Search

Serology of West Nile virus vectors and non-human reservoirs was surveyed at Acapulco, Jose Azueta, and Ometepec, three Pacific Coast localities of Guerrero State, Mexico. The objectives of this study were to use enzyme-linked immnosorbent assay (ELISA) to assess West Nile virus antibodies of bird and equine serum samples and use reverse transcription of polymerase chain reaction (RT-PCR) to detect the virus in field-collected resting mosquitoes. Forty birds trapped using mist nets yielded 10% seroprevalence. Similarly, 18.6% of 102 equine blood samples had West Nile virus. In addition, 4,854 mosquitoes were caught using motorized backpack aspirators and grouped into 116 pools. Of the 16 species and seven genera, no mosquito was positive for West Nile virus. Our study demonstrated West Nile virus seroprevalence on resident birds and equines in Guerrero State, Mexico. [ABSTRACT FROM AUTHOR]

Background:Ehrlichia canis is transmitted by ticks causing Canine monocytic ehrlichiosis, which is considered one of the most critical tickborne pathogens. Materials and Methods: This study aimed to identify by PCR technique E. canis in ticks associated with dogs from urban and rural homes in Nuevo Leon, Mexico. The study was conducted at 13 localities in eight municipalities from 2012 to 2021. Results: A total of 1873 ticks of three species were captured: Amblyomma tenellum, Dermacentor variabilis, and Rhipicephalus sanguineus s.l. The overall infection rate of E. canis in ticks was 59.12% (149/252). Of the 15 sequences, three haplotypes were identified. Conclusion: The urban transmission cycle of canine ehrlichiosis is demonstrated, where the potential vector is the tick R. sanguineus s.l. [ABSTRACT FROM AUTHOR]

Simple Summary: Globally, current efforts to contain the transmission and spread of dengue, chikungunya fever, and Zika have not proven to be effective. Aedes aegypti is a mosquito that remains inside houses throughout the day, limiting some strategies such as outdoor spatial spraying and using nighttime nets treated or not with insecticides. It is also important to mention that vector control is completely reactive, as it is only used to respond to confirmed clinical cases that are susceptible to delays in reporting, and even worse, this activity is carried out with limited human, material, and financial resources. Therefore, there is an urgent need to reformulate current control strategies and enhance the household surveillance of adult populations to have a significant and measurable impact on infective mosquito populations and the transmission of these diseases. This study aims to design and evaluate a low-cost attractant sticky trap that provides significant surveillance results for monitoring the presence of indoor Ae. aegypti and relative density populations. Decision-making authorities may have access to field-realistic vectors and data from cases in time and space to establish a risk outbreak threshold and start implementing control measurements. Surveillance consists of systematic data collection, analysis, and interpretation and is essential for planning and implementing control activities. The lack of success in the control and surveillance of the Ae. aegypti mosquito elsewhere demands the development of new accessible and effective strategies. This work aimed to develop and evaluate an adhesive lure trap for household indoor surveillance of Ae. aegypti. Based on a bibliographic review, four compounds that have significant attraction percentages for Ae. aegypti were considered. Our more effective blend was determined through preliminary bioassays using the high-throughput screening system (HITSS) and 90 × 90 cm mosquito cages. We designed a low-cost, pyramid-shaped, sticky cardboard trap to incorporate the selected blend. Semi-field 2 × 2 m cages and field tests were utilized to evaluate its effectiveness through mosquito capture percentages. In laboratory tests, blend number 2 presented an attraction percentage of 47.5 ± 4.8%; meanwhile, in semi-field cages, a 4-inch, 110 v powered fan was used to disperse the attractants, and then a similar capture percentage of 43.2 ± 4.0% was recorded. Results were recorded during the field evaluation of the at-house indoor environment and were compared with those recorded with the golden-standard BG-Sentinel trap, i.e., our prototype trapped an average of 6.0 ± 1.5 mosquitoes versus 10.0 ± 2.6. In most Latin American countries, there is a lack of formal and accessible strategies for monitoring adult populations of Ae. Aegypti; therefore, we must develop tools that reinforce entomological surveillance methods. [ABSTRACT FROM AUTHOR]

One of the most important steps in biomedical longitudinal studies is choosing a good experimental design that can provide high accuracy in the analysis of results with a minimum sample size. Several methods for constructing efficient longitudinal designs have been developed based on power analysis and the statistical model used for analyzing the final results. However, development of this technology is not available to practitioners through user-friendly software. In this paper we introduce LADES (Longitudinal Analysis and Design of Experiments Software) as an alternative and easy-to-use tool for conducting longitudinal analysis and constructing efficient longitudinal designs. LADES incorporates methods for creating cost-efficient longitudinal designs, unequal longitudinal designs, and simple longitudinal designs. In addition, LADES includes different methods for analyzing longitudinal data such as linear mixed models, generalized estimating equations, among others. A study of European eels is reanalyzed in order to show LADES capabilities. Three treatments contained in three aquariums with five eels each were analyzed. Data were collected from 0 up to the 12th week post treatment for all the eels (complete design). The response under evaluation is sperm volume. A linear mixed model was fitted to the results using LADES. The complete design had a power of 88.7% using 15 eels. With LADES we propose the use of an unequal design with only 14 eels and 89.5% efficiency. LADES was developed as a powerful and simple tool to promote the use of statistical methods for analyzing and creating longitudinal experiments in biomedical research. [ABSTRACT FROM AUTHOR]

• Five Phlebotominae species of medical importance collected in northeastern Mexico. • Highest diversity, abundance and activity of Phlebotominae in northeastern Mexico. • New barcode information for Psathyromyia cratifer. • w Whi Wolbachia and human blood DNA in Lutzomyia cruciata and Psathyromyia cratifer. More than 90 species of phlebotomines are vectors of parasites, bacteria, and viruses, which cause disease in animals and humans. Therefore, their study is necessary to establish prevention and control strategies. Mexico is an endemic country for leishmaniasis, mostly in the center and southern regions of the country, yet only few studies have been conducted in the northern part of the country. The present study aims to: (a) assess the alpha diversity of Phlebotominae in an annual cycle, (b) to correlate climatic variables with abundance, (c) to generate barcodes of these insects as part of the integrative taxonomy, and (d) to detect Leishmania, Wolbachia and blood sources in an area close to where a case of autochthonous leishmaniasis has been detected in Nuevo Leon, Mexico. A systematic sampling was conducted during three consecutive nights from 17:00 to 22:00 h., placing Shannon traps, CDC traps with incandescent light, and BG Sentinel 2 + BG Lure traps. A total catch effort of 660 nights/traps/hours was achieved, in which a total number of 707 phlebotomines (58% female and 42% male) of six species were collected and identified. The most abundant species were Psathyromyia cratifer (57%) and Psathyromyia shannoni sensu stricto (26%). The highest abundance (72%; 507/707) was collected during March, April and May 2021. Barcodes were generated for four species of phlebotomines, which represent new records for Mexico. For the molecular detection of microorganisms, 302 specimens were analyzed, although no specimens were positive for Leishmania spp. Wolbachia strains were detected in phlebotomines with an infection rate of 1.32% (4/302) and found in Pa. cratifer and Lu. cruciata. Likewise, human DNA was identified in female Lu. cruciata and Pa. cratifer phlebotomines. These findings indicate the presence of potential vector species of the parasite Leishmania spp. This result shows the need for further entomological surveillance to elucidate the transmission mechanisms in these northern areas of the country. [Display omitted] [ABSTRACT FROM AUTHOR]

A trap made from low-cost materials and using an attractant of a yeast mixture producing carbon dioxide was designed and evaluated to collect adult Aedes aegypti (L.) mosquitoes. The Trap Mosquito Box prototype was tested against the "standards" BG-Sentinel traps and CDC backpack aspirator in the field. The mean numbers of mosquitoes (± standard deviation) caught by the three different collection methods were: Trap Mosquito Box 2.42 (± 3.08), BG-Sentinel trap 2.86 (± 3.71), and backpack aspirator 0.59 (± 0.90). Statistical tests showed the Trap Mosquito Box and BG-Sentinel trap were equally effective in collecting A. aegypti and both methods were significantly different than the backpack aspirator. Emission of carbon dioxide produced by the yeast mixture was greatest during the first hours after incubation in a laboratory and captured the most mosquitoes in the Trap Mosquito Box. Production of carbon dioxide [Y = -631.24 + 941.26 (log x)] and the rate of mosquitoes captured per time period [Y = 20.29 + 23.50 (log x)] were best explained by logarithmic regressions. Advantages and disadvantages of the Trap Mosquito Box for mosquito surveillance are discussed. [ABSTRACT FROM AUTHOR]