Occurrence of i n M arin, Sonoma, and A l ameda Counti es i n

Northern California

Valkyrie P. Kimball*†, D ee Young*, Ron Kei th †, Kevi n R. Kazacos‡, and Judy Sakanari *

*Dept. of Bi ol ogy, Sonoma State Uni versi ty, Rohnert Park, CA 94928; †M ari n/ Sonoma

M osqui to and Vector Control Di stri ct, Cotati , CA 94931; ‡D ept. of Veteri nar y

Pathbi ol ogy, Purdue Uni versi ty, West Lafayette, IN 47907

Correspondence and Proofs:

Dr. Judy Sakanari , Dept. of Bi ol ogy, Sonoma State Uni versi ty, Rohnert Park, Ca 94928

EM : sakanari @sonoma.edu

1 ABSTRACT: Bay l i sascar i s pr ocy oni s, a common intestinal parasite of , Procyon

lotor, i n N orth A meri ca, can cause seri ous and someti mes fatal l arva mi grans i n

humans and many speci es of mammal s and birds. The pur pose of thi s stud y w as to

d eter mi ne the pr ev al ence of i nf ecti on of Baylisascari s adul ts and eggs i n raccoons and

latrines in Marin and Sonoma Counties and at a university student housing

facility in Alameda County in northern California. We found that 4 of 6 (67%) and 2 of

4 (50%) r accoons necr opsi ed i n M ar i n and Sonoma Counti es, r especti v el y , w er e posi ti v e

for B. procyonis, w i th an av er age i ntensi ty of i nf ecti on of 3 w or ms (r ange = 1-10). 13 of

35 (37%) and 5 of 9 (56%) capti ve raccoons at w i ldlife centers in Marin and Sonoma

counti es, r especti v el y , w ere shedd i ng B. procyonis eggs i n their feces. 12 of 17 (71%), 1 of 3 (33%), and 13 of 19 (68%) raccoon l atri nes exami ned i n Sonoma and M ari n counti es and at the University of California - Ber kel ey student housing complex in Alameda county , r especti v el y , w er e posi ti v e f or B. procyonis eggs. These findings, although

somewhat limited in scope, indicate that B. procyonis is common in these counties in

northern California and that appropriate precautions should be taken concerning

raccoons and their feces in order to prevent human and infection with this

parasi te.

2

The l ar ge r ound w or m, Bayl i sascari s procyonis (A scaridoi dea: A scari di dae) i s a

common intestinal parasite of raccoons, Procyon lotor, i n N or th A mer i ca. Pr ev al ences

of infection have ranged from 68% to 82% in the Midwestern and Northeastern United

States to 58%, to 100% on the West Coast (Kazacos and Boyce, 1989; Kazacos, 2001).

Although the parasite causes little pathology in the raccoon, mi grati ng l arvae can cause

ser i ous and someti mes f atal centr al ner v ous sy stem (CN S) d i sease i n humans and many

ani mal s. B. procyonis has caused f atal or sev er e CN S d i sease i n ov er 90 speci es of bi r d s and mammals, including humans, in North Ameri ca (Kazacos 2001).

14 cases of human CN S i nfecti on by B. procyonis hav e been di agnosed i n the

Uni ted States from 1975 - 2002 (Kazacos 2000; Kazacos 2001). Four cases occurred i n

Cal i f or ni a, thr ee i nv ol v i ng sev er e CN S d i sease i n y oung chi l d r en f r om the San

Franci sco Bay area (Row l ey et al. 2000; Park et al . 2000) and Santa Barbara County (E.

Schul man, Santa Barbara County Publi c H eal th Department, DCDC Cal i forni a CD Bri ef

CDH S 5/ 08/ 02 w eek 19). The fourth case w as di agnosed i n a 17 year-old male residing

i n L os A ngel es (W . A . Kenned y, H ar bor-U CLA M ed i cal Center , per sonal

communi cati on 2001). In addi ti on, B. procyonis i s recogni zed as an i mportant cause of

human ocul ar l arva mi grans, w i th cases di agnosed throughout N orth A meri ca,

including the San Francisco Bay area (Goldberg et al., 1993). The objecti ve of thi s study

w as to d eter mi ne the occur r ence of i nf ecti on of B. procyonis adults and eggs in raccoons

3 and raccoon latrines in Marin and Sonoma counties and at a university student-housing

facility in Alameda County in northern California.

Raccoon f eces w er e col l ected f or exami nati on f r om: 1) i ntesti nal contents of d ead

raccoons at necropsy; 2) capti ve raccoons housed at M ari n Wil dCare, San Rafael , CA

and Sonoma County Wi l dl i fe Rescue Center, Santa Rosa, CA ; and 3) natural l y occurri ng

r accoon l atr i ne si tes. Raccoons f or necr opsy w er e ei ther r oad -ki l l speci mens (n = 4;

Sonoma County) or that died or were euthanized while under the care of the

w i l d l i f e center s (n = 6; M ar i n Wi l d Car e). N ecr opsi es w ere performed within 48 hours

postmortem on fresh or refrigerated raccoon carcasses or w ithin one to tw o w eeks for

frozen carcasses. A midline abdominal incision was made, and the small and large

i ntesti nes w er e r emov ed and opened. A ny B. procyonis pr esent w er e r emov ed and

pl aced i nto 70% ethanol . Car casses w ere i nci ner ated af ter necr opsy .

Fecal sampl es (appr oxi matel y 5 gr ams each) w er e col l ected d ur i ng June 1999-

N ovember 2000 from 39 raccoon l atri ne si tes in Sonoma (n = 17) and M ari n (n = 3)

counti es and at the Uni versi ty of Cal iforni a -Ber k el ey stud ent-housing complex in

A l ameda county (n = 19). Latri ne si tes w ere identi fi ed as raccoon feces accordi ng to size, coloration and texture consistent with raccoon stool and that these latrines had the common characteristic of being “ piled up” in one concentrated area. The distribution of the latrines was highly variable among all three counties. Several sites in Sonoma

County were isolated in fields, pastures or along hiking trails with less than 10 separate stool s per si te. I n sev er al ur ban ar eas (back y ar d s, gar d en ar eas, etc.), the l atr i nes contained substantial amounts of fecal piles with up to 30 separate stool specimen in an

4 area often less than one square foot. To prevent redundancy, none of the latri ne si tes w ere sampl ed more than once. Fecal sampl es (n = 44) from raccoons at the w il dli fe r ehabi l i tati on center s w er e al so col l ected and anal y zed f or B. procyonis eggs prior to the ani mal s’ r el ease i nto the w i l d (Tabl e 1 ages, sex, etc). I ntesti nal contents f r om the 10 necropsi ed raccoons w ere al so analyzed for eggs and adul t w orms. 6 out the 10 ani mal s necr opsi ed w er e ad ul ts. The other 4 w ere i d enti f i ed as juv eni l es (> 6 months ol d).

Fecal speci mens w er e anal y zed f or B. procyonis eggs by standing flotation using

Fecal y zer ki ts (Evsco Pharmaceuti cal Corp., Oceansi de, N Y) and sodi um ni trate flotation solution (specific gravity 1.25 – 1.30). A fter 10-15 mi nutes, cov er sl i ps w er e removed, pl aced on gl ass sl i des and exami ned mi croscopi cal ly at 100x magni fication.

B. procyonis eggs were identified based on their size, ellipsoidal shape, brown color, and fi nel y granul ar surface (Kazacos, 2000; Kazacos, 2001).

In M ari n and Sonoma counti es, 4 of 6 (67%) and 2 of 4 (50%), respecti vel y, of necropsi ed raccoons contained B. procyonis ad ul t w or ms, with a mean intensity of infection of 3 w orms (range 1-10). N ecropsi ed raccoons checked for fecal sampl es i nd i cated that i ntesti nal f eces w er e present w hen ad ul t w or ms w er e pr esent i n the i ntesti ne. Fecal sampl es of 5 of 9 (56%) capti ve raccoons at Sonoma County Wi l dl ife

Rescue center w er e posi ti v e f or B. procyonis eggs, w hi l e 13 of 35 (37%) fecal sampl es col l ected fr om r accoons at M ar i n Wi l d Car e w er e posi ti v e.

In Sonoma County, 12 of 17 (71%) l atri ne sampl es w ere positive for B. procyonis eggs and 1 of 3 (33%) l atri nes i n M ari n County contai ned eggs. The U.C. Berkel ey stud ent-housing complex in Alameda County had 13 of 19 (68%) latrine sites containing

5 B. procyonis eggs. These f i ndi ngs consti tute new county r ecor d s for Sonoma and

A l amed a counti es.

I ngesti on of i nf ecti v e B. procyonis eggs can hav e sev er e neur ol ogi cal consequences, with one to four year old children being at particular risk of infection due to thei r propensi ty for pi ca and geophagi a (Kazacos, 2000; Kazacos, 2001; Park et al .,

2000). Larvae hatch from i ngested eggs i n the i ntesti ne and mi grate vi a portal and systemic circulation to various tissues including the musculature, heart, lungs, eyes, and brain. Migrating larvae induce a strong host inflammator y r esponse i n w hi ch eosinophils predominate. In heavy infections, larval migration within the CNS may result in major damage leading to loss of motor and visual function, muscle weakness, ataxi a, decreased head control , and other abnormal i ti es that may progress to coma and death (Kazacos, 2000). Because ante mortem di agnosi s i s di ffi cul t and often del ayed, and anthelminthics given during the clinical disease are often ineffective, prevention of infection is essential. Information regarding the prevalence of i nf ecti on and d egree of environmental contamination in a particular area facilitate prevention.

Based on a combi nati on of r accoon necr opsy and f ecal d ata, w e f ound B. procyonis infections occurring in raccoons in Marin and Sonoma counties at the rates of

42% (17 of 41) and 54% (7 of 13), respecti vely. In these counti es, 33% and 71% of r accoon l atr i nes, r especti v el y , w ere f ound to contai n B. procyonis eggs. W e al so f ound

68% (13 of 19) of l atri nes contai ned B. procyonis eggs at the U.C. Ber k el ey housi ng si te an ar ea w i th a pl ay gr ound fr equented by chi l d r en. I n a prev i ous stud y cond ucted i n

6 Marin County the prevalence of infection of B. procyonis i n raccoons w as 67% (8 of 12),

similar to our findings in necropsied raccoons from this county.

Bayl i sascari s procyonis was first reported from northern California in raccoons f r om M onter ey County i n 1956 (Voge, 1956), and subsequentl y f r om L os A ngel es

(Ov er str eet, 1970). M or e r ecent stud i es, i ncl ud i ng thi s sur v ey , i nd i cate that B. procyonis

is probably common in raccoons throughout California and that raccoon fecal

contamination containing B. procyonis eggs i s w idespread (Kazacos, 2001). In

M onter ey County , w her e an 11-month ol d boy contr acted sev er e CN S d i sease d ue to B.

procyonis, all latrine sites on the pati ent’ s pr oper ty and ad jacent l ot w er e posi ti v e f or

eggs, and 12 of 27 (44%) of l atr i nes sampl ed el sew her e i n the communi ty w er e posi ti v e

(Par k et al ., 2000). The numer ous r epor ti ngs of the pr esence of B. procyonis eggs in

areas with the potential for human contact make it prudent to alert the public about the

risk of infection with this parasite and appropriate precautions.

In our study, 68% of the raccoon feces found on the grounds at the U.C. Berkeley

stud ent-housing facility were positive for B. procyonis eggs. M any of the f ecal sampl es

w er e concentr ated on l aw ns near the chi l d r en’s pl ay ar eas, i n a communi ty gard en si te,

or on the stairwells of the apartments. Upon further investigation, we determined that

l ocal r esi d ents w er e f eed i ng commer ci al cat food to this urban raccoon population.

Because of the high potential for zoonotic transmission of this parasite to children living

at that housing complex, public health brochures and posters were circulated and

displayed. The information provided in the br ochur es i ncl ud ed suggesti ons of w ay s to

d i scour age r accoons and other w i l dl i fe fr om fr equenti ng the ar ea, e.g. pl aci ng al l

7 garbage in cans with tight lids and preventing access of wild animals to pet food left

outdoors. Both the information and suggesti ons w er e w el l -r ecei v ed by the r esi d ents of the compl ex.

We also found a risk of infection for animal handlers at wildlife rehabilitation centers in both Marin and Sonoma counties, because both facilities held captive raccoons that tested positive for B. procyonis. Brochures and suggested precautions

w er e al so pr ov i d ed to these w i l d l i f e center s i nf or mi ng per sonnel of pr ev entati v e

measures and risks of handling raccoons and other animals housed in these facilities.

Because of the pr obabl e hi gh pr ev al ence of infection of B. procyonis in raccoons in

northern California, public education remains one of the most important aspects of

preventing infections with this parasite.

We thank the staff at M ari n Wil dCare and Sonoma County Wi l dli fe Rescue and

M argaret Hurlbert, University of California, Berkeley for their assistance in collecting samples; and Chris Canterbury and the staff at the Marin/ Sonoma Mosquito and

Vector Control District for their assistance. We also thank the Department of Biology and the Under gr ad uate Resear ch Gr ant Pr ogram, Sonoma State U ni v er si ty , f or f i nanci al support of this project.

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