More West Nile virus-infected mosquitoes in lower-income areas of
Baltimore

Date:
December 17, 2020
Source:
University of Maryland
Summary:
Researchers found higher rates of West Nile virus-infected
mosquitoes in lower-income neighborhoods in urban areas of
Baltimore, Maryland. This preliminary data provides another piece of
the puzzle pointing to higher risk of mosquito-transmitted diseases
in these neighborhoods already struggling with environmental
injustices and poorer health outcomes.



FULL STORY ==========================================================================
In a new study published in the Journal of Medical Entomology, researchers
at the University of Maryland (UMD) found higher rates of West Nile virus-infected mosquitoes in lower-income neighborhoods in urban areas
of Baltimore, Maryland.

Continuing a collaboration with the Cary Institute of Ecosystem Studies
and building on previous work finding larger mosquitoes (which may
be more likely to transmit disease) in lower-income neighborhoods,
this preliminary data provides another piece of the puzzle pointing to
higher risks of mosquito- transmitted diseases like West Nile virus in
these neighborhoods already struggling with environmental injustices and
poorer health outcomes. This paper points to a need for more research in lower-income communities to inform policy and programs that can protect
the health of those most at risk.


==========================================================================
"In order to effectively address environmental injustices, we have
to understand where they occur and why," says Sarah Rothman, doctoral
student in Environmental Science & Technology at UMD and lead author of
this paper. "Urban mosquito sampling often takes place in city parks
or other areas where traps are easily accessible to personnel, but we
need to ensure we are sampling for mosquitoes in neighborhoods that are
diverse in socioeconomic status.

Representative surveillance is the first step. Only after identifying
where disease risk is actually greatest can we direct public health
resources to communities that need them most." This study acts
as a first step in addressing environmental justice, providing
another important connection between lower-income neighborhoods and
risky mosquito populations, according to Paul Leisnham, associate
professor in Environmental Science & Technology at UMD. "A higher
infection rate was shown in two species of mosquito, the invasive
tiger mosquito and the northern house mosquito. In previous studies,
we have shown that mosquito abundances and female body sizes, two other ecological parameters that promote virus transmission, are also larger in lower-income neighborhoods. Now we have introduced another piece of the
puzzle pointing to higher risks in lower-income areas." Leisnham spends
time interacting with locals in urban Baltimore through his research and Extension efforts, highlighting an important point for mosquito population growth that isn't exactly intuitive: "Less trash, fewer mosquitoes."
Mosquitoes can surprisingly breed in an amount of water as small as what gathers in a bottle cap left outside in a shady area for four or five
days. If the water gathers in a shaded container and isn't infiltrating
into the ground through managed stormwater practices, it can easily become
a mosquito breeding ground that can produce hundreds of biting adults.

Cary Institute disease ecologist Shannon LaDeau, collaborator on the
study, explains, "More people are living in cities. At the same time,
many other species are also adapting to city living. Invasive species
like the tiger mosquito increasingly thrive in temperate urban areas,
living among us and fundamentally altering the risk of local disease
emergence. People living in neighborhoods with abandoned infrastructure
are more at risk, because tiger mosquitoes flourish in less managed landscapes." While the connection between vacant lots, more trash,
and more mosquitoes is established, more research is needed to further
connect these environmental injustices to higher infection rates in
humans. "West Nile virus incidence in the human population is often underestimated," says Rothman. "Most cases are asymptomatic, and mild symptomatic cases are easily confused with other illnesses that present similarly, like the flu. We are likely especially missing cases in
underserved populations with reduced access to quality medical care. Since
it's hard to track the prevalence of West Nile virus in people, we
suggest additional sampling of the virus in mosquitoes. Additional
research could also help us figure out why we're seeing patterns of
higher mosquito infection rates in lower-income neighborhoods and how
these patterns are affected by environmental factors such as weather."
"It's important, especially in populations from lower-income areas
since they are often immunocompromised with other infections, including
HIV and likely COVID-19," adds Leisnham. "The CDC [Centers for Disease
Control and Prevention] has reported that the U.S. is not prepared for
mosquito and tick-borne risks based on local health agencies' surveys."
Rothman stresses the need for this work to improve environmental justice
in lower-income areas of cities like Baltimore. "Our research supports
the notion that residents in these neighborhoods are disproportionately
at risk for mosquito-borne illness," says Rothman. "We need additional
research to understand and address the underlying factors, and ultimately protect urban residents."

========================================================================== Story Source: Materials provided by University_of_Maryland. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Sarah E Rothman, Jennifer A Jones, Shannon L LaDeau, Paul T
Leisnham.

Higher West Nile Virus Infection in Aedes albopictus (Diptera:
Culicidae) and Culex (Diptera: Culicidae) Mosquitoes From Lower
Income Neighborhoods in Urban Baltimore, MD. Journal of Medical
Entomology, 2020; DOI: 10.1093/jme/tjaa262 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/12/201217135237.htm

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