Pigs infected with isolates of low virulence may seroconvert without symptoms, abort or develop chronic African swine fever [ 20, 29].
Whether subclinical infections occur and whether one may seroconvert to the SARS-CoV with minimal or no symptoms are concerns for HCWs and others.
In addition, lambs grazing on tick pastures may seroconvert to E. phagocytophila after 3 weeks of tick exposure, although synthetical pyrethroids have been applied [ 11].
The United States's national Q fever seroprevalence was recently estimated at 3.1% [ 27] and though subjects may seroconvert, antibody levels measured before being challenged may have been below detection level.
Findings from this study suggest that women identified as negative for syphilis and HIV during ANC visits may seroconvert in the course of pregnancy and could benefit from re-screening.
Animals were considered to have seroconverted when a change from negative to positive between the first and second serum sampling was observed.
Cats were identified as having seroconverted when their RAL crossed the threshold of seropositivity, calculated as the mean of the preinoculation RALs for all cats in group A plus 3 standard deviations (SD) (23).
Rapid HIV test providers should also be aware that some HIV-infected clients with discordant test results may take time to fully seroconvert, even when repeat confirmatory tests are performed on serum or plasma.
In addition, the time to seroconversion may be lengthy and those infected may not seroconvert at all [ 9].
In addition, it is possible that some infected individuals may not seroconvert and that some antibody positive individuals have non-specific antibody against H5 and do not represent true prior infections.
