Shaping the Caribbean's response to Zika, UWI’s Zika Task Force (www.uwi.edu/zika) is gathering and providing expert advice and developing a strategic, scientific approach to tackling the Zika virus.
2. Preventing disease, promoting and protecting health
Zika Virus (ZIKV)
Surveillance and Reporting
Dr. Joy St. John
Director
Surveillance, Disease-Prevention and Control Division
Caribbean Public Health Agency (CARPHA)
3. Preventing disease, promoting and protecting health
Outline
• Zika Virus (ZIKV)
– Global Movement of ZIKV
– ZIKV - Case Definition
– The Caribbean Situation
– ZIKV Testing Guidelines
– Feedback on Testing to date
– Surveillance for Neurological Sequelae
• Microcephaly
• Guillain Barre Syndrome
– The pregnancy question
13. Preventing disease, promoting and protecting health
201
6
Active transmission in the Americas 2016 (and other areas worldwide in previous 15 months, ECDC)
14. Preventing disease, promoting and protecting health
Case Definition
• The working case definition for Zika, is:
• Rash or elevated body temperature (> 37.2 °C) with one or more of the following symptoms, not
explained by other medical conditions
• Arthralgia or myalgia (joint or muscle pain)
• Non-purulent conjunctivitis or conjunctival hyperemia (reddened eyes, without mucous/discharge)
• Headache or malaise
AND
• History of travel to a region with reported transmission (see following slide)
– NB – travel history becomes less essential, the further ZIKV spreads through the
region
16. Preventing disease, promoting and protecting health
Regional Territories With Confirmed local ZIKV cases
CARPHA Member States
• Aruba
• Barbados
• Bonaire
• Curaçao
• Guyana
• Haiti
• Jamaica
• Sint Maarten
• St. Vincent
and the
Grenadines
• Suriname
• Trinidad and
Tobago
Non-CMS Caribbean Islands
• The
Dominican
Republic
• Guadeloupe
• Martinique
• Puerto Rico,
a US territory
• Saint Martin
(French)
• U.S. Virgin
Islands
Level 2 Travel Notices (Practice Enhanced Precautions) have been posted to the CDC Website for each
country *except USA
17. Preventing disease, promoting and protecting health
Regional Territories With Confirmed local ZIKV cases
• Bolivia
• Brazil
• Colombia
• Ecuador
• French
Guiana
• Paraguay
• Venezuela
Level 2 Travel Notices (Practice Enhanced
Precautions) have been posted to the CDC
Website for each country *except USA
North American
Territories
Central America
• Costa Rica
• El Salvador
• Guatemala
• Honduras
• Nicaragua
• Panama
South American
Territories
• Mexico
• USA
• *Sexual
transmission
(~15 cases)
20. Preventing disease, promoting and protecting health
ZIKV Testing at CARPHA
• If suspected cases with compatible clinical and epidemiological features are found in
any CMS, CARPHA can provide diagnostic confirmation.
• ZIKV can only be confirmed by PCR in our Dengue-endemic region
– Extensive cross-reactivity between DENV IgM and ZIKV IgM makes serology
uninterpretable in our Member States
• Viraemia is highest within first 3 days of onset of symptoms and falls to undetectable
levels after day 5
• Samples should therefore be taken from suspect cases between day 1 (day of onset)
and day 5 and submitted to the local Public Health Lab for referral to CARPHA
– Lab request forms should be appropriately filled out
• Samples are subjected to an algorithm to rule out other prevalent arboviruses
• Turn-around time ~ 5 (working) days
21. Preventing disease, promoting and protecting health
Summary of results from Arboviral Algorithm
(to Mid-February)
34
12
166
15
100
0
120
0
147
13
112
6
0
20
40
60
80
100
120
140
160
180
Tested Positive Tested Positive
Jan Feb
Results from Algorithm for PCR Testing for DENV
CHIKV ZIKV
DENV CHIKV ZIKV
22. Preventing disease, promoting and protecting health
Dengue PCR breakdown
Den I
17%
Den II
8%
Den III
33%
Den IV
42%
January Dengue PCR
Den III
53%
Den IV
47%
February Dengue PCR
23. Preventing disease, promoting and protecting health
Feedback from Laboratory
• Need to reinforce completion of lab request forms – but vast
improvements noted over previous outbreaks
• Volume of requests affects turnaround time
– Large numbers of samples sent at height of outbreak investigation
needs to be reviewed. More judicious filtering needed in some
instances
• Testing window starts counting from day of onset as day 1
– (e.g. if fever or rash started on a Saturday, that would be is day 1 and
the last day on which a sample could be taken would be the following
Wednesday)
25. Preventing disease, promoting and protecting health
The Cause for Concern
• In Late 2015 Brazil announced an unusual increase in Microcephaly cases in
areas hard-hit by ZIKV
• Initially > 3500 cases of microcephaly were identified, raising the incidence rate
by a factor of ~ 20
• Subsequent review of the data revealed
– >3000 cases were misclassified and discarded leaving ~ 500+ Microcephaly
cases
– Baseline data on Microcephaly may have been under-ascertained initially
– Even the more modest increase is a cause for precautionary measures,
however and WHO declared the phenomenon a PHEIC in February
• There has also been a noted increase in Guillain Barre Syndrome in other
States affected by ZIKV
26. Preventing disease, promoting and protecting health
ZIKV: - Potential Neurological Sequelae
• Surveillance for potential Neurological Sequelae of ZIKV
– Monitoring Microcephaly
• Member States encouraged to strengthen or develop developmental anomaly registries
• Standardised criteria are needed.
– Proportionality criterion - Head circ = [((length/2)+10)±2] is useful as an initial flag
» See table on following slide
– Need for consultation with Specialist Stakeholders – Virtual meeting?
– Pilot database under construction for use in country and for data submission to CARPHA
– GBS Surveillance
• Standardised case definition needs to be employed for ascertainment
– Use and expansion of AFP system?
– Development of New reporting channel?
• There is need to prepare health systems to deal with potential surges of GBS
• CARPHA is refining tools to facilitate reporting and collation of data on both GBS and Microcephaly in Member
States
27. Preventing disease, promoting and protecting health
Sample Table – Head circ. flagged according to
proportionality criteria
Case
Head Circ
(cm)
Length
(cm)
Lower
Proportionalit
y Criterion
Upper
Proportionalit
y Criterion
Weight
(kg)
Head
Circ
Centile
Height
Centile
Weight
Centile
Actual 1 31.75 48.3 32.15 36.15 2.83<3 15 15
Actual 2 35 51 33.5 37.5 3.21 85 85 50
Actual 3 35.5 53 34.5 38.5 3.36 8585-97 50
Actual 4 34.5 51 33.5 37.5 3.3150-85 85 50
Actual 5 35 57.5 36.75 40.75 3.84 85>97 85
Fictional
1 37.5 50 33 37
Microcephaly
Normal Head Size
Macrocephaly
NB Head circumference is also generally proportionate to other foetal
measurements in terms of percentiles. Comparisons along these lines can also
be made
28. Preventing disease, promoting and protecting health
Photo credit: Image provided by mother of newborn (Rio de Janeiro,
Brazil), with authorization for dissemination exclusively among public
health workers.
First reports in Brazil:
Unusual increase of newborns with microcephaly
29. Preventing disease, promoting and protecting health
AUTHORIZED PHOTOS OF CHILDREN WITH MICROCEPHALY.
METROPOLITAN REGION OF RECIFE, 01/08 THROUGH 31/10/2015.
Microcephaly cases
30. Preventing disease, promoting and protecting health
CARPHA’s Advice to Pregnant Women
• CARPHA recommends that women of childbearing age living in
ZIKA affected take all preventive measures to avoid being
bitten by mosquitoes, which in addition to Zika can also
transmit diseases such as dengue and chikungunya.
• Women who believe they have been exposed to Zika virus
should consult with their healthcare provider for close
monitoring of their pregnancy.
31. Preventing disease, promoting and protecting health
Zika and Pregnancy
• Association between ZIKV infection and congenital anomalies including
Microcephaly is still under investigation
• Precautionary principle is being applied:
– WHO PHEIC
– Close follow-up of pregnant women who manifest symptoms of ZIKA
• Questions on ethics of active screening in pregnancy do need
consideration
– What actions will be considered after a positive diagnosis of ZIKV?
– What actions will be considered if constrained brain growth is
discovered?
– What actions are permissible within our legal frameworks?
32. Preventing disease, promoting and protecting health
Preventive measures
Personal preventive measures:
• The best way to prevent Zika is to avoid being bitten by mosquitoes. CARPHA advises
that you take proper precautions to prevent being bitten:
– Use insect repellants containing DEET (>10%), picaridin, oil of lemon eucalyptus or
IR3535 on exposed skin.
• Re-apply in accordance with instructions
– Wear long-sleeved shirts and long pants.
– Use air conditioning or have windows/doors securely closed or screened when
indoors.
– Sleep under mosquito nets.
Environmental Preventive Measures
• Identify and eliminate breeding sites in and around homes
• Cooperate with activities of local Vector Control Agencies
33. Preventing disease, promoting and protecting health
Conclusions
• Zika is likely to continue its spread through the Caribbean region
• Vigilance is advised, to detect index cases and heighten vector control
activities
• All persons are advised to employ both environmental and personal
strategies to reduce the risk of being bitten
• Pregnant women are advised to take special care to avoid mosquito
bites and to report any symptoms suggestive of ZIKV to their
obstetrician/doctors
• Surveillance for neurological sequelae needs to be established
• Preparations for surges in GBS in member states are needed
