Last data update: May 13, 2024. (Total: 46773 publications since 2009)
Records 1-9 (of 9 Records) |
Query Trace: Burkot TR[original query] |
---|
Performance of a fully-automated system on a WHO malaria microscopy evaluation slide set.
Horning MP , Delahunt CB , Bachman CM , Luchavez J , Luna C , Hu L , Jaiswal MS , Thompson CM , Kulhare S , Janko S , Wilson BK , Ostbye T , Mehanian M , Gebrehiwot R , Yun G , Bell D , Proux S , Carter JY , Oyibo W , Gamboa D , Dhorda M , Vongpromek R , Chiodini PL , Ogutu B , Long EG , Tun K , Burkot TR , Lilley K , Mehanian C . Malar J 2021 20 (1) 110 BACKGROUND: Manual microscopy remains a widely-used tool for malaria diagnosis and clinical studies, but it has inconsistent quality in the field due to variability in training and field practices. Automated diagnostic systems based on machine learning hold promise to improve quality and reproducibility of field microscopy. The World Health Organization (WHO) has designed a 55-slide set (WHO 55) for their External Competence Assessment of Malaria Microscopists (ECAMM) programme, which can also serve as a valuable benchmark for automated systems. The performance of a fully-automated malaria diagnostic system, EasyScan GO, on a WHO 55 slide set was evaluated. METHODS: The WHO 55 slide set is designed to evaluate microscopist competence in three areas of malaria diagnosis using Giemsa-stained blood films, focused on crucial field needs: malaria parasite detection, malaria parasite species identification (ID), and malaria parasite quantitation. The EasyScan GO is a fully-automated system that combines scanning of Giemsa-stained blood films with assessment algorithms to deliver malaria diagnoses. This system was tested on a WHO 55 slide set. RESULTS: The EasyScan GO achieved 94.3 % detection accuracy, 82.9 % species ID accuracy, and 50 % quantitation accuracy, corresponding to WHO microscopy competence Levels 1, 2, and 1, respectively. This is, to our knowledge, the best performance of a fully-automated system on a WHO 55 set. CONCLUSIONS: EasyScan GO's expert ratings in detection and quantitation on the WHO 55 slide set point towards its potential value in drug efficacy use-cases, as well as in some case management situations with less stringent species ID needs. Improved runtime may enable use in general case management settings. |
Comparative evaluation of anopheline sampling methods in three localities in Indonesia
St Laurent B , Sukowati S , Burton TA , Bretz D , Zio M , Firman S , Sumardi , Sudibyo H , Safitri A , Suwito , Asih PB , Kosasih S , Shinta , Hawley WA , Burkot TR , Collins FH , Syafruddin D , Lobo NF . Malar J 2018 17 (1) 13 BACKGROUND: The effectiveness of vector control efforts can vary based on the interventions used and local mosquito behaviour and adaptability. In many settings, biting patterns of Anopheles mosquitoes can shift in response to interventions targeting indoor-biting mosquitoes, often resulting in higher proportions of mosquitoes feeding outside or at times when people are not protected. These behaviourally resistant mosquitoes have been shown to sustain residual malaria transmission and limit control efforts. Therefore, it is important to accurately sample mosquitoes to understand their behaviour. METHODS: A variety of traps were evaluated in three geographically diverse sites in malaria-endemic Indonesia to investigate local mosquito feeding behaviour and determine effective traps for surveillance. RESULTS: Eight traps were evaluated in three sites: Canti village, Lampung, Kaliharjo village, Purworejo, and Saketa village, Halmahera, Indonesia, including the gold standard human landing collection (HLC) and a variety of traps targeting host-seeking and resting mosquitoes both indoors and outdoors. Trapping, using indoor and outdoor HLC, the Ifakara tent trap C, goat and human-occupied tents, resting pots and boxes, and CDC miniature light traps was conducted for 16 nights in two sites and 8 nights in a third site, using a Latin square design. Trap efficacy varied by site, with outdoor HLC yielding the highest catch rates in Canti and Kaliharjo and a goat-baited tent trap proving most effective in Saketa. In Canti village, anthropophilic Anopheles sundaicus were caught indoors and outdoors using HLCs, peaking in the early morning. In Kaliharjo, a variety of mosquitoes were caught, mostly outdoors throughout the night. HLC was ineffective in Saketa, the only site where a goat-baited tent trap was tested. This trap was effective in catching zoophilic vectors outdoors before midnight. CONCLUSIONS: Different trapping methods were suitable for different species, likely reflecting differences in behaviour among species. The three villages, each located on a different island in the Indonesian archipelago, contained mosquito populations with unique behaviours. These data suggest that the effectiveness of specific vector monitoring and control measures may vary by location. |
Host attraction and biting behaviour of Anopheles mosquitoes in South Halmahera, Indonesia
St Laurent B , Burton TA , Zubaidah S , Miller HC , Asih PB , Baharuddin A , Kosasih S , Shinta , Firman S , Hawley WA , Burkot TR , Syafruddin D , Sukowati S , Collins FH , Lobo NF . Malar J 2017 16 (1) 310 BACKGROUND: Indonesia is home to a variety of malaria vectors whose specific bionomic traits remain largely uncharacterized. Species-specific behaviours, such as host feeding preferences, impact the dynamics of malaria transmission and the effectiveness of vector control interventions. METHODS: To examine species-specific host attraction and feeding behaviours, a Latin square design was used to compare Anopheles mosquitoes attracted to human, cow, and goat-baited tents. Anopheles mosquitoes were collected hourly from the inside walls of each baited tent. Species were morphologically and then molecularly identified using rDNA ITS2 sequences. The head and thorax of individual specimens were analysed for Plasmodium DNA using PCR. Bloodmeals were identified using a multiplex PCR. RESULTS: A total of 1024, 137, and 74 Anopheles were collected over 12 nights in cow, goat, and human-baited tents, respectively. The species were identified as Anopheles kochi, Anopheles farauti s.s., Anopheles hackeri, Anopheles hinesorum, Anopheles indefinitus, Anopheles punctulatus, Anopheles tessellatus, Anopheles vagus, and Anopheles vanus, many of which are known to transmit human malaria. Molecular analysis of blood meals revealed a high level of feeding on multiple host species in a single night. Anopheles kochi, An. indefinitus, and An. vanus were infected with Plasmodium vivax at rates comparable to primary malaria vectors. CONCLUSIONS: The species distributions of Anopheles mosquitoes attracted to human, goat, and cow hosts were similar. Eight of nine sporozoite positive samples were captured with animal-baited traps, indicating that even predominantly zoophilic mosquitoes may be contributing to malaria transmission. Multiple host feeding and flexibility in blood feeding behaviour have important implications for malaria transmission, malaria control, and the effectiveness of intervention and monitoring methods, particularly those that target human-feeding vectors. |
Tiger on the prowl: Invasion history and spatio-temporal genetic structure of the Asian tiger mosquito Aedes albopictus (Skuse 1894) in the Indo-Pacific
Maynard AJ , Ambrose L , Cooper RD , Chow WK , Davis JB , Muzari MO , van den Hurk AF , Hall-Mendelin S , Hasty JM , Burkot TR , Bangs MJ , Reimer LJ , Butafa C , Lobo NF , Syafruddin D , Maung Maung YN , Ahmad R , Beebe NW . PLoS Negl Trop Dis 2017 11 (4) e0005546 BACKGROUND: Within the last century, increases in human movement and globalization of trade have facilitated the establishment of several highly invasive mosquito species in new geographic locations with concurrent major environmental, economic and health consequences. The Asian tiger mosquito, Aedes albopictus, is an extremely invasive and aggressive daytime-biting mosquito that is a major public health threat throughout its expanding range. METHODOLOGY/PRINCIPAL FINDINGS: We used 13 nuclear microsatellite loci (on 911 individuals) and mitochondrial COI sequences to gain a better understanding of the historical and contemporary movements of Ae. albopictus in the Indo-Pacific region and to characterize its population structure. Approximate Bayesian computation (ABC) was employed to test competing historical routes of invasion of Ae. albopictus within the Southeast (SE) Asian/Australasian region. Our ABC results show that Ae. albopictus was most likely introduced to New Guinea via mainland Southeast Asia, before colonizing the Solomon Islands via either Papua New Guinea or SE Asia. The analysis also supported that the recent incursion into northern Australia's Torres Strait Islands was seeded chiefly from Indonesia. For the first time documented in this invasive species, we provide evidence of a recently colonized population (the Torres Strait Islands) that has undergone rapid temporal changes in its genetic makeup, which could be the result of genetic drift or represent a secondary invasion from an unknown source. CONCLUSIONS/SIGNIFICANCE: There appears to be high spatial genetic structure and high gene flow between some geographically distant populations. The species' genetic structure in the region tends to favour a dispersal pattern driven mostly by human movements. Importantly, this study provides a more widespread sampling distribution of the species' native range, revealing more spatial population structure than previously shown. Additionally, we present the most probable invasion history of this species in the Australasian region using ABC analysis. |
Quantifying the epidemiological impact of vector control on dengue
Reiner RC Jr , Achee N , Barrera R , Burkot TR , Chadee DD , Devine GJ , Endy T , Gubler D , Hombach J , Kleinschmidt I , Lenhart A , Lindsay SW , Longini I , Mondy M , Morrison AC , Perkins TA , Vazquez-Prokopec G , Reiter P , Ritchie SA , Smith DL , Strickman D , Scott TW . PLoS Negl Trop Dis 2016 10 (5) e0004588 Dengue virus (DENV) is a self-limiting illness in tropical and subtropical regions around the globe caused by four closely related, but distinct, virus serotypes (DENV-1, -2, -3, and -4) that are transmitted among humans by mosquitoes, primarily Aedes aegypti [1]. Approximately 4 billion people living in more than 128 countries are at risk of infection [2]. Each year there are an estimated 400 million new infections, of which about 100 million manifest as apparent illness [3]. The outcome of human infections ranges from asymptomatic to mild illness to severe, life-threatening disease [4]. DENV not only causes more human morbidity and mortality than any other arthropod-borne virus but it is also a growing public health threat. There has been a dramatic 4-fold increase in dengue cases between 1990–2013 and dengue continues to expand in geographic range [2,3,5,6]. | Presently, vector control is the primary means for preventing dengue [7]. Several vaccine constructs are in clinical trials and initial results are encouraging [8]; recently licensure was granted for the Sanofi Pasteur vaccine in Mexico, Brazil, and the Philippines [9]. A few well-documented successes indicate that, when rigorously applied, vector control can reduce dengue. The advent of DDT in 1947 led to a hemisphere-wide program in the 1950s and 1960s across Central and South America that dramatically reduced Ae. aegypti populations, resulting in impressive reductions in yellow fever and dengue [10]. During the 1970s–1980s [11] and the 1980s–1990s [12], respectively, Singapore and Cuba successfully used vector control and larval source reduction to reduce the force of DENV infection (i.e., per capita risk of human infection [13]) and, thus, disease. Recent trials of indoor residual spraying [14] and indoor space spraying [15] appeared to reduce human DENV infections. Regrettably, these control achievements were rare and ultimately transient. Dengue reinvaded Latin America after the Ae. aegypti eradication campaign ended, rebounded in Singapore and Cuba after 20 and 16 years of successful control, respectively, and is increasingly being reported in Africa due to improved surveillance [16]. |
Mosquito genomics. Highly evolvable malaria vectors: the genomes of 16 Anopheles mosquitoes.
Neafsey DE , Waterhouse RM , Abai MR , Aganezov SS , Alekseyev MA , Allen JE , Amon J , Arca B , Arensburger P , Artemov G , Assour LA , Basseri H , Berlin A , Birren BW , Blandin SA , Brockman AI , Burkot TR , Burt A , Chan CS , Chauve C , Chiu JC , Christensen M , Costantini C , Davidson VL , Deligianni E , Dottorini T , Dritsou V , Gabriel SB , Guelbeogo WM , Hall AB , Han MV , Hlaing T , Hughes DS , Jenkins AM , Jiang X , Jungreis I , Kakani EG , Kamali M , Kemppainen P , Kennedy RC , Kirmitzoglou IK , Koekemoer LL , Laban N , Langridge N , Lawniczak MK , Lirakis M , Lobo NF , Lowy E , MacCallum RM , Mao C , Maslen G , Mbogo C , McCarthy J , Michel K , Mitchell SN , Moore W , Murphy KA , Naumenko AN , Nolan T , Novoa EM , O'Loughlin S , Oringanje C , Oshaghi MA , Pakpour N , Papathanos PA , Peery AN , Povelones M , Prakash A , Price DP , Rajaraman A , Reimer LJ , Rinker DC , Rokas A , Russell TL , Sagnon N , Sharakhova MV , Shea T , Simao FA , Simard F , Slotman MA , Somboon P , Stegniy V , Struchiner CJ , Thomas GW , Tojo M , Topalis P , Tubio JM , Unger MF , Vontas J , Walton C , Wilding CS , Willis JH , Wu YC , Yan G , Zdobnov EM , Zhou X , Catteruccia F , Christophides GK , Collins FH , Cornman RS , Crisanti A , Donnelly MJ , Emrich SJ , Fontaine MC , Gelbart W , Hahn MW , Hansen IA , Howell PI , Kafatos FC , Kellis M , Lawson D , Louis C , Luckhart S , Muskavitch MA , Ribeiro JM , Riehle MA , Sharakhov IV , Tu Z , Zwiebel LJ , Besansky NJ . Science 2015 347 (6217) 1258522 Variation in vectorial capacity for human malaria among Anopheles mosquito species is determined by many factors, including behavior, immunity, and life history. To investigate the genomic basis of vectorial capacity and explore new avenues for vector control, we sequenced the genomes of 16 anopheline mosquito species from diverse locations spanning ~100 million years of evolution. Comparative analyses show faster rates of gene gain and loss, elevated gene shuffling on the X chromosome, and more intron losses, relative to Drosophila. Some determinants of vectorial capacity, such as chemosensory genes, do not show elevated turnover but instead diversify through protein-sequence changes. This dynamism of anopheline genes and genomes may contribute to their flexible capacity to take advantage of new ecological niches, including adapting to humans as primary hosts. |
Barrier screens: a method to sample blood-fed and host-seeking exophilic mosquitoes
Burkot TR , Russell TL , Reimer LJ , Bugoro H , Beebe NW , Cooper RD , Sukawati S , Collins FH , Lobo NF . Malar J 2013 12 49 BACKGROUND: Determining the proportion of blood meals on humans by outdoor-feeding and resting mosquitoes is challenging. This is largely due to the difficulty of finding an adequate and unbiased sample of resting, engorged mosquitoes to enable the identification of host blood meal sources. This is particularly difficult in the south-west Pacific countries of Indonesia, the Solomon Islands and Papua New Guinea where thick vegetation constitutes the primary resting sites for the exophilic mosquitoes that are the primary malaria and filariasis vectors. METHODS: Barrier screens of shade-cloth netting attached to bamboo poles were constructed between villages and likely areas where mosquitoes might seek blood meals or rest. Flying mosquitoes, obstructed by the barrier screens, would temporarily stop and could then be captured by aspiration at hourly intervals throughout the night. RESULTS: In the three countries where this method was evaluated, blood-fed females of Anopheles farauti, Anopheles bancroftii, Anopheles longirostris, Anopheles sundaicus, Anopheles vagus, Anopheles kochi, Anopheles annularis, Anopheles tessellatus, Culex vishnui, Culex quinquefasciatus and Mansonia spp were collected while resting on the barrier screens. In addition, female Anopheles punctulatus and Armigeres spp as well as male An. farauti, Cx. vishnui, Cx. quinquefasciatus and Aedes species were similarly captured. CONCLUSIONS: Building barrier screens as temporary resting sites in areas where mosquitoes were likely to fly was an extremely time-effective method for collecting an unbiased representative sample of engorged mosquitoes for determining the human blood index. |
The risk of West Nile Virus infection is associated with combined sewer overflow streams in urban Atlanta, Georgia, USA
Vazquez-Prokopec GM , Vanden Eng JL , Kelly R , Mead DG , Kolhe P , Howgate J , Kitron U , Burkot TR . Environ Health Perspect 2010 118 (10) 1382-8 BACKGROUND: At present, the factors favoring transmission and amplification of West Nile Virus (WNV) within urban environments are poorly understood. In urban Atlanta, Georgia, the highly polluted waters of streams affected by combined sewer overflow (CSO) represent significant habitats for the WNV mosquito vector Culex quinquefasciatus. However, their contribution to the risk of WNV infection in humans and birds remains unclear. OBJECTIVES: Our goals were to describe and quantify the spatial distribution of WNV infection in mosquitoes, humans, and corvids, such as blue jays and American crows that are particularly susceptible to WNV infection, and to assess the relationship between WNV infection and proximity to CSO-affected streams in the city of Atlanta, Georgia. MATERIALS & METHODS: We applied spatial statistics to human, corvid, and mosquito WNV surveillance data from 2001 through 2007. Multimodel analysis was used to estimate associations of WNV infection in Cx. quinquefasciatus, humans, and dead corvids with selected risk factors including distance to CSO streams and catch basins, land cover, median household income, and housing characteristics. RESULTS: We found that WNV infection in mosquitoes, corvids, and humans was spatially clustered and statistically associated with CSO-affected streams. WNV infection in Cx. quinquefasciatus was significantly higher in CSO compared with non-CSO streams, and WNV infection rates among humans and corvids were significantly associated with proximity to CSO-affected streams, the extent of tree cover, and median household income. CONCLUSIONS: Our study strongly suggests that CSO-affected streams are significant sources of Cx. quinquefasciatus mosquitoes that may facilitate WNV transmission to humans within urban environments. Our findings may have direct implications for the surveillance and control of WNV in other urban centers that continue to use CSO systems as a waste management practice. |
Detection of Dirofilaria immitis (Nematoda: Filarioidea) by polymerase chain reaction in Aedes albopictus, Anopheles punctipennis, and Anopheles crucians (Diptera: Culicidae) from Georgia, USA
Licitra B , Chambers EW , Kelly R , Burkot TR . J Med Entomol 2010 47 (4) 634-638 Potential mosquito vectors of Dirofilaria immitis (Leidy) (Nematoda: Filarioidea), the causative agent of dog heartworm in the southeastern region of the United States, were collected with CDC light traps and gravid traps in seven counties in the state of Georgia, USA. The presence of D. immitis in these mosquitoes was detected by polymerase chain reaction using species-specific primers for the D. immitis surface or cuticular antigen. Overall, 1,574 mosquitoes of 13 species in seven genera were collected; 92% of the specimens were Aedes albopictus (Skuse), Aedes vexans (Meigen), or Anopheles punctipennis (Say). Ae. albopictus, An. punctipennis, and Anopheles crucians Wiedemann were positive for D. immitis DNA. Ae. albopictus had the highest maximum likelihood rate of infection (2.30%; 95% confidence interval [CI] = 1.15-4.00%) followed by An. crucians (1.38%: 95% CI = 0.04-6.93%), and An. punctipennis (0.85%; 95% CI 0.03-4.29%). The detection of D. immitis DNA in the heads and thoraxes of Ae. albopictus (0.40%; 95% CI = 0.12-2.02%) indicates that these mosquitoes can support the development of D. immitis to the infective stage 3 larvae. |
- Page last reviewed:Feb 1, 2024
- Page last updated:May 13, 2024
- Content source:
- Powered by CDC PHGKB Infrastructure