- I would like to bring up the good news with this update.
Pa. has only 4 cases of WNV and no deaths.
-
- Patricia Doyle
-
- WEST NILE VIRUS UPDATE 2004 - WESTERN HEMISPHERE (16)
-
- A ProMED-mail post
- ProMED-mail is a program of the
- International Society for Infectious Diseases
-
- In this update:
-
- Canada
- -----
- [1] Health Canada, Surveillance Data 2004 Program (As
of Wed 15 Sep 2004)
-
- United States
- -----
- [2] MMWR, CDC/ArboNET Report (Wed 8 Sep to Tue 14 Sep
2004)
- [3] Arizona - Transfusion-associated transmission
- [4] Pennsylvania - Drop in case numbers
- [5] California - Outbreak peaking
-
- Mexico
- -----
- [6] Resumen Epidemiologico - Thu 9 Sep 2004
-
- ******
- [1] Health Canada, Surveillance Data 2004 Program (As
of Wed 15 Sep 2004)
- Date: Thu 16 Sep 2004
- From: ProMED-mail <promed@promedmail.org>
- Source: Health Canada, Surveillance Data 2004 Program,
Wed 15 Sep 2004 [edited]
- <http://www.hc-sc.gc.ca/pphb-dgspsp/wnv-vwn/mon_e.html>
-
-
- Surveillance Data 2004 data - as of Wed 15 Sep 2004
- -----------------------------------------------
- Human Cases (As of 15 Sep 2004)
- -----
- As of Wed 15 Sep 2004, the number of human cases in Canada
has been revised, and the total is now 20 confirmed cases, an increase
of 3 cases overall since Thu 2 Sep 2004. There have been 3 confirmed cases
in Manitoba (up one - one neuroinvasive, one fever, and one unspecified),
8 in Ontario (up one - 6 neuroinvasive, one fever, and one unspecified),
and 9 in Saskatchewan (up 2 - all fever). The single case in Quebec has
been removed from the current list.
-
- Dead Bird Test Results (As of Wed 15 Sep 2004)
- -----
- Province / Tested / Presumed Positive / Confirmed Positive
-
- Newfoundland & Labrador / 83 / 0 / 0
- Prince Edward Island / 99 / 0 / 0
- Nova Scotia / 427 / 0 / 0
- New Brunswick /471 / 0 / 0
- Quebec / 801 / 5 / 93
- Ontario / 1352 / 4 / 231
- Manitoba / 316 / 0 / 16
- Saskatchewan / 362 / 0 / 29
- Alberta / 620 / 0 / 6
- British Columbia / 1332 / 0 / 0
- Yukon / 11 / 0 / 0
- Northern Territories / 10 / 0 / 0
- Nunavut / 2 / 0 / 0 /
-
- Canada Total / 5886 / 9 / 375
-
- [An additional 134 dead birds have been tested since
the figures released 7 days ago on Wed 8 Sep 2004 and posted in the preceding
update. The number of confirmed West Nile virus-positive birds has increased
from 361 to 375 (plus 9 classified as presumed positives). Alberta, Manitoba,
Ontario, Quebec, and Saskatchewan remain the only provinces to report West
Nile virus-positive birds so far in 2004. The total of 14 West Nile virus-positive
birds confirmed during the past week [2nd week of September 2004] compares
with 35 in the preceding week, and, represents the 1st decline in virus-affected
birds. - Mod.CP]
-
- Equines and other domestic animals
- -----
- The total number of equine cases in Canada is now given
as 7: 2 presumed positive cases in Alberta, 4 confirmed cases in Ontario,
and one presumed-positive case in Quebec.
-
- Mosquito Pools
- -----
- As of Wed 15 Sep 2004, 137 mosquito pools (an increase
of 11) have tested West Nile virus-positive: one in Alberta, 54 in Manitoba,
49 in Ontario, 6 in Quebec and 27 in Saskatchewan. These 5 are the only
provinces to report WNV-positive mosquito pools in 2004 so far.
-
- --
- ProMED-mail
- <promed@promedmail.org>
-
- [The provinces of Newfoundland and Labrador, Prince Edward
Island, Nova Scotia, New Brunswick, British Columbia, Yukon Territory,
Northwest Territories, and Nunavut have not reported confirmed cases of
West Nile virus in 2004 so far. - Mod.CP]
-
- ******
- [2] MMWR, CDC/ArboNET Report (Wed 8 Sep to Tue 14 Sep
2004)
- Date: Thu 16 Sep 2004
- From: ProMED-mail <promed@promedmail.org>
- Source: Morbidity and Mortality Weekly Report (MMWR),
Fri 17 Sep 2004
- / 53(36);850-851 [edited]
- <http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5336a7.htm>
-
-
- West Nile virus activity -- United States: Wed 8 Sep
to Tue 14 Sep 2004
- -----------------------------------------------
- Human Cases
- -----
- During the period Wed 8 Sep to Tue 14 Sep 2004, a total
of 195 cases of human West Nile virus (WNV) illness were reported from
26 states (Alabama, Arizona, Arkansas, California, Colorado, Florida, Georgia,
Idaho, Illinois, Iowa, Kansas, Maryland, Minnesota, Missouri, Nebraska,
Nevada, New Mexico, New York, North Dakota, Oklahoma, Oregon, Pennsylvania,
South Dakota, Tennessee, Texas, and Wisconsin).
-
- During 2004, a total of 39 states have reported 1386
cases of human WNV illness to CDC through ArboNET (see Table). Of these,
392 (28 percent) cases were reported from California, 345 (25 percent)
from Arizona, and 225 (16 percent) from Colorado. A total of 764 (57 percent)
of the 1347 cases, for which all data were available, occurred in males;
the median age of patients was 51 years (range: 1 month to 99 years). Illness
onset ranged from 23 Apr to 8 Sep 2004; a total of 35 cases were fatal.
-
- Table: Number of human cases of WNV illness by state
-- United States 2004
-
- See: http://www.cdc.gov/ncidod/dvbid/westnile/surv&controlCaseCount04_detailed.htm
-
- Notes:
- As of Tue 14 Sep 2004; * Cases with neurologic manifestations
(e.g. WN meningitis, WN encephalitis, WN myelitis) ** Cases with no evidence
of neuroinvasion *** Illnesses for which sufficient clinical information
was not provided **** Total number of human cases of WNV illness reported
to ArboNET by state and local health departments.
-
- Blood Donors
- -----
- A total of 124 presumptive West Nile viremic blood donors
(PVDs) have been reported to ArboNET in 2004. Of these, 37 (30 percent)
were reported from Arizona; 35 from California; 15 from Texas; 11 from
New Mexico; 5 from Colorado; 4 from Georgia; 3 each from Florida and South
Dakota; 2 each from Missouri, Oklahoma, and Wisconsin; and one each from
Iowa, Louisiana, Minnesota, Nebraska, and North Dakota. Of the 124 PVDs,
5 persons aged 35, 50, 66, 69, and 77 years subsequently had neuroinvasive
illness, and 27 persons (median age: 54 years; range: 17 to 73 years) subsequently
had West Nile fever.
-
- Dead Birds
- -----
- In addition, during 2004, a total of 3946 dead corvids
and 868 other dead birds with WNV infection have been reported from 44
states and New York City.
-
- Equines
- -----
- WNV infections have been reported in horses from 34 states
(Alabama, Arizona, Arkansas, California, Colorado, Florida, Georgia, Idaho,
Illinois, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, Mississippi,
Missouri, Montana, Nevada, New Jersey, New Mexico, North Carolina, Ohio,
Oklahoma, Oregon, Pennsylvania, South Dakota, Tennessee, Texas, Utah, Virginia,
Wisconsin, West Virginia, and Wyoming).
-
- [Details of the numbers and distribution of equine cases
can be obtained by accessing the APHIS-USDA map. <http://www.aphis.usda.gov/vs/nahps/equine/wnv/map2004.html>
As of Thu 16 Sep 2004, the total number of equine cases in the USA in 2004
now stands at 657, an increase of 246 cases since 3 Sep 2004. California
heads the list with 253 cases (39 percent of the total), followed by Nevada
with 70 cases, Arizona with 81 cases, Nevada with 38 cases, Texas with
36 cases, Wyoming with 30 cases, Colorado with 25 cases, and another 28
states with lesser numbers. - Mod.CP]
-
- Other Mammals
- -----
- 5 dogs have tested WNV-positive in Nevada and New Mexico.
3 squirrels with WNV infection were reported from Arizona. 4 unidentified
animal species with WNV infection were reported from Idaho, Illinois, Iowa,
and Nevada.
-
- Sentinel Chickens and others
- -----
- WNV seroconversions have been reported in 690 sentinel
chicken flocks from 13 states (Alabama, Arizona, Arkansas, California,
Delaware, Florida, Iowa, Louisiana, Nebraska, Nevada, Pennsylvania, South
Dakota, and Utah) and in 7 wild hatchling birds from Missouri and Ohio.
3 seropositive sentinel horses were reported from Puerto Rico.
-
- Mosquito Pools
- -----
- A total of 5248 WNV-positive mosquito pools have been
reported from 32 states and New York City.
-
- Additional information about national WNV activity is
available from CDC at <http://www.cdc.gov/ncidod/dvbid/westnile/index.htm>
and at <http://westnilemaps.usgs.gov>.
-
- [The above report is supplemented by a figure showing
the location of the 39 states reporting cases of human WNV infection in
relation to the states reporting non-human cases of WNV infection only,
and the few remaining states still to report cases of WNV this year [2004].
-
- During the past 7 days, the number of human cases has
increased from 1191 to 1386, and the total number of WNV-related deaths
has increased by 5 from 30 to 35. Idaho and Oregon were added to the list
of states reporting human cases of WNV infection. - Mod.CP]
-
- --
- ProMED-mail
- <promed@promedmail.org>
-
- ******
- [3] Arizona - Transfusion-associated transmission
- Date: Thu 16 Sep 2004
- From: ProMED-mail <promed@promedmail.org>
- Source: Morbidity and Mortality Weekly Report (MMWR),
Fri 17 Sep 2004
- / 53(36);842-844 [edited]
- <http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5336a4.htm>
-
-
- Transfusion-associated transmission of West Nile virus;
Arizona, 2004
- -----------------------------------------------
- Blood transfusion-associated transmission (TAT) of West
Nile virus (WNV) in the United States was 1st identified in 2002 (1). In
2003, blood collection agencies (BCAs) responded by screening donations
for WNV by using nucleic acid-amplification tests (NATs) (2). The majority
of BCAs use a 2-tiered NAT-screening algorithm. On the basis of the test
manufacturer's format, NATs are conducted on minipools of samples from
either 6 or 16 blood donations. If a minipool is nonreactive, its constituent
donations are released for transfusion. If a minipool is reactive, the
constituent donations undergo individual testing. If an individual donation
is reactive, associated blood components are impounded, and the donor is
notified for further testing to confirm the infection. In 2003, blood-donation
screening for WNV resulted in the impounding of approximately 800 blood
components potentially containing WNV. However, 6 reported cases of transfusion-associated
WNV disease were associated with units of blood components with viral concentrations
too small to be detected by minipool NAT (3). In 2004, to improve the sensitivity
of WNV screening, BCAs implemented systems to trigger a switch from minipool
NAT to individual NAT in areas with epidemic WNV transmission. This report
describes the 1st transfusion-associated WNV infection identified in 2004;
the implicated blood donation was collected before the switch to individual
testing. Clinicians should remain aware of the risk for WNV transmission
through blood-product transfusion and alert state health officials to hospitalized
patients with WNV disease symptoms who have had a transfusion during the
preceding 28 days.
-
- Case Report
- -----
- In July 2004, a man aged 43 years was admitted to a tertiary-care
hospital in Maricopa County, Arizona, for an above-knee amputation necessitated
by complications of diabetes mellitus. The patient was anemic and received
2 units of packed red blood cells (RBCs). His surgery occurred 3 days after
admission, and he was discharged in stable condition 8 days later.
-
- 2 days after discharge, after a day of malaise, anorexia,
and diarrhea, the man was found unresponsive and was admitted to a local
hospital. On admission, his wound site was clean, but he was hypoglycemic
and had an erythematous maculopapular rash on his upper extremities. He
remained poorly responsive, despite treatment for hypoglycemia, and the
next day he was transferred to the tertiary-care hospital that had performed
his amputation. On admission, he was febrile, had altered mental status,
oscillopsia, and cogwheel rigidity. Magnetic resonance imaging of the brain
was consistent with WNV encephalitis (4). The patient's cerebrospinal fluid
was positive for WNV-specific IgM antibody by enzyme-linked immunosorbent
assay at the Arizona Bureau of State Laboratory Services, and, positive
for WNV RNA by reverse transcriptase--polymerase chain reaction at CDC.
-
- The patient was discharged to a nursing home in mid-August
[2004] and died 3 days later. Primary cause of death was cardiorespiratory
failure secondary to severe progressive neurologic dysfunction. An autopsy
was not performed.
-
- The RBC units the patient received were produced from
2 donations collected in June 2004 in Maricopa County. Both donations were
nonreactive by minipool NAT screening. 2 fresh frozen plasma units associated
with these donations were recalled and tested individually for WNV. One
plasma unit was nonreactive by NAT, and a follow-up sample from the donor
was negative for WNV IgM. The other plasma unit was reactive by NAT, but
negative for WNV-specific IgM antibody. To determine the efficacy of minipool
testing for this unit, a minipool including this plasma unit was reconstructed
and was reactive in 2 of 10 replicated minipool NAT tests. Individual NAT
was reactive in 9 of 10 replicated tests. Follow-up donor serum was positive
for WNV IgM.
-
- Because the transfusion recipient had a confirmed WNV
infection, the implicated donation was NAT reactive, and the associated
donor seroconverted; this is considered a probable case of WNV TAT (3).
As of 27 Jul 2004, only one WNV-infected horse, and no human cases of WNV
disease, had been reported in the recipient's county of residence. However,
this case does not meet the criteria for a confirmed case of WNV TAT, because
the patient traveled to an area experiencing epidemic WNV transmission
for his amputation. Exposure of the patient to infectious mosquitoes while
in this area cannot be ruled out.
-
- (Reported by: S Caglioti, Blood Systems Laboratories,
Tempe; P Tomasulo, MD, Blood Systems Incorporated, Scottsdale; R Raschke,
MD, M Rodarte, DO, Banner Good Samaritan Medical Center, Phoenix; T Sylvester,
A Diggs, MPH, Maricopa County Dept of Public Health; C Kioski, MPH, C Levy,
MS, Arizona Dept of Health Svcs. M Traeger, MD, J Redd, MD, J Cheek, MD,
Indian Health Svc. M Kuehnert, MD, Div of Viral and Rickettsial Diseases;
S Montgomery, DVM, Div of Bacterial and Mycotic Diseases; A Marfin, MD,
R Lanciotti, PhD, G Campbell, MD, T Smith, MD, Div of Vector-Borne Infectious
Diseases, National Center for Infectious Diseases; J Brown, DVM, EIS Officer,
CDC.)
-
- MMWR Editorial Note:
- -----
- As of 7 Sep 2004, a total of 98 blood components potentially
containing WNV had been removed from the U.S. blood supply during 2004.
The risk for WNV transmission via blood products has been reduced, but,
not eliminated. Minipool NAT is an effective screening method for WNV,
but donations containing low levels of virus can escape detection by this
test. Although individual NAT is more sensitive than minipool NAT, the
United States has limited laboratory capacity and test reagent availability
for NAT. For this reason, BCAs developed systems to trigger a switch from
minipool to individual NAT in areas of epidemic WNV transmission (5). Nonetheless,
in the case described in this report, results of testing the implicated
donation revealed that even individual NAT might not have detected WNV
(i.e., in one of 10 tests).
-
- BCAs in the United States had not planned to implement
their trigger systems until June 2004. However, the WNV epidemic in Maricopa
County began in May 2004, earlier than widespread WNV was expected. Evidence
of year-round WNV activity has been documented in east Texas and Louisiana
(6). This year's [2004] experience demonstrates that BCAs might need to
prepare for onset of human WNV transmission as early as May in areas of
the country similar to Arizona. As a result of the case described in this
report, the BCA involved plans to implement its trigger system year-round
in all of its collection areas.
-
- Clinicians should consider WNV disease in any patient
with consistent symptoms who has received a blood transfusion during the
28 days preceding illness onset. Suspected cases should be reported to
state health authorities, who are encouraged to notify CDC. The vigilance
of clinicians and public health officials is essential to identify breakthrough
TAT cases. Identification of such cases allows recovery of stored components
that might contain WNV, which further increases the safety of the blood
supply.
-
- The benefits of blood transfusion far outweigh the risk
for transfusion-associated WNV disease. However, clinicians should use
blood products judiciously to reduce the risk of adverse events, and, should
be alert for cases of transfusion-associated WNV disease. BCAs will continue
to evaluate WNV-screening strategies in consultation with the CDC, and
the Food and Drug Administration, to ensure that blood products are as
safe as possible.
-
- References
- -----
-
- (1) Pealer LN, Marfin AA, Petersen LR, et al. Transmission
of West Nile virus through blood transfusion in the United States in 2002.
N Engl J Med 2003;349:1236--45.
-
- (2) CDC. Detection of West Nile virus in blood donations---United
States, 2003. MMWR 2003;52:769--72.
-
- (3) CDC. Update: West Nile virus screening of blood donations
and transfusion-associated transmission---United States, 2003. MMWR 2004;53:281--4.
-
- (4) Solomon T. Flavivirus encephalitis [Review]. N Engl
J Med 2004;351: 370--8.
-
- (5) Custer B, Tomasulo PA, Murphy EL, et al. Triggers
for switching from mini-pool nucleic acid technology testing to individual
donation testing: analysis of 2003 data to inform 2004 decision-making.
Transfusion 2004 (in press).
-
- (6) Tesh RB, Parsons R, Siirin M, et al. Year-round West
Nile virus activity, Gulf Coast region, Texas and Louisiana. Emerg Infect
Dis 2004;10:1649--52.
-
- --
- ProMED-mail
- <promed@promedmail.org>
-
- ******
- [4] Pennsylvania - Drop in case numbers
- Date: Sun 12 Sep 2004
- From: ProMED-mail <promed@promedmail.org>
- Source: New York Times, Associated Press report, Sun
12 Sep 2004 [edited]
- <http://www.nytimes.com/aponline/health/AP-West-Nile-Virus.html>
-
-
- Pennsylvania: sharp decline in West Nile case numbers
- -----------------------------------------------
- A year after Pennsylvania experienced a surge in West
Nile cases, the number of people infected with the mosquito-borne virus
appear to be headed back down. State agencies have received reports of
only 4 Pennsylvanians contracting the virus so far this year [2004], compared
to 63 at this time a year ago. Officials say cooler weather, more rain,
a more careful public, and better mosquito control efforts are probably
responsible for the decline.
-
- "The fact that we've had a lot of rain makes you
think mosquitoes would be breeding more," Department of Health spokeswoman
Jessica Seiders told The Morning Call of Allentown. "But we think
the continual rainfall actually helped flush out stagnant water."
Frequent rains can flush out pools of standing water that serve as breeding
grounds for mosquitoes, which are also less active in the cool than in
the heat. The state has also used chemical sprays to kill mosquitoes in
areas where they were a problem last year [2003].
-
- Last year [2003], Pennsylvania had about 240 human cases
of West Nile virus infection. 8 people died. This summer's [2004] numbers
are more like 2002, when the state had 62 cases of the disease. Cases have
been reported this year [2004] in Lancaster, Bucks, York, and Erie counties.
None of the cases were fatal. It's unclear whether this year's numbers
will remain low. Mosquito season generally ends with the 1st frost, but
last year [2003], the state continued to receive reports of cases through
December.
-
- --
-
- ProMED-mail
- <promed@promedmail.org>
-
- ******
- [5] California - Outbreak peaking
- Date: Sat 11 Sep 2004
- From: Pablo Nart <p.nart@ntlworld.com>
- Source: SingOnSanDiego.com, Associated Press report,
Fri 10 Sep 2004 [edited]
- <http://www.signonsandiego.com/news/state/20040910-2245-ca-westnile.html>
-
-
- California: epidemic may be peaking now
- ---------------------------------------
- A Los Angeles County woman has become the 13th Californian
to die from West Nile virus, but the epidemic may be peaking, as summer
ends and cooler weather arrives, officials said on Fri 10 Sep 2004. A 69-year-old
woman was the latest confirmed fatality, authorities said, although details
of her death were not disclosed.
-
- To date, 186 county residents have been reported infected
with the mosquito-borne illness. That was up 11 percent from last week
[1st week of September 2004], which was far from the 69 percent increase
reported in late August 2004. "It's not as steep a rise now,"
said Mike Shaw, operations director for the Greater Los Angeles County
Vector Control District. "I think we are seeing the peak of the number
of human cases ... Hopefully, it will go down the rest of this month and
taper off in October." Statewide, 486 people have been infected, up
10 percent from last week [1st week of September 2004], state officials
said.
-
- --
- Pablo Nart
- <p.nart@ntlworld.com>
-
- ******
- [6] Resumen Epidemiologico - Thu 9 Sep 2004
- Date: Thu 16 Sep 2004
- From: ProMED-mail <promed@promedmail.org>
- Source: National Center for Epidemiologic Surveillance
of Mexico
- web-site, Resumen Epidemiologico, Thu 9 Sep 2004 [edited]
- <http://www.cenave.gob.mx/von/default.asp?id=43>
-
-
- Mexico: West Nile virus infection surveillance data as
of Thu 9 Sep 2004
- -----------------------------------------------
- [The following figures have been extracted from the Resumen
Epidemiologico file <http://www.cenave.gob.mx/von/archivos/ResumenCASOSVON.xls>
accompanying the pictorial Maps of West Nile Virus Activity in Mexico.
- Mod.CP]
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