Diagnosis and Genomic Characterization of the Largest Western Equine Encephalitis Virus Outbreak in Uruguay During 2023–2024

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Diagnosis and Genomic Characterization of the Largest Western Equine Encephalitis Virus Outbreak in Uruguay During 2023–2024. Tomas, G. et al. 2024, Research Square Preprint.

Abstract [shortened]. The most recent large outbreak of WEEV occurred in the Southern cone of South America from November 2023 to April 2024, affecting many equines and humans in Argentina and Uruguay. The virus affected 1,086 horses and caused 388 deaths in all regions of Uruguay. We obtained genomes from 15 strains using a novel multiplex PCR assay combined with next-generation Illumina sequencing. The phylogenetic analysis revealed that samples from Uruguay and Brazil collected during 2023–2024 and an Argentine strain from 1958 share a common evolutionary origin and are distinct from North American strains. Phylogenetic and epidemiological data on the outbreak suggest that it originated in Argentina and spread to Uruguay and Brazil, likely by movements of infected birds. Genomic analysis also revealed mispairing in real-time PCR primers and probes that may affect official diagnostic protocols, highlighting the need for assay updates. Our research emphasizes the need to map the genetic diversity of WEEV in South America to understand their epidemiology and develop effective control approaches.

Note: Although the WEEV strains isolated here differed from those historically found in North America, the recent introduction of SLEV strains found in California were most similar to historical isolates from Argentina, perhaps indicating a proven path for introduction. Comments concerning RT-PCR diagnosis were similar to minor problems CVEC encountered detecting WNV using the current RT-PCR probes and problems encountered developing the current WEEV probes.

Full Paper

MVCAC Annual Conference Hotel Scam

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MVCAC has become aware of companies contacting our exhibitors and possibly our members, falsely claiming to be a housing bureau authorized to secure rooms at the Oakland Marriott where the MVCAC Annual Conference will be taking place next year. We want to remind you to book your conference hotel room only through the official MVCAC booking link.

These entities may offer rooms at purportedly discounted rates. Please be aware that these are unauthorized third-party entities without any affiliation with MVCAC or the Oakland Marriott. They have no authority to make reservations on behalf of attendees.

These companies may book rooms for you at fully prepaid rates with no option for cancellation or changes, and they offer no support if issues arise with your reservation. They are essentially poachers of hotel room blocks. 

The only legitimate way to reserve accommodations for any MVCAC event is through the booking link provided directly by us in partnership with the hotel. Reservations made through any other means will not be credited within our block and could potentially put us in an attrition risk.

We are actively monitoring this situation and urge you to inform us if you are contacted by such companies. Unfortunately, there is little recourse against their actions.

Booking through the official MVCAC booking link ensures both you and MVCAC are protected! Find the booking link here.

Duration of Fever in Patients with Dengue: A Systematic Review and Meta-Analysis

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Duration of Fever in Patients with Dengue: A Systematic Review and Meta-Analysis. Gupta, N., et al. Am.J. Trop. Med. Hyg., 111(1), 2024, pp. 5–10. doi:10.4269/ajtmh.23-0542.

Abstract [Shortened]. There is a need to establish the average fever duration with a confidence interval among patients with dengue. Studies up to October 21, 2022 from two databases (PubMed and Embase) were included using the search terms related to dengue and duration of fever. Studies where the average duration of fever was available were included for systematic review. A total of 643 articles were included from the two databases after duplicate deletion. After two rounds of screening, 31 articles (n 57,905) were finally included. The mean duration of fever in the 20 articles included for meta-analysis was 5.1 (95% CI: 4.7–5.5) days. Longer duration of fever was seen in those with a higher grade of fever, those with higher disease severity, and those with concurrent bacterial infections.

Note: The is considerable overlap between the onset of febrile and viremia stages following dengue infection, especially as it relates to infectivity to mosquitoes [see ]. Most likely the onset of fever is the first indication of illness to the patient and may provide a ‘skeletal’ timeline for the 1st recognition of the onset of dengue viremia. As the time window is short, early detection and reporting are important for surveillance to detect infected Aedes and possible secondary infections.

Full Paper

Call for Research Proposals – Coachella Valley Mosquito and Vector Control District

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The Coachella Valley Mosquito and Vector Control District is requesting research proposals. This funding opportunity is aimed at improving our Integrated Vector Management Program targeting mosquitoes, red imported fire ants, and flies in the Coachella Valley. Past research projects have included spatial mosquito repellents, virus transmission models, vegetation management in wetlands, biological control of fire ants, and activity of house flies. Because of the unique environment including very high temperatures and low precipitation, projects designed to work with the environmental conditions for surveillance of vectors and vector-borne diseases and projects that tailor control methods to the habitat here are of great interest.

Please see our website for guidelines on proposal submission, interests of the District, and a budget worksheet (you can obtain these at https://www.cvmosquito.org/bids-rfqs-rfps under Research Program FY 2024-2025).

Supervising Vector Ecologist – County of San Diego

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Job description: Supervising Vector Ecologists are assigned to the Department of Environmental Health and Quality and supervise the work of professional, technical and support personnel, and are responsible for planning, organizing and coordinating multiple program areas throughout the county involved in vector-borne disease and vector nuisance abatement through surveillance, identification, analysis, prevention, and control of vertebrate and invertebrate vectors, their hosts, and sources. This position oversees compilation, preparation, analysis, and presentation of reports, records, documents, and other information pertaining to vector biology, vector-borne disease surveillance, and vector prevention efforts.

Apply here. 

District Manager – Churchill County Mosquito, Vector, & Noxious Weed Abatement District

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Job description: This position will be selected by a Board of Trustees and in a public meeting. All application paperwork, memos, and resumes may be considered public records. Definition: The District Manager, under the general direction of the Board of Trustees, acts as the executive officer of the District. This person organizes, plans, directs, and delegates the operations of the District, and represents the District and the Board of Trustees in its relations with the community, media, and other agencies. The District Manager handles a wide variety of complex managerial and technical mosquito and weed ecology functions, and programs and performs related work as required. This person acts with a high degree of discretion and integrity in making program, fiscal, operational, personnel, and technical entomological decisions under routine and emergency conditions.

More Information

Apply Here

Territory Sales Representative – Mosquito Control Products – Southern CA

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Job description: Clarke – the leading provider of solutions for public health mosquito control is seeking to hire an Outside Sales professional to drive the growth of our Mosquito Control products business in Southern California and surrounding geographies. With Clarke, you are a trusted consultant – designing and offering solutions to help your customers to control mosquitoes and the risk of mosquito borne disease within their communities. As you would expect in an outside sales role, your schedule will vary depending on the time of the year. During the Spring and Summer months, you can expect to spend a significant amount of time traveling and calling on mosquito control districts and municipalities to help them to prepare for and manage their busy mosquito season. During other parts of the year, you will conduct educational workshops, attend regional and national meetings, develop your sales strategy, plan, forecast and budget, and participate in customer trials to provide support and stewardship in the launch of Clarke’s innovative mosquito control products. 

Click here to apply

Job description

Summer Legislative Recess

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Legislators will be home in their districts from July 4-August 2. This is a great time to schedule a meeting at their district office or invite them to tour your MVCD. On the Leg Day Google site you can find a list of legislators and the collateral materials used for Leg Day in Sacramento. You can also find resources in the Grassroots Advocacy Toolkit which includes a compilation of outreach best practices, a sample tour invite email, a mosquito 101 presentation, and an evergreen story map for you to use when inviting and hosting a legislator at your district. 

Seasonal Vector Control Assistant – Placer Mosquito and Vector Control District

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The Placer Mosquito and Vector Control District is seeking seasonal staff to assist in mosquito and vector surveillance, control, and other support roles. Our District is based in Roseville, CA and serves all of Placer County.

Position Status: Temporary, Full-Time
Application Deadline: Open until filled

Positions will be assigned to mosquito duties that may involve field work, laboratory work or a combination of both and will necessitate driving around the County in a District vehicle. This position can expect to be assigned a range of duties that support the District’s mission to protect
public health.

All positions will be based at District headquarters in Roseville; however, work area may change depending on need and be anywhere in Placer County.

Duties may include, but are not limited to, some or all of the following:

• Observe, assess, and inspect areas for immature and adult mosquito presence or habitat
• Collect samples of mosquito larvae that occur in many different habitats both urban and rural
• Apply mosquito control insecticides under the supervision of a certified vector control technician
• Assist with mosquito control efficacy testing operations during daytime and nighttime hours as requested
• Collect and prepare mosquito samples for further identification or disease testing
• Communicate District messages when interacting with members of the public
• Use a laptop or other device to collect and enter field data
• Safely operate and navigate District vehicles to perform work-related activities

Full Job Posting

Apply Here

93rd Annual MVCAC Conference – Call for Papers

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The theme for the 93rd Annual MVCAC Conference is “Vector Control- A path to a more hospitable world”. The prime topics for consideration are below but please consider submitting even if your paper does not fit into one of these topics. All submissions will be considered. The deadline for submission has been extended to October 18, 2024. Requests made following this date may not be honored and may not appear in the conference program.

  • Network System Security Preparedness
  • Droplet Deposition/Characterization
  • Data Visualization Tools/CalSurv
  • Reducing Vector-borne Disease Risk through Messaging Campaigns
  • Vertebrate Vector Control
  • Vector-borne Disease in California
  • WNV, SLE, Zika, Dengue, Malaria
  • Hantavirus, Plague, Typhus
  • Invasive Aedes Successes & Failures
  • Novel Mosquito Control Trials
  • Application Equipment
  • 3D Printing Symposium
  • Mosquitofish Rearing & Transport
  • Suspect Pool ID Access and treatment strategies

Questions? Please reach out to Senior Meeting Manager, Rachel Hickerson at rhickerson@amgroup.us.

CLICK HERE TO SUBMIT

National Mosquito Control Awareness Week – June 16-22, 2024

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National Mosquito Control Awareness Week, observed June 16-22, 2024, educates residents about mosquitoes and how to help prevent the spread of mosquito-transmitted diseases. Join us in spreading the word within your districts by posting our press release and on social media using our content calendar.

MVCAC Corporate Member Fiscal Status Report Submission for 2024-25 Dues

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It’s that time of year again! Please fill out and email or fax back this year’s MVCAC Fiscal Status Report Form for your district’s MVCAC dues to be calculated.

Dues for Corporate Members are due on July 1st of each year for the fiscal year ending June 30th of the following year. Unpaid dues will be considered late on September 1st. After September 1st, a late notice will be sent which will include a $50 late payment fee. Corporate members that do not pay their dues and late fee by October 31st will be dropped from the membership rolls.

If you are interested in continuing to contribute to the West Nile Virus Call Center and indicate the amount you would like to contribute. That information then will be passed along to Heluyna Health who will provide the billing. MVCAC is only providing them the information and not providing billing services.

Second, as more and more work is being done assisting our International districts, we established a fund to help offset costs if a district member should want to go help with these efforts but may have a district that cannot fully provide monetary support. If you are able to give a little bit into this fund, please note on the dues sheet how much and we will bill you for the amount. This fund is not being budgeted into our annual budget, will only show as a pass through amount and will not be used for any other association costs.

Also, please do note that if you pay your membership dues via credit card, we will then bill you for the credit card fee per MVCAC policy.

Please feel free to contact the office if you have any questions. Thank you for supporting MVCAC. 

Fill Out Form Here

2025 MVCAC Plenary Speaker Announced

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Monday morning,  January 27

Historical and Personal Reflections on Mosquito Ecology and Control

Phil Lounibos, PHD

Bio:

A sixth-generation Californian, Phil Lounibos grew up on a chicken farm in Petaluma. He attended the University of Notre Dame, where he was introduced to mosquito research in the lab of the late George Craig. After a PhD in biology at Harvard University, as a postdoctoral fellow at the Mosquito Biology Unit of the International  Centre for Insect Physiology and Ecology, he oversaw the first trials for genetic control of Aedes aegypti on the Kenya coast and performed independent research on other East African container mosquitoes. From 1977-2017, from the Florida Medical Entomology Laboratory he conducted in both Florida and South America ecological, behavioral, and physiological studies on a wide range of mosquito species. The ecology of invasive mosquito species, especially Ae. aegypti  and Aedes albopictus, and mechanisms of displacement and segregation, were major themes of his final two decades of research at FMEL, funded by NIH. Lounibos mentored numerous graduate students and postdocs as a faculty member of the University of Florida.

SB 1251 (Stern) Passed the Senate

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SB 1251 (Stern), sponsored by MVCAC, passed the Senate almost unanimously and now goes on to the Assembly. SB 1251 would allow mosquito control districts to request a plan be filed with utility corporations for the purposes of entering into vector management agreements within 6 months of a request being sent. We will keep you posted on when the bill will be heard next.

May is Lyme Disease Awareness Month

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Nymphal Ixodes pacificus are most active in the spring and early summer in California. These tiny ticks pose a greater risk of transmitting Lyme disease.\

Messaging and resources to share in May:

  • Weblinks:

MVCAC- California Air Resources Board Fact Sheet

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Beginning in 2024, the California Air Resources Board (CARB) is implementing new equipment and vehicle regulations to limit the purchase of gasoline powered equipment and promote the use of electric instead. The MVCAC Regulatory Affairs and IVM Committees have created a fact sheet to guide the membership through these changes.

VIEW FACT SHEET.

Want insecticide resistance training and testing in your area?

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If you would like to collect and test mosquito (Aedes or Culex) samples for insecticide resistance, PacVec provides training and testing services at no charge. Michael Bollinger in Dr. Anton Cornel’s laboratory is leading this activity and is available to discuss testing strategies or to provide on-site training on bottle bioassay testing in your area. We offer three options for testing or training:

1. Partnering with a local agency to host a resistance testing workshop that includes the host agency and neighboring agencies in a single event.

2. Partnering with a local agency to perform mosquito collection and testing with the agency’s staff.

3.Collecting and testing mosquitoes from areas where data are lacking with/without involvement of local agency staff.

Any of the above activities will yield immediate data to guide your control decisions. Involvement of local agency staff is ideal to provide a learning experience. If a single agency would like to host a training that can involve neighboring agencies, that is also very helpful to increase the value of each workshop. If larval bioassays are wanted in addition to CDC bottle bioassays, please let us know that as well.

Contact us as soon as possible at bioassays@pacvec.us to make plans for summer testing and training.

 

Call for Nominations: Treasurer Position at MVCAC!

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Dear MVCAC Members,

The Mosquito and Vector Control Association of California (MVCAC) is excited to announce an open call for nominations for the position of Treasurer. This is a pivotal role within our organization, responsible for overseeing the financial affairs that drive our mission forward.

We are thankful to our long-time Treasurer David I’Anson for his work in the role and wish him well as he heads into other volunteer endeavors.

With that, we are now soliciting nominations for our Treasurer to be sworn-in at the July Board of Directors Meeting.

Per our bylaws, the Treasurer serves as a non-voting member of the Board and holds a term of three years, with the possibility of reappointment for a second term subject to the approval of the Board. As the financial steward of MVCAC, the Treasurer plays a crucial role in maintaining our fiscal health and ensuring compliance with all financial reporting and tax requirements applicable to nonprofit organizations.

The duties and responsibilities of the Treasurer include, but are not limited to:

  • Receiving and reviewing monthly financial reports, including investment reports.
  • Presenting the financial report at each board meeting.
  • Collaborating with staff to develop and present the annual budget.
  • Serving as custodian for all MVCAC financial accounts and approving all financial transactions.
  • Ensuring compliance with all financial reporting and tax requirements applicable to nonprofit organizations.

To be eligible for nomination, candidates must meet the following qualifications:

  • Active membership in MVCAC (required).
  • Understanding of financial and tax reporting requirements for nonprofit organizations.

We invite you to nominate yourself or encourage fellow member who possesses the necessary skills, experience, and dedication to serve as MVCAC’s Treasurer. Nominations can be submitted by emailing MVCAC Executive Director Megan MacNee at mmacnee@amgroup.us  no later than May 30th.  Please include a brief statement outlining the nominee’s qualifications and commitment to the role.

The MVCAC Nomination’s Committee will review the nomination and make a recommendation to the board in July.

Thank you for your continued support and engagement in advancing the mission of MVCAC. Together, we can make a meaningful impact in mosquito and vector control efforts across California.

Successful introgression of wMel Wolbachia into Aedes aegypti populations in Fiji, Vanuatu and Kiribati.

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Simmons CP, Donald W, Tagavi L, Tarivonda L, Quai T, Tavoa R, et al. (2024)Successful introgression of wMel Wolbachia into Aedes aegypti populations in Fiji, Vanuatu and Kiribati. PLoS Negl Trop Dis 18(3): e0012022. https://doi.org/10.1371/journal.pntd.0012022

Abstract. Introgression of the intracellular bacterium Wolbachia pipientis (wMel strain) into Ae. aegypti populations reduces their vector competence and consequently lowers dengue incidence in the human population. Here we describe successful area-wide deployments of wMel-infected Ae. aegypti in Suva, Lautoka, Nadi (Fiji), Port Vila (Vanuatu) and South Tarawa (Kiribati). With community support, weekly releases of wMel-infected Ae. aegypti mosquitoes for between 2 to 5 months resulted in wMel introgression in nearly all locations. Long term monitoring confirmed a high, self-sustaining prevalence of wMel infecting mosquitoes in almost all deployment areas. Measurement of public health outcomes were disrupted by the Covid19 pandemic but are expected to emerge in the coming years.

Note: Successful introgression into these ‘closed’ island populations was encouraging and should reduce dengue disease cases. However, this DID NOT impact the Ae. aegypti nuisance biting pressure and therefore might not be a useful tool in areas with low arbovirus transmission.

Click Here for Full Abstract

West Nile Virus and Dead Bird Call Center Now Live

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The California WNV and Dead Bird Call Center opened for the season on Monday, April 8, 2024. Now through mid-October, members of the public can report a dead bird by calling 1-877-WNV-BIRD (1-877-968-2473). Online reporting continues to be available year-round at: https://westnile.ca.gov/report. 

For questions about Call Center operations, please contact: Marie.Cerda@cdph.ca.gov.

As you plan for the upcoming WNV season, CDPH has resources available to assist your communication and outreach efforts:

Roaming Dogs, Intense Brown Dog Tick Infestation, and Emerging Rocky Mountain Spotted Fever in Tijuana, Mexico.

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Foley J., et al. Am. J. Trop. Med. Hyg., 00(00), 2024, pp. 1–16 doi:10.4269/ajtmh.23-0410

Abstract. A two decades–long epidemic of Rocky Mountain spotted fever in northern Mexico reached the U.S. border city of Tijuana in 2021. Cases were near the city periphery in marginalized areas, some lacking infrastructure such as streets or utilities. We worked in the three census areas where human cases were reported and in 12 additional control Areas Geoestadisticas Basicas. Of 191 examined dogs, 61.8% were tick-infested, with 6-fold increased odds if they were allowed to roam. Although no dogs were Rickettsia polymerase chain reaction–positive, we found one R. rickettsii and 11 Rickettsia massiliae–infected ticks. The rickettsial IgG seroprevalence by immunofluorescence antibody assay was 76.4%, associated with unhealthy body condition, adults, dogs with> 10 ticks, more dogs being seen in the area, and dogs being permitted in the street. Insufficient medical and canine management resources have contributed to a case fatality rate of RMSF that has exceeded 50% in areas. High canine seroprevalence suggests risks to people and dogs; unfortunately, herd immunity is impeded by high turnover in the canine population owing to the birth of puppies and high death rates. Binational One Health workers should monitor disease spread, enact canine population management and tick eradication, and provide prevention, diagnostic, and treatment support.

Note: Abandoning dogs in Mexico by legal and illegal immigrants may only add to this public health issue and perhaps provide some risk for border communities.

Surveillance of Fleas and Their Small Mammal Hosts for Plague Risks in Some Main Seaports of the Islands of the Southwestern Indian Ocean.

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M. Harimalala et al. Am. J. Trop. Med. Hyg., 110(2), 2024, pp. 311–319. doi:10.4269/ajtmh.23-0363.

Abstract. Beginning in the 1920s/1930s, rodent and flea surveillance was carried out as part of plague hazard management in seaports of the world. Nowadays, such activity is not done regularly. In the southwestern Indian Ocean (SWIO) region, plague surveillance is of great importance given plague endemicity in Madagascar and thus the incurred risk for neighboring islands. This study reports animal-based surveillance aimed at identifying fleas and their small mammal hosts in 5 SWIO seaports as well as Yersinia pestis detection: Madagascar (Toamasina and Mahajanga), Mauritius (Port Louis), and the Union of Comoros (Moroni and Mutsamudu). Mammals were euthanized and their fleas collected and morphologically identified before Y. pestis detection. In total, 145 mammals were trapped: the brown rat Rattus norvegicus (76.5%), the black rat Rattus rattus (8.3%), and the Asian house shrew Suncus murinus (15.2%). Fur brushing allowed collection of 1,596 fleas exclusively identified as Xenopsylla cheopis. All tested fleas were negative for Y. pestis DNA. This study shows that both well-known plague mammal hosts and flea vectors occur in SWIO seaports. It also highlights the necessity of carrying out regular animal-based surveillance for plague hazard management in this region.

Note: This study describes a high X. cheopis flea index among mammals collected at SWOI port areas. With increasing global trade from a variety of sources and routes, it would seem MVCAC agencies that include port areas should be aware of this continuing threat to the public health and the importance of the proper use of rodent guards on ship mooring lines.

Don’t Forget – Send Your Legislative Day Thank You Notes ASAP!

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Thank you to all those who joined us last week for MVCAC’s Legislative Day in Sacramento. There is one more step to help us MVCAC make a lasting impact on those we’ve met.
 
If you haven’t already had the chance, take a few minutes and send a quick thank you note to those you met with. You can find a template letter you can use on the MVCAC Leg Day site here.
 
Didn’t make it to Legislative Days, feel free to save this letter to work off on future visits with your local electeds. 

Female Aedes aegypti mosquitoes use communal cues to manage population density at breeding sites.

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Costa-da-Silva AL, et al.

COMMUNICATIONS BIOLOGY | (2024) 7:143 | https://doi.org/10.1038/s42003-024-05830-5 | www.nature.com/commsbio 1 1234567890

Abstract: Where a female mosquito lays her eggs creates the conditions for reproductive success. Here, we identify a communal behavior among ovipositing female mosquitoes. When choosing equal breeding sites, gravid Aedes aegypti aggregate more often than expected. This aggregation occurs when water contact is restricted and does not require the presence of eggs. Instead, the aggregation is regulated by the number of females present at the breeding site. Using assays with both occupied and empty oviposition sites, we show that the Orco olfactory co-receptor and a carbon dioxide receptor, Gr3, detect the presence of mosquitoes. Orco mutants aggregate more often in empty sites, suggesting attractive olfactory cues influence females to associate with one another. Gr3 mutant females do not prefer either site, suggesting that the CO2 receptor is necessary to evaluate mosquito population density at breeding sites. Further, raising CO2 levels is sufficient to cause wild-type mosquitoes to avoid empty oviposition sites. Our results demonstrate that female mosquitoes can regulate their own population density at breeding sites using attractive and repellent communal cues.

Note: These results are based on a series of well done laboratory choice experiments that begin to tease apart the patterns of oviposition site choice and therefore the distribution of this mosquito in nature — information useful for surveillance and control.

Emerging and lesser-known arboviruses impacting animal and human health

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A Faraji1, G Molaei, T Andreadis. J Med Entomol, 60(6), 2023, 1139–1141.

https://doi.org/10.1093/jme/tjad140.

In an effort to address problems surrounding emerging vector-borne pathogens, we have dedicated a series of Forum Articles for a special issue of the Journal of Medical Entomology titled “Emerging and Lesser-Known Arboviruses Impacting Animal and Human Health”. It is our hope that this series will further contribute to our understanding of these lesser-known arboviruses for the benefit of vector control personnel, clinicians, and public health stewards within a One Health approach. This issue will encompass arboviruses transmitted by biting midges (Diptera: Ceratopogonidae), mosquitoes (Diptera: Culicidae), and hard ticks (Ixodida: Ixodidae).

Note: Included within this series are papers on Cache Valley, Jamestown Canyon and Snow shoe hare, viruses thought to occur in California [see Reeves’ Monograph published by the MVCAC], but not included within current molecular surveillance diagnostics.

The mosquito knows no borders: Regional challenges for global confrontation in the dengue battle

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Barcante JMP, Cherem J (2024)

https://doi.org/10.1371/journal.pntd.0011830

Note: Paper reviews the increasing international public health importance of dengue and calls for improved prevention focusing on vector control. The remarkable increase in cases throughout Central and South America undoubtedly will increase the risk of cases imported into California. The expanding distribution and abundance of Aedes aegypti concurrently will increase the risk of local transmission.

Do it yourself: 3D-printed miniature CDC trap for adult mosquito (Diptera: Culicidae) surveillance

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Bibbs CS, Reissen N, Dewsnup MA, Sorensen RB, Faraji A, White GS (2024)

https://doi.org/10.1371/journal.pntd.0011899

Abstract: 3D printing could improve the accessibility of the CDC trap by eliminating some of the supply chain variables. We present here several trials with the Salt Lake City (SLC) trap, a three-dimensional (3D) printed trap design. No statistically significant differences were found when comparing CO2 line height(above vs. below fan), battery types (sealed lead acid vs. USB battery pack), and trap body collection shape (funnel body vs. simple/straight body). The SLC trap was compared directly to a commercial equivalent, the Clarke ABC trap, with comparative assessment on species diversity and abundance and found to be statistically equivalent on all metrics. Our final design is presented here with the publicly published stereolithography (STL) files and a detailed outline of the transport container system.

Note: This trap design was presented at the Annual MVCAC conference and is cited here for reference.

Response to An Outbreak of Locally Transmitted Dengue in Key Largo, FL

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The Florida Keys Mosquito Control District. J Am Mosq Control Assoc., 39 (4), 2023, pp. 251–257.

Doi: https://doi.org/10.2987/23-7145

ABSTRACT: Seventy-two cases of locally acquired dengue were contracted by residents and visitors of Key Largo, FL, in 2020. The primary vector, Aedes aegypti, has been a large focus of the Florida Keys Mosquito Control District’s (FKMCD) control measures for over a decade. This paper recounts the 2020 outbreak of DENV in Key Largo, FL, and the FKMCD’s Ae. aegypti operational response. The overall House Index (13.43%) during the outbreak was considered high (>5%) risk for local transmission. Larval habitat characterized from property inspections was similar to previous larval and pupal habitat studies. Adult surveillance of the active dengue transmission area provided 3 positive pools out of 1,518 mosquitoes tested resulting in a minimum infection rate of 1.976. Increased personnel response with long-term larvicide formulations and increased aerial, truck, and handheld ultra-low-volume adulticide control measures quickly reduced the Ae. aegypti surveillance numbers below the action threshold. No active cases of dengue have been reported since October 2020.

Note: This article provides a case study of one district’s response to a local dengue outbreak. Here, two initial cases were reported on 3 Mar 2020 but subsequent suspect cases were not recognized until 17 Jun after considerable transmission. Two cases that occurred in Jan 2020 were not reported until late 2021. This cascade of events clearly shows the importance of case surveillance and reporting and fits well with our conference discussions as districts review existing response plans following California’s first two cases of locally transmitted dengue.

MVCAC 2024 Yearbook Questionnaire

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Please take a moment to provide the MVCAC office with your agency’s information for 2024. Contact the MVCAC office at
(916) 440-0826 with any questions about this form.

This questionnaire is due via e-mail or fax to MVCAC by February 29, 2024. If a questionnaire is not received from your agency by the deadline, the MVCAC office will list your agency’s information from the 2023 Yearbook in the 2024 Yearbook.

View the form

Tick Resources Reminder

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Adult Ixodes pacificus ticks are most active in California from fall through early spring. Now is a great time to encourage repellent use and tick checks for tick bite prevention.

For sample messaging and educational materials about ticks and tick bite prevention, please visit go.cdph.ca.gov/ticks and the following resources:

2024 Sentinel Chicken Order Forms Available Now!

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ORDER NOW!

Chickens are being supplied by Gemperle Family Farms in Turlock, CA

Please return order form by March 1, 2024 Via email or fax to 916-444-7462

Northern and Southern Region

Pick-up date: Mid-April. Specific date, and location TBD (Turlock/Hilmar area)

 

The address for the farm will be provided as soon as we have it.

Questions: please email or call R’Mani White in Membership at rwhite@amgroup.us or (916) 440-0826 ext 125.

Epidemiological Update — Western Equine Encephalitis in the Region of the Americas

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January 10, 2024

Summary of the situation: On 19 Dec 2023, the Pan American Health Organization/World Health Organization (PAHO/WHO) warned about the risk to human health associated with the circulation of the western equine encephalitis virus (WEE). From that date until 9 Jan 2024, 374 additional outbreaks (equine outbreak: occurrence of one or more cases of WEE in equines) in animals were reported (338 in Argentina and 36 in Uruguay) and 21 human cases, all of them in Argentina. Note: Human cases of WEEV have been absent from Argentina for more than 2 decades, similar to the long time absence of WEEV from California. We should remember that the SLEV strains now circulating in the SW USA [including California] were most closely aligned with strains previously isolated from Argentina, perhaps establishing a route/corridor for introduction by migrant birds? Testing Culex mosquitoes by triplex during 2024 would again seem prudent.

Read full article here

Surveillance of Flea-Borne Typhus in California, 2011–2019

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Yomogida K, Kjemtrup A, et al. Am. J. Trop. Med. Hyg., 110(1), 2024, pp. 142–149.

doi:10.4269/ajtmh.23-0272.

Abstract. Flea-borne typhus (FBT) is an acute febrile disease in humans caused by the bacteria Rickettsia typhi. In California, healthcare providers and testing laboratories are mandated to report to their respective local public health jurisdictions whenever R. typhi or antibodies reactive to R. typhi are detected in a patient. This study characterized the epidemiology of 881 flea-borne typhus cases in California from 2011 to 2019, with most cases reported among residents of Los Angeles and Orange Counties (97%). Demographics, animal exposures, and clinical courses for case patients were summarized. Additionally, spatiotemporal cluster analyses pointed to five areas in southern California with persistent FBT transmission.

Note: Additional detailed information has been published in the Proceedings of the MVCAC Annual Conference.

Call for Volunteers

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Are you attending MVCAC 2024 in Monterey, CA?!? 

We are hosting an AMCA YPs booth at the upcoming MVCAC annual meeting in Monterey, CA! To make this event a success, we are seeking enthusiastic volunteers to assist with the YPs booth and various conference logistics. If you are attending, volunteer at our AMCA YPs booth! Connect and engage with your fellow California YP peers and seasoned professionals. If you’re eager to be a part of this dynamic experience, please complete the volunteer form: bit.ly/24MVCAC_YPsBooth

Biologist, Delta Mosquito and Vector Control District

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Description: Under the general direction of the Scientific Program Manager, the Biologist conducts a variety of field and laboratory procedures to support the District’s vector and vector-borne disease surveillance programs and completes other related tasks that support the District mission as required.

POSITION STATUS Full-time, FLSA exempt, probationary position.

APPLICATION PROCESS Please send CV/Resume, cover letter and application to: a.troupin@deltamvcd.gov.

DISTINGUISHING CHARACTERISTICS The Biologist position differs from the lower class of Laboratory Technician II in that the Biologist must obtain and maintain the California Department of Public Health Vector Control Technician certification in Categories A, B, C, and D. Biologists are qualified to perform laboratory operations including vector surveillance, vector-borne pathogen surveillance, insecticide resistance monitoring, insectary tasks, and fish hatchery tasks. Additionally, Biologists assist in purchasing laboratory supplies, inventory, preparing reports, maintaining laboratory equipment and facilities, and are encouraged to actively participate in Mosquito and Vector Control Association (MVCAC) and publishing in peer-reviewed journals.

Apply Here

CalSurv Seeking Examples of Visualizations and Data Summaries

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The CalSurv development team is seeking examples of visualizations and data summaries your agency includes in reports. If you’re willing to submit examples of reports that are useful to you, we’ll do our best to incorporate some of the examples in our workshops and resources. Please upload any example reports here.

 

If you missed our October training on creating your own reports in R using the new VectorSurv API, it’s not too late! You can check out the video on our YouTube channel. To get periodic updates from our team, sign up for our newsletter here.

Large-scalereleases and establishment of wMel Wolbachia in Aedes aegypti mosquitoes throughout the Cities of Bello, Medellı´n and Itagu¨ı´, Colombia. PLoS Negl

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Velez ID, Uribe A, Barajas J, Uribe S, A´ ngel S, Suaza-Vasco JD, et al. (2023)

Trop Dis 17(11): e0011642.

https://doi.org/10.1371/journal.pntd.0011642

The introduction of the naturally occurring wMel Wolbachia strain into Aedes aegypti mosquitoes has been shown to reduce the ability of the mosquitoes to transmit dengue and other viruses. Following engagement with communities to gain acceptance and support, a series of large-scale releases of Ae. aegypti mosquitoes that contained wMel Wolbachia, were undertaken across the cities of Bello, Medellı´n and Itagu¨ı´ in Colombia. These releases were undertaken under operational conditions with the aim of rapidly scaling the intervention in response to the Zika virus crisis. Mosquito populations were monitored during and after releases to determine the levels of Wolbachia and whether it persisted in the local mosquitoes. Wolbachia was found to be stable and established at consistent levels in local mosquito populations in the majority of areas. On-going monitoring in these areas will determine whether Wolbachia persists and also whether it establishes at a high level in the remaining areas. This intervention forms the basis of an epidemiological study to assess the impact of operational deployment of wMel Wolbachia on the reduction of the incidence of notified dengue cases and virologically-confirmed dengue.

Note: This important study shows the establishment of the wMel Wolbachia and the companion paper shows the reduction of dengue in the treated cities. However, this method does not reduce the biting pressure of Aedes aegypti and insecticide applications would be counter intuitive to this public health response.

Fitness costs in the presence and absence of insecticide use explains abundance of two common Aedes aegypti kdr resistance alleles found in the Americas.

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Silva JJ, Fisher CR, Dressel AE, Scott JG (2023) 

PLoS Negl Trop Dis 17(11): e0011741

https://doi.org/10.1371/journal.pntd.0011741 

Resistance to widely used pyrethroid insecticides can occur by mutations in the voltage gated sodium channel (Vgsc) and alleles with these mutations are collectively known as knockdown resistance (kdr). The frequency of resistance alleles is driven by selection with pyrethroid insecticides, but kdr alleles decrease in frequency in the absence of insecticide. The relative fitness of different kdr alleles to each other is largely unknown. We show through cage experiments that the 1534C allele is favored in the absence of pyrethroid applications, but that the 410L+1016I+1534C allele is favored when deltamethrin selection occurs. These results help to explain the relative frequency of these alleles that have been detected in field collections.

Special Collection: Emerging and Lesser-Known Arboviruses Impacting Animal and Human Health: Emerging and lesser-known arboviruses impacting animal and human health.

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A Faraji, G Molaei, T Andreadis. Special Collection: Emerging and Lesser-Known Arboviruses Impacting Animal and Human Health: Emerging and lesser-known arboviruses impacting animal and human health. J Medical Entomol, 60(6), 2023, 1139–1141.

https://doi.org/10.1093/jme/tjad140

This paper is the introduction to Special Collection of 10 papers on the epidemiology and ecology of emerging and lesser-known viruses of public and veterinary importance within the United States. Included within the series are papers on orbiviruses transmitted by Culicoides, lesser known viruses transmitted by mosquitoes including Cache Valley, Everglades, Jamestown Canyon, and LaCrosse, and recently discovered viruses transmitted by ticks including Bourbon, Heartland, Colorado tick fever, and Powassan.

Aedes Aegypti Oviposition-Sites Choice Under Semi-Field Conditions

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David,M.R.,Maciel-de-Freitas,R., Petersen,M.T.,Bray,D.,Hawkes,F.M.,Fernández-Grandon, G.M.etal.(2023)

Aedes aegypti oviposition-sites choice under semi-field conditions. Medical and Veterinary Entomology, 37(4),683–692.

Available from:https://doi.org/10.1111/mve.12670

Aedes aegypti in Brazil were offered a variety of oviposition containers within a semi-field cage. Gravid females preferred to oviposit close to the ground and in open water containers with organic compounds from plant watering. Domestic large artificial containers containing tap water received significantly fewer eggs, except for car tires, which received as many eggs as potted plants. Visual (potted plant shape) and olfactory clues (odor of the plant or from water containing organic matter) were equally attractive separately as they were together. These data may be useful in surveillance and control operations searching for larval sources.

Head Outrunning Mosquito Volunteer Needed

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MVCAC is currently looking for a lead volunteer to coordinate the day of efforts for the annual MVCAC 5K “Outrunning Mosquitoes” at the 2024 Annual Conference. The role is key in making sure we can continue to hold this fun and rewarding event!
 
The person in this volunteer role should be prepared to be at the event by Sunday morning to verify the route, then work with other volunteers to walk the participants to the start line, and stay until all have completed their 5K. This person usually also times the participants, reports back the results to staff, and if available would give out the award at the banquet on Wednesday night. 
 
If you are interested, please email Rachel Hickerson in the MVCAC office at rhickerson@amgroup.us

Rodent-targeted approaches to reduce acarological risk of human exposure to pathogen-infected Ixodes ticks.

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Lars Eisen

Ticks Tick Borne Dis. 2023 Mar;14(2):102119, https://doi.org/10.1016/j.ttbdis.2023.102119

Condensed abstract: In the United States, rodents serve as important hosts of medically important Ixodes ticks, including Ixodes scapularis and Ixodes pacificus, as well as reservoirs for human pathogens, including Anaplasma phagocytophilum, Borrelia burgdorferi sensu stricto (s.s.), and Babesia microti. Over the last four decades, different methods to disrupt enzootic transmission of these pathogens between tick vectors and rodent reservoirs have been developed and evaluated. These techniques include the application of topical acaricides, antibiotics, or a vaccine against Bo. burgdorferi s.s., delivered orally via rodent food baits. This review outlines the general benefits and drawbacks of rodent-targeted tick and pathogen control methods, and then describes the empirical evidence for different approaches to impact enzootic pathogen transmission and acarological risk of human exposure to pathogen-infected Ixodes ticks. Note: This review paper describes various rodent-targeted tick management techniques, summarizing results of experiments and compiling the benefits and drawbacks.