WHO director general Margaret Chan said the agency will work closely with the affected countries to stop the sale of blood used as a convalescent serum
in the black market.
Surprisingly, some isolates survived in convalescent serum
, raising the possibility that specific antibodies were either absent, not sufficient to elicit a response or surface proteins of GAS like immunoglobulin binding proteins and other factors than M type bound antibodies non-type specifically and rendered them ineffective for opsonophagocytosis.
Cadham to produce convalescent serum
, and set out the parameters regarding which cases would be suitable for serum treatment.
Bacterial culture was attempted for 246 (96%) cases, and convalescent serum
was available for 109 (43%) cases.
Early convalescent serum
collected on January 14 (10 days after illness onset) was submitted to CDC for testing and demonstrated no evidence of MARV infection by virus isolation, antigen-detection enzyme-linked immunosorbent assay (ELISA), or anti-MARV immunoglobulin M (IgM) and IgG ELISA.
To develop the WU ELISA and the KI ELISA, we used as positive controls 2 convalescent serum
samples from a child known to be infected with WUPyV and rabbit hyperimmune serum for WUPyV VP1 or KIPyV VP1, and we used as negative controls rabbit preimmune serum and serum derived from pediatric patients ([less than or equal to] 3 years of age).
pestis or a four-fold change in antibody titer to F1 antigen between paired acute and convalescent serum
samples with a least one sample having a titer [greater than or equal to]1:16.
Acute and convalescent serum
samples were also obtained from probable cases.
Optimum serologic testing includes paired acute and convalescent serum
specimens, the latter obtained approximately 21 days after symptom onset.
A convalescent serum
sample was obtained from the implicated donor 45 days after the initial donation.
CDC has revised the laboratory criteria in the SARS case definition to require that convalescent serum
be collected >28 days after symptom onset, instead of >21 days after symptom onset.
Of the remaining 26 probable cases, convalescent serum
specimens for 25 persons have not been submitted to CDC, and one person, who has recovered, has refused further testing.