Vaccine-Derived Poliovirus Infections in an Amish Population Minnesota, 2005 Harry F. Hull, M.D. State Epidemiologist Minnesota Department of Health

Index Patient  Sept 29 – Poliovirus type 1 identified in stool sample  Unvaccinated, immunocompromised 7 m Amish girl  No paralysis  Recurring fevers, Outpatient Antibiotic Rx  Pneumonia, community hospital July  Continuously hospitalized since August 22 –Regional Medical Center, Children’s Hospital, University Hospital –Failure to thrive, diarrhea, recurrent infections –Contact precautions beginning August 30  Diagnosed Severe Combined Immunodeficiency Sept 15  Enterovirus isolated from stool collected Aug 27  Rx high PV1 titre IVIG with assistance from FDA  Still shedding after failed Bone Marrow Transplant

Epidemiological Investigation  Born at home  3 unvaccinated siblings < 5 yrs  Parents and some elders vaccinated 1979  Travel to visit grandparents in Wisconsin – 3 mo  Visitors from Amish Communities in MN, WI, MI, Ontario including large weddings  No community members with travel outside North America

Epidemiological Investigation  No known immunodeficient persons in MN Amish communities  No immunodeficient persons on staff of hospitals  No international immunodeficient persons of appropriate age in medical facilities in MN  No international VAPP in Shriner’s hospitals

Virological Investigation  2.3% divergent from Sabin 1  Clusters with iVDPV  Initially thought to arise from a healthcare source  Subsequent data suggest circulation in the community prior to index case’s infection

Virological Investigation  3/3 siblings –All anti-PV1 +, negative anti-PV2, anti PV3 –Stool cultures negative  Stool samples collected 32 persons/5 households  4 well children ages 2-14 yrs in 2 households shedding virus  Minimal contact with index household  30 HCWs and 35 patients culture neg at Hospital 4

Index Family

Immunization  IPV was offered to –community members –All MN Amish communities –Non-Amish community members  Many elders vaccinated in 1979  IPV offered to staff and patients at Hospital 4

Immunization  9 out of 24 families in index community  31 out of 32 Amish families in nearby community which requested vaccination  9 out of 11 Amish families in another nearby community where vaccine was offered  Another nearby Amish community refused  Other MN Amish communities –35% to 100% initiated IPV  135 staff vaccinated Hospital 4

Disease Surveillance  AFP surveillance initiated for potential adverse reactions to Menactra  9 GBS in 3 years in 4 Amish counties  All 4 GBS in 2005 >45 years  No Amish with GBS/polio  Aseptic meningitis in Amish counties  No Amish with aseptic meningits  No illness compatible with polio in HCWs or patients at all 4 hospitals  National and international notifications

Conclusions  29 th known chronically infected immunodeficient poliovirus excreter  Origin unknown, probably chronically infected immunodeficient #30 overseas  Virus circulated in community  Index case infected in community  No evidence of circulation beyond MN Amish

Concerns  Prevalence of chronic VDPV infection unknown  iVPDV transmitted person-to-person  Optimum strategy for control unclear –IPV coverage incomplete –Virus circulating for weeks before campaign –Silent transmission, no neurologic disease  Will BMT clear infection?  Stopping vaccination after polio eradicated