A mosquito carrying a possibly debilitating virus rarely seen in Northern California has been found in the town of Plumas Lake, 30 mi [approx. 48 km] north of Sacramento, local health officials said on [Mon 7 Aug 2017]. The virus is spread through bites from infected mosquitoes, and symptoms include fever, headache, nausea and vomiting.
According to the U.S. Centers for Disease Control and Prevention, many people do not experience any symptoms after being bitten by mosquitoes with St. Louis encephalitis [virus]. But, in some serious cases, the virus can cause infections in the central nervous system and even lead to death.
The Sutter-Yuba Mosquito and Vector Control District learned [Fri 4 Aug 2017] evening that a _Culex_ mosquito in Yuba County had tested positive for the virus, the first time in the area, said Steve Abshier, the district’s general foreman. The _Culex_ mosquito can also carry West Nile virus and Japanese encephalitis [virus].
Mosquitoes with St. Louis encephalitis [virus] have also been reported in central and southern California. The virus is transmitted from infected birds to mosquitoes, which means it’s likely an infected bird traveling north to the Sacramento area was bitten by a mosquito, Abshier said. The virus cannot be transmitted by mosquito between people.
The Sutter-Yuba Mosquito and Vector Control District has deployed 16 traps that use light and carbon dioxide emitted from dry ice to attract mosquitoes. “This will help us determine if it is more pervasive or an isolated incident,” Abshier said. In the meantime, to reduce the risk of infection, the town of Plumas Lake will be sprayed with a compound to kill larvae on Monday and Thursday evenings.
Agricultural lands in Yuba County will also be sprayed.
Areas of standing water are prime breeding grounds for mosquito larvae, so underground drainage areas have been treated with a compound that’s released over 150 days to kill the larvae, Abshier said. The mosquito and vector control district has also used an aerial photographer to identify and treat more than 80 swimming pools.
To prevent mosquito bites, health officials recommend people wear mosquito repellent that contains DEET and long-sleeved clothing. Also, people should avoid going outside during dawn and dusk when mosquitoes are the most active. To keep mosquitoes out of your home, screens on doors and windows should be checked for any tears, and standing water should be drained.
[Byline: Molly Sullivan]
—
Communicated by:
ProMED-mail from HealthMap Alerts
******
[2] Mosquitoes in Stanislaus county
Date: Mon 7 Aug 2017, 9:54 AM
Source: ABC 10 [edited]
The East Side and Turlock Mosquito Abatement Districts (MADs) have received confirmation from a mosquito sample in Stanislaus County testing positive for St. Louis encephalitis [virus] [SLEV]. Though this is the 1st detection of SLEV in Stanislaus County in more than 40 years, statewide, there have been 17 mosquito samples that have tested positive for the virus this year [2017]. The samples tested positive in Fresno, Kern, Kings and Riverside counties.
No people have tested positive for the virus, according to MADs. In 2016, there were 3 reports of people infected with SLEV in California.
Those were the 1st cases in the state since 1997.
Like West Nile [virus] [WNV], most people who become infected with SLEV will never feel sick, according to MADs. Most people who do will experience mild flu-like symptoms.
“It is very important that people take precautions to protect themselves and their families from mosquito bites, said Dr. Julie Vaishampaya, Stanislaus County Public Health Officer. MADs researchers note WNV has been on the rise with a total of 80 mosquitoes testing positive this year in Stanislaus County. WNV has also been confirmed in 2 dead birds. There are precautions people can take to mitigate infection, including:
– Dump or drain standing water. These are places mosquitoes like to lay their eggs.
– Defend yourself against mosquitoes by using repellants containing DEET, Picaridin or Oil of Lemon Eucalyptus.
– Avoid being outdoors at dusk and dawn. These are the times when WNV carrying mosquitoes are generally most active.
– Report neglected swimming pools to your local MAD.
– Use tight fitting door and window screens to keep mosquitoes from entering your home.
—
Communicated by:
ProMED-mail from HealthMap Alerts
[Active St. Louis encephalitis [SLE] virus transmission is occurring in 2 locations in northern California this year (2017). Fortunately, no human cases have been reported there so far this summer. SLE virus is endemic in the south western USA and sporadic cases in humans occur there infrequently. In 2015, human cases occurred in the adjoining states of Nevada and Arizona and positive mosquitoes were found in California. SLE virus was found in mosquitoes in Nevada in 2005.
Wild birds are the reservoir host and mosquitoes in the genus _Culex_ are vectors that transmit SLE virus. The mosquito species in which SLEV was detected are not mentioned in the above report. Avoidance of mosquito bites and elimination of mosquito breeding sites in this area is good advice that should be heeded by the local residents.
A HealthMap/ProMED-mail map showing the location of California in the western USA can be accessed at <http://healthmap.org/promed/p/370> and a map of California counties at <http://geology.com/county-map/california.shtml>. – Mod.TY
]
[See Also:
2016
—-
St. Louis encephalitis virus – USA (05): (CA)
http://promedmail.org/post/20161119.4641379
St. Louis encephalitis virus – USA (04): (CA)
http://promedmail.org/post/20161023.4578634
St. Louis encephalitis virus – USA (03): (NV)
http://promedmail.org/post/20160903.4463247
St. Louis encephalitis virus – USA (02): (CA)
http://promedmail.org/post/20160902.4459222
St. Louis encephalitis virus – USA: (NV)
http://promedmail.org/post/20160828.4446524
2015
—-
St. Louis encephalitis & West Nile viruses – USA (02): (AZ)
http://promedmail.org/post/20151213.3859129
St. Louis encephalitis and West Nile viruses – USA (AZ)