Seroconversion to filarial antigens in Australian defence force personnel in Timor-Leste.
To investigate whether Australian soldiers were exposed to filarial parasites that cause lymphatic filariasis during a 6-month deployment to Timor-Leste, antifilarial antibody levels were measured in 907 soldiers using an enzyme linked immunosorbent assay (ELISA). Initial testing using Dirofilaria immitis antigen demonstrated that 49 of 907 (5.4%) soldiers developed antifilarial antibodies of the IgG1 subclass after deployment, whereas 1 of 944 (0.1%) seroconverted to the IgG4 subclass. When a sub sample of 88 D. immitis-reactive sera was subject to testing with an antifilarial antibody test using Brugia malayi antigen, 46 had elevated IgG antibodies, whereas 5 had elevated antibodies of the IgG4 subclass. A total of 24 soldiers seroconverted to B. malayi, as measured by parasite-specific IgG, whereas 1 seroconverted to IgG4. The relatively low number of seroconversions indicates a low but measurable risk of exposure to human filarial parasites among Australian soldiers deployed to Timor-Leste. However, to reduce the risk of exposure to these parasites, soldiers deploying to endemic areas should practice strict adherence to personal protective measures against mosquito bites.
Frances
Stephen P
SP
Australian Army Malaria Institute, Gallipoli Barracks, Enoggera, Queensland, Australia. steve.frances@defence.gov.au
Baade
Lisa M
LM
Kubofcik
Joseph
J
Nutman
Thomas B
TB
Melrose
Wayne D
WD
McCarthy
James S
JS
Nissen
Michael D
MD
D000818:Animals; D000909:Antibodies, Helminth / Q000276:immunology; D000947:Antigens, Helminth / Q000032:analysis; D001315:Australia / Q000208:ethnology; D004182:Dirofilaria; D004605:Elephantiasis, Filarial / Q000453:epidemiology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007214:Indonesia / Q000453:epidemiology; D008889:Military Personnel
D000909:Antibodies, Helminth; D000947:Antigens, Helminth; D007074:Immunoglobulin G