bims-mosdis Biomed News
on Mosquito distribution and disease
Issue of 2022–11–06
seventeen papers selected by
Richard Halfpenny, Staffordshire University
  1. Mosquito Surveillance for West Nile Virus.
  2. Entomological Surveillance of the Invasive Aedes Species at Higher-Priority Entry Points in Northern Iran: Exploratory Report on a Field Study.
  3. Molecular Surveillance of West Nile Virus in Mosquitoes and Sentinel Chickens.
  4. A sterile insect technique pilot trial on Captiva Island: defining mosquito population parameters for sterile male releases using mark-release-recapture.
  5. Habitat Diversity, Stability, and Productivity of Malaria Vectors in Irrigated and Nonirrigated Ecosystems in Western Kenya.
  6. Knowledge, practices and perceptions of communities during a malaria larviciding randomized trial in the city of Yaoundé, Cameroon.
  7. North American House Sparrows Are Competent for Usutu Virus Transmission.
  8. Limited Capacity for Aedes aegypti to Mechanically Transmit Chikungunya Virus and Dengue Virus.
  9. A Swin Transformer-based model for mosquito species identification.
  10. Community surveillance of Aedes albopictus associated with Wolbachia detection in low-rise residential areas in Selangor, Malaysia.
  11. Identifying hidden Zika hotspots in Pernambuco, Brazil: a spatial analysis.
  12. Prevalence of malaria and its risk factors in Lake Tana and surrounding areas, northwest Ethiopia.
  13. Autochthonous dengue in mainland France, 2022: geographical extension and incidence increase.
  14. Spatio-temporal dynamics of three diseases caused by Aedes-borne arboviruses in Mexico.
  15. Introduction to West Nile Virus.
  16. The presence of Plasmodium malariae and Plasmodium knowlesi in near malaria elimination setting in western Indonesia.
  17. No association between habitat, autogeny and genetics in Moroccan Culex pipiens populations.
  1. Methods Mol Biol. 2023 ;2585 145-156
    Mosquito Surveillance for West Nile Virus.
    Donald A Yee, Ary Faraji, Ilia Rochlin.
      Identifying the mosquitoes responsible for transmitting human disease-causing pathogens is of critical importance for effective control of mosquito-borne outbreaks. West Nile virus is often transferred by adult female mosquitoes in the genus Culex, which deposit eggs in a variety of aquatic habitats throughout the world. Herein we describe several methodological approaches to monitor these species in nature, as well as offering details for data collection and analysis.
    Keywords:  Aedes; Culex; Modeling; Mosquito adult; Surveillance; Traps; Vector control
    DOI:  https://doi.org/10.1007/978-1-0716-2760-0_14
  2. JMIR Public Health Surveill. 2022 Oct 31. 8(10): e38647
    Entomological Surveillance of the Invasive Aedes Species at Higher-Priority Entry Points in Northern Iran: Exploratory Report on a Field Study.
    Seyed Hassan Nikookar, Alireza Maleki, Mahmoud Fazeli-Dinan, Razieh Shabani Kordshouli, Ahmadali Enayati.
       BACKGROUND: Arboviral diseases such as dengue, Zika, and chikungunya are transmitted by Aedes aegypti and Ae albopictus and are emerging global public health concerns.
    OBJECTIVE: This study aimed to provide up-to-date data on the occurrence of the invasive Aedes species in a given area as this is essential for planning and implementing timely control strategies.
    METHODS: Entomological surveillance was planned and carried out monthly from May 2018 to December 2019 at higher-priority entry points in Guilan Province, Northern Iran, using ovitraps, larval collection, and human-baited traps. Species richness (R), Simpson (D), evenness (E), and Shannon-Wiener indexes (H̕) were measured to better understand the diversity of the Aedes species. The Spearman correlation coefficient and regression models were used for data analysis.
    RESULTS: We collected a total of 3964 mosquito samples including 17.20% (682/3964) belonging to the Aedes species, from 3 genera and 13 species, and morphologically identified them from May 2018 to December 2019. Ae vexans and Ae geniculatus, which showed a peak in activity levels and population in October (226/564, 40.07% and 26/103, 25.2%), were the eudominant species (D=75.7%; D=21.2%) with constant (C=100) and frequent (C=66.7%) distributions, respectively. The population of Ae vexans had a significant positive correlation with precipitation (r=0.521; P=.009) and relative humidity (r=0.510; P=.01), whereas it was inversely associated with temperature (r=-0.432; P=.04). The Shannon-Wiener Index was up to 0.84 and 1.04 in the city of Rasht and in July, respectively. The rarefaction curve showed sufficiency in sampling efforts by reaching the asymptotic line at all spatial and temporal scales, except in Rasht and in October.
    CONCLUSIONS: Although no specimens of the Ae aegypti and Ae albopictus species were collected, this surveillance provides a better understanding of the native Aedes species in the northern regions of Iran. These data will assist the health system in future arbovirus research, and in the implementation of effective vector control and prevention strategies, should Ae aegypti and Ae albopictus be found in the province.
    Keywords:  Aedes; Guilan; Northern Iran; biodiversity; mosquito surveillance
    DOI:  https://doi.org/10.2196/38647
  3. Methods Mol Biol. 2023 ;2585 157-169
    Molecular Surveillance of West Nile Virus in Mosquitoes and Sentinel Chickens.
    Steven T Peper.
      Arboviral surveillance is a critical step in any effective mosquito control program. Surveillance aids in the early detection of pathogen transmission as well as establishes a baseline of transmission activity. Two of the most practical forms of arboviral surveillance is through the use of testing mosquito pools for the presence of pathogen and screening sentinel chickens for pathogen exposure. This chapter describes the process for each of these methods for West Nile virus.
    Keywords:  ELISA; Molecular techniques; Mosquitoes; PCR; Sentinel chickens; West Nile virus
    DOI:  https://doi.org/10.1007/978-1-0716-2760-0_15
  4. Parasit Vectors. 2022 Nov 01. 15(1): 402
    A sterile insect technique pilot trial on Captiva Island: defining mosquito population parameters for sterile male releases using mark-release-recapture.
    Danilo O Carvalho, Rachel Morreale, Steven Stenhouse, Daniel A Hahn, Maylen Gomez, Aaron Lloyd, David Hoel.
       BACKGROUND: The sterile insect technique (SIT), which involves area-wide inundative releases of sterile insects to suppress the reproduction of a target species, has proven to be an effective pest control method. The technique demands the continuous release of sterilized insects in quantities that ensure a high sterile male:wild male ratio for the suppression of the wild population over succeeding generations.
    METHODS: For these releases, it is important to determine several ecological and biological population parameters, including the longevity of the released males in the field, the dispersal of the released males and the wild pest population size. The Lee County Mosquito Control District initiated a study in a 47-ha portion of Captiva Island (Florida, USA), an island with a total area of 230 ha, to define biological SIT parameters for Aedes aegypti (L.), an invasive disease-vectoring mosquito known to be difficult to control due to a combination of daytime biting activity, use of cryptic breeding habitats that are difficult to target with conventional night-time ultra-low volume methods, and emerging resistance to commonly used insecticides. Another goal was to assess patterns of dispersal and survival for laboratory-reared sterile Ae. aegypti males released over time in the pilot site. These parameters will be used to evaluate the efficacy of a SIT suppression program for Ae. aegypti on Captiva Island.
    RESULTS: Over the course of seven mark-release-recapture studies using single- and multiple-point releases, 190,504 sterile marked males were released, for which the recapture rate was 1.5% over a mean period of 12 days. The mean distance traveled by sterile males of the local strain of Ae. aegypti that has colonized Captiva Island was 201.7 m from the release point, with an observed maximum traveled distance of 404.5 m. The released sterile mosquitoes had a probability of daily survival of 0.67 and an average life expectancy of ~ 2.46 days.
    CONCLUSIONS: These data together with the population size estimate and sterile:wild ratio provide a solid basis for planning the SIT operational phase which is aimed at mosquito population suppression.
    Keywords:  Aedes aegypti; Mark–release–recapture; Mosquito dispersal; Mosquito population size; Sterile insect technique
    DOI:  https://doi.org/10.1186/s13071-022-05512-3
  5. J Med Entomol. 2022 Nov 05. pii: tjac168. [Epub ahead of print]
    Habitat Diversity, Stability, and Productivity of Malaria Vectors in Irrigated and Nonirrigated Ecosystems in Western Kenya.
    Pauline Winnie Orondo, Xiaoming Wang, Ming-Chieh Lee, Steven G Nyanjom, Harrysone Atieli, Benyl M Ondeto, Kevin O Ochwedo, Collince J Omondi, Wilfred Ouma Otambo, Guofa Zhou, Daibin Zhong, Andrew K Githeko, James W Kazura, Guiyun Yan.
      Several sub-Saharan African countries rely on irrigation for food production. This study examined the impact of environmental modifications resulting from irrigation on the ecology of aquatic stages of malaria vectors in a semi-arid region of western Kenya. Mosquito larvae were collected from irrigated and non-irrigated ecosystems during seasonal cross-sectional and monthly longitudinal studies to assess habitat availability, stability, and productivity of anophelines in temporary, semipermanent, and permanent habitats during the dry and wet seasons. The duration of habitat stability was also compared between selected habitats. Emergence traps were used to determine the daily production of female adult mosquitoes from different habitat types. Malaria vectors were morphologically identified and sibling species subjected to molecular analysis. Data was statistically compared between the two ecosystems. After aggregating the data, the overall malaria vector productivity for habitats in the two ecosystems was estimated. Immatures of the malaria vector (Anopheles arabiensis) Patton (Diptera: Culicidae) comprised 98.3% of the Anopheles in both the irrigated and non-irrigated habitats. The irrigated ecosystem had the most habitats, higher larval densities, and produced 85.8% of emerged adult females. These results showed that irrigation provided conditions that increased habitat availability, stability, and diversity, consequently increasing the An. arabiensis production and potential risk of malaria transmission throughout the year. The irrigated ecosystems increased the number of habitats suitable for Anopheles breeding by about 3-fold compared to non-irrigated ecosystems. These results suggest that water management in the irrigation systems of western Kenya would serve as an effective method for malaria vector control.
    Keywords:   Anopheles ; environmental modification; irrigation; larval ecology; malaria
    DOI:  https://doi.org/10.1093/jme/tjac168
  6. PLoS One. 2022 ;17(11): e0276500
    Knowledge, practices and perceptions of communities during a malaria larviciding randomized trial in the city of Yaoundé, Cameroon.
    Carmène Sandra Ngadjeu, Abdou Talipouo, Sévilor Kekeunou, Patricia Doumbe-Belisse, Idriss Nasser Ngangue-Siewe, Landre Djamouko-Djonkam, Edmond Kopya, Roland Bamou, Nadège Sonhafouo-Chiana, Leslie Nkahe, Metoh Theresia Njuabe, Parfait Awono-Ambene, Charles Sinclair Wondji, Christophe Antonio-Nkondjio.
       BACKGROUND: Urban malaria is becoming a major public health concern in major cities in Cameroon. To improve malaria vector control, a pilot larviciding trial was conducted to assess its impact on mosquito density and malaria transmission intensity in Yaoundé. The present study investigated perceptions and practices of communities on malaria control during the larviciding trial implemented in Yaoundé.
    METHODS: Quantitative and qualitative data were collected in non-intervention and intervention areas. Quantitative data were collected during three cross-sectional surveys using a structured pre-tested questionnaire while qualitative data were obtained through interviews. A total of 26 in-depth interviews and eight focus group discussions with community members were performed. A binary logistic regression model was used to assess the perception of the community on larviciding impact on some malaria or bed nets use indicators.
    RESULTS: People living in intervention areas were 2.64 times more likely to know the mode of malaria transmission (95% CI: 1.82-3.84; p<0.001) and 1.3 time more likely to know mosquito breeding habitats (95% CI: 1.06-1.56; p = 0.009) compared to those living in non-intervention areas. In intervention areas, interviewee opinions on larviciding were generally good i.e. most interviewees reported having noticed a reduction in mosquito nuisance and malaria cases following larviciding implementation; whereas in non-intervention areas no report of reduction of mosquito nuisance was recorded. LLINs were regularly used by the population despite the implementation of larviciding treatments. There was high interest in larviciding program and demand for continuation, even if this needs the community involvement.
    CONCLUSION: The larviciding program in the city of Yaoundé did not negatively affected community members' behaviour and practices concerning the use of treated nets. The study indicated the acceptance of larviciding program by the population. This positive environment could favour the implementation of future antilarval control activities in the city of Yaoundé.
    DOI:  https://doi.org/10.1371/journal.pone.0276500
  7. mSphere. 2022 Nov 01. e0029522
    North American House Sparrows Are Competent for Usutu Virus Transmission.
    Sarah C Kuchinsky, Jeffrey Marano, Seth A Hawks, Emma Loessberg, Christa F Honaker, Paul B Siegel, Chloé Lahondère, Tanya LeRoith, James Weger-Lucarelli, Nisha K Duggal.
      Usutu virus (USUV, Flaviviridae) is an emerging mosquito-borne virus that has been implicated in neuroinvasive disease in humans and epizootic deaths in wild birds. USUV is maintained in an enzootic cycle between ornithophilic mosquitoes, primarily Culex spp., and wild birds, predominantly passerine species. However, limited experimental data exist on the species competent for USUV transmission. Here, we demonstrate that house sparrows are susceptible to multiple USUV strains. Our study also revealed that Culex quinquefasciatus mosquitoes are susceptible to USUV, with a significantly higher infection rate for the Netherlands 2016 USUV strain compared to the Uganda 2012 USUV strain at 50% and 19%, respectively. To assess transmission between avian host and mosquito vector, we allowed mosquitoes to feed on either juvenile chickens or house sparrows inoculated with USUV. Both bird models transmitted USUV to C. quinquefasciatus mosquitoes. Linear regression analyses indicated that C. quinquefasciatus infection rates were positively correlated with avian viremia levels, with 3 to 4 log10 PFU/mL representing the minimum avian viremia threshold for transmission to mosquitoes. Based on the viremia required for transmission, house sparrows were estimated to more readily transmit the Netherlands 2016 strain compared to the Uganda 2012 strain. These studies provide insights on a competent reservoir host of USUV. IMPORTANCE Usutu virus (USUV) is a zoonotic mosquito-borne virus that can cause neuroinvasive disease, including meningitis and encephalitis, in humans and has resulted in hundreds of thousands of deaths in wild birds. The perpetuation of USUV in nature is dependent on transmission between Culex spp. mosquitoes and various avian species. To date, few experimental data exist for determining which bird species are important for the maintenance of USUV. Our studies showed that house sparrows can transmit infectious Usutu virus, indicating their role as a competent host species. By identifying reservoir species of USUV, we can predict areas of USUV emergence and mitigate its impacts on global human and wildlife health.
    Keywords:  arbovirus; house sparrow; mosquito; transmission
    DOI:  https://doi.org/10.1128/msphere.00295-22
  8. Am J Trop Med Hyg. 2022 Oct 31. pii: tpmd220323. [Epub ahead of print]
    Limited Capacity for Aedes aegypti to Mechanically Transmit Chikungunya Virus and Dengue Virus.
    Angela B Bransfield, Michael J Misencik, Doug E Brackney, Philip M Armstrong.
      Mechanical transmission is an understudied mode of arbovirus transmission that occurs when a biting insect transmits virus among hosts by the direct transfer of virus particles contaminating its mouthparts. Multiple arboviruses have been shown to be capable of utilizing this transmission route, but most studies were conducted 40 to 70 years ago using dated methodologies. To gain a better understanding of this phenomenon, we used molecular techniques to evaluate the efficiency of mechanical transmission by Aedes aegypti mosquitoes for two evolutionarily divergent arboviruses, chikungunya virus (CHIKV) and dengue virus (DENV). Viral RNA and/or infectious DENV could be detected on 13.8% of mosquito proboscises sampled immediately after an infectious bloodmeal, but positivity rates declined within hours. CHIKV RNA and/or infectious virus was detected on 38.8% of proboscises immediately after feeding but positivity rates dropped to 2.5% within 4 hours. RNA copy numbers were low for both viruses, and we were unable to demonstrate mechanical transmission of CHIKV using an established animal model, suggesting that this mode of transmission is unlikely under natural conditions.
    DOI:  https://doi.org/10.4269/ajtmh.22-0323
  9. Sci Rep. 2022 Nov 04. 12(1): 18664
    A Swin Transformer-based model for mosquito species identification.
    De-Zhong Zhao, Xin-Kai Wang, Teng Zhao, Hu Li, Dan Xing, He-Ting Gao, Fan Song, Guo-Hua Chen, Chun-Xiao Li.
      Mosquito transmit numbers of parasites and pathogens resulting in fatal diseases. Species identification is a prerequisite for effective mosquito control. Existing morphological and molecular classification methods have evitable disadvantages. Here we introduced Deep learning techniques for mosquito species identification. A balanced, high-definition mosquito dataset with 9900 original images covering 17 species was constructed. After three rounds of screening and adjustment-testing (first round among 3 convolutional neural networks and 3 Transformer models, second round among 3 Swin Transformer variants, and third round between 2 images sizes), we proposed the first Swin Transformer-based mosquito species identification model (Swin MSI) with 99.04% accuracy and 99.16% F1-score. By visualizing the identification process, the morphological keys used in Swin MSI were similar but not the same as those used by humans. Swin MSI realized 100% subspecies-level identification in Culex pipiens Complex and 96.26% accuracy for novel species categorization. It presents a promising approach for mosquito identification and mosquito borne diseases control.
    DOI:  https://doi.org/10.1038/s41598-022-21017-6
  10. J Vector Ecol. 2022 Dec;47(2): 142-152
    Community surveillance of Aedes albopictus associated with Wolbachia detection in low-rise residential areas in Selangor, Malaysia.
    Muhammad Aidil Roslan, Romano Ngui, Indra Vythilingam, Wan Yusoff Wan Sulaiman.
      The study assessed the distribution of Malaysian Ae. albopictus adults associated with Wolbachia detection in low-rise residential areas using a modified sticky ovitrap (MSO). The relationship between Ae. albopictus and climatological parameters were also determined. Fifty-two weeks of surveillance using 273 MSOs were conducted in four installation areas of eleven sampling sites. Specimens were subjected to PCR using wsp-specific primers for Wolbachia detection. The relationship between climatological parameters and Ae. albopictus captured were analyzed using Spearman rank correlation coefficient test. The majority of Ae. albopictus were captured in residential houses (87%), followed by playgrounds or parks (11.5%), guardhouses (1%), and community halls (0.5%). Most of the specimens (92%) were superinfected with wAlbA and wAlbB strains. A positive correlation with no significant association was found for rainfall (r = 0.015, P = 0.072), relative humidity (r = 0.005, P = 0.526), minimum temperature (r = 0.005, P = 0.516), and mean temperature (r = 0.003, P = 0.689). MSO effectively captured a high number of Ae. albopictus that was determined to be the predominant mosquito species found in low-rise residential areas. The adult collection is not only influenced by climatological parameters but also by other factors, including environmental conditions and general sanitation status.
    Keywords:  Aedes albopictus; Wolbachia; climatological parameters; modified sticky ovitrap
    DOI:  https://doi.org/10.52707/1081-1710-47.2.142
  11. Trans R Soc Trop Med Hyg. 2022 Nov 03. pii: trac099. [Epub ahead of print]
    Identifying hidden Zika hotspots in Pernambuco, Brazil: a spatial analysis.
    Laís Picinini Freitas, Rachel Lowe, Andrew E Koepp, Sandra Valongueiro Alves, Molly Dondero, Letícia J Marteleto.
       BACKGROUND: Northeast Brazil has the world's highest rate of Zika-related microcephaly. However, Zika case counts cannot accurately describe burden because mandatory reporting was only established when the epidemic was declining in the region.
    METHODS: To advance the study of the Zika epidemic, we identified hotspots of Zika in Pernambuco state, Northeast Brazil, using Aedes-borne diseases (dengue, chikungunya and Zika) and microcephaly data. We used Kulldorff's Poisson purely spatial scan statistic to detect low- and high-risk clusters for Aedes-borne diseases (2014-2017) and for microcephaly (2015-2017), separately. Municipalities were classified according to a proposed gradient of Zika burden during the epidemic, based on the combination of cluster status in each analysis and considering the strength of the evidence.
    RESULTS: We identified 26 Aedes-borne diseases clusters (11 high-risk) and 5 microcephaly clusters (3 high-risk) in Pernambuco. According to the proposed Zika burden gradient, our results indicate that the northeast of Pernambuco and the Sertão region were hit hardest by the Zika epidemic. The first is the most populous area of Pernambuco, while the second has one of the highest rates of social and economic inequality in Brazil.
    CONCLUSION: We successfully identified possible hidden Zika hotspots using a simple methodology combining Aedes-borne diseases and microcephaly information.
    Keywords:  Zika; dengue; epidemiology; microcephaly; scan statistics; spatial analysis
    DOI:  https://doi.org/10.1093/trstmh/trac099
  12. Malar J. 2022 Nov 04. 21(1): 313
    Prevalence of malaria and its risk factors in Lake Tana and surrounding areas, northwest Ethiopia.
    Fasil Adugna, Melaku Wale, Endalkachew Nibret.
       BACKGROUND: In Ethiopia, malaria is a major concern to the health, and socio-economic development of the country because of its occurrence at the peak agricultural activities. Factors such as environmental, human host, parasite, and vector determine malaria transmission. Therefore, the present study was conducted to determine the prevalence and associated factors of malaria among febrile patients who visited selected health centres.
    METHODS: Institutional-based cross-sectional study was conducted between October 2020 to July 2021 in eight selected health centres located in Lake Tana and its surrounding areas. A simple random sampling technique was used to select febrile patients. Thick and thin blood films were prepared and processed according to the WHO guidelines. Socio-demographic and malaria risk factors were collected from study participants who could read and write using a self-administered questionnaire, whereas face-to-face interview was used to collect information from those participants who could not write and read. The strength of association between risk factors and malaria was assessed using univariate and multivariate logistic regression models.
    RESULTS: Of the total (531) febrile patients, 75.3% were malaria negative and 24.7% (overall prevalence) were malaria confirmed cases. Most of the infections were caused by Plasmodium falciparum (72.5%) followed by Plasmodium vivax (23.7%) and mixed-species (3.8%). The highest prevalence was recorded in Kidist Hana (51.5%) followed by Robit (34.8%), Gorgora (30.3%), and Wusha Tiris (25%) health centres. In terms of months, the highest prevalence (37.5%) was detected in October whereas the lowest (14%) was in March. Logistic regression analysis revealed that gender (p = 0.023), educational level (p = 0.025), study month (p = 0.036), presence of eave in the house (p = 0.002) and wall openings (p = 0.041), not using bed nets (p = 0.001), sleeping in the same house with cattle (p = 0.031) and the distance between mosquito-breeding site and living house (p = 0.020) were explanatory risk factors significantly associated with malaria among studied participants.
    CONCLUSIONS: In this study, we confirmed that the occurrence of malaria prevalence was high and continued against the Ethiopian malaria elimination plan of 2021-2025. Therefore, to meet the goals of this plan, the current prevention and control efforts should be stepped up even better in the coming years.
    Keywords:  Ethiopia; Malaria; Plasmodium infection; Prevalence; Risk factor
    DOI:  https://doi.org/10.1186/s12936-022-04310-7
  13. Euro Surveill. 2022 Nov;27(44):
    Autochthonous dengue in mainland France, 2022: geographical extension and incidence increase.
    Investigation team
      France faced an unusual situation of dengue transmission in 2022, with 65 autochthonous cases spread over nine transmission events by 21 October. This exceeded the number of cases observed during the entire period 2010 to 2021. Six of these events occurred in departments that had never experienced autochthonous dengue transmission. We provide an update of dengue surveillance data in mainland France in 2022. The multiplication of transmission events calls for continuous adaption of preparedness and response to arbovirus-related risks.
    Keywords:  Dengue; autochthonous; mainland France; vector-borne disease
    DOI:  https://doi.org/10.2807/1560-7917.ES.2022.27.44.2200818
  14. Commun Med (Lond). 2022 ;2 134
    Spatio-temporal dynamics of three diseases caused by Aedes-borne arboviruses in Mexico.
    Bo Dong, Latifur Khan, Madison Smith, Jesus Trevino, Bingxin Zhao, Gabriel L Hamer, Uriel A Lopez-Lemus, Aracely Angulo Molina, Jailos Lubinda, Uyen-Sa D T Nguyen, Ubydul Haque.
       Background: The intensity of transmission of Aedes-borne viruses is heterogeneous, and multiple factors can contribute to variation at small spatial scales. Illuminating drivers of heterogeneity in prevalence over time and space would provide information for public health authorities. The objective of this study is to detect the spatiotemporal clusters and determine the risk factors of three major Aedes-borne diseases, Chikungunya virus (CHIKV), Dengue virus (DENV), and Zika virus (ZIKV) clusters in Mexico.
    Methods: We present an integrated analysis of Aedes-borne diseases (ABDs), the local climate, and the socio-demographic profiles of 2469 municipalities in Mexico. We used SaTScan to detect spatial clusters and utilize the Pearson correlation coefficient, Randomized Dependence Coefficient, and SHapley Additive exPlanations to analyze the influence of socio-demographic and climatic factors on the prevalence of ABDs. We also compare six machine learning techniques, including XGBoost, decision tree, Support Vector Machine with Radial Basis Function kernel, K nearest neighbors, random forest, and neural network to predict risk factors of ABDs clusters.
    Results: DENV is the most prevalent of the three diseases throughout Mexico, with nearly 60.6% of the municipalities reported having DENV cases. For some spatiotemporal clusters, the influence of socio-economic attributes is larger than the influence of climate attributes for predicting the prevalence of ABDs. XGBoost performs the best in terms of precision-measure for ABDs prevalence.
    Conclusions: Both socio-demographic and climatic factors influence ABDs transmission in different regions of Mexico. Future studies should build predictive models supporting early warning systems to anticipate the time and location of ABDs outbreaks and determine the stand-alone influence of individual risk factors and establish causal mechanisms.
    Keywords:  Epidemiology; Viral infection
    DOI:  https://doi.org/10.1038/s43856-022-00192-7
  15. Methods Mol Biol. 2023 ;2585 1-7
    Introduction to West Nile Virus.
    Shazeed-Ul Karim, Fengwei Bai.
      West Nile virus (WNV) is a mosquito-borne, single-stranded, positive-sense RNA virus belonging to the Flaviviridae family. After WNV gains entry through an infected mosquito bite, it replicates in a variety of human cell types and produces a viremia. Although the majority of infected individuals remain asymptomatic, the manifested symptoms in some people range from a mild fever to severe neurological disorder with high morbidity and mortality. In addition, many who recover from WNV neuroinvasive infection present with long-term deficits, including weakness, fatigue, and cognitive problems. Since entering the USA in 1999, WNV has become the most common mosquito-borne virus in North America. Despite the intensive research over 20 years, there are still no approved vaccines or specific treatments for humans, and it remains an urgent need to understand the pathogenesis of WNV and develop specific therapeutics and vaccines.
    Keywords:  Pathogenesis; Transmission; Viral proteins; West Nile virus
    DOI:  https://doi.org/10.1007/978-1-0716-2760-0_1
  16. Malar J. 2022 Nov 05. 21(1): 316
    The presence of Plasmodium malariae and Plasmodium knowlesi in near malaria elimination setting in western Indonesia.
    Irbah Rea Alvieda Nainggolan, Rycha Dwi Syafutri, Monica Nadya Sinambela, Clara Devina, Handayani, Beby Syofiani Hasibuan, Sriwipa Chuangchaiya, Paul C S Divis, Zulkarnain Md Idris, Ranti Permatasari, Inke Nadia Diniyanti Lubis.
       BACKGROUND: Indonesia is progressing towards malaria elimination. To achieve this goal, intervention measures must be addressed to cover all Plasmodium species. Comprehensive control measures and surveillance programmes must be intensified. This study aims to determine the prevalence of microscopic and submicroscopic malaria in Langkat district, North Sumatera Province, Indonesia.
    METHODS: A cross-sectional survey was conducted in six villages in Langkat district, North Sumatera Province in June 2019. Data were recorded using a standardized questionnaire. Finger pricked blood samples were obtained for malaria examination using rapid diagnostic test, thick and thin blood smears, and polymerase chain reaction.
    RESULTS: A total of 342 individuals were included in the study. Of them, one (0.3%) had a microscopic Plasmodium malariae infection, no positive RDT examination, and three (0.9%) were positive for P. malariae (n = 1) and Plasmodium knowlesi (n = 2). The distribution of bed net ownership was owned by 40% of the study participants. The participants had a house within a radius of 100-500 m from the forest (86.3%) and had the housing material of cement floor (56.1%), a tin roof (82.2%), wooden wall (35.7%), bamboo wall (28.1%), and brick wall (21.6%).
    CONCLUSION: Malaria incidence has substantially decreased in Langkat, North Sumatera, Indonesia. However, submicroscopic infection remains in the population and may contribute to further transmission. Surveillance should include the detection of microscopic undetected parasites, to enable the achievement of malaria elimination.
    Keywords:  Elimination; Indonesia; Malaria; North Sumatera; P. knowlesi; P. malariae
    DOI:  https://doi.org/10.1186/s12936-022-04335-y
  17. Parasit Vectors. 2022 Nov 03. 15(1): 405
    No association between habitat, autogeny and genetics in Moroccan Culex pipiens populations.
    Soukaina Arich, Yuki Haba, Najlaa Assaid, Megan L Fritz, Carolyn S McBride, Mylène Weill, Hassan Taki, M'hammed Sarih, Pierrick Labbé.
       BACKGROUND: Mosquitoes of the Culex pipiens complex are found across the globe and are the focus of many research studies. Among the temperate species C. pipiens sensu stricto (s.s.), two forms are usually described: molestus and pipiens. These two forms are indistinguishable in terms of morphology but show behavioral and physiological differences that may have consequences for their associated epidemiology. The two forms are well defined in the northern part of the species distribution, where autogeny is strictly associated with the molestus form. However, whether the two remain distinct and show the characteristic differences in behavior is less clear in North Africa, at the southern edge of their range.
    METHODS: The association between autogeny, as determined by ovarian dissection, and molecular forms, based on the CQ11 microsatellite marker, was studied in six Moroccan populations of C. pipiens.
    RESULTS: An overall low prevalence of autogeny was found at three of the Moroccan regions studied, although it reached 17.5% in the Agadir population. The prevalence of form-specific CQ11 alleles was quite similar across all populations, with the molestus allele being rarer (approx. 15%), except in the Agadir population where it reached 43.3%. We found significant deficits in heterozygotes at the diagnostic CQ11 locus in three populations, but the three other populations showed no significant departure from panmixia, which is in line with the results of a retrospective analysis of the published data. More importantly, we found no association between the autogeny status and CQ11 genotypes, despite the many females analyzed.
    CONCLUSIONS: There was limited evidence for two discrete forms in Morocco, where individuals carrying pipiens and molestus alleles breed and mate in the same sites and are equally likely to be capable of autogeny. These observations are discussed in the epidemiological context of Morocco, where C. pipiens is the main vector of several arboviruses.
    Keywords:  Autogeny; Culex; Morocco; Vector
    DOI:  https://doi.org/10.1186/s13071-022-05469-3
This page is being maintained by Thomas Krichel. It was last updated on 2024‒11‒22 at 4:24.