Human metapneumovirus reinfection among children in Thailand determined by ELISA using purified soluble fusion protein.
BACKGROUND
Human metapneumovirus (hMPV) is a newly discovered paramyxovirus that causes acute respiratory illness. Despite apparent near-universal exposure during early childhood, immunity is transient.


METHODS
An indirect screening enzyme-linked immunosorbent assay using a recombinant soluble fusion (F) glycoprotein derived from hMPV was used to test for anti-F IgG in 1,380 pairs of acute- and convalescent-stage serum samples collected from children in Kamphaeng Phet, Thailand.


RESULTS
Of the 1,380 serum sample pairs tested, 1,376 (99.7%) showed evidence of prior infection with hMPV. Sixty-six paired specimens demonstrated a >or=4-fold rise in titer, for an overall reinfection rate of 4.9%. Two children demonstrated evidence of an initial infection. Forty-eight of the 68 new infections or reinfections occurred in 2000, accounting for 13.2% of all nonflaviviral febrile illnesses in the study population in that year. Of 68 positive cases, 85.3% complained of cough and 66.2% complained of rhinorrhea, compared with 61.4% and 49.0% of negative cases, respectively (P < .01). All positive samples were also tested for an increase in titer of antibodies to respiratory syncytial virus F, and 27% exhibited a >or=4-fold rise.


CONCLUSIONS
These results demonstrate that hMPV reinfections cause illness at a rate equal to that seen for initial infections. hMPV may have a more significant impact in older children than previously realized and may be the cause of significant outbreaks in this population.
Pavlin
Julie A
JA
Department of Microbiology and Immunology, Uniformed Services University, Bethesda, USA. julie.pavlin@afrims.org
Hickey
Andrew C
AC
Ulbrandt
Nancy
N
Chan
Yee-Peng
YP
Endy
Timothy P
TP
Boukhvalova
Marina S
MS
Chunsuttiwat
Supamit
S
Nisalak
Ananda
A
Libraty
Daniel H
DH
Green
Sharone
S
Rothman
Alan L
AL
Ennis
Francis A
FA
Jarman
Richard
R
Gibbons
Robert V
RV
Broder
Christopher C
CC
D000293:Adolescent; D002648:Child; D003710:Demography; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D029121:Metapneumovirus; D018184:Paramyxoviridae Infections / Q000453:epidemiology* / Q000276:immunology; D012008:Recurrence; D013785:Thailand / Q000453:epidemiology
D007074:Immunoglobulin G