>Dan McLeod's response to my request that he comment on his 1984 paper on
>Hantavirus seroprevalence in Canada was routed to me as E-mail rather
>than as a follow-up post. For those interested, here it is:
Thanx for the fix. I used pine to reply and it did me in :)
Speaking of antibody titres and their relevance. Many infer that high
titres mean high neutralizing titres. This is not necessarily true. For
many years I used a herpes immune rabbit sera to differentiate type I and
II that had a measly (pun intended) neutralizing titre of 1:20 (yes, 1:20,
that is not a typo). But at its endpoint dilution of 1:20 it could
neutralize more than 6 logs of infectious virus. I tested some * 20 *
other batches of high titred antisera that could barely neutralize 2 or 3
logs of infectious virus. Most neutralizing antibody titres are derived
against a fixed dose of virus (usually 110 TCID50), but strain analysis
requires constant amount of sera reacted with high titred virus to determine
rate of neutralization curves. BTW, I've seen this same phenomemon with
high titred enterovirus antisera.
A further note of interest, which may be of some relevance here. I have a
Gammacell 220 which is used to inactivate various infectious materials for
clients. It recently suffered damage when the elevator dropped due to a
faulty solenoid. As of to-day it is repaired ($$$) and fully operational.
We can now continue to radiate mouse sera etc. suspected of Hantaan as
before. Also please take note those users from ADRI and AIDs P3 and P4 labs.
And yes, the service is ***still free***! But only until I move to the
new P4 lab in Winnipeg because to refurbish the Gammacell and move it is
going to cost 250K!!!
National Laboratory for Viral Oncology,
dmcleod at hpb.hwc.ca
Ottawa, Ontario, Canada
e-mail dmcleod at hpb.hwc.ca