scholarly journals Entomological Surveillance in Former Malaria-endemic Areas of Southern Italy

Pathogens ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1521
Author(s):  
Donato Antonio Raele ◽  
Francesco Severini ◽  
Daniela Boccolini ◽  
Michela Menegon ◽  
Luciano Toma ◽  
...  
Keyword(s):  
Malaria Vectors ◽  
Public Health Issue ◽  
Entomological Surveillance ◽  
Widespread Species ◽  
Animal Shelters ◽  
Breeding Sites ◽  
Artificial Breeding ◽  
Anopheles Vectors ◽  
Gargano Promontory ◽  
Anopheles Algeriensis

Malaria still represents a potential public health issue in Italy, and the presence of former Anopheles vectors and cases imported annually merit continuous surveillance. In areas no longer endemic, the concurrent presence of gametocyte carriers and competent vectors makes re-emergence of local transmission possible, as recently reported in Greece. In October 2017, due to the occurrence of four suspected introduced malaria cases in the province of Taranto (Apulia region), entomological investigations were performed to verify the involvement of local anopheline species. In 2019–2020 entomological surveys were extended to other areas historically prone to malaria between the provinces of Taranto and Matera and the province of Foggia (Gargano Promontory). Resting mosquitoes were collected in animal shelters and human dwellings, larvae were sampled in natural and artificial breeding sites, and specimens were both morphologically and molecularly identified. A total of 2228 mosquitoes were collected, 54.3% of which were anophelines. In all the investigated areas, Anopheles labranchiae was the most widespread species, while Anopheles algeriensis was predominant at the Gargano sites, and Anopheles superpictus and Anopheles plumbeus were recorded in the province of Matera. Our findings showed a potentially high receptivity in the surveyed areas, where the abundance of the two former malaria vectors, An. labranchiae and An. superpictus, is related to environmental and climatic parameters and to anthropic activities.

scholarly journals Development of a chimeric odour blend for attracting gravid malaria vectors

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Betelehem Wondwosen ◽  
Mengistu Dawit ◽  
Yared Debebe ◽  
Habte Tekie ◽  
Sharon R. Hill ◽  
...  
Keyword(s):  
Vector Control ◽  
Binary Logistic Regression ◽  
Ground Level ◽  
Malaria Vectors ◽  
Volatile Components ◽  
Innovative Strategy ◽  
Breeding Sites ◽  
Logistic Regression Models ◽  
Plant Feeding ◽  
Global Vector

Abstract Background Odour-based tools targeting gravid malaria vectors may complement existing intervention strategies. Anopheles arabiensis are attracted to, and stimulated to oviposit by, natural and synthetic odours of wild and domesticated grasses associated with mosquito breeding sites. While such synthetic odour lures may be used for vector control, these may have limited efficacy when placed in direct competition with the natural source. In this study, workflows developed for plant-feeding pests was used to design and evaluate a chimeric odour blend based on shared attractive compounds found in domesticated grass odours. Methods Variants of a synthetic odour blend, composed of shared bioactive compounds previously identified in domesticated grasses, was evaluated sequentially in a two-choice olfactometer to identify a ratio-optimized attractive blend for malaria vectors. During this process, blends with ratios that were significantly more attractive than the previously identified synthetic rice blend were compared to determine which was most attractive in the two-choice olfactometer. To determine whether all volatile components of the most attractive blend were necessary for maximal attraction, subtractive assays were then conducted, in which individual components were removed for the most attractive blend, to define the final composition of the chimeric blend. Binary logistic regression models were used to determine significance in all two-choice assays. The chimeric blend was then assessed under field conditions in malaria endemic villages in Ethiopia, to assess the effect of dose, trap type, and placement relative to ground level. Field data were analyzed both descriptively and using a Welch-corrected t-test. Results A ratio-optimized chimeric blend was identified that significantly attracted gravid An. arabiensis under laboratory conditions. In the field, trap captures of An. arabiensis and Anopheles pharoensis were dependent on the presence of the lure, trap type (CDC, BG Sentinel and Suna traps), placement relevant to ground level, with low release rates generally luring more mosquitoes. Conclusions The workflow designed for the development of chimeric lures provides an innovative strategy to target odour-mediated behaviours. The chimeric lure identified here can be used in existing trapping systems, and be customized to increase sustainability, in line with goals of the Global Vector Control Response Group.

scholarly journals Mosquitoes of the Maculipennis complex in Northern Italy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mattia Calzolari ◽  
Rosanna Desiato ◽  
Alessandro Albieri ◽  
Veronica Bellavia ◽  
Michela Bertola ◽  
...  
Keyword(s):  
Abundant Species ◽  
Northern Italy ◽  
Malaria Vectors ◽  
Distribution Data ◽  
Correct Identification ◽  
Ecological Niche Models ◽  
Breeding Sites ◽  
Anopheles Atroparvus ◽  
Species Inquirenda ◽  
Maculipennis Complex

AbstractThe correct identification of mosquito vectors is often hampered by the presence of morphologically indiscernible sibling species. The Maculipennis complex is one of these groups that include both malaria vectors of primary importance and species of low/negligible epidemiological relevance, of which distribution data in Italy are outdated. Our study was aimed at providing an updated distribution of Maculipennis complex in Northern Italy through the sampling and morphological/molecular identification of specimens from five regions. The most abundant species was Anopheles messeae (2032), followed by Anopheles maculipennis s.s. (418), Anopheles atroparvus (28) and Anopheles melanoon (13). Taking advantage of ITS2 barcoding, we were able to finely characterize tested mosquitoes, classifying all the Anopheles messeae specimens as Anopheles daciae, a taxon with debated rank to which we referred as species inquirenda (sp. inq.). The distribution of species was characterized by Ecological Niche Models (ENMs), fed by recorded points of presence. ENMs provided clues on the ecological preferences of the detected species, with An. daciae sp. inq. linked to stable breeding sites and An. maculipennis s.s. more associated to ephemeral breeding sites. We demonstrate that historical Anopheles malaria vectors are still present in Northern Italy.

scholarly journals Data-driven and interpretable machine-learning modeling to explore the fine-scale environmental determinants of malaria vectors biting rates in rural Burkina Faso

2021 ◽  
Author(s):  
Paul Taconet ◽  
Angélique Porciani ◽  
Dieudonné Diloma Soma ◽  
Karine Mouline ◽  
Frédéric Simard ◽  
...  
Keyword(s):  
Machine Learning ◽  
High Resolution ◽  
Burkina Faso ◽  
Environmental Variables ◽  
Data Driven ◽  
Malaria Vectors ◽  
Environmental Determinants ◽  
Breeding Sites ◽  
Landscape Variables ◽  
Interpretable Machine Learning

AbstractBackgroundImproving the knowledge and understanding of the environmental determinants of malaria vectors abundances at fine spatiotemporal scales is essential to design locally tailored vector control intervention. This work aimed at exploring the environmental tenets of human-biting activity in the main malaria vectors (Anopheles gambiae s.s., Anopheles coluzzii and Anopheles funestus) in the health district of Diébougou, rural Burkina Faso.MethodsAnopheles human-biting activity was monitored in 27 villages during 15 months (in 2017-2018), and environmental variables (meteorological and landscape) were extracted from high resolution satellite imagery. A two-step data-driven modeling study was then carried-out. Correlation coefficients between the biting rates of each vector species and the environmental variables taken at various temporal lags and spatial distances from the biting events were first calculated. Then, multivariate machine-learning models were generated and interpreted to i) pinpoint primary and secondary environmental drivers of variation in the biting rates of each species and ii) identify complex associations between the environmental conditions and the biting rates.ResultsMeteorological and landscape variables were often significantly correlated with the vectors’ biting rates. Many nonlinear associations and thresholds were unveiled by the multivariate models, both for meteorological and landscape variables. From these results, several aspects of the bio-ecology of the main malaria vectors were precised or hypothesized for the Diébougou area, including breeding sites typologies, development and survival rates in relation to weather, flight ranges from breeding sites, dispersal related to landscape openness.ConclusionsUsing high resolution data in an interpretable machine-learning modeling framework proved to be an efficient way to enhance the knowledge of the complex links between the environment and the malaria vectors at a local scale. More broadly, the emerging field of interpretable machine-learning has significant potential to help improving our understanding of the complex processes leading to malaria transmission.

scholarly journals Large males have a mating advantage in a species of darter with smaller, allopaternal males Etheostoma olmstedi

2010 ◽  
Vol 56 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Kelly A. Stiver ◽  
Suzanne H. Alonzo
Keyword(s):  
Mating Success ◽  
Breeding Population ◽  
Male Mating ◽  
Breeding Sites ◽  
Spawning Site ◽  
Egg Deposition ◽  
Artificial Breeding ◽  
Mean Size ◽  
Natural Breeding ◽  
To Receive

Abstract Theory suggests that males that are larger than their competitors may have increased mating success, due to both greater competitive ability and increased attractiveness to females. We examined how male mating success varies with male size in the tessellated darter Etheostoma olmstedi. Previous work has shown that large males tend to move around and breed in vacant breeding sites, and consequently provide less care for their eggs, while smaller individuals can be allopaternal, caring for the eggs of other males as well as for their own. We studied female egg deposition in a natural breeding population using artificial breeding sites and in the laboratory, where female choice of spawning site was restricted to two breeding sites tended by two males of different sizes. In both the field and the laboratory, nests tended by larger males were more likely to receive new eggs. Additionally, the mean size of males associated with a nest was positively correlated with both the maximum coverage of eggs at the nest and the number of times new eggs were deposited. We discuss how the increased mating success of larger males, despite their decreased parental care, may help explain allopaternal care in this species.

scholarly journals Species Composition and Diversity of Malaria Vector Breeding Habitats in Trincomalee District of Sri Lanka

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Nayana Gunathilaka ◽  
Wimaladharma Abeyewickreme ◽  
Menaka Hapugoda ◽  
Rajitha Wickremasinghe
Keyword(s):  
Sri Lanka ◽  
Larval Habitat ◽  
Malaria Vectors ◽  
Entomological Surveillance ◽  
Anopheles Subpictus ◽  
Control Programs ◽  
Breeding Habitats ◽  
Elimination Programme ◽  
Total Dissolved Solid ◽  
The Relationship

Introduction. Mosquito larval ecology is important in determining larval densities and species assemblage. This in turn influences malaria transmission in an area. Therefore, understanding larval habitat ecology is important in designing malaria control programs.Method. Larval surveys were conducted in 20 localities under five sentinel sites (Padavisiripura, Gomarankadawala, Thoppur, Mollipothana, and Ichchallampaththu) in Trincomalee District, Eastern Province of Sri Lanka, between June 2010 and July 2013. The relationship between seven abiotic variables (temperature, pH, conductivity, Total Dissolved Solid (TDS), turbidity, Dissolved Oxygen (DO), and salinity) was measured.Results. A total of 21,347 anophelines were recorded representing 15 species.Anopheles subpictus24.72% (5,278/21,347) was the predominant species, followed by 24.67% (5,267/21,347) ofAn. nigerrimusand 14.56% (3,109/21,347) ofAn. peditaeniatus. A total of 9,430 breeding habitats under twenty-one categories were identified.An. culcicifacieswas noted to be highest from built wells (20.5%) with high salinity (1102.3 ± 81.8 mg/L), followed by waste water collections (20.2%) having low DO levels (2.85 ± 0.03 mg/L) and high TDS (1,654 ± 140 mg/L).Conclusion. This study opens an avenue to explore new breeding habitats of malaria vectors in the country and reemphasizes the requirement of conducting entomological surveillance to detect potential transmission of malaria in Sri Lanka under the current malaria elimination programme.

scholarly journals Simulations reveal the power and peril of artificial breeding sites for monitoring and managing animals

2017 ◽  
Vol 27 (4) ◽  
pp. 1155-1166 ◽  
Author(s):  
Christopher J. W. McClure ◽  
Benjamin P. Pauli ◽  
Julie A. Heath
Keyword(s):  
Breeding Sites ◽  
Artificial Breeding

THE MATING PATTERNS OF FEMALES WHEN TERRITORIAL DIFFERENCES AMONG MALES ARE REDUCED: A TEST IN THE POLYGYNOUS BEAUGREGORY DAMSELFISH

Behaviour ◽  
2001 ◽  
Vol 138 (6) ◽  
pp. 691-708 ◽  
Author(s):  
◽  
◽  
◽  
Keyword(s):  
Random Mating ◽  
Breeding Site ◽  
Male Reproduction ◽  
Male Reproductive Success ◽  
Mating Pattern ◽  
Breeding Sites ◽  
Site Structure ◽  
Artificial Breeding ◽  
Stegastes Leucostictus

AbstractUsing the Caribbean beaugregory damselfish (Stegastes leucostictus) we tested whether patterns of male reproduction could be modified by reducing differences among males, in this case by giving males identical artificial breeding sites. Previous studies have shown that very few males using the natural small rubble habitat reproduced and variations in male reproductive success were based mainly on the differences in the quality of their natural breeding sites. By providing males with identical artificial breeding sites, we tested whether females would be less likely to confine their reproduction to only a few of the available males. We examined male reproductive patterns by first simulating females choosing males (1) 'randomly,' (i.e. the number of males that receive eggs is based on each female randomly choosing a mate from a group of males), or (2) 'exclusively' (i.e. only one female mates with one male on a given day), or (3) 'highly selectively' (i.e. this is the typical polygynous pattern in which many females select the same few males). We tested these simulations against the actual daily amounts of eggs deposited and the number of different males that received eggs in each of 4 summers. Although the regression trend line from the daily patterns did resemble the Random Mating Pattern, egg clutches were more widely dispersed than random but less dispersed than the Exclusive Mating Pattern. That is, with more females mating on a particular day, more males received eggs. We speculated that this might have resulted from females aggressively excluding other females from mating with the same male on a given day. In contrast, males using the variable quality natural sites rarely mated and those that did receive eggs, received them in larger amounts than males using the artificial sites. Thus, for natural sites, more females seemed to be mating with the same few males. Perhaps for these natural sites any intra-female aggression may have been ineffective when so few superior spawning sites were available. For males using the artificial sites, the total amount of eggs received over a two-month period was nonrandom and resembled the 'highly selected pattern.' This resulted from some males receiving egg clutches on more days. Other traits, besides breeding site structure, may have been important in causing different females to select the same males on subsequent days.

Building multi‐layered resilience in a malaria control programme in Dar es Salaam, Tanzania

2010 ◽  
Vol 10 (4) ◽  
pp. 309-324 ◽  
Author(s):  
Stefan Dongus ◽  
Constanze Pfeiffer ◽  
Emmy Metta ◽  
Selemani Mbuyita ◽  
Brigit Obrist
Keyword(s):  
Malaria Control ◽  
Breeding Site ◽  
Control Programme ◽  
Malaria Vectors ◽  
Malaria Control Programme ◽  
Social Resilience ◽  
Breeding Sites ◽  
Mosquito Breeding ◽  
Field Workers ◽  
Local Leaders

This study applied the multi‐layered social resilience framework in the context of an urban malaria control programme by using a qualitative approach. It was found that exchange between and within administrative levels supported resilience‐building processes in terms of mosquito breeding site elimination. ‘Reactive’ and ‘proactive’ capacities were successfully built among programme staff. However, more potential could be tapped among local leaders and household members, by increasing their competence in eliminating breeding sites of malaria vectors. Improving the communication skills of the programme’s field workers might support such processes. Together with local leaders, they could act as multipliers of sensitisation messages.

scholarly journals A community-level investigation of the yellow fever virus outbreak in South Omo Zone, South-West Ethiopia, 2012–2014

2018 ◽  
Author(s):  
Ranya Mulchandani ◽  
Fekadu Massebo ◽  
Fekadu Bocho ◽  
Claire L Jeffries ◽  
Thomas Walker ◽  
...  
Keyword(s):  
Yellow Fever ◽  
Yellow Fever Virus ◽  
Mosquito Species ◽  
Breeding Site ◽  
Fever Virus ◽  
Entomological Surveillance ◽  
Breeding Sites ◽  
South Omo ◽  
South West Ethiopia ◽  
Aedes Simpsoni

AbstractBackgroundA yellow fever (YF) outbreak occurred in South Omo Zone, Ethiopia in 2012-2014. This study aimed to analyse historical epidemiological data, to assess the risk for future YF outbreaks through entomological surveillance, including mosquito species identification and molecular screening for arboviruses, and finally to determine the knowledge, attitudes and current preventative practices within the affected communities.Methodology/Principal FindingsFrom October 2012 to March 2014, 165 cases and 62 deaths were reported, principally in rural areas of South Ari region (83.6%), south-west Ethiopia. The majority of patients were 15-44 years old (74.5%) and most case deaths were males (76%). Between June and August 2017, 688 containers were sampled from across 177 households to identify key breeding sites forAedesmosquitoes.Ensete ventricosum(“false banana”) was identified as the primary natural breeding site, and clay pots outside the home as the most productive artificial breeding site. Entomological risk indices from the majority of sites were classified as “high risk” for future outbreaks under current World Health Organization criteria. Adult trapping resulted in the identification of members of theAedes simpsonicomplex in and around households. Screening of adult females revealed no detection of yellow fever virus (YFV) or other arboviruses. 88% of 177 participants had heard of YF, however many participants easily confused transmission and symptoms of YF with malaria, which is also endemic in the area.Conclusions/SignificanceStudy results emphasise the need for further entomological studies to improve our understanding of local vector species and transmission dynamics. Disease surveillance systems and in-country laboratory capacity also need to be strengthened to facilitate more rapid responses to future YF outbreaks.Author SummaryDespite the availability of a highly effective vaccine, yellow fever virus (YFV) remains an important public health problem across Africa and South America due to its high case-fatality rate. This study aimed to assess and reduce the risk for future outbreaks. During this study, historical data analysis was conducted to understand the epidemiology of the recent outbreak in 2012-2014. Entomological surveillance was also carried out, including both mosquito species identification and molecular screening for arboviruses, as well as a household survey to understand the knowledge and attitudes towards yellow fever (YF) within the affected areas and to assess community-level practices for YF prevention. We found a high abundance ofAedes simpsonicomplex in the context of low vaccination coverage. Community knowledge and practice levels were low for reducing potential breeding sites, highlighting the need for increased dissemination of information to community members on how to reduce their risk of exposure to mosquito vectors of arboviruses.

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