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BAYLISASCARIASIS - USA: (NEW YORK CITY), REQUEST FOR INFORMATION
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A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the
International Society for Infectious Diseases
<http://www.isid.org>
Date: 9 Apr 2009
Source: New York City Department of Health, Health Alert Network
<http://www.nyc.gov/html/doh/html/hcp/hcp.shtml#han> [registration required]
Raccoon Roundworm Infection Identified in New York City
-------------------------------------------------------
So far, 2 cases of Baylisascaris procyonis (_B. procyonis_ or raccoon
roundworm) infection have been identified in children from Brooklyn,
both with serious sequelae:
- An infant with eosinophilic meningoencephalitis from neural larva migrans
resulting in severe permanent brain damage, and
- A teenager with ocular larva migrans resulting in loss of vision in
one eye.
The New York City (NYC) Health Department asks providers to consider
and test for baylisascariasis in patients presenting with
encephalopathy with peripheral eosinophilia or a CSF eosinophilic
pleocytosis, ocular larva migrans, diffuse unilateral subacute
neuroretinitis (DUSN) or eosinophilic pseudotumor.
Suspected cases should be reported immediately to the NYC Health
Department for consultation and diagnostic assistance at 212-788-9830
during business hours or the Poison Control Center at 212-764-7667
after hours and on weekends.
******
On [30 Mar 2009], 2 cases of baylisascariasis among children from
Brooklyn were reported to the Health Department. The 1st case was
identified in a previously healthy infant who presented with an acute
onset of developmental regression, irritability, postural deficits and
seizures in [October 2008] resulting in a diagnosis of eosinophilic
meningoencephalitis. The patient had a history of geophagia [eating
soil] and travel to upstate New York. Serologic testing for _B.
procyonis_ was positive and anthelmintic and steroid therapy were
initiated but did not result in improvement. The child remains
hospitalized with permanent brain damage.
The 2nd child, a teenager, developed an acute onset of blindness of
the right eye in [January 2009]. This patient had not traveled outside
NYC during the incubation period. Visual inspection of the eye
revealed a larva and lesions consistent with ocular larva migrans
(OLM). The large dimensions and morphological characteristics of the
larva were consistent with _B. procyonis_ rather than _Toxocara
canis_, the more common cause of OLM in the United States. Serologic
testing is pending. Laser photocoagulation was conducted to
successfully destroy the larva, along with steroidal therapy, but the
child remains blind in the right eye. The Health Department is
conducting an investigation to attempt to determine when and how these
children became infected and to assess any risk to others.
Baylisascariasis is an uncommon disease caused by the raccoon
roundworm _B. procyonis_. Fewer than 30 cases have been reported in
the medical literature, although unpublished cases are known. While
most were infants or young children, adult cases have also been
reported. Infection occurs following ingestion of _B. procyonis_ eggs
which are shed in the feces of infected raccoons. Upon ingestion the
eggs hatch and the larvae migrate through the body. The larvae cause
particular damage to the eyes and central nervous system due to OLM or
neural larva migrans (NLM), although viscera and various somatic
tissues are commonly affected. The incubation period is not well
defined but estimated to be 2 to 4 weeks for NLM and 1 to 2 weeks for
OLM. Asymptomatic, mild and covert infections have been reported.
Onset and severity of illness is often associated with the number of
eggs ingested, the extent of larval migration, and the degree of
inflammation and necrosis. Young children, persons with pica and/or
developmental disabilities and those who have an exposure to raccoon
habitats are at greatest risk for severe, overwhelming, irreversible
neurologic disease or death.
Of 14 cases of NLM summarized recently, 10 were under 20 months of age
and 3 had a history of developmental delay (refs: i , ii). Outcomes
included death (5), severe/persistent residual deficits (9) along with
visual impairment, blindness and epilepsy.
Studies suggest that the parasite is very common among raccoons, with
carriage rate estimates as high as 90 percent among juvenile and 60-70
percent of adult raccoons sampled (iii). The eggs are extremely
resilient, can overwinter and persist in the environment for months to
years. Raccoons are the definitive host and humans are not capable of
shedding eggs. This alert asks providers to consider baylisascariasis
in the differential diagnosis for patients presenting with
encephalopathy and peripheral or CSF eosinophilia, diffuse unilateral
subacute neuroretinitis (DUSN) or eosinophilic pseudotumor, especially
if there is a history of exposure to raccoons or raccoon habitat.
DIAGNOSIS: Diagnosis of baylisascariasis is based on clinical illness,
exposure history and laboratory findings including a CSF eosinophilic
pleocytosis, a peripheral eosinophilia and deep white matter
abnormalities on MRI [Magnetic resonance imaging] (refs i,ii). For
OLM, peripheral eosinophilia is not always present, but ocular
examinations may reveal a migrating larva, larval tracks, or lesions
consistent with a nematode larva. _B. procyonis_ larvae grow
relatively large in size, [adult worms measure 15 to 20 cm in length
and 1 cm in width, see with photo:
<http://www.michigan.gov/dnr/0,1607,7-153-10370_12150_12220-27261--,00.html>
- Mod.JW]
This helps to distinguish them from _Toxocara_ larvae which [are only
one-fifth of that length. - Mos.JW]. Identification of larva in tissue
biopsies is diagnostic, but the chances of a biopsy containing a larva
are relatively low. Immunodiagnostic tests of serum or cerebrospinal
fluid (CSF) are helpful in suspected cases but are not widely available.
Please contact the Bureau of Communicable Disease (BCD) to discuss
suspect cases and obtain assistance with diagnostic testing.
Call BCD at 212-788-9830 during business hours and the
Poison Control Center at 212-764-7667 after hours and weekends.
TREATMENT: Anthelmintic treatment has had limited
effectiveness in preventing death or severe
outcome, except in cases with low infections and
early aggressive therapy. While data from animal
models show that preventive treatment is
effective before _B. procyonis_ larvae enter the
brain, most human cases are not recognized until
well after CNS damage has already occurred.
Theoretically if started within 1-3 days of
possible infection, anthelmintics should prevent
clinical disease by killing larvae before they
enter the CNS and should be considered for anyone
with a recent history of ingestion of raccoon
feces (refs ii, iii).
Time is of the essence in the treatment of this infection. Albendazole
is the treatment of choice because of its CNS penetration, minimal
toxicity and larvacidal activity. In addition, systemic
corticosteroids should be administered to reduce the damage associated
with the inflammatory response. Summaries of treatments administered
to published NLM (National Library of Medicine) cases are cited below
(i, ii, iv, v). Laser photocoagulation along with the administration
of systemic corticosteroids is the treatment of choice for patients
with OLM and diffuse unilateral subacute neuroretinitis (DUSN).
RESOURCES: For more information on baylisascariasis visit
<http://www.cdc.gov/ncidod/dpd/parasites/baylisascaris/default.htm> or
<http://www.avma.org/reference/zoonosis/znbaylis.asp>.
Please call the
Bureau of Communicable Disease at 212-788-9830
with questions regarding testing, diagnosis, or management of
suspected cases of baylisascariasis. As always, we greatly appreciate
your cooperation and collaboration in our efforts to detect,
investigate and prevent infectious diseases in New York City.
Sincerely,
Sally Slavinski, DVM, MPH, ACVPM, Assistant Director
Zoonotic, Influenza and Vectorborne Disease Unit (ZIVDU)
Bureau of Communicable Disease
Annie Fine, MD, Medical Director
ZIVDU Bureau of Communicable Disease
References:
i Gavin et. al. 2005. Baylisascariasis. Clinical
Microbiology Reviews, Oct 2005, p. 703-718.
ii Murray and Kazacos 2004. Raccoon roundworm
encephalitis. CID 2004;39(10)1484-92.
iii Roussere et. al. 2003 Raccoon Roundworm Eggs
near Homes and Risk for Larva M igrans Disease,
California Communities. EID:9;December 2003 1516-22.
iv Gavin et. al. 2002 Neural larva migrans
caused by the raccoon roundworm Baylisascaris
procyonis. Pediatr Infect Dis J. 2002;21:971-5.
v Park et. al. 2000. Raccoon Roundworm
(Baylisascaris procyonis) Encephalitis: Case
Report and Field Investigation. Pediatrics
2000;106 <http://www.pediatrics.org/cgi/content/full/106/4/e56>.
--
Communicated by:
ProMED-mail
<promed@promedmail.org>
[ProMED-mail would like to thank Dr. Marci
Layton, Assistant Commissioner, Bureau of
Communicable Disease, New York City (NYC)
Department of Health for permission to reproduce
this announcement from the NYC, Health Alert
Network. As mentioned above, there have been
fewer than 30 reports of illness attributable to
baylisascariasis in the medical literature to
date. ProMED-mail has reported on cases in
Ontario (Canada), California and Illinois (see
prior ProMED-mail posts listed below).
If there are other cases consistent with a
diagnosis of baylisascariasis in surrounding
states in the USA, ProMED-mail would greatly
appreciate receiving information on these cases.
Given the rarity of reported cases, if there are
other reports of cases elsewhere, ProMED-mail
would appreciate receiving information on those cases as well.
For the interactive HealthMap/ProMED map of Brooklyn, New York, see
<http://healthmap.org/r/009d>. - Mod.MPP
_Baylisascaris_ photo at:
<http://www.stanford.edu/class/humbio103/ParaSites2006/Baylisascariasis/03-0039_1t.jpg>
_Baylisascaris_ life cycle shown at:
<http://www.geocities.com/RainForest/Vines/4892/wormlife.gif>
- Mod.JW]
[see also:
2005
----
Baylisascaris - Canada (ON) 20050907.2660
2002
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Baylisascaris - USA (California) 20020520.4282
Baylisascaris procyonis, decontamination 20020112.3238
Baylisascaris procyonis, humans - USA (02) 20020109.3214
Baylisascaris procyonis, humans - USA 20020108.3197
2000
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Roundworms, human ex raccoons - USA (California) 20000525.0828
1997
----
Eosinophilic meningitis, raccoons (03) 19970208.0300
Eosinophilic meningitis, raccoons (02) 19970205.0268]
............................mpp/ejp/jw
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