ProMED-mail is a program of the
International Society for Infectious Diseases
Date: Fri 18 Dec 2009
Source: Report of the 5th Annual Meeting of the Network of OIE/FAO
Reference Laboratories for Foot-and-Mouth Disease, 23-27 Nov 2009,
Delhi [extracts, pages 9-12, edited]
Regional discussions
--------------------
The participants split into groups to discuss current threats and
vaccine priorities according to regional virus pools and under the
following headings: (1) significant epidemiological events; (2)
antigenic changes noted; (3) serological vaccine matching tests done;
(4) priority vaccines; (5) gaps in submission; (6) gaps in vaccine
selection; (7) threats for 2010.
Pool 1. Eastern Asia
--------------------
A small number of cases of serotype A and Asia 1 have been detected
in China this year [2009]. The Asia 1 viruses appear to be matched by
the current vaccine used in China, whilst the suitability of vaccines
to cover the serotype A viruses is still under study. In South East
Asian (SEA) countries, serotypes O and A have predominated with no
reports of Asia 1. Whereas all serotype A viruses in SEA appear to be
derived from the same lineage that has evolved within the region for
many years, the situation for serotype O is more complex with a
mixture of indigenous and introduced viruses. Samples have been
analysed at Pakchong from Myanmar, Laos, Vietnam, Cambodia, and
Thailand. The vaccines used in the different countries are as follows:
1. China, O China 99, A China F/72, Asia 1 China JSWX052;
2. Viet Nam, O Manisa and O 3039, A May 97 and A22 Iraq, Asia 1 Shamir;
3. Malaysia, O Manisa and O 3039, A May 97, Asia 1 Shamir;
4. Thailand, O 189/87 (Manisa-like), A 118/87, Asia 1/85 (Asia 1 Shamir-like).
There were considered to be no major gaps in submission, although the
number of samples analysed is quite small and there have been no
submissions this year [2009] to Pakchong from Malaysia. In 2010, the
main concern in China is over possible continuation of outbreaks
caused by serotype A, whilst outbreaks of both serotype O and A are
expected to recur in South East Asia.
Pool 2. Southern Asia
---------------------
In India, outbreaks of serotype O have predominated. About 10 percent
of the approximately 334 isolates made thus far have undergone
testing for vaccine matching to O IND R2/75 and 95 percent have shown
a good match. Until this year [2009], the PanAsia 2 strain was the
main one, but in 2009, the "India 2001" strain has predominated.
PanAsia 2 has been associated with significant disease in wildlife
during 2005-08. Most of the 26 serotype A isolates have shown a match
to A IND 40/00 and all of the 16 Asia 1 field isolates matched to
Asia 1 63/72. These A and Asia 1 virus lineages seem to be unique to
India. The predominant strain of serotype A is genotype VII, which
has an amino acid deletion in an antigenic site of VP3. This virus is
distinct from the A Iran 05 strain found throughout the Middle East.
The priority vaccine strains are those stipulated in India, namely O
IND R2/75, A IND 40/00 and Asia 1 IND 63/72. The meeting agreed on
the importance of making a full antigenic and genetic comparison
between representative Indian strains and those held in the WRLFMD database.
Pool 3. Eurasia
---------------
The main epidemiological events have been the continued spread and
circulation of serotype O and A viruses belonging to O PanAsia 2 and
A Iran 05 strains. It seems probable that antigenic changes may have
conferred an advantage for the spread of the A Iran 05 strain, but
this is less clear for O PanAsia 2 which mostly still matches O
Manisa vaccine. An isolated case of Asia 1 virus was reported in
Bahrain caused by an isolate with closest match to earlier Indian
sequences held in the WRLFMD database. An outbreak in 2009, fatally
affecting gazelle in the United Arab Emirates, was caused by viruses
of the O India 2001" strain. Recent isolates sent to WRLFMD from
Pakistan show continued evolutionary change, with some A and a single
Asia 1 viruses showing a poor match to A Turkey 06 (A Iran 05 strain)
and Asia 1 Shamir, respectively. Elsewhere in the region, Egypt
continues to submit samples containing unique viruses of serotype O
(related to the O Sharquia 72 vaccine strain) and type A (of the A
Africa topotype closely related to that introduced into the country
in 2006). In all, about 35 isolates have been matched to a variety of
vaccine strains as well as 10 O PanAsia 2 viruses isolated in 2008.
The priority vaccines are O Manisa (or similar strains), A Iran 05
strain and Asia 1 Shamir (or similar strains). The major gaps in
submission are considered to be from some central Asian Republics,
the Caucasus, and some Middle East countries concerned about the
impact of transparency on trade. The main problems for vaccine
selection are an inability to compare vaccine matching results
between centres due to the use of different vaccine strains,
unstandardised methods, and field isolates that are not shared. Based
on previous experience, it may be expected that serotype O but not A
will be sustained within the region. An Asia 1 epidemic may be due,
since cases are occurring in Pakistan, whilst countries like Iran and
Turkey will by now have a low population immunity to this serotype
(last seen in 2004). Plans to increase imports of live cattle and
small ruminants into the Middle East from Africa and through new
trade routes may increase the risk of African strains being
introduced. It was felt that the discrepancy between the vaccine
strain recommendations from the WRLFMD and those made on a regional
basis by the Network caused confusion and it needed to be clearer
that the former were intended primarily as a guide for vaccine bank
managers in free countries and only included vaccine strains
available to WRLFMD and that met the standards of the European Pharmacopoeia.
Pool 4. Western Africa
--------------------
There is very little available information. In 2008, viruses
submitted from Nigeria to WRLFMD were of serotypes O and SAT 2 and
revealed a link to other African regions such as Sudan. In 2009, 31
samples were submitted to PIADC-FADDL [Plum Island Animal Disease
Center - Foreign Animal Disease Diagnostic Laboratory]. Epithelial
samples had been collected from an outbreak affecting mainly cattle
that had lasted from October 2008 to February 2009. 21 of 31 samples
were positive and typed as serotype A. Phylogenetic analysis of the
P1 and VP1 regions revealed close identity to A Kenya 1984 virus.
Collectively, these isolates are more linked to the European and
South American old isolates rather than to those of Asiatic lineage
of Thailand, Iraq, Iran, Pakistan, and India.
Pool 5. Eastern Africa
----------------------
Samples from Kenya have been typed as SAT 1, SAT 2, O, and A, with
SAT 1 predominating. The samples were also referred to WRLFMD who
have also received samples from some neighbouring countries. Within
the region, there are gaps in laboratory capacity and both in
technical capability and ability to interpret results. There is a
need to develop a strategic plan and network for the region. It would
be helpful to identify a specialist from each country who could act
as a local animator to encourage action on FMD control initiatives.
Pool 6. Southern Africa
-----------------------
In Southern Africa, SAT 1 isolates from 2001-2006 belonged to
topotypes I, II and III with outbreaks characterised in Mozambique
during 2001-2002, Zimbabwe in 2003, Zambia during 2005 and 2006 and
Botswana in 2006. The SAT 2 isolates were from Botswana 2002 and
2006; Zimbabwe during 2000/2001-2003, and recently from Namibia and
Malawi during 2008 and 2009. Recently, SAT 1 had infected domestic
cattle in the buffer zone (Makoko diptank and Phameni diptank). They
had heard of outbreaks in Zimbabwe but no confirmation had been
received so far. In Botswana, after 20 years with no outbreaks, a
series of 9 outbreaks have occurred since 2002. These have been
mostly of SAT 2 and attributed either to incursions from neighbouring
countries or due to contact between domestic cattle and wildlife. The
2008 outbreaks appeared to have been exacerbated by antigenic
mismatch between the field virus and the vaccine strains. To try to
address the problems associated with lower vaccine matches, efforts
are being made to increase antigen payload, introduce new vaccine
strains and improve the surveillance of buffalo. The priority
vaccines are SAT 2 and SAT 1, but there is insufficient information
to be more precise about the strains that should be included. For SAT
1, past vaccine matching results have indicated that vaccine strains
are relevant. For SAT 2, recent outbreaks have shown some
differences. However, viruses with good correlation to vaccine caused
outbreaks recently as well.
Pool 7. South America
---------------------
There are multiple zones (regarding OIE FMD status) in different
countries of the region and maps need to be carefully drawn in order
to illustrate the situation accurately. Most of the countries are now
FMD-free with or without vaccination. 9 samples were received at
PANAFTOSA from Ecuador (n=6) and Colombia (n=3), whilst 19 samples
from Ecuador were sent to the Argentinean OIE Reference Laboratory.
All of the samples were of serotype O and are of strains indigenous
to the region. Venezuela has reported during 2008-2009 a total of 60
FMD outbreaks, (25 serotype O virus and 35 serotype A virus) but has
not submitted samples to an OIE reference Laboratory. Nationally,
both serotypes O and A have been confirmed. The vaccines used in the
region are all single oil emulsions. O Campos and A24 Cruzeiro are
used throughout the region, whilst C3 Indaial is included in Bolivia,
Brazil, and Paraguay. The justification has been the Amazonas
outbreak in 2004. In Argentina, a tetravalent vaccine is used
incorporating A ARG 2001 in addition to O Campos and A24 Cruzeiro and
C3 Indaial. The role of the OIE reference Laboratories in advising on
methodology and standards for vaccine control is considered extremely
important. Cattle up to 2 years old are vaccinated every 6 months and
thereafter annually, aiming for 100 percent coverage. For vaccine
matching, r1 values of 0.25 or greater are considered acceptable and
the 2009 type O viruses gave values over this threshold when tested
at 2 OIE Reference Laboratories. In some cases r1 values from Ecuador
strains were slightly over threshold. Considering the importance of
vaccine potency, expectancy of protection is also used to gauge
antigenic match rather than relying on r1 values alone.
[Byline: David Paton]
--
Communicated by:
ProMED-mail
[The information above, addressing the very recent worldwide FMD
situation, provided by those on the frontline of FMD surveillance and
diagnosis, is timely and useful. Additional information on discussed
topics such as collaborative vaccine matching trials, proficiency
test schemes, recent research subjects, and others, can be found in
the full report (21 pages) at the source URL above.
The early publication of this report by the WRLFMD, Pirbright is
exemplary. - Mod.AS]
[see also:
Foot & mouth disease, bovine - South Korea: (KG), OIE 20100108.0089
2009
----
Foot & mouth disease, bovine - Viet Nam (06): vaccination, RFI 20091203.4120
Foot & mouth disease, bovine - Viet Nam (05): (PY), (YB) 20091202.4112
Foot & mouth disease - Turkey, Syria: susp. RFI 20091129.4081
Foot & mouth disease, bovine - China (06): (XJ), OIE 20091128.4080
Foot & mouth disease, bovine - India: (KL), susp., RFI 20091120.4002
Foot & mouth disease, bovine - Congo (DR): (IT) susp. RFI 20090920.3293
Foot & mouth disease - South Africa: suspected, RFI 20090915.3241
Foot & mouth disease, porcine - Taiwan (08): (TY) 20090905.3123
Foot & mouth disease, bovine - Viet Nam (02): (QG) RFI 20090826.3005
Foot & mouth disease, bovine - Bangladesh: susp., RFI 20090823.2974
Foot & mouth disease - Middle East (06): WRLFMD update, vac. 20090808.2806
Foot & mouth disease, bovine - Rwanda: (ES) susp, RFI 20090807.2795
Foot & mouth disease, bovine - Ecuador (02): conf 20090804.2755
Foot & mouth disease, domestic ruminants - India: (SK), RFI 20090804.2751
Foot & mouth disease - Israel: serotype A, resolved, OIE 20090803.2732
Foot & mouth disease - Middle East (05): FAO/OIE surveill., control
20090731.2686
Foot & mouth disease - Israel, Palestinian Authority: serotype A 20090714.2510
Foot & mouth disease - Nepal 20090625.2318
Foot & mouth disease, porcine - Taiwan (04): (TY) sentinels 20090624.2301
Foot & mouth disease, bovine - China (05): (SD) serotype A 20090609.2129
Foot & mouth disease, bovine - Angola: (CC) OIE 20090605.2082
Foot & mouth disease, bovine - Ecuador: susp. 20090601.2036
Foot & mouth disease - Middle East (04): FAO 20090509.1735
Foot & mouth disease - Lebanon: serotype A 20090422.1519
Foot & mouth disease - Middle East (03): serotypes, update 20090410.1377
Foot & mouth disease - Bahrain: serotype A 20090409.1366
Foot & mouth disease - Taiwan, Lebanon 20090404.1295
Foot & mouth disease, bovine - China (04): (SC) serotype Asia 1 20090403.1283
Foot & mouth disease - Middle East (02): serotypes A, O, update 20090331.1242
Foot & mouth disease, porcine - Taiwan (03): conf.OIE 20090331.1239
Foot & mouth disease - Middle East: serotypes A, O, update 20090317.1082
Foot & mouth disease - Malaysia (02): (Peninsular) clarificn. 20090305.0903
Foot & mouth disease, bovine - Laos: (BL) RFI 20090304.0877
Foot & mouth disease, cattle, buffaloes - Egypt: serotype A 20090303.0865
Foot & mouth disease - Malaysia (Peninsular) 20090303.0864
Foot & mouth disease - Palestinian Auton Terr: (JN), RFI 20090227.0816
Foot & mouth disease, bovine - China (03): (HB, SH) serotype A 20090223.0757
Foot & mouth disease - Lebanon: OIE, untyped 20090222.0734
Foot & mouth disease, porcine - Taiwan: serotype O 20090219.0689
Foot & mouth disease - Israel (02): OIE, serotype O, spread 20090218.0680
Foot & mouth disease - Iraq: (BA) 20090208.0577
Foot & mouth disease - Saudi Arabia (02): vaccination 20090201.0447
Foot & mouth disease - Saudi Arabia: east, RFI 20090128.0387
Foot & mouth disease, bovine - Uganda (03): (N., E, & Central) 20090127.0364
Foot & mouth disease, bovine - China: (HB, A), (XJ, Asia1) 20090124.0318
Foot & mouth disease, bovine - Viet Nam: (LA, KT) serotype A 20090122.0273]
...................................arn/mj/dk
*##########################################################*
************************************************************
ProMED-mail makes every effort to verify the reports that
are posted, but the accuracy and completeness of the
information, and of any statements or opinions based
thereon, are not guaranteed. The reader assumes all risks in
using information posted or archived by ProMED-mail. ISID
and its associated service providers shall not be held
responsible for errors or omissions or held liable for any
damages incurred as a result of use or reliance upon posted
or archived material.
************************************************************
Become a ProMED-mail Premium Subscriber at
************************************************************
Visit ProMED-mail's web site at
Send all items for posting to: promed@promedmail.org
(NOT to an individual moderator). If you do not give your
full name and affiliation, it may not be posted. Send
commands to subscribe/unsubscribe, get archives, help,
etc. to: majordomo@promedmail.org. For assistance from a
human being send mail to: owner-promed@promedmail.org.
############################################################
############################################################
Posts
No comments:
Post a Comment