NEW WORLD SCREWWORM – PANAMA (02): CATTLE, HUMAN

A ProMED-mail post

http://www.promedmail.org

ProMED-mail is a program of the International Society for Infectious Diseases

http://www.isid.org [1]

Date: Wed 2 Oct 2024

Source: Prensa Latina [in Spanish, machine trans., edited]

https://www.prensa-latina.cu/2024/10/02/alertan-en-panama-sobre-rebrote-epidemico-de-gusano-barrenador/

Panama warns of new outbreak of screwworm epidemic

————————————————–

Panamanian authorities have warned of a new epidemic the country is currently facing with cases of the cattle screwworm which also affects humans.

In statements to Prensa Latina, Carlos Moreno, from the Panama-United States Commission for the Eradication of the Screwworm (COPEG) specified the rise of the plague in mid-2023 was due to the lack of vigilance by both citizens and authorities during the COVID-19 pandemic.

In addition, he explained, the increase in cases, some 27 330 from 2022 to date, was due to other factors such as climate change, movement control, and greater awareness among the population.

The screwworm is not only affecting livestock; humans and other animal species are also being harmed.

In Panama, the Ministry of Health (MINSA) has recorded some 79 cases, according to epidemiologist Damaris Contreras, who called on people not to treat wounds at home but to go to health centers or hospitals.

The screwworm, which is laid by the fly _Cochliomyia hominivorax_, feeds on the living tissue of animals and can be fatal if not treated properly. This fly seeks to lay its eggs in “fresh wounds” of any type of warm-blooded animal. In a single wound, this fly can lay between 150 and 300 eggs, explained Lester Reyes, from Animal Health Epidemiology at the Ministry of Agricultural Development (MIDA). Once the larvae develop, they leave the wound and drop to the ground, where they bury themselves until they reach the pupal stage and thenbecome adult flies. Therefore, when healing these wounds, the maggots must be removed and eliminated immediately, because if they are left alive they turn into flies.

Panama has the only plant for the production of sterile flies which counteract the reproduction of flies laying the eggs of the screwworm. Specifically, the impact is occurring in other countries has led Panama to suspend the distribution of sterile flies, said Reynaldo Vivero, from MIDA, who also explained sterile flies are not being distributed in the country, since they are being sent to other countries to control the outbreak.

See attached for additional postings, comment and information.

Communicated by: ProMED

Note: The screwworm fly historically was endemic in the USA and was eradicated by the first SIT program. The fly eventually was pushed south of Mexico, with Panama being the southern border maintained by surveillance and further fly releases. Panama has the only remaining sterile fly production facility. The fly is still endemic in parts of South America. Northern dispersal, if not immediately contained, would require a large scale eradication effort that would be very costly.

DENGUE/DHF UPDATE (87): USA (CALIFORNIA) MORE TRANSMISSION

A ProMED-mail post http://www.promedmail.org

ProMED-mail is a program of the International Society for Infectious Diseases http://www.isid.org

Date: Thu 3 Oct 2024

Source: KOST [edited] https://kost1035.iheart.com/featured/la-local-news/content/2024-10-03-5th-locally-acquired-dengue-case-confirmed-in-la-county/

Los Angeles County health officials Thursday [3 Oct 2024] continue to investigate a 5th locally acquired case of the mosquito-borne illness dengue, this time in a resident of El Monte. The latest patient does not appear to have any connection with the 4 previous reported infections, the county Department of Public Health said Wednesday [2 Oct 2024].

Health officials again stressed that locally acquired cases of dengue are extremely rare in areas where it has not been previously transmitted by mosquitoes. The county previously reported a cluster of 3 infections in the Baldwin Park area, and last week a 4th case was confirmed in a Panorama City resident. Health officials called the spate of local cases “unprecedented.”

None of the local patients had any history of travel to areas where dengue is endemic. In October and November of last year [2023], single locally acquired cases of dengue were confirmed by health officials in Pasadena and Long Beach.

Health officials noted that the symptoms of dengue often mirror those of other viruses, and they urged health-care providers to be “vigilant for dengue fever in patients with acute febrile illness and test for and report such cases of mosquito-borne diseases.”

— Communicated by: ProMED

FROM PROMED [It is interesting to note that the latest patient does not appear to have any connection with the 4 previous reported infections. There is a previously reported cluster of 3 cases in the Baldwin Park area, a single case in Panama City and now the latest one in El Monte. One wonders if there are several other dengue virus infected individuals in these 3 localities that have asymptomatic or very mild infections that have not resulted in medical attention so are not reported.

The above report does not indicate which vector mosquito was likely involved in dengue virus transmission in the 3 localities. As noted in the previously posted comment, the mosquitoes most likely involved are _Aedes aegypti_ or _Aedes albopictus_, both of which have been detected in California over the past 20 years. The preventive measures to avoid ongoing transmission are avoidance of mosquito bites and reduction of the mosquito populations. Mosquito control districts are undoubtedly attempting to control these vector mosquitoes, but that is a difficult task and requires collaboration with local residents to eliminate the water catchments in which these mosquitoes breed around their homes and other buildings.

Note that both _Aedes aegypti_ and _Aedes albopictus_ have been found in Los Angeles County. Which of these transmitted dengue virus to the residents is unknown. Locally acquired dengue virus infections remain extremely rare in California but occurrence of this cluster of cases indicates that local acquisition of dengue virus can occur. – Mod.TY

Note: The juxtaposition of these cases to the primary or imported cases has not been reported. As indicated above, it would seem that potentially other perhaps milder secondary cases have gone unnoticed, although these could still be a source of virus for mosquito infection making a vector control response difficult to focus geographically.

DENGUE/DHF UPDATE (80): USA (CALIFORNIA) LOCALLY ACQUIRED

A ProMED-mail post
Date: Tue 17 Sep 2024 17:05 EDT
Source: Newswise [edited]

Amid southern California’s recent record-breaking heat wave and fast-moving wildfires, public health officials reported the third locally acquired case of dengue fever in the Los Angeles area. Although the events seem unrelated, they actually are connected — and for troubling reasons. Communicated by: ProMED “”This is the third locally acquired dengue case in the Los Angeles, California area this year (2024). This resident was bitten by a dengue virus-infected mosquito, most likely _Aedes aegypti_ or _Aedes albopictus_, both of which have been detected in California over the past 20 years. The question with all these locally acquired infections is: where, when and from whom did the vector take the infectious blood meal? Did that infected individual acquire their dengue infection locally or in a dengue-endemic country and subsequently traveled to Los Angeles County, California while viremic? The risk of ongoing transmission depends on the presence of vector mosquitoes. There are 24 counties in California in which _Aedes aegypti_ and _Aedes albopictus_ have been found over the past 20 years.”

Read more

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

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).

93rd Annual MVCAC Conference – Call for Papers

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

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.

CDPR has approved WB1 Males for use in California

Following the U.S. Environmental Protection Agency’s registration of Mosquito Mate’s Aedes aegypti WB1 male mosquitoes, the California Department of Pesticide Regulation approved the use of WB1 males in California. For information about plans to use Wolbachia in California please contact Stephen Dobson with Mosquito Mate at sdobson@mosquitomate.com.

May is Lyme Disease Awareness Month

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

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?

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.

 

West Nile Virus and Dead Bird Call Center Now Live

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.

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.

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

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

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

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

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

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.

Tick Resources Reminder

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!

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

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

Help Support the 2024 WNV Call Center

The WNV Call Center needs YOUR help meeting their 2024 funding goal!

The West Nile Virus Call Center helps keep California safe from disease outbreaks by allowing the public to report dead birds on their area.

If other agencies are interested in contributing, please email Vicki.Kramer@cdph.ca.gov

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

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

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

CalSurv Seeking Examples of Visualizations and Data Summaries

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

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.

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.

Q&A: New York Times Reporter Reflects on Global Malaria Fight

November 28, 2023

From Pest Control Technology

New York Times Global Health Reporter Stephanie Nolen traveled to five countries in Africa and Latin America to crack the code on what’s being done to control mosquito-borne diseases. Here’s what she found.

Read full article

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

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.

FDA Approves First Vaccine Against Mosquito-Borne Virus Chikungunya

November 10, 2023

From The Washington Post

The Food and Drug Administration has approved the world’s first vaccine to prevent chikungunya, a mosquito-borne illness that can cause debilitating joint pain for months to years.

Read more here

Aedes Aegypti Oviposition-Sites Choice Under Semi-Field Conditions

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.

First locally acquired case of dengue virus discovered in Pasadena

From CBS Los Angeles

October 20, 2023

Public health officials confirmed Friday the first locally acquired case of dengue virus in a Pasadena resident. This case is the first in California that is not associated with travel, according to Manuel Carmona, acting director of Public Health for the City of Pasadena. 

Read More

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

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.

MVCAC’s Response to Dengue Case in Pasadena

In response to the locally acquired dengue case recently reported in Pasadena, MVCAC drafted a statement to assist with your outreach efforts and if you receive questions from residents and stakeholders.

Podcast Episode: The Mosquitoes Are Winning

From The Daily

For decades, the world seemed to be winning the war against mosquitoes and tamping down the deadly diseases they carried. But in the past few years, progress has not only stalled, it has reversed. Stephanie Nolen, who covers global health for The Times, explains how the mosquito has once again gained the upper hand in the fight.

Listen Now

CA West Nile Virus & Dead Bird Call Center closes for the season on October 13, 2023

This season, the California Department of Public Health received over 5,900 dead bird reports to the CA West Nile Virus & Dead Bird Call Center (1-877-WNV-BIRD) and website. Over 1,700 dead birds were collected for testing, with 773 birds testing positive for West Nile virus (WNV). On October 13, the Call Center will transition to internet-only reporting at https://westnile.ca.gov/. WNV testing is limited in the fall and winter as WNV activity decreases, but dead bird reports are appreciated all year round.

 

Dengue Will ‘Take Off’ in Southern Europe, US, Africa This Decade, WHO Scientist Says

October 9, 2023

From MedScape

Dengue fever will become a major threat in the southern United States, southern Europe and new parts of Africa this decade, the WHO’s chief scientist said, as warmer temperatures create the conditions for the mosquitoes carrying the infection to spread.

Read more

AMCA Research Fund Day of Contributing: October 10, 2023

Date: Tuesday, October 10th, 2023

What Is It? It’s a day for everyone in the AMCA community to come together and support mosquito control research. Your contribution, no matter the amount, can make a significant impact.

How Can You Participate?

  1. Mark Your Calendar: Set a reminder for October 10th.
  2. Donate: We’ll provide a donation link on the day.
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Why Do We Need Your Support? Your involvement can help us advance research, nurture young scientists, and protect public health. We are hoping our community can gather together to help us support one additional project each year!

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Convergent Trends and Spatiotemporal Patterns of Aedes-Borne Arboviruses in Mexico and Central America

Bernardo Gutierrez ,Darlan da Silva Candido,Sumali Bajaj,Abril Paulina Rodriguez Maldonado,Fabiola Garces Ayala,María de la Luz Torre Rodriguez,Adnan Araiza Rodriguez,Claudia Wong Arámbula,Ernesto Ramírez González,Irma López Martínez,José Alberto Díaz-Quiñónez,Mauricio Vázquez Pichardo,Sarah C. Hill, [ … ],Marina Escalera-Zamudio [ view all ]

Published: Plos Neglected Tropical Diseases, September 6, 2023

https://doi.org/10.1371/journal.pntd.0011169

Results indicate that CHIKV, DENV-1 and DENV-2 in Mexico share evolutionary and epidemiological trajectories. The southwest region of the country was determined to be the most likely location for viral introductions from abroad, with a subsequent spread into the Pacific coast towards the north of Mexico. Virus diffusion patterns observed across the country are likely driven by multiple factors, including mobility linked to human migration from Central towards North America. Considering Mexico’s geographic positioning displaying a high human mobility across borders, our results prompt the need to better understand the role of anthropogenic factors in the transmission dynamics of Aedes-borne arboviruses, particularly linked to land-based human migration.

Direct Mosquito Feedings on Dengue-2 Virus-Infected People Reveal Dynamics of Human Infectiousness

Louis Lambrechts, Robert C. Reiner et.al.

Plos Neglected Tropical Diseases Sept 2023

https://doi.org/10.1371/journal.pntd.0011593

This study in Iquitos, Peru, showed that dengue patients with mild disease were most infectious to Aedes aegypti mosquitoes 2 d after the onset of symptoms and that these mosquitoes were able to transmit their infection 7 – 16 d after blood feeding.  This empirical study provided a timeline for when secondary dengue cases could be expected following the onset of symptoms in an imported dengue case, thereby providing a timeline for preventive control operations.    

Article Series: Mosquitoes Are a Growing Public Health Threat, Reversing Years of Progress

September 29, 2023

From New York Times

Climate change and the rapid evolution of the insect have helped drive up malaria deaths and brought dengue and other mosquito-borne viruses to places that never had to worry about them.

Read more here

The late-summer itch: Ankle-biting mosquitoes are in extra full force in L.A. Why?

From LA Times

September 21, 2023

When you think “so L.A.,” Erewhon smoothies, Barbie-pink sunsets and baristas with IMDB credits might come to mind. Now you can add mosquitoes to the list.

Read more here

 

CA Endures Worst Mosquito Season In Years. When Will It End?

From Patch

September 16, 2023

As the blood-sucking ankle-biters take bite out of the Golden State, human West Nile Virus cases are spiking.

Read Here

The biting rate of Aedes aegypti and its variability: A systematic review(1970–2022).

:ZahidMH, VanWykH, MorrisonAC, ColomaJ, LeeGO, CevallosV, etal.(2023)

https://doi.org/10.1371/journal.pntd.0010831

Author summary: Half of the world’s population is now at risk of dengue infection, which transmits to humans mostly through the bite of an infected female Aedes aegypti mosquito. Disease transmission models have played an important role in understanding the dynamics of dengue transmission and helping to develop control measures. The mosquito biting rate is one of the central parameters used in these models. Mosquito biting rates used in existing works are taken from a variety of studies, each with its strengths and limitations. To understand how existing study designs are used to estimate biting rate and how these estimates may vary over time, space, and environmental factors, we perform a systematic review of biting rate studies. We identify three study designs (human landing catch, marked-release-recapture, and histological) that play an important role in estimating per mosquito biting rates and capturing variability across a number of environmental factors. In particular, human landing catch studies can capture the variability of biting rates and marked-released-recapture studies along with histological studies can quantify the multiple feeding that occurs between ovipositions. Transmission modeling studies should be more informed by the biology of mosquito behavior. By understanding the biology of blood-feeding and context-specific factors, we can arrive at more informed per mosquito biting rate estimates for site-specific transmission model analysis.

[Submitted by the Vector and Vector-Borne Disease Committee]

West Nile virus is a growing threat this summer in California. What you need to know

August 30, 2023

From Los Angeles Times

West Nile virus infections are on the rise this year in California after a particularly wet winter led to more mosquito reproduction, according to health experts.

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In the US, West Nile virus is leading cause of viral disease spread by insects, CDC study says

August 24, 2023

From CNN

The United States has seen a flurry of West Nile virus deaths reported in the last few days, including most recently in Illinois, Nebraska and Colorado.

Read More 

Community-based Integrated Tick Management Programs: Cost and Feasibility Scenarios

TL Schulze, L Eisen, K Russell, RA Jordan
Journal of Medical Entomology, tjad093, https://doi.org/10.1093/jme/tjad093
 
Abstract: Numerous studies have assessed the efficacy of environmentally based control methods to suppress populations of the blacklegged tick (Ixodes scapularis Say), but few of these estimated the cost of control. We estimated costs for a range of tick control methods (including habitat management, deer exclusion or population reduction, broadcast of acaricides, and use of host-targeted acaricides) implemented singly or in combination and applied to a model community comprising 320 residential properties and parklands. Using the high end for cost ranges, tick control based on a single method was estimated to have mean annual costs per household ranging from $132 for treating only forest ecotone with a broadcast synthetic acaricide to kill host-seeking ticks (or $404 for treating all residential forested habitat) to >$2,000 for deployment of bait boxes (SELECT TCS) across all residential tick habitat to treat rodents topically with acaricide to kill infesting ticks. Combining different sets of multiple methods in an integrated tick management program placed the annual cost between $508 and 3,192 annually per household, underscoring the disconnect between what people in Lyme disease endemic areas say they are willing to pay for tick control (not more than $100–150 annually) and the actual costs for tick control. Additional barriers to implementing community-based tick management programs within residential communities are discussed.
 
Notes: Surveillance and determination of pathogen risk provide a basis for public health messaging to warn the public in affected areas, but do little to actually mitigate the problem. As risk elevates so does the mandate for a coordinated response. Schulze et al. provide estimates of mitigation costs to residents residing within Lyme disease endemic areas in the Eastern USA. These data are useful for MVCAC agencies considering mitigation in response to increasing threats of tick-borne diseases. 
 
[Submitted by the Vector and Vector-Borne Disease Committee]
 
 

Delftia Tsuruhatensis TC1 Symbiont Suppresses Malaria Transmission by Anopheline Mosquitoes

Huang, W., J. Rodrigues, E. Bilgo, J. R. Tormo, J. D. Challenger, C. De Cozar-Gallardo, I. Pérez-Victoria, F. Reyes, P. Castañeda-Casado, E. J. Gnambani, D. F. Hien, M. Konkobo, B. Urones, I. Coppens, A. Mendoza-Losana, L. Ballell, A. Diabate, T. S. Churcher, and M. Jacobs-Lorena. 2023. delftia tsuruhatensis TC1 symbiont suppresses malaria transmission by Anopheline Mosquitoes. Science. 381: 533–540. DOI: https://doi.org/10.1126/science.adf8141
 
Abstract: Malaria control demands the development of a wide range of complementary strategies. We describe the properties of a naturally occurring, non–genetically modified symbiotic bacterium, Delftia tsuruhatensis TC1, which was isolated from mosquitoes incapable of sustaining the development of Plasmodium falciparum parasites. D. tsuruhatensis TC1 inhibits early stages of Plasmodium development and subsequent transmission by the Anopheles mosquito through secretion of a small-molecule inhibitor. We have identified this inhibitor to be the hydrophobic molecule harmane. We also found that, on mosquito contact, harmane penetrates the cuticle, inhibiting Plasmodium development. D. tsuruhatensis TC1 stably populates the mosquito gut, does not impose a fitness cost on the mosquito, and inhibits Plasmodium development for the mosquito’s life. Contained field studies in Burkina Faso and modeling showed that D. tsuruhatensis TC1 has the potential to complement mosquito-targeted malaria transmission control.
 
Notes: This article describes the findings of a study investigating the role of harmane, a compound secreted by Delftia tsuruhatensis TC1 bacteria, in the disruption of Plasmodium development in the midgut and the reduction of sporozoite prevalence in salivary glands of anopheline mosquitoes. The authors also describe the efficacious delivery of D. tsuruhatensis TC1 to larvae and adult mosquitoes in laboratory and field settings, indicating the versatility of potential deployment in the field.  Studies like this show the importance of understanding the mosquito microbiome in variability seen in pathogen transmission in the laboratory and field. 
 
[submitted by the Vector and Vector-Borne Disease Committee]