Human parainfluenza virus 4 outbreak and the role of diagnostic tests.
Owing to the difficulties in isolating the virus and the lack of routine surveillance, the clinical significance of human parainfluenza virus 4 (HPIV-4) is less well defined than that of the other human parainfluenza viruses. We describe the first outbreak of HPIV-4 infection in a developmental disabilities unit, involving 38 institutionalized children and three staff members, during a 3-week period in autumn 2004. Most subjects had upper respiratory tract infections (URTI), while lower respiratory tract infections (LRTI) occurred in three children (7%), one complicated by respiratory failure requiring ventilation support. All patients recovered. Nasopharyngeal aspirates tested for HPIV-4 were positive by reverse transcriptase PCR (RT-PCR) in all 41 cases (100%), by direct immunofluorescence in 29 of 39 tested cases (74%), and by cell cultures in 6 of 37 cases (16%), and serum was positive for antibodies against HPIV-4 in all 35 cases (100%) with serum samples available. In addition, RT-PCR detected HPIV-4 in four children (three LRTI and one URTI) out of 115 patients with community-acquired respiratory tract infection. Molecular analysis of the 1,198-bp phosphoprotein sequences showed that HPIV-4 isolates among the cases were genetically similar, whereas the community controls were more genetically distant, supporting nosocomial transmission of a single HPIV-4 genotype during the outbreak. Moreover, the HPIV-4 causing the outbreak is more closely related to HPIV-4A than HPIV-4B. HPIV-4 may be an important cause of more severe respiratory illness in children. The present RT-PCR assay is a sensitive, specific, and rapid method for the diagnosing HPIV-4 infection. To better define the epidemiology and clinical spectrum of disease of HPIV-4 infections, HPIV-4 should be included in the routine panels of respiratory virus detection on respiratory specimens.
Lau
Susanna K P
SK
Department of Microbiology, The University of Hong Kong, University Pathology Building, Queen Mary Hospital.
To
Wing-Kin
WK
Tse
Philomena W T
PW
Chan
Alex K H
AK
Woo
Patrick C Y
PC
Tsoi
Hoi-Wah
HW
Leung
Annie F Y
AF
Li
Kenneth S M
KS
Chan
Paul K S
PK
Lim
Wilina W L
WW
Yung
Raymond W H
RW
Chan
Kwok-Hung
KH
Yuen
Kwok-Yung
KY
D000293:Adolescent; D000328:Adult; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002648:Child; D002675:Child, Preschool; D002522:Chlorocebus aethiops; D019411:Clinical Laboratory Techniques; D003428:Cross Infection / Q000175:diagnosis* / Q000453:epidemiology* / Q000821:virology; D004196:Disease Outbreaks; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D029482:Parainfluenza Virus 4, Human / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D012141:Respiratory Tract Infections / Q000175:diagnosis / Q000453:epidemiology / Q000821:virology; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D019351:Rubulavirus Infections / Q000175:diagnosis* / Q000453:epidemiology* / Q000821:virology; D012680:Sensitivity and Specificity; D014709:Vero Cells; D014776:Virus Cultivation
D000914:Antibodies, Viral