, and nocturnal activity of female Anopheles (Diptera: Culicidae) in malaria-endemic villages of Papua New Guinea: assessment with barrier screen sampling. Malar J 2019; 18:96. [PMID: 30909928 PMCID: PMC6434780 DOI: 10.1186/s12936-019-2742-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 03/21/2019] [Indexed: 11/18/2022] Open
Abstract
Background Community composition of Anopheles mosquitoes, and their host-seeking and peridomestic behaviour, are important factors affecting malaria transmission. In this study, barrier screen sampling was used to investigate species composition, abundance, and nocturnal activity of Anopheles populations in villages of Papua New Guinea. Methods Mosquitoes were sampled from 6 pm to 6 am in five villages from 2012 to 2016. The barrier screens were positioned between the village houses and the perimeter of villages where cultivated and wild vegetation (“the bush”) grew thickly. Female Anopheles that rested on either village or bush side of the barrier screens, as they commuted into and out of the villages, were captured. Similarity in species composition among villages was assessed. Mosquitoes captured on village and bush sides of the barrier screens were sorted by feeding status and by hour of collection, and their numbers were compared using negative binomial generalized linear models. Results Females of seven Anopheles species were present in the sample. Species richness ranged from four to six species per village, but relative abundance was highly uneven within and between villages, and community composition was similar for two pairs of villages and highly dissimilar in a fifth. For most Anopheles populations, more unfed than blood-fed mosquitoes were collected from the barrier screens. More blood-fed mosquitoes were found on the side of the barrier screens facing the village and relatively more unfed ones on the bush side, suggesting commuting behaviour of unfed host-seeking females into the villages from nearby bush and commuting of blood-fed females away from villages towards the bush. For most populations, the majority of host-seeking mosquitoes arrived in the village before midnight when people were active and unprotected from the mosquitoes by bed nets. Conclusion The uneven distribution of Anopheles species among villages, with each site dominated by different species, even among nearby villages, emphasizes the importance of vector heterogeneity in local malaria transmission and control. Yet, for most species, nocturnal activity patterns of village entry and host seeking predominantly occurred before midnight indicating common behaviours across species and populations relative to human risk of exposure to Anopheles bites. Electronic supplementary material The online version of this article (10.1186/s12936-019-2742-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- John B Keven
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea. .,Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA.
| | - Michelle Katusele
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Rebecca Vinit
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Gussy Koimbu
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Naomi Vincent
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | | | - Stephan Karl
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea.,Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, Melbourne University, Parkville, VIC, Australia
| | - Lisa J Reimer
- Liverpool School of Tropical Medicine, Liverpool, UK
| | - Edward D Walker
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA
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18
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Pulford J, Saweri OPM, Jeffery C, Siba PM, Mueller I, Hetzel MW. Does test-based prescription of evidence-based treatment for malaria improve treatment seeking and satisfaction? Findings of repeated cross-sectional surveys in Papua New Guinea. BMJ Glob Health 2018; 3:e000915. [PMID: 30498587 PMCID: PMC6254749 DOI: 10.1136/bmjgh-2018-000915] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Revised: 10/01/2018] [Accepted: 10/06/2018] [Indexed: 11/23/2022] Open
Abstract
Introduction The presumptive treatment of febrile illness with antimalarial medication is becoming less common in low-income and middle-income countries as access to reliable diagnostic tests improves. We explore whether the shift towards test-based antimalarial prescription, and the introduction of highly efficacious artemisinin combination therapies (ACTs), reduces critical delays in seeking treatment for febrile illness or increases patient satisfaction. Methods We conducted countrywide repeat, cross-sectional surveys in 118 randomly selected primary healthcare services in Papua New Guinea. The clinical case management of 1765 consecutively presenting febrile patients was observed and exit interviews were completed at discharge. This was done prior to implementation of test-based ACT prescription (2011) and at 12 (2012) and 60 months (2016) postimplementation. We conducted multiple logistic regressions. Treatment response time was dichotomised as <24 hours from symptom onset vs 24+ hours. Satisfaction was dichotomised as a ‘high’ vs ‘low’ rating based on participant response to a visual, 7-point Likert-type scale. Results 62% (322/517) of febrile patients reported seeking treatment within 24 hours of symptom onset in 2011 compared with 53% (230/434) in 2012 and 42% (339/814) in 2016. Adjusted ORs for reporting a treatment response time <24 hours in the postimplementation surveys were 0.77 (95% CI 0.48 to 1.26) and 0.45 (95% CI 0.31 to 0.65), respectively when compared with the preimplementation period. 53% (230/533) of febrile patients reported ‘high’ satisfaction with the service received in 2011 compared with 32% (143/449) in 2012 and 35% (278/803) in 2016. Adjusted ORs for reporting high satisfaction in the postimplementation surveys were 0.52 (95% CI 0.32 to 0.85) and 0.65 (95% CI 0.39 to 1.10), respectively when compared with the preimplementation period. Conclusion Nationwide implementation of test-based ACT prescription in Papua New Guinea has increased the likelihood of critical treatment seeking delays and decreased patient satisfaction with the service received.
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Affiliation(s)
- Justin Pulford
- International Public Health, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Olga P M Saweri
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Caroline Jeffery
- International Public Health, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Peter M Siba
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Ivo Mueller
- Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,University of Melbourne, Melbourne, Australia.,Institut Pasteur, Paris, France
| | - Manuel W Hetzel
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
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19
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Sekihara M, Tachibana SI, Yamauchi M, Yatsushiro S, Tiwara S, Fukuda N, Ikeda M, Mori T, Hirai M, Hombhanje F, Mita T. Lack of significant recovery of chloroquine sensitivity in Plasmodium falciparum parasites following discontinuance of chloroquine use in Papua New Guinea. Malar J 2018; 17:434. [PMID: 30477515 PMCID: PMC6260888 DOI: 10.1186/s12936-018-2585-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Accepted: 11/21/2018] [Indexed: 11/20/2022] Open
Abstract
Background Chloroquine treatment for Plasmodium falciparum has been discontinued in almost all endemic regions due to the spread of resistant isolates. Reversal of chloroquine susceptibility after chloroquine discontinuation has been reported in dozens of endemic regions. However, this phenomenon has been mostly observed in Africa and is not well documented in other malaria endemic regions. To investigate this, an ex vivo study on susceptibility to chloroquine and lumefantrine was conducted during 2016–2018 in Wewak, Papua New Guinea where chloroquine had been removed from the official malaria treatment regimen in 2010. Genotyping of pfcrt and pfmdr1 was also performed. Results In total, 368 patients were enrolled in this study. Average IC50 values for chloroquine were 106.6, 80.5, and 87.6 nM in 2016, 2017, and 2018, respectively. These values were not significantly changed from those obtained in 2002/2003 (108 nM). The majority of parasites harboured a pfcrt K76T the mutation responsible for chloroquine resistance. However, a significant upward trend was observed in the frequency of the K76 (wild) allele from 2.3% in 2016 to 11.7% in 2018 (P = 0.008; Cochran–Armitage trend test). Conclusions Eight years of chloroquine withdrawal has not induced a significant recovery of susceptibility in Papua New Guinea. However, an increasing tendency of parasites harbouring chloroquine-susceptible K76 suggests a possibility of resurgence of chloroquine susceptibility in the future. Electronic supplementary material The online version of this article (10.1186/s12936-018-2585-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Makoto Sekihara
- Department of Tropical Medicine and Parasitology, Juntendo University, Faculty of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Shin-Ichiro Tachibana
- Department of Tropical Medicine and Parasitology, Juntendo University, Faculty of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Masato Yamauchi
- Department of Tropical Medicine and Parasitology, Juntendo University, Faculty of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Shoki Yatsushiro
- Health Technology Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Takamatsu, Japan
| | - Steven Tiwara
- Wewak General Hospital, Wewak, East Sepik Province, Papua New Guinea
| | - Naoyuki Fukuda
- Department of Tropical Medicine and Parasitology, Juntendo University, Faculty of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Mie Ikeda
- Department of Tropical Medicine and Parasitology, Juntendo University, Faculty of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Toshiyuki Mori
- Department of Tropical Medicine and Parasitology, Juntendo University, Faculty of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Makoto Hirai
- Department of Tropical Medicine and Parasitology, Juntendo University, Faculty of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Francis Hombhanje
- Centre for Health Research & Diagnostics, Divine Word University, P.O. Box 483, Madang, Papua New Guinea
| | - Toshihiro Mita
- Department of Tropical Medicine and Parasitology, Juntendo University, Faculty of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan.
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20
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Tavul L, Hetzel MW, Teliki A, Walsh D, Kiniboro B, Rare L, Pulford J, Siba PM, Karl S, Makita L, Robinson L, Kattenberg JH, Laman M, Oswyn G, Mueller I. Efficacy of artemether-lumefantrine and dihydroartemisinin-piperaquine for the treatment of uncomplicated malaria in Papua New Guinea. Malar J 2018; 17:350. [PMID: 30290825 PMCID: PMC6173938 DOI: 10.1186/s12936-018-2494-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 09/27/2018] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND In 2009, the Papua New Guinea (PNG) Department of Health adopted artemether-lumefantrine (AL) and dihydroartemisinin-piperaquine (DHA-PPQ) as the first- and second-line treatments for uncomplicated malaria, respectively. This study was conducted to assess the efficacy of both drugs following adoption of the new policy. METHODS Between June 2012 and September 2014, a therapeutic efficacy study was conducted in East Sepik and Milne Bay Provinces of PNG in accordance with the standard World Health Organization (WHO) protocol for surveillance of anti-malarial drug efficacy. Patients ≥ 6 months of age with microscopy confirmed Plasmodium falciparum or Plasmodium vivax mono-infections were enrolled, treated with AL or DHA-PPQ, and followed up for 42 days. Study endpoints were adequate clinical and parasitological response (ACPR) on days 28 and 42. The in vitro efficacy of anti-malarials and the prevalence of selected molecular markers of resistance were also determined. RESULTS A total of 274 P. falciparum and 70 P. vivax cases were enrolled. The day-42 PCR-corrected ACPR for P. falciparum was 98.1% (104/106) for AL and 100% (135/135) for DHA-PPQ. The day-42 PCR-corrected ACPR for P. vivax was 79.0% (15/19) for AL and 92.3% (36/39) for DHA-PPQ. Day 3 parasite clearance of P. falciparum was 99.2% with AL and 100% with DHA-PPQ. In vitro testing of 96 samples revealed low susceptibility to chloroquine (34% of samples above IC50 threshold) but not to lumefantrine (0%). Molecular markers assessed in a sub-set of the study population indicated high rates of chloroquine resistance in P. falciparum (pfcrt SVMNT: 94.2%, n = 104) and in P. vivax (pvmdr1 Y976F: 64.8%, n = 54). CONCLUSIONS AL and DHA-PPQ were efficacious as first- and second-line treatments for uncomplicated malaria in PNG. Continued in vivo efficacy monitoring is warranted considering the threat of resistance to artemisinin and partner drugs in the region and scale-up of artemisinin-based combination therapy in PNG.
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Affiliation(s)
- Livingstone Tavul
- Papua New Guinea Institute of Medical Research, PO Box 378, Madang, Papua New Guinea.
| | - Manuel W Hetzel
- Swiss Tropical and Public Health Institute, PO Box, 4002, Basel, Switzerland.,University of Basel, Petersplatz 1, 4003, Basel, Switzerland
| | - Albina Teliki
- Papua New Guinea Institute of Medical Research, PO Box 378, Madang, Papua New Guinea
| | - Dorish Walsh
- Papua New Guinea Institute of Medical Research, PO Box 378, Madang, Papua New Guinea
| | - Benson Kiniboro
- Papua New Guinea Institute of Medical Research, PO Box 378, Madang, Papua New Guinea
| | - Lawrence Rare
- Papua New Guinea Institute of Medical Research, PO Box 378, Madang, Papua New Guinea
| | - Justin Pulford
- Papua New Guinea Institute of Medical Research, PO Box 378, Madang, Papua New Guinea.,Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L35QA, UK
| | - Peter M Siba
- Papua New Guinea Institute of Medical Research, PO Box 378, Madang, Papua New Guinea
| | - Stephan Karl
- Papua New Guinea Institute of Medical Research, PO Box 378, Madang, Papua New Guinea.,Infection and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Leo Makita
- National Department of Health, PO Box 807, Waigani, NCD, Papua New Guinea
| | - Leanne Robinson
- Papua New Guinea Institute of Medical Research, PO Box 378, Madang, Papua New Guinea.,Infection and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Johanna H Kattenberg
- Papua New Guinea Institute of Medical Research, PO Box 378, Madang, Papua New Guinea.,Institute of Tropical Medicine in Antwerp, Kronenburgstraat 43, 2000, Antwerp, Belgium
| | - Moses Laman
- Papua New Guinea Institute of Medical Research, PO Box 378, Madang, Papua New Guinea
| | - Gilchrist Oswyn
- Milne Bay Provincial Health Authority, Lock Bag 402, Alotau, Papua New Guinea
| | - Ivo Mueller
- Infection and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Australia.,Institut Pasteur, 25-28, rue du Docteur-Roux, Cedex 15, 75724, Paris, France
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21
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White MT, Walker P, Karl S, Hetzel MW, Freeman T, Waltmann A, Laman M, Robinson LJ, Ghani A, Mueller I. Mathematical modelling of the impact of expanding levels of malaria control interventions on Plasmodium vivax. Nat Commun 2018; 9:3300. [PMID: 30120250 PMCID: PMC6097992 DOI: 10.1038/s41467-018-05860-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 07/23/2018] [Indexed: 01/07/2023] Open
Abstract
Plasmodium vivax poses unique challenges for malaria control and elimination, notably the potential for relapses to maintain transmission in the face of drug-based treatment and vector control strategies. We developed an individual-based mathematical model of P. vivax transmission calibrated to epidemiological data from Papua New Guinea (PNG). In many settings in PNG, increasing bed net coverage is predicted to reduce transmission to less than 0.1% prevalence by light microscopy, however there is substantial risk of rebounds in transmission if interventions are removed prematurely. In several high transmission settings, model simulations predict that combinations of existing interventions are not sufficient to interrupt P. vivax transmission. This analysis highlights the potential options for the future of P. vivax control: maintaining existing public health gains by keeping transmission suppressed through indefinite distribution of interventions; or continued development of strategies based on existing and new interventions to push for further reduction and towards elimination.
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Affiliation(s)
- Michael T White
- Malaria: Parasites and Hosts, Department of Parasites and Insect Vectors, Institut Pasteur, 25-28 Rue du Dr Roux, 75015, Paris, France.
| | - Patrick Walker
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London, Norfolk Place, W2 1PG, UK
| | - Stephan Karl
- Vector-borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang 511, Papua New Guinea
- Division of Population Health and Immunity, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, 3052, Australia
- Department of Medical Biology, Melbourne University, Melbourne, VIC, 3052, Australia
| | - Manuel W Hetzel
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051, Basel, Switzerland
- University of Basel, Petersplatz 1, 4001, Basel, Switzerland
| | - Tim Freeman
- Rotarians Against Malaria, Port Moresby 121, Papua New Guinea
| | - Andreea Waltmann
- Division of Population Health and Immunity, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, 3052, Australia
- Department of Medical Biology, Melbourne University, Melbourne, VIC, 3052, Australia
| | - Moses Laman
- Vector-borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang 511, Papua New Guinea
| | - Leanne J Robinson
- Vector-borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang 511, Papua New Guinea
- Division of Population Health and Immunity, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, 3052, Australia
- Department of Medical Biology, Melbourne University, Melbourne, VIC, 3052, Australia
- Burnet Institute, Melbourne, VIC, 3004, Australia
| | - Azra Ghani
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London, Norfolk Place, W2 1PG, UK
| | - Ivo Mueller
- Malaria: Parasites and Hosts, Department of Parasites and Insect Vectors, Institut Pasteur, 25-28 Rue du Dr Roux, 75015, Paris, France
- Division of Population Health and Immunity, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, 3052, Australia
- Department of Medical Biology, Melbourne University, Melbourne, VIC, 3052, Australia
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22
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Mita T, Hombhanje F, Takahashi N, Sekihara M, Yamauchi M, Tsukahara T, Kaneko A, Endo H, Ohashi J. Rapid selection of sulphadoxine-resistant Plasmodium falciparum and its effect on within-population genetic diversity in Papua New Guinea. Sci Rep 2018; 8:5565. [PMID: 29615786 PMCID: PMC5882878 DOI: 10.1038/s41598-018-23811-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 03/21/2018] [Indexed: 11/18/2022] Open
Abstract
The ability of the human malarial parasite Plasmodium falciparum to adapt to environmental changes depends considerably on its ability to maintain within-population genetic variation. Strong selection, consequent to widespread antimalarial drug usage, occasionally elicits a rapid expansion of drug-resistant isolates, which can act as founders. To investigate whether this phenomenon induces a loss of within-population genetic variation, we performed a population genetic analysis on 302 P. falciparum cases detected during two cross-sectional surveys in 2002/2003, just after the official introduction of sulphadoxine/pyrimethamine as a first-line treatment, and again in 2010/2011, in highly endemic areas in Papua New Guinea. We found that a single-origin sulphadoxine-resistant parasite isolate rapidly increased from 0% in 2002/2003 to 54% in 2010 and 84% in 2011. However, a considerable number of pairs exhibited random associations among 10 neutral microsatellite markers located in various chromosomes, suggesting that outcrossing effectively reduced non-random associations, albeit at a low average multiplicity of infection (1.35–1.52). Within-population genetic diversity was maintained throughout the study period. This indicates that the parasites maintained within-population variation, even after a clonal expansion of drug-resistant parasites. Outcrossing played a role in the preservation of within-population genetic diversity despite low levels of multiplicity of infection.
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Affiliation(s)
- Toshihiro Mita
- Department of Tropical Medicine and Parasitology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo, Tokyo, 113-8421, Japan.
| | - Francis Hombhanje
- Centre for Health Research & Diagnostics, Divine Word University, Nabasa Road, P.O. Box 483, Madang, Papua New Guinea
| | - Nobuyuki Takahashi
- Department of International Affairs and Tropical Medicine, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan
| | - Makoto Sekihara
- Department of Tropical Medicine and Parasitology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo, Tokyo, 113-8421, Japan
| | - Masato Yamauchi
- Department of Tropical Medicine and Parasitology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo, Tokyo, 113-8421, Japan
| | - Takahiro Tsukahara
- Department of International Affairs and Tropical Medicine, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan
| | - Akira Kaneko
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, SE-171 77, Stockholm, Sweden.,Department of Parasitology, Osaka City University Graduate School of Medicine, Asahi-cho 1-4-3, Abeno-ku, Osaka, 545-8585, Japan
| | - Hiroyoshi Endo
- Department of International Affairs and Tropical Medicine, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan
| | - Jun Ohashi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
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23
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Sougoufara S, Thiaw O, Cailleau A, Diagne N, Harry M, Bouganali C, Sembène PM, Doucoure S, Sokhna C. The Impact of Periodic Distribution Campaigns of Long-Lasting Insecticidal-Treated Bed Nets on Malaria Vector Dynamics and Human Exposure in Dielmo, Senegal. Am J Trop Med Hyg 2018; 98:1343-1352. [PMID: 29557325 DOI: 10.4269/ajtmh.17-0009] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The implementation of long-lasting insecticidal-treated bed nets (LLINs) has contributed to halving the mortality rate due to malaria since 2000 in sub-Saharan Africa. These tools are highly effective against indoor-feeding malaria vectors. Thus, to achieve the World Health Assembly's new target to reduce the burden of malaria over the next 15 years by 90%, it is necessary to understand how the spatiotemporal dynamics of malaria vectors and human exposure to bites is modified in the context of scaling up global efforts to control malaria transmission. This study was conducted in Dielmo, a Senegalese village, after the introduction of LLINs and two rounds of LLINs renewals. Data analysis showed that implementation of LLINs correlated with a significant decrease in the biting densities of the main malaria vectors, Anopheles gambiae s.l. and Anopheles funestus, reducing malaria transmission. Other environment factors likely contributed to the decrease in An. funestus, but this trend was enhanced with the introduction of LLINs. The bulk of bites occurred during sleeping hours, but the residual vector populations of An. gambiae s.l. and An. funestus had an increased propensity to bite outdoors, so a risk of infectious bites remained for LLINs users. These results highlight the need to increase the level and correct use of LLINs and to combine this intervention with complementary control measures against residual exposure, such as spatial repellents and larval source management, to achieve the goal of eliminating malaria transmission.
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Affiliation(s)
- Seynabou Sougoufara
- Aix Marseille University, Institut de Recherche pour le Développement (IDR) (Dakar, Marseille, Papeete), AP-HM, Institut Hospitalo-Universitaire-Méditerranée Infection, UMR Vecteurs-Infections Tropicales et Méditerranéennes (VITROME), Marseille, France.,Département de Biologie Animale, Faculté des Sciences et Techniques, Université Cheikh Anta Diop de Dakar, Dakar Fann, Sénégal
| | - Omar Thiaw
- Aix Marseille University, Institut de Recherche pour le Développement (IDR) (Dakar, Marseille, Papeete), AP-HM, Institut Hospitalo-Universitaire-Méditerranée Infection, UMR Vecteurs-Infections Tropicales et Méditerranéennes (VITROME), Marseille, France
| | - Aurélie Cailleau
- Centre Suisse de Recherches Scientifiques en Cote d'Ivoire (CSRS), Yopougon, Abidjan, Côte d'Ivoire.,Unité d'Entomologie Médicale (UME), Institut Pasteur Dakar, Dakar, Sénégal
| | - Nafissatou Diagne
- Aix Marseille University, Institut de Recherche pour le Développement (IDR) (Dakar, Marseille, Papeete), AP-HM, Institut Hospitalo-Universitaire-Méditerranée Infection, UMR Vecteurs-Infections Tropicales et Méditerranéennes (VITROME), Marseille, France
| | - Myriam Harry
- UMR Évolution, Génomes, Comportement, Écologie (EGCE) Centre National de la Recherche Scientifique (CNRS), IRD-University Paris-Sud, IDEEV, University Paris-Saclay, Gif-sur-Yvette Cedex, France
| | - Charles Bouganali
- Aix Marseille University, Institut de Recherche pour le Développement (IDR) (Dakar, Marseille, Papeete), AP-HM, Institut Hospitalo-Universitaire-Méditerranée Infection, UMR Vecteurs-Infections Tropicales et Méditerranéennes (VITROME), Marseille, France
| | - Pape M Sembène
- Département de Biologie Animale, Faculté des Sciences et Techniques, Université Cheikh Anta Diop de Dakar, Dakar Fann, Sénégal
| | - Souleymane Doucoure
- Aix Marseille University, Institut de Recherche pour le Développement (IDR) (Dakar, Marseille, Papeete), AP-HM, Institut Hospitalo-Universitaire-Méditerranée Infection, UMR Vecteurs-Infections Tropicales et Méditerranéennes (VITROME), Marseille, France
| | - Cheikh Sokhna
- Aix Marseille University, Institut de Recherche pour le Développement (IDR) (Dakar, Marseille, Papeete), AP-HM, Institut Hospitalo-Universitaire-Méditerranée Infection, UMR Vecteurs-Infections Tropicales et Méditerranéennes (VITROME), Marseille, France
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Increasingly inbred and fragmented populations of Plasmodium vivax associated with the eastward decline in malaria transmission across the Southwest Pacific. PLoS Negl Trop Dis 2018; 12:e0006146. [PMID: 29373596 PMCID: PMC5802943 DOI: 10.1371/journal.pntd.0006146] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 02/07/2018] [Accepted: 12/01/2017] [Indexed: 01/17/2023] Open
Abstract
The human malaria parasite Plasmodium vivax is more resistant to malaria control strategies than Plasmodium falciparum, and maintains high genetic diversity even when transmission is low. To investigate whether declining P. vivax transmission leads to increasing population structure that would facilitate elimination, we genotyped samples from across the Southwest Pacific region, which experiences an eastward decline in malaria transmission, as well as samples from two time points at one site (Tetere, Solomon Islands) during intensified malaria control. Analysis of 887 P. vivax microsatellite haplotypes from hyperendemic Papua New Guinea (PNG, n = 443), meso-hyperendemic Solomon Islands (n = 420), and hypoendemic Vanuatu (n = 24) revealed increasing population structure and multilocus linkage disequilibrium yet a modest decline in diversity as transmission decreases over space and time. In Solomon Islands, which has had sustained control efforts for 20 years, and Vanuatu, which has experienced sustained low transmission for many years, significant population structure was observed at different spatial scales. We conclude that control efforts will eventually impact P. vivax population structure and with sustained pressure, populations may eventually fragment into a limited number of clustered foci that could be targeted for elimination. Plasmodium vivax is a major human malaria parasite, common in endemic areas outside sub-Saharan Africa, and more difficult to control than other malaria parasite species. The distinct lifecycle biology of P. vivax is thought to contribute to its more stable and efficient transmission allowing the maintenance of high diversity and potentially, gene flow. Independent studies are therefore needed to understand how P. vivax populations respond to changing transmission levels, in order to inform malaria control and elimination efforts. Here we have determined parasite population genetic structure in three countries of the Southwest Pacific, an island chain with a natural west to east decline in transmission intensity (Papua New Guinea > Solomon Islands > Vanuatu). With declining transmission, P. vivax populations experience only a modest decline in diversity but a significant increase in multilocus linkage disequilibrium and population structure, indicating that parasite populations become more inbred and begin to fragment into clustered foci. Analysis of two time points in one study area (Tetere, Solomon Islands) also show similar changes in association with intensifying malaria control. The results indicate that with long term sustained malaria control P. vivax populations will eventually fracture into population clusters that could be targeted for elimination.
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25
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Koimbu G, Czeher C, Katusele M, Sakur M, Kilepak L, Tandrapah A, Hetzel MW, Pulford J, Robinson L, Karl S. Status of Insecticide Resistance in Papua New Guinea: An Update from Nation-Wide Monitoring of Anopheles Mosquitoes. Am J Trop Med Hyg 2018; 98:162-165. [PMID: 29141726 DOI: 10.4269/ajtmh.17-0454] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Insecticide resistance (IR) monitoring is an important component of vector-borne disease control. The last assessment of IR in Papua New Guinea (PNG) was conducted in 2010. Since then, vector populations have been exposed to higher levels of pyrethroids with the continued nation-wide distribution of insecticide-treated nets. Here, we provide an update on phenotypic IR in four highly malaria-endemic areas of PNG. IR against deltamethrin, lambda-cyhalothrin, and dichlorodiphenyltrichloroethane was assessed using World Health Organization bioassays. A total of 108 bioassays for each insecticide were conducted screening 2,290 adult female anopheline mosquitoes. No phenotypic resistance was observed. Bioassay parameters agreed well with those observed in other studies that used the same assays and insecticides. These results indicate that the three tested insecticides are still universally effective in PNG. Continued IR monitoring (every 1-2 years) in PNG is recommended to detect reduced susceptibility early and adjust guidelines to prevent widespread resistance.
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Affiliation(s)
- Gussy Koimbu
- Papua New Guinea Institute of Medical Research, Madang, Madang Province, Papua New Guinea
| | - Cyrille Czeher
- Papua New Guinea Institute of Medical Research, Madang, Madang Province, Papua New Guinea
| | - Michelle Katusele
- Papua New Guinea Institute of Medical Research, Madang, Madang Province, Papua New Guinea
| | - Muker Sakur
- Papua New Guinea Institute of Medical Research, Madang, Madang Province, Papua New Guinea
| | - Lemen Kilepak
- Papua New Guinea Institute of Medical Research, Madang, Madang Province, Papua New Guinea
| | - Anthony Tandrapah
- Papua New Guinea Institute of Medical Research, Madang, Madang Province, Papua New Guinea
| | - Manuel W Hetzel
- University of Basel, Basel, Switzerland.,Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Justin Pulford
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
| | - Leanne Robinson
- University of Melbourne, Melbourne, Australia.,Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria, Australia.,Papua New Guinea Institute of Medical Research, Madang, Madang Province, Papua New Guinea
| | - Stephan Karl
- Papua New Guinea Institute of Medical Research, Madang, Madang Province, Papua New Guinea.,Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria, Australia.,University of Melbourne, Melbourne, Australia
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26
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Nationwide genetic surveillance of Plasmodium vivax in Papua New Guinea reveals heterogeneous transmission dynamics and routes of migration amongst subdivided populations. INFECTION GENETICS AND EVOLUTION 2017; 58:83-95. [PMID: 29313805 DOI: 10.1016/j.meegid.2017.11.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 10/27/2017] [Accepted: 11/30/2017] [Indexed: 11/20/2022]
Abstract
The Asia Pacific Leaders in Malaria Alliance (APLMA) have committed to eliminate malaria from the region by 2030. Papua New Guinea (PNG) has the highest malaria burden in the Asia-Pacific region but with the intensification of control efforts since 2005, transmission has been dramatically reduced and Plasmodium vivax is now the dominant malaria infection in some parts of the country. To gain a better understanding of the transmission dynamics and migration patterns of P. vivax in PNG, here we investigate population structure in eight geographically and ecologically distinct regions of the country. A total of 219 P. vivax isolates (16-30 per population) were successfully haplotyped using 10 microsatellite markers. A wide range of genetic diversity (He=0.37-0.87, Rs=3.60-7.58) and significant multilocus linkage disequilibrium (LD) was observed in six of the eight populations (IAS=0.08-0.15 p-value<0.05) reflecting a spectrum of transmission intensities across the country. Genetic differentiation between regions was evident (Jost's D=0.07-0.72), with increasing divergence of populations with geographic distance. Overall, P. vivax isolates clustered into three major genetic populations subdividing the Mainland lowland and coastal regions, the Islands and the Highlands. P. vivax gene flow follows major human migration routes, and there was higher gene flow amongst Mainland parasite populations than among Island populations. The Central Province (samples collected in villages close to the capital city, Port Moresby), acts as a sink for imported infections from the three major endemic areas. These insights into P. vivax transmission dynamics and population networks will inform targeted strategies to contain malaria infections and to prevent the spread of drug resistance in PNG.
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27
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Lufele E, Umbers A, Ordi J, Ome-Kaius M, Wangnapi R, Unger H, Tarongka N, Siba P, Mueller I, Robinson L, Rogerson S. Risk factors and pregnancy outcomes associated with placental malaria in a prospective cohort of Papua New Guinean women. Malar J 2017; 16:427. [PMID: 29065884 PMCID: PMC5655867 DOI: 10.1186/s12936-017-2077-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 10/19/2017] [Indexed: 12/19/2022] Open
Abstract
Background Plasmodium falciparum in pregnancy results in substantial poor health outcomes for both mother and child, particularly in young, primigravid mothers who are at greatest risk of placental malaria (PM) infection. Complications of PM include maternal anaemia, low birth weight and preterm delivery, which contribute to maternal and infant morbidity and mortality in coastal Papua New Guinea (PNG). Methods Placental biopsies were examined from 1451 pregnant women who were enrolled in a malaria prevention study at 14–26 weeks gestation. Clinical and demographic information were collected at first antenatal clinic visits and women were followed until delivery. Placental biopsies were collected and examined for PM using histology. The presence of infected erythrocytes and/or the malaria pigment in monocytes or fibrin was used to determine the type of placental infection. Results Of 1451 placentas examined, PM infection was detected in 269 (18.5%), of which 54 (3.7%) were acute, 55 (3.8%) chronic, and 160 (11.0%) were past infections. Risk factors for PM included residing in rural areas (adjusted odds ratio (AOR) 3.65, 95% CI 1.76–7.51; p ≤ 0.001), being primigravid (AOR 2.45, 95% CI 1.26–4.77; p = 0.008) and having symptomatic malaria during pregnancy (AOR 2.05, 95% CI 1.16–3.62; p = 0.013). After adjustment for covariates, compared to uninfected women, acute infections (AOR 1.97, 95% CI 0.98–3.95; p = 0.056) were associated with low birth weight babies, whereas chronic infections were associated with preterm delivery (AOR 3.92, 95% CI 1.64–9.38; p = 0.002) and anaemia (AOR 2.22, 95% CI 1.02–4.84; p = 0.045). Conclusions Among pregnant PNG women receiving at least one dose of intermittent preventive treatment in pregnancy and using insecticide-treated bed nets, active PM infections were associated with adverse outcomes. Improved malaria prevention is required to optimize pregnancy outcomes.
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Affiliation(s)
- Elvin Lufele
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Alexandra Umbers
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea.,Department of Medicine and Radiology, Peter Doherty Institute, University of Melbourne, Melbourne, VIC, Australia
| | - Jaume Ordi
- Barcelona Centre for International Health Research (CRESIB), Barcelona, Spain
| | - Maria Ome-Kaius
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Regina Wangnapi
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Holger Unger
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea.,Department of Medicine and Radiology, Peter Doherty Institute, University of Melbourne, Melbourne, VIC, Australia
| | - Nandao Tarongka
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Peter Siba
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Ivo Mueller
- Population Health and Immunity Division, Walter and Eliza Hall Institute, Melbourne, VIC, Australia.,Institute Pasteur, Paris, France
| | - Leanne Robinson
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea.,Population Health and Immunity Division, Walter and Eliza Hall Institute, Melbourne, VIC, Australia.,Burnet Institute, Melbourne, VIC, Australia
| | - Stephen Rogerson
- Department of Medicine and Radiology, Peter Doherty Institute, University of Melbourne, Melbourne, VIC, Australia.
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28
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Hetzel MW, Pulford J, Ura Y, Jamea-Maiasa S, Tandrapah A, Tarongka N, Lorry L, Robinson LJ, Lilley K, Makita L, Siba PM, Mueller I. Insecticide-treated nets and malaria prevalence, Papua New Guinea, 2008-2014. Bull World Health Organ 2017; 95:695-705B. [PMID: 29147042 PMCID: PMC5689189 DOI: 10.2471/blt.16.189902] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 08/08/2017] [Accepted: 08/09/2017] [Indexed: 12/21/2022] Open
Abstract
Objective To investigate changes in malaria prevalence in Papua New Guinea after the distribution of long-lasting Insecticide-treated nets, starting in 2004, and the introduction of artemisinin-based combination therapy in 2011. Methods Two malaria surveys were conducted in 2010–2011 and 2013–2014. They included 77 and 92 randomly selected villages, respectively. In each village, all members of 30 randomly selected households gave blood samples and were assessed for malaria infection by light microscopy. In addition, data were obtained from a malaria survey performed in 2008–2009. Results The prevalence of malaria below 1600 m in altitude decreased from 11.1% (95% confidence interval, CI: 8.5–14.3) in 2008–2009 to 5.1% (95% CI 3.6–7.4) in 2010–2011 and 0.9% (95% CI 0.6–1.5) in 2013–2014. Prevalence decreased with altitude. Plasmodium falciparum was more common than P. vivax overall, but not everywhere, and initially the prevalence of P. vivax infection decreased more slowly than P. falciparum infection. Malaria infections were clustered in households. In contrast to findings in 2008–2009, no significant association between net use and prevalence was found in the later two surveys. The prevalence of both fever and splenomegaly also decreased but their association with malaria infection became stronger. Conclusion Large-scale insecticide-treated net distribution was associated with an unprecedented decline in malaria prevalence throughout Papua New Guinea, including epidemic-prone highland areas. The decline was accompanied by broader health benefits, such as decreased morbidity. Better clinical management of nonmalarial fever and research into residual malaria transmission are required.
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Affiliation(s)
- Manuel W Hetzel
- Swiss Tropical and Public Health Institute, Socinstrasse 57, Basel, 4002, Switzerland
| | - Justin Pulford
- International Public Health, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Yangta Ura
- Papua New Guinea Institute of Medical Research, Goroka and Madang, Papua New Guinea
| | - Sharon Jamea-Maiasa
- Papua New Guinea Institute of Medical Research, Goroka and Madang, Papua New Guinea
| | - Anthony Tandrapah
- Papua New Guinea Institute of Medical Research, Goroka and Madang, Papua New Guinea
| | - Nandao Tarongka
- Deceased, formerly, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Lina Lorry
- Papua New Guinea Institute of Medical Research, Goroka and Madang, Papua New Guinea
| | - Leanne J Robinson
- Papua New Guinea Institute of Medical Research, Goroka and Madang, Papua New Guinea
| | - Ken Lilley
- Australian Army Malaria Institute, Enoggera, Australia
| | - Leo Makita
- National Department of Health, Waigani, Papua New Guinea
| | - Peter M Siba
- Papua New Guinea Institute of Medical Research, Goroka and Madang, Papua New Guinea
| | - Ivo Mueller
- Division of Population Health and Immunity, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
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29
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Sesay SSS, Giorgi E, Diggle PJ, Schellenberg D, Lalloo DG, Terlouw DJ. Surveillance in easy to access population subgroups as a tool for evaluating malaria control progress: A systematic review. PLoS One 2017; 12:e0183330. [PMID: 28813522 PMCID: PMC5558981 DOI: 10.1371/journal.pone.0183330] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 08/02/2017] [Indexed: 11/29/2022] Open
Abstract
Background The need for surveillance systems generating targeted, data-driven, responsive control efforts to accelerate and sustain malaria transmission reduction has been emphasized by programme managers, policy makers and scientists. Surveillance using easy-to-access population subgroups (EAGs) may result in considerable cost saving compared to household surveys as the identification and selection of individuals to be surveyed is simplified, fewer personnel are needed, and logistics are simpler. We reviewed available literature on the validation of estimates of key indicators of malaria control progress derived from EAGs, and describe the options to deal with the context specific bias that may occur. Methods A literature search was conducted of all documents reporting validation of estimates of malaria control indicators from EAG surveys before the 31st of December 2016. Additional records were identified through cross-reference from selected records, other applicable policy documents and grey literature. After removal of duplicates, 13, 180 abstracts were evaluated and 2,653 eligible abstracts were identified mentioning surveillance in EAGs, of which 29 full text articles were selected for detailed review. The nine articles selected for systematic review compared estimates from health facility and school surveys with those of a contemporaneous sample of the same population in the same geographic area. Results Review of the available literature on EAGs suitable for surveillance of malaria control progress revealed that little effort has been made to explore the potential approach and settings for use of EAGs; and that there was wide variation in the precision of estimates of control progress between and within studies, particularly for estimates of control intervention coverage. Only one of the studies evaluated the geospatial representativeness of EAG samples, or carried out geospatial analyses to assess or control for lack of geospatial representativeness. Two studies attempted to measure the degree of bias or improve the precision of estimates by controlling for bias in a multivariate analysis; and this was only successful in one study. The observed variability in accuracy of estimates is likely to be caused by selection and/or information bias due to the inherent nature of EAGs. The reviewed studies provided insight into the design and analytical approaches that could be used to limit bias. Conclusion The utility EAGs for routine surveillance of progress in malaria control at the district or sub-district programmatic level will be driven by several factors including whether serial point estimates to measure transmission reduction or more precise geospatial distribution to track ‘hot-spots’ is required, the acceptable degree of precision, the target population, and the resources available for surveillance. The opportunities offered by novel geostatistical analyses and hybrid sampling frames to overcome bias justify a renewed exploration of use of EAGs for malaria monitoring and evaluation.
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Affiliation(s)
- Sanie S. S. Sesay
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- * E-mail:
| | - Emanuele Giorgi
- Medical School, Lancaster University, Lancaster, United Kingdom
- Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
| | - Peter J. Diggle
- Medical School, Lancaster University, Lancaster, United Kingdom
- Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
| | | | - David G. Lalloo
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Dianne J. Terlouw
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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30
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Thomsen EK, Koimbu G, Pulford J, Jamea-Maiasa S, Ura Y, Keven JB, Siba PM, Mueller I, Hetzel MW, Reimer LJ. Mosquito Behavior Change After Distribution of Bednets Results in Decreased Protection Against Malaria Exposure. J Infect Dis 2017; 215:790-797. [PMID: 28007921 PMCID: PMC5388271 DOI: 10.1093/infdis/jiw615] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 12/07/2016] [Indexed: 11/21/2022] Open
Abstract
Background. Behavioral resilience in mosquitoes poses a significant challenge to mosquito control. Although behavior changes in anopheline vectors have been reported over the last decade, there are no empirical data to suggest they compromise the efficacy of vector control in reducing malaria transmission. Methods. In this study, we quantified human exposure to both bites and infective bites of a major malaria vector in Papua New Guinea over the course of 4 years surrounding nationwide bednet distribution. We also quantified malaria infection prevalence in the human population during the same time period. Results. We observed a shift in mosquito biting to earlier hours of the evening, before individuals are indoors and protected by bednets, followed by a return to preintervention biting rates. As a result, net users and non–net users experienced higher levels of transmission than before the intervention. The personal protection provided by a bednet decreased over the study period and was lowest in the adult population, who may be an important reservoir for transmission. Malaria prevalence decreased in only 1 of 3 study villages after the distribution. Discussion. This study highlights the necessity of validating and deploying vector control measures targeting outdoor exposure to control and eliminate malaria.
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Affiliation(s)
| | - Gussy Koimbu
- Papua New Guinea Institute of Medical Research, Vector Borne Diseases Unit, Madang, 511, Madang, Papua New Guinea
| | | | | | - Yangta Ura
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - John B Keven
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA
| | - Peter M Siba
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Ivo Mueller
- Walter and Eliza Hall Institute, Parkville, Victoria, Australia
| | - Manuel W Hetzel
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Switzerland
| | - Lisa J Reimer
- Liverpool School of Tropical Medicine, United Kingdom
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31
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Fola AA, Harrison GLA, Hazairin MH, Barnadas C, Hetzel MW, Iga J, Siba PM, Mueller I, Barry AE. Higher Complexity of Infection and Genetic Diversity of Plasmodium vivax Than Plasmodium falciparum Across All Malaria Transmission Zones of Papua New Guinea. Am J Trop Med Hyg 2017; 96:630-641. [PMID: 28070005 DOI: 10.4269/ajtmh.16-0716] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Plasmodium falciparum and Plasmodium vivax have varying transmission dynamics that are informed by molecular epidemiology. This study aimed to determine the complexity of infection and genetic diversity of P. vivax and P. falciparum throughout Papua New Guinea (PNG) to evaluate transmission dynamics across the country. In 2008-2009, a nationwide malaria indicator survey collected 8,936 samples from all 16 endemic provinces of PNG. Of these, 892 positive P. vivax samples were genotyped at PvMS16 and PvmspF3, and 758 positive P. falciparum samples were genotyped at Pfmsp2. The data were analyzed for multiplicity of infection (MOI) and genetic diversity. Overall, P. vivax had higher polyclonality (71%) and mean MOI (2.32) than P. falciparum (20%, 1.39). These measures were significantly associated with prevalence for P. falciparum but not for P. vivax. The genetic diversity of P. vivax (PvMS16: expected heterozygosity = 0.95, 0.85-0.98; PvMsp1F3: 0.78, 0.66-0.89) was higher and less variable than that of P. falciparum (Pfmsp2: 0.89, 0.65-0.97). Significant associations of MOI with allelic richness (rho = 0.69, P = 0.009) and expected heterozygosity (rho = 0.87, P < 0.001) were observed for P. falciparum. Conversely, genetic diversity was not correlated with polyclonality nor mean MOI for P. vivax. The results demonstrate higher complexity of infection and genetic diversity of P. vivax across the country. Although P. falciparum shows a strong association of these parameters with prevalence, a lack of association was observed for P. vivax and is consistent with higher potential for outcrossing of this species.
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Affiliation(s)
- Abebe A Fola
- Department of Medical Biology, University of Melbourne, Parkville, Australia.,Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - G L Abby Harrison
- Department of Medical Biology, University of Melbourne, Parkville, Australia.,Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Mita Hapsari Hazairin
- Department of Epidemiology and Preventative Medicine, Monash University, Clayton, Australia.,Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Céline Barnadas
- Statens Serum Institut, Copenhagen, Denmark.,European Public Health Microbiology (EUPHEM) Training Programme, European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden.,Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Manuel W Hetzel
- University of Basel, Basel, Switzerland.,Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Jonah Iga
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Peter M Siba
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Ivo Mueller
- Institut Pasteur, Paris, France.,Department of Medical Biology, University of Melbourne, Parkville, Australia.,Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Alyssa E Barry
- Department of Medical Biology, University of Melbourne, Parkville, Australia.,Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
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Keven JB, Reimer L, Katusele M, Koimbu G, Vinit R, Vincent N, Thomsen E, Foran DR, Zimmerman PA, Walker ED. Plasticity of host selection by malaria vectors of Papua New Guinea. Parasit Vectors 2017; 10:95. [PMID: 28222769 PMCID: PMC5320767 DOI: 10.1186/s13071-017-2038-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 02/15/2017] [Indexed: 11/20/2022] Open
Abstract
Background Host selection is an important determinant of vectorial capacity because malaria transmission increases when mosquitoes feed more on humans than non-humans. Host selection also affects the outcome of long-lasting insecticidal nets (LLIN). Despite the recent nationwide implementation of LLIN-based malaria control program in Papua New Guinea (PNG), little is known about the host selection of the local Anopheles vectors. This study investigated the host selection of Anopheles vectors in PNG. Methods Blood-engorged mosquitoes were sampled using the barrier screen method and blood meals analyzed for vertebrate host source with PCR-amplification of the mitochondrial cytochrome b gene. Abundance of common hosts was estimated in surveys. The test of homogeneity of proportions and the Manly resource selection ratio were used to determine if hosts were selected in proportion to their abundance. Results Two thousand four hundred and forty blood fed Anopheles females of seven species were sampled from five villages in Madang, PNG. Of 2,142 samples tested, 2,061 (96.2%) yielded a definitive host source; all were human, pig, or dog. Hosts were not selected in proportion to their abundance, but rather were under-selected or over-selected by the mosquitoes. Four species, Anopheles farauti (sensu stricto) (s.s.), Anopheles punctulatus (s.s.), Anopheles farauti no. 4 and Anopheles longirostris, over-selected humans in villages with low LLIN usage, but over-selected pigs in villages with high LLIN usage. Anopheles koliensis consistently over-selected humans despite high LLIN usage, and Anopheles bancroftii over-selected pigs. Conclusions The plasticity of host selection of an Anopheles species depends on its opportunistic, anthropophilic or zoophilic behavior, and on the extent of host availability and LLIN usage where the mosquitoes forage for hosts. The high anthropophily of An. koliensis increases the likelihood of contacting the LLIN inside houses. This allows its population size to be reduced to levels insufficient to support transmission. In contrast, by feeding on alternative hosts the likelihood of the opportunistic species to contact LLIN is lower, making them difficult to control. By maintaining high population size, the proportion that feed on humans outdoors can sustain residual transmission despite high LLIN usage in the village. Electronic supplementary material The online version of this article (doi:10.1186/s13071-017-2038-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- John B Keven
- Papua New Guinea Institute of Medical Research, Vector Borne Diseases Unit, Madang, 511, Madang, Papua New Guinea. .,Department of Microbiology and Molecular Genetics, Michigan State University, 48824, East Lansing, MI, USA.
| | - Lisa Reimer
- Liverpool School of Tropical Medicine and Hygiene, Liverpool, UK
| | - Michelle Katusele
- Papua New Guinea Institute of Medical Research, Vector Borne Diseases Unit, Madang, 511, Madang, Papua New Guinea
| | - Gussy Koimbu
- Papua New Guinea Institute of Medical Research, Vector Borne Diseases Unit, Madang, 511, Madang, Papua New Guinea
| | - Rebecca Vinit
- Papua New Guinea Institute of Medical Research, Vector Borne Diseases Unit, Madang, 511, Madang, Papua New Guinea.,Department of Entomology, Michigan State University, 48824, East Lansing, MI, USA
| | - Naomi Vincent
- Papua New Guinea Institute of Medical Research, Vector Borne Diseases Unit, Madang, 511, Madang, Papua New Guinea
| | - Edward Thomsen
- Liverpool School of Tropical Medicine and Hygiene, Liverpool, UK
| | - David R Foran
- School of Criminal Justice and Department of Integrative Biology, Michigan State University, 48824, East Lansing, MI, USA
| | - Peter A Zimmerman
- Center for Global Health and Diseases, Case Western Reserve University, 44106, Cleveland, OH, USA
| | - Edward D Walker
- Department of Microbiology and Molecular Genetics, Michigan State University, 48824, East Lansing, MI, USA.,Department of Entomology, Michigan State University, 48824, East Lansing, MI, USA
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Kweka EJ. Roles and challenges of construction firms and public health entomologists in ending indoor malaria transmission in African setting. Malar J 2016; 15:554. [PMID: 27842588 PMCID: PMC5109782 DOI: 10.1186/s12936-016-1607-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 11/08/2016] [Indexed: 11/20/2022] Open
Abstract
Indoor malaria transmission reduction across sub-Saharan Africa has been attained through implementation of long-lasting insecticidal nets and indoor residual spray interventions with small-scale larval source management. Improvement of house structures in sub-Saharan Africa can lead to zero indoor malaria transmission with evidence from West Africa, East Africa and Middle East countries. Residual malaria transmission cannot be targeted well with LLINs and IRS alone, but with incorporation of house structures modifications it may be possible.
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Affiliation(s)
- Eliningaya J Kweka
- Division of Livestock and Human Diseases Vector Control, Tropical Pesticides Research Institute, P.O. Box 3024, Arusha, Tanzania. .,Department of Medical Parasitology and Entomology, Catholic University of Health and Allied Sciences, P.O. Box 1464, Mwanza, Tanzania.
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