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Published Date: 2012-08-14 04:16:58
Subject: PRO/AH/EDR> West Nile virus - USA (03): (TX,LA) human
Archive Number: 20120814.1242832

WEST NILE VIRUS - USA (03): (TEXAS, LOUISIANA) HUMAN
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In this posting:
[1] Texas (Dallas County)
[2] Louisiana

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[1] Texas
Date: Sat 11 Aug 2012
Source: CNN [edited]
http://edition.cnn.com/2012/08/10/us/texas-west-nile-virus-emergency/index.html

A West Nile virus epidemic has prompted a public health emergency in Dallas County, Texas, where the disease has killed 9 people, a judge declared Friday [10 Aug 2012]. The virus there infected 175 people, said Patricia Huston of Dallas County Health and Human Services.

Dallas County judge Clay Jenkins declared the emergency in his capacity as director of the county's Homeland Security and Emergency Management and instructed the department to file a local disaster declaration with the state. "This declaration will expand our avenues for assistance in our ongoing battle with West Nile virus," Jenkins stated.

Insecticide spraying by planes will be offered to certain communities hit hard by the virus as long as those local governments request it, Jenkins told reporters. The aerial spraying would occur from 10 p.m. to 6 a.m., when children are inside, Jenkins said. "The insecticide is safe," Jenkins said. "The planes are quite sophisticated, and they get the spray to where it needs to go."

The judge organized an invitation-only work session Friday [10 Aug 2012] with county, state, and federal officials to discuss a response to the epidemic.

The United States is experiencing its biggest spike in West Nile virus [human cases] since 2004, with 241 cases of the disease reported nationwide this year [2012] so far, including 4 deaths, health officials said last weekend [4-5 Aug 2012], before the latest totals.

Of the 42 states that have reported infections in people, birds, or mosquitoes, 80 per cent of them have been in Texas, Mississippi, and Oklahoma, the US Centers for Disease Control and Prevention stated. CDC listed a breakdown of infections by state.

"It is not clear why we are seeing more activity than in recent years," said Marc Fischer, a CDC medical epidemiologist. "Regardless of the reasons for the increase, people should be aware of the West Nile virus activity in their area and take action to protect themselves and their family." The virus is transmitted through infected mosquitoes. In the United States, most infections occur between June and September, and peak in August, according to CDC.

Symptoms include fever, headache, body aches, joint pains, vomiting, diarrhea, or rash. "Less than 1 per cent develop a serious neurologic illness such as encephalitis or meningitis (inflammation of the brain or surrounding tissues)," CDC said. Those at greater risk are people older than 50 and those with conditions such as cancer, diabetes, and kidney disease, or with organ transplants.

There are no medications to treat West Nile virus or vaccines to prevent infection. People with milder illnesses typically recover on their own, but those more seriously affected may need hospital care.

Health experts say prevention measures include avoiding mosquito bites, using insect repellant, and getting rid of insect breeding sites.

[byline: Michael Martinez]

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[The state of Texas can be located on the HealthMap/ProMED-mail interactive map at http://healthmap.org/r/2E*U. Dallas County in north eastern Texas can be seen on the map at http://www.digital-topo-maps.com/county-map/texas.shtml. - Sr.Tech.Ed.MJ]

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[2] Louisiana
Date: Sun 12 Aug 2012
Source: Examiner [edited]
http://www.examiner.com/article/louisiana-records-the-most-neuroinvasive-wnv-cases-since-2006

The number of West Nile virus (WNV) [infection] cases continues to rise in the Bayou State as health officials report another 15 cases of the mosquitoborne disease [virus] along with 4 more fatalities. This brings the totals to 68 human cases of WNV and 6 deaths so far this year [2012] according to a press release from Louisiana Department of Health and Hospitals (DHH) dated Friday [10 Aug 2012]. In addition, a troublesome figure reported is that more than half of the cases seen this year in Louisiana have been the more serious type, neuroinvasive disease (NID).

The DHH reports 37 cases of NID as of Friday [10 Aug 2012] making this the worst year for this type in 6 years. 8 of the 15 new cases reported were NID and were from the following parishes [county equivalent]: Bossier, Caddo, Concordia, Jefferson, Tangipahoa, Union, Washington, and Webster.

So far this year, St Tammany Parish has reported the most West Nile virus infections, with 6 neuroinvasive disease cases, 4 West Nile fever cases, and one asymptomatic case.

DHH state epidemiologist, Dr Raoult Ratard warns the public about the seriousness of WNV saying, "We know from 10 years of surveillance that this disease is active in every corner of the state, and people are at risk of getting it regardless of whether cases or deaths occurred in their parishes. Everyone should own their own health and take precautions against mosquito bites."

West Nile virus is a mosquitoborne disease [virus] that can cause encephalitis, a brain inflammation. West Nile virus was first detected in North America in 1999 in New York. Prior to that it had only been found in Africa, Eastern Europe, and West Asia. According to the Centers for Disease Control and Prevention (CDC), about 4 out of 5 people who are infected with WNV will not show any symptoms at all.

Up to one in 5 of people who become infected have symptoms such as fever, headache, and body aches, nausea, vomiting, and sometimes swollen lymph glands or a skin rash on the chest, stomach, and back. Symptoms can last for as short as a few days, though even healthy people have become sick for several weeks.

About one in 150 people infected with WNV will develop severe illness. The severe symptoms can include high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness, and paralysis. These symptoms may last several weeks, and neurological effects may be permanent.

There is no specific treatment for WNV infection.

[byline: Robert Herriman]

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communicated by:
ProMED-mail from HealthMap alerts
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[The state of Louisiana can be located on the HealthMap/ProMED-mail interactive map at http://healthmap.org/r/348T. A Louisiana parish map can be seen at http://www.digital-topo-maps.com/county-map/louisiana.shtml. - Sr.Tech.Ed.MJ]

[Because West Nile virus is now endemic in the continental USA and human and equine cases can be expected each year, ProMED-mail has not been posting human and equine cases this year, except in unusual circumstances, such as the recent cluster of equine cases in California. The clusters of human cases in one county (Dallas) in Texas and in Louisiana are noteworthy.

A recent study of human WNV infection convalescent people (cited in ProMED-mail archive no. 20120714.1202043) indicated that 40 per cent of the study participants showed evidence of chronic kidney disease, with 10 per cent having stage III or greater and 30 per cent with stages I or II. The researchers further found that 26 per cent of patients had proteinuria and 23 per cent had hematuria. Plasma NGAL (neutrophil gelatinase-associated lipocalin) levels were also elevated in 14 per cent of the patients. It would be of interest to know if there are similar findings in those convalescing after WNV infection in Texas.

It would also be of interest to know if the _Culex_ vector mosquito population is unusually abundant in these 2 foci and has a high WNV infection rate, or if many WNV positive dead wild birds have been found.

Reference
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Nolan MS, Podoll AS, Hause AM, et al. Prevalence of chronic kidney disease and progression of disease over time among patients enrolled in the Houston West Nile Virus Cohort. PLoS One. 2012; 7(7): e40374. Epub 2012 Jul 6. Available at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3391259

A US CDC fact sheet on West Nile virus, with a map of 2012 equine and human cases in the USA, including these 2 foci, can be accessed at http://www.cdc.gov/ncidod/dvbid/westnile/index.htm. - Mod.TY]

See Also