All articles tagged with #vector borne diseases
A warming climate and disrupted ecosystems are expanding the range of disease-carrying mosquitoes and fleas in California, fueling spikes in West Nile virus and raising dengue and flea-borne typhus risks; experts say multiple factors—heat, urban expansion, wildlife interactions, and rodenticide bans—are at play, making California a focal point for the growing threat of vector-borne diseases.
Rising temperatures and climate-driven changes are expanding vectors—mosquitoes, ticks, fleas—in California, fueling West Nile virus activity in birds and humans, signaling growing dengue risk in urban areas, and contributing to flea-borne typhus outbreaks. Experts emphasize there isn’t a single cause; rather a mix of warming, habitat disruption, and ecosystem changes that are increasing opportunities for disease transmission statewide.
Public health officials in the Salt Lake City district report West Nile virus detected in roughly one-third of mosquitoes tested, signaling ongoing local transmission risk and the need for preventive measures such as repellents and eliminating standing water.
A lab study finds three mosquito species—Aedes aegypti, Aedes albopictus and Culex quinquefasciatus—are attracted to humans for different reasons: the yellow-fever mosquito links to male-associated scents and skin bacteria, the Asian tiger mosquito to ketones and plant-like volatiles, and the southern house mosquito to the skin’s microbial ecosystem; these insights could guide targeted vector-control strategies, but field validation is needed and distributions of each species vary across Europe.
Climate change, land-use shifts, and rising deer populations are expanding tick habitats across the United States, leading to more tick bites and the spread of diseases such as Lyme disease and Alpha-gal syndrome, while changing how people spend time outdoors and challenging public health responses.
Climate change and landscape changes are helping ticks and mosquitoes spread to new regions in the U.S., boosting the incidence of Lyme disease, babesiosis, anaplasmosis, alpha-gal syndrome, and other vector-borne illnesses. Emergency department visits for tick bites are at a multi-year high, and experts warn the trend will worsen as warming continues. Prevention via repellents, permethrin-treated clothing, reducing standing water, and other environmental tweaks is key, with vaccines and new tick-control tools in development.
Powassan virus, a rare tick-borne illness transmitted by deer ticks, has been detected in a Maine resident in Penobscot County—the state’s first case this year—as tick activity rises to its highest levels in about a decade. Powassan remains rare and has no vaccine; severe infections can inflame the brain or spinal cord and cause long-term problems, with roughly 40 Maine cases recorded since 2000.
A laboratory study shows mosquitoes can form a learned association between the repellent DEET and a blood meal, with about 60% of trained mosquitoes attempting to bite DEET when later exposed to it. This suggests repellents can be less effective under certain conditions, though experts stress normal use remains valid and travelers should continue reapplying as directed; more research is needed to understand how long such memories last and how this translates outside the lab.
Researchers used Bayesian inference to build a dynamic, ~30-parameter model of Aedes aegypti flight from 53 million data points collected in 20 experiments, revealing that mosquitoes integrate visual cues and carbon dioxide to locate humans. They identified two flight modes (active exploration and idle/landing prep) and found visual cues alone attract mosquitoes to dark objects but don’t trigger landing without additional cues, while CO2 prompts rapid speed changes and erratic flight. When both cues are present, mosquitoes cluster closer to targets, suggesting multisensory lure designs could improve traps and disease control.
Georgia Tech researchers used a mesh suit, a Styrofoam dummy, and a high-speed camera to record millions of mosquito flight trajectories around a human, then applied Bayesian inference to model how heat, moisture, carbon dioxide, and visual cues drive host-seeking. The result is a predictive model that identifies “zones of danger” and could inform smarter traps and deterrents, aiding efforts to reduce mosquito-borne disease transmission.
A Frontiers in Ecology and Evolution study in Rio de Janeiro’s Atlantic Forest remnants shows mosquitoes feeding on humans more often than on other animals, likely because biodiversity loss reduces alternative hosts. From 1,714 mosquitoes across 52 species, 24 blood meals were identified, with 18 traced to humans. The findings suggest that host availability and proximity drive this shift, increasing the risk of pathogen transmission (dengue, Zika, Yellow Fever, Mayaro, Chikungunya) and underscoring the need for targeted surveillance and ecosystem-aware disease control.
New research links deforestation in the Atlantic Forest to mosquitoes increasingly feeding on humans, suggesting biodiversity decline and habitat destruction push mosquitoes to human blood and raise the risk of new disease vectors; reversing habitat destruction could help, but the reversibility of this shift remains uncertain.
A study in Nature Communications warns that the global spread of mosquitoes through trade and travel has increased significantly since the 1950s, raising the risk of vector-borne diseases like West Nile virus and encephalitis, which pose serious health and economic challenges. The expansion is driven by global shipping, trade routes, and climate change, emphasizing the need for preventive measures such as protective clothing and eliminating standing water.
Recent research reveals that male mosquitoes can feed on blood under certain conditions, challenging long-held beliefs and raising concerns about their potential role in disease transmission, although further studies are needed to understand the implications fully.
The Texas State Department of Public Health Services is actively studying dangerous mosquitoes to prevent the resurgence of vector-borne diseases like malaria and yellow fever, which are re-emerging in the US as efforts to control these insects have waned.