Human Parechovirus in Respiratory Specimens from Children in
Kansas City, Missouri
Justin Sharp,aJeremiah Bell,a,bChristopher J. Harrison,a,bW. Allan Nix,cM. Steven Oberste,cand Rangaraj Selvarangana,b
Children’s Mercy Hospitals and Clinics, Kansas City, Missouri, USAa; University of Missouri Kansas City-SOM, Kansas City, Missouri, USAb; and Centers for Disease Control
and Prevention, Atlanta, Georgia, USAc
sense RNA viruses previously categorized within the Enterovirus
genus. However, genetic differences from enteroviruses led to
reclassification in a separate genus in Picornaviridae (8). Sixteen
HPeV types have been discovered, with varied tropisms ranging
from the respiratory and gastrointestinal tracts to the central ner-
vous system (CNS) (12). HPeV-1 and HPeV-2, formerly echovi-
ruses 22 and 23, respectively, were initially the most commonly
isolated in culture. Because culture has lower sensitivity than cur-
rent molecular techniques, the true incidence of infection, distri-
bution of genotypes, and clinical spectrum of HPeV disease re-
performed a retrospective and descriptive study at the Children’s
Mercy Hospitals and Clinics (CMH) in Kansas City, MO and KS.
We hypothesized that HPeV infects the respiratory tract of chil-
dren in the United States but has not been frequently detected
because it is not included in routine respiratory viral testing. We
noticed a relatively high incidence of HPeV-3 CNS infections in
ratory infections during the same year. Individual respiratory
specimens were eligible for HPeV testing if no other virus had
PCR (RVP PCR) testing performed per routine clinical care. The
RVP PCR panel included 12 viruses and subtypes: influenza virus
(A, B, H1, H3, unsubtypeable), respiratory syncytial virus (A, B),
parainfluenza virus (1, 2, 3), adenovirus, human metapneumovi-
enza strain is reported by this RVP PCR as FluA unsubtypeable.
During calendar year 2009, a total of 2,359 respiratory speci-
mens (either nasal aspirates or nasopharyngeal swabs) were sub-
mitted for RVP PCR testing. Frozen aliquots of total nucleic acid
extracts from 720 RVP-negative specimens from 637 children
were included in this study and tested by a two-step real-time
HPeV reverse transcription (RT)-PCR assay as previously de-
scribed (3, 18), with substitution of the AgPath-ID one-step RT-
all HPeV-positive specimens, the cDNA and an aliquot of nucleic
acid extract were shipped to the Centers for Disease Control and
Prevention (CDC) for confirmation by HPeV RT-PCR and for
he human parechoviruses (HPeVs) are increasingly detected
worldwide as pathogens, particularly in infants and children
as previously described (14). All patients had been evaluated by
health care providers within the CMH system during their care in
2009. We reviewed records from that health care visit and their
electronic medical record and collected clinical, laboratory, and
study was approved by the Institutional Review Board at CMH.
prevalence in July and August. HPeV was detected in 20 of 720
specimens from 19/637 unique individuals, resulting in a 3%
prevalence rate. Molecular typing identified 15/20 samples as
HPeV-3 and 2 as HPeV-1. Three specimens could not be typed.
The HPeV-3 VP1 sequences were closely related to one another
phylogenetically (Fig. 1). All 19 HPeV-positive patients were less
old (Table 1). While 14 HPeV-positive patients presented with
modest clinical symptoms, five patients exhibited signs that the
clinician considered indicative of septic shock with poor perfu-
sion, requiring volume resuscitation. Severe respiratory symp-
toms were universally absent, with mild symptoms being more
common. Bacterial and/or fungal respiratory cultures were per-
formed only on one subject with negative results. Chest radio-
graph abnormalities were noted on three of 20 patients; findings
included one each with perihilar infiltrate, increased perihilar in-
terstitial markings, and right middle lobe/lingular pneumonia
versus atelectasis. Of the 14 patients who underwent diagnostic
lumbar puncture, none demonstrated pleocytosis. Eleven of the
14 CSF specimens had also been tested by a two-step HPeV RT-
PCR assay in the 2009 HPeV-CNS infection study (18a), and 7
CSF specimens were found to be positive for HPeV. Bacterial
blood cultures from all 19 HPeV-positive subjects were negative.
Bordetella pertussis was isolated from one HPeV-positive patient,
and urine culture yielded methicillin-susceptible Staphylococcus
aureus in another.
Received 25 June 2012 Returned for modification 18 September 2012
Accepted 19 September 2012
Published ahead of print 26 September 2012
Address correspondence to Rangaraj Selvarangan, email@example.com.
Copyright © 2012, American Society for Microbiology. All Rights Reserved.
December 2012 Volume 50 Number 12 Journal of Clinical Microbiologyp. 4111–4113jcm.asm.org
the prevalence, epidemiology, and clinical characteristics of pa-
tients in whom HPeV was detected in respiratory specimens. In a
comparable study from 2007 in Edinburgh, Scotland, an HPeV
prevalence rate in respiratory specimens of patients less than 5
only respiratory specimens negative for the common respiratory
viruses detected by RVP assay (12 virus types and subtypes) in an
attempt to allow clinical and laboratory characteristics to more
clearly be attributed to HPeV and not the result of the alternative
precluded the determination of the true HPeV incidence in the
our multiplex PCR.
The majority of HPeV respiratory infections (79%) occurred
in children less than 3 months old, consistent with early acquisi-
tion of the virus. This is also consistent with seroprevalence stud-
ies from Finland and Japan and previous data regarding HPeV-
CNS infections (7, 9, 10, 18, 19, 23). The peak seasonality was in
late summer, similar to previous reports of HPeV in the CNS and
the seasonality of enteroviruses (2, 17, 18, 21). Of the 20 HPeV-
positive respiratory specimens identified in our study, 15 were
4 to 6 were more common in respiratory specimens (1, 2, 4, 6, 13,
15, 16, 20).
Over the past 5 years, we had observed the highest prevalence
of HPeV CNS infections (66/388 CSF specimens tested) in our
region during summer 2009 (18a). In our current study, HPeV
respiratory infection. Sequencing analysis confirmed the HPeV-3
genotype in both CSF and respiratory specimens in each of the
age at diagnosis and presented with fever and irritability but only
modest, nonspecific respiratory symptoms. There appear to be
different potential outcomes of HPeV respiratory tract infection.
One is that HPeV in respiratory samples reflects the initial portal
of entry for a subsequent CNS infection. Alternatively, infection
may be confined to the respiratory tract. The duration of local
HPeV surveillance data are limited in the United States and
depend on passive reporting through the National Enterovirus
was among the 15 most common viruses reported to NESS (22).
TABLE 1 Clinical characteristics of patients with HPeV respiratory
No. of patients with HPeV
Age, mean ? 1 SD (in days)
No. of males/females
No. hospitalized (yes/no)
Mean no. of hospital days
No. with full-term gestation
No. with fever, by history (yes/no)
Mean admission temp (°C)
Mean Tmaxin hospital (°C)
No. of days with fever
No. with irritability
144 ? 256
5.3 ? 3.4
37.6 ? 0.7
38.8 ? 1.0
3.2 ? 1.6
No. with respiratory symptoms
No. with rash
No. with emesis
No. with chest X-ray abnormality
No. with HPeV in CSF
Mean CSF WBC (per ?l)
No. with CSF pleocytosis
Mean peripheral WBC ?103(per ?l)
Mean ANC ?103(per ?l)
No. with antibiotic therapy
5.9 ? 5.4
9.4 ? 7.8
5.0 ? 6.0
aCSF, cerebrospinal fluid; WBC, white blood cells; ANC, absolute neutrophil count;
Tmax, maximum temperature.
FIG 1 Dendrogram of VP1 sequences from HPeV isolated from respiratory
history was inferred using the neighbor-joining method. HPeV viral isolates
are indicated by the country of origin: BAN, Bangladesh; BRA, Brazil; JPN,
Japan; PAK, Pakistan; NET, Netherlands; USA, United States.
Sharp et al.
jcm.asm.orgJournal of Clinical Microbiology
tem, coupled with a limited network of laboratories, precludes
estimation of the true HPeV prevalence in the U.S. population.
Additionally, since HPeV cannot be detected by enterovirus-spe-
cific RT-PCR assays conventionally utilized in clinical laborato-
ries, the CDC’s Picornavirus Laboratory has performed the ma-
EV and HPeV occurs during the summer months of traditional
EV season, HPeV presence at other times of the year may be
missed. To further categorize the prevalence as well as clinical
characteristics of HPeV in other organ systems, an active surveil-
lance system for HPeV infections would be ideal.
This study contributes to a growing understanding of HPeV
the published literature, HPeV-3 was the dominant type in respi-
ratory specimens from our population of U.S. patients. Because
there seems to be no specific respiratory presentation attributable
to HPeV infection, e.g., bronchiolitis or pneumonia, we have in-
sufficient evidence for a strong recommendation for routine
Additionally, the presence of HPeV in both respiratory and CNS
compared to that of routinely tested viruses renders the addition
of routine respiratory testing for HPeV unwarranted at this time.
However, testing respiratory secretions for HPeV may be a rea-
sonable adjunct to CSF testing in infants younger than 3 months
of age with fever and irritability of unknown etiology.
This study was funded by research residual funds from R.S. and funds
from Section of Neonatology.
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