Recently, it has been a problem in the Philippines that no facility can
perform rabies gold standard test (RFFIT and FAVN tests adapted by WHO and OIE)
test to measure antibody (Immunity after vaccination) in human and animals. Rabies
is a fatal but vaccine-preventable disease. The antibody test is indispensable
to know whether humans and animals have adequate immunities against Rabies
virus. The information of the antibody level (immunity level) for rabies is
important for rabies-related health workers and to determine the vaccination
coverage rate in dogs, and to certificate animals exported to other countries.
The challenge
virus standard strain CVS-11 (the laboratory standard strain) is required for the tests.
Therefore, the Research Institute for Tropical Medicine (RITM), The Philippines, and our JAPOHR project collaborated to import the strain from a
world professional institution with the permission of DA-BAI.
Then, in July 2019, Prof. Nishizono (JAPOHR project leader) and Dr. Yamada, Department of Microbiology, Faculty of Medicine, Oita University, visited RITM. Their the laboratory is the sole medical laboratory researching rabies in Japan and has lots of experience of the laboratory procedures of the laboratory strain.
 |
Ms. Lindsay Fajardo and Dr. Criselda Bautista
doing culture while
Dr. Yamada observes on their technique. |
To conduct the
virus neutralizing antibody test in RITM, it was necessary to culture and amplify the freeze-dried virus in cell lines at first. However, the first trial
using BHK-21 cells according to the protocol from OIE was failed.
It is well known
that RABV is a neurotropic virus, NA-C1300 is more preferable than the cell line
BHK-21. Therefore, Dr. Yamada brought NA-C1300 cells to the Special Pathogens
Laboratory (SPL) of RITM from Japan just in case. NA-C1300 cells are used to
amplify the rabies virus in the Oita laboratory.
 |
| The smile of success. Dr Yamada with Ms Leilanie Nacion, Ms. Lindsay Fajardo and Ms. Joanna Sorino smiling while showing rabies positive NA-C1300 cells. |
 |
Rabies virus (CVS-11)
infected NA-C1300 cells. |
Then, Prof.
Nishizono and Dr. Yamada gave technical advice for the special laboratory
procedures using NA-C1300 cells to the SPL staff.
After incubation
for a week,
Finally, we did
it!!!
The increasing the
laboratory rabies virus was confirmed. And the immunochromatographic test (ICT)
that was developed by Prof. Nishizono was used for the confirmation. Of note,
the ICT was able to detect the viral antigen in the culture supernatant within
15 min without special equipment.
Before leaving
the RITM, both Dr. Nishizono and Dr. Yamada also gave advice and did technical
transfer to the SPL staff how to check the virus strain increased to prepare
the virus stock used for the antibody tests.
RFFIT (Rapid
Fluorescent Focus Inhibition Test) can measure the titer of rabies
neutralizing antibodies present in the blood within 30 hours. We believe that RITM will introduce the test in
close cooperation with JAPOHR team members soon. Implementation of “gold
standard” virus neutralization test (RFFIT) into RITM will strengthen
laboratory capacity for rabies diagnosis and make it the only institution
capable of performing it in the Philippines and facilitate the rabies control
activities.
We would like to
thank and congratulate members of RITM (Ms. Nacion and Sorino, and Dr. Bautista)
and JAPOHR (Prof. Nishizono, Drs Yamada and Kimitsuki, and Ms. Fajardo) teams
on very good and promising preliminary results. We would also like to wish them
the best of luck in the remainder of their experimental processes until they
reach our goal.
An update on the data share system was made by Mr. Richard Edades, the project IT programmer.
