Background: Lower respiratory tract infections
(LRTI) are a leading cause of morbidity and
mortality in young children. A number of new
viruses associated with LRTI in young children
have recently been discovered. These include
Human Bocavirus (HBoV), Human
Polyomavirus strains WU (WUPyV) and KI
(KIPyV) and Human Coronavirus strains NL63
(HCoV-NL63) and HKU-1 (HCoV-HKU-1). There
is, however, limited data on the epidemiology
of these newly discovered respiratory viruses
in industrializing country settings, including
South Africa.
Objective: To determine the clinical
epidemiology of HBoV, HCoV-NL63, HCoVHKU1,
HCoV-OC43, HCoV strain 229E (HCoV-
229E), WUPyV, KIPyV and human rhinovirus
(HRV) in young children.
Methods: Nasopharyngeal aspirates where
taken from children who were hospitalized at
Chris Hani Baragwanath Hospital between
February 2000 and January 2002 with severe
LRTI. These children had been enrolled in a
double-blind, randomized, placebo-controlled
trial of a 9-valent pneumococcal conjugate
vaccine (PCV). Nucleic acid extraction was
undertaken from archived nasopharyngeal
aspirate samples and the respiratory viruses
identified using real time duplex PCR. The
study was limited to examining samples from
HIV uninfected children with LRTI who were
less than 24 months of age.
Results: Overall, samples were available for
895 of 1565 nasopharyngeal aspirates, from
children hospitalized with LRTI, collected from
February 2000 to January 2002. A comparison
between those LRTI episodes for which
samples were unavailable compared to those
for which samples were available indicated
that children in whom samples were
unavailable were younger than children with
available samples (9.9±6.4 vs. 11.8±6.5 months; p<0.0001). In addition there was a
higher frequency of wheezing episodes in
children for whom samples were unavailable
(60.4 vs. 54.6%; p=0.022).
The overall prevalence of the viruses in
children with any LRTI were 33.2% for HRV,
21.2% for HBoV, 16.1% for WUPyV, 10.1% for
HCoV-OC43, 7.0% for KIPyV, 3.2% for HCoVNL63,
2.6% for HCoV-HKU-1, and 0.6% for
HCoV-229E. There was a higher probability of
detecting a selected virus in LRTI episodes
among PCV-compared to placebo-recipients
for HBoV (24.2% vs. 18.2%, respectively;
p=0.028) and HRV (36.7% vs. 29.5%,
respectively; p=0.023). Conversely, viruses
identified more frequently in LRTI episodes
among children who received placebo
compared to PCV-recipients included WUPyV
(20.2% vs. 12.1%, respectively; p=0.001),
KIPyV (10% vs. 4.2%, respectively; p=0.001),
HCoV-OC43 (14.1% vs. 6.2%, respectively;
p≤0.0001) and HCoV-HKU1 (4.5% vs. 0.1%,
respectively; p≤0.0001).
Overall, the prevalence of the studied-viruses
in the subgroup of children categorized as
having bronchiolitis was 33.8% for HRV, 33.4%
for WUPyV, 22.3% for HBoV, 11.1% for HCoVOC43,
5.3% for KIPyV, 2.3% for HCoV-NL63,
1.9% for HCoV-HKU1 and 0.4% for HCoV-229E.
Viruses more commonly identified in placebocompared
to PCV-recipients among children
hospitalized with bronchiolitis included
WUPyV (20.0% vs. 12.3%, respectively;
p=0.029), HCoV-OC43 (15.9% vs. 7.2%,
respectively; p=0.004) and HCoV-HKU1 (3.6%
vs. 0.5%, respectively; p=0.015).
The prevalence of the newly studied viruses in
the subgroup of children categorized as having
clinical pneumonia was 30.8% for HRV, 20.3%
for HBoV, 16.4% for WUPyV, 9.1% for HCoVOC43,
8.6% for KIPyV, 4.1% for HCoV-NL63,
3.2% for HCoV-HKU1 and 0.6% for HCoV-229E.
Viruses identified more frequently among
placebo- compared to PCV-recipients, in those
with clinical pneumonia, included WUPyV
(20.4% vs. 11.9%, respectively; p=0.013),HCoV-HKU1 (5.3% vs. 0.9%, respectively;
p=0.008). Conversely, HCoV-OC43 was
identified more frequently in children with
clinical pneumonia among PCV- (5.0%)
compared to placebo-recipients (2.7%,
p=0.004).
There were seasonal peaks, during autumnwinter
months (April to June), in the detection
of HRV, WUPyV, HCoV-OC43, HCov-NL63 and
HCoV-HKU1, whereas KIPyV, HBoV and HCoV-
229E were identified perennially.
Conclusion: Prevalence of respiratory viruses
is high in industrializing countries and the
presence of these viruses is frequently
associated with co-infections of more than
one etiological agent. In industrializing
countries such as in South Africa, the recently
identified respiratory viruses play a role in
development of pneumonia.
KIPyV (12.7% vs. 4.1%, respectively; p=0.001),
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/12286 |
| Date | 23 January 2013 |
| Creators | Radebe, Zelda |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis (M.Sc.(Med.))--University of the Witwatersrand, Faculty of Health Sciences, School of Pathology, 2012 |
| Format | application/pdf |
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