Transcript Rubella - An-Najah National University

An-Najah 2nd Medical International
Conference
“Evidence
based
advances in
women
healthcare”
8-10/10/2009
Nablus- Palestine
Rubella immune status of
Palestinian women.
study of more than 870 ladies tested
for Rubella IgG in the period 2002
and 2009
Dr. Bashar Adnan Karmi
Medicare-MediPal laboratories
MD, MSC
Clinical Pathologist
Immunologist/Microbiologist
History
• The name rubella is derived from Latin,
• meaning “little red”
• Rubella was initially considered to be a variant
of measles or scarlet fever and was called
“third disease.”
• In1814 Rubella was first described as separate
disease in the German medical literature,
hence the common name “German measles.”
About rubella virus
•
•
•
•
First isolated in 1962 by Parkman and Weller.
Classified as a toga virus, genus Rubivirus.
Most closely related to group A arboviruses,
It is an enveloped RNA virus, with a single
antigenic type that does not cross-react with
other members of the toga virus group.
Following a widespread epidemic of
rubella infection in 1940
Norman Gregg, Australian •
ophthalmologist, reported
in 1941 the occurrence of
congenital cataracts
among 78 infants born
following maternal rubella
infection in early
pregnancy.
This was the first reported recognition
of congenital rubella syndrome (CRS)
Maintenance of long-term antibody
responses
• Is critical for
protective
immunity.
About rubella vaccine
About rubella vaccine
About the vaccine
The single component live attenuated •
vaccines of measles, mumps,
and rubella have been licensed in the USA •
since the 1960s •
Combined live attenuated measles, mumps •
and rubella (MMR) vaccine was introduced
in the United States in the 1970s •
In total,
• over 90 countries around the world use MMR
including our Palestine.
The RA 27/3 strain is used most often
because
1) it gives consistent •
immunogenicity
2) has low rate of side effects.
The role of MMR in reducing the
incidence of these three
diseases is agreed upon.
The vaccine used in Palestine
• Is TRIMOVAX from Sanofi Pasteur.
• Contains WHO approved Wistar RA 27/3M
strain cultivated in human diploid cells.
• Each dose contains at least 1000 Cell Culture
Infectious Dose 50% (CCID).
Currently according to MoH
• MMR is given in two dosages at age of 12 and
18 months.
• A third boosting dose is given to girls in 6th
class.
• The coverage is nearly 100%
• Since 1995 no registered CRS in Palestine.
As we have no data regarding the
immune status for rubella, the aim of our
Cohort retrospective study
To assess
1) the % of rubella susceptible of age bearing
women in Palestinian community.
2) efficiency of used vaccine vaccination •
program.
3) subsequently the need for including rubella •
test as a routine test for pregnant ladies in
their first pregnancies.
Samples
• Samples were obtained from ladies attending
Medicare MediPal laboratories in Ramallah,
Nablus, Hebron, Jericho and Al Eizaria cities.
• Usually this was part of their pregnancy follow
up.
• Serum samples was taken for rubella IgG and
other ordered tests.
• Tests were done the same day or the day after.
Method used
The method used in
•
Medicare- Medipal
• is the Abbott FDA approved AxSYM method
which uses the Micro-particle Enzyme
Immunoassay (MEIA) for qualitative and
quantitative measurement of IgG antibodies
to rubella virus in human serum or plasma.
Hemagglutination Inhibition (HIA)
• Is often referred as the reference method.
• Since 1980, rubella virus IgG assays have been
calibrated against the same WHO
international standard rubella virus serum
(second St. preparation) and test results
reported in IU/ml.
Results
• According to Abbott manufacturers, the
presence of at least 10 International Units of
antibody/ ml of sample is indicative of post
exposure to rubella virus.
• Antibody levels below 10 IU/ml may be
insufficient to provide protection from clinical
illness.
Initial Relative Sensitivity
• MEIA method used in AxSYM Abbott showed
99.5% (1082/1088) sensitivity
• The 95% CI 98.8%-99.8%
Initial Relative Specificity
• MEIA method used in AxSYM Abbott showed
90.8% (316/348) specificity
• The 95% CI 87.3%-93.6%
Number of tested subjects
2002-2009
Year
2002
2003
2004
2005
2006
2007
2008
2009
TOTAL
Number tested
22
19
44
78
57
92
287
277
876
Immunity status of tested subjects
Year
<5 IU /ml
6-9 IU /ml
> 10 IU /ml
No. tested
2002
1
0
21
22
2003
0
1
18
19
2004
3
0
41
44
2005
5
4
69
78
2006
2
2
53
57
2007
1
1
90
92
2008
2
3
282
287
2009
7
6
264
277
Total
21
17
838
876
%
2.5
1.9
95.6
100%
WHO Literature accepts
• Approximately 5% of vaccenees Not
responding to vaccination ( negative seroconversion) and will develop No ANTIBODIES
to Rubella virus.
• This is due to:
• 1) concurrent infection or to a
• 2) low level of pre-existing antibodies.
Age distribution of
tested females
Age/
years
15-19
20-24
25-29
30-34
35-39
40-44
45-49
total
0-5
IU/ml
0
5
6
5
2
1
0
19
6-9
IU/ml
5
9
7
5
1
0
0
27
≥ 10 Sub
IU/ml total
59
64
288
302
239
252
146
156
59
62
9
10
1
1
801
847
%
12.4
39.9
26.8
14.2
6.1
0.5
0.1
100
Age-Specific Fertility Rates and Total
Fertility Rates by Region-1995 (PCBS)
Age Group
15-19
West Bank
100
Gaza Strip
144
Total
114
20-24
25-29
30-34
273
264
229
340
347
289
294
291
248
35-39
40-44
45-49
155
62
5
230
123
5
177
82
5
Total Fertility
Rate (TFR)
5.44
7.41
6.06
Dose Rubella IgG levels change with
age?
• Do we have deferent IgG levels with different
women age groups?
Rubella IgG IU levels with age
IU IgG Level
Age 15-29
YEARS
%
Age 30-49
YEARS
%
0-1000
100-1000
50-99
10-49
0-9
646
196
202
208
27
100%
30.34
31.27
32.2
4.2
241
75
71
80
13
100%
31.12
29.46
33.2
5.4
Back to the aim of our study
1) Finding out the % of rubella susceptible of
age bearing women in Palestinian
community.
The answer is 4.4 % according to our findings
Back to the aim of our study cont.
2) Efficiency of vaccination program •
According to our findings, the vaccine •
outcome consists with the expected results
proposed by the manufacturers.
Back to the aim of our study cont.
3) Subsequently the need for including rubella •
test as a routine test for pregnant ladies in
their first pregnancies.
We believe it is worth thinking of including •
rubella IgG as regular test in pregnant ladies
follow up.
Conclusions and Recommendations
According to our results:1) 4.4 % of Palestinian age bearing women are
Rubella susceptible.
2) The above figures consists with data from
international research findings as well as with
the expected outcome from the vaccine.
3) As the cost estimate of CRS is 200,000$ (USA
figures) it might be recommended doing the
rubella IgG test for all pregnant ladies in their
first pregnancy and keeping the results in
their files for following pregnancies.
4) It is rather better to conceder the lady as
rubella susceptible when equivocal result is
obtained.
Thank you