2. 2
WHO has already declared the Zika virus
as a Public Health Emergency of
International Concern over its suspected
link to microcephaly.
From 2010 to 2014, Brazil
only saw an average of 156
cases of microcephaly per
year. But from Oct. 2015 to
Jan. 2016, Brazil
has recorded over 4,000
reported cases, though they
have been able to investigate
and discard 462 initial
diagnoses according to an
update last month.
3. INTRODUCTION
Zika virus is an emerging mosquito-borne virus that
was first identified in Uganda in 1947 in rhesus
monkeys through a monitoring network of sylvatic
yellow fever. It was subsequently identified in humans
in 1952 in Uganda and the United Republic of
Tanzania. Outbreaks of Zika virus disease have been
recorded in Africa, the Americas, Asia and the Pacific.
Genre: Flavivirus
Vector: Aedes mosquitoes (which usually bite during
the morning and late afternoon/evening hours)
Reservoir: Unknown
3
4. SIGNS AND SYMPTOMS
The incubation period (the time from exposure to symptoms) of
Zika virus disease is not clear, but is likely to be a few days.
The symptoms are similar to other arbovirus infections such as
dengue, and include fever, skin rashes, conjunctivitis, muscle
and joint pain, malaise, and headache. These symptoms are
usually mild and last for 2-7 days.
During large outbreaks in French Polynesia and Brazil in 2013
and 2015 respectively, national health authorities reported
potential neurological and auto-immune complications of Zika
virus disease. Recently in Brazil, local health authorities have
observed an increase in Zika virus infections in the general
public as well as an increase in babies born with microcephaly
in northeast Brazil. Agencies investigating the Zika outbreaks
are finding an increasing body of evidence about the link
between Zika virus and microcephaly. However, more
investigation is needed before we understand the relationship
between microcephaly in babies and the Zika virus. Other 4
5. TRANSMISSION
Zika virus is transmitted to people through the bite of
an infected mosquito from the Aedes genus,
mainly Aedes aegypti in tropical regions. This is the
same mosquito that transmits dengue, chikungunya
and yellow fever.
Zika virus disease outbreaks were reported for the
first time from the Pacific in 2007 and 2013 (Yap and
French Polynesia, respectively), and in 2015 from the
Americas (Brazil and Colombia) and Africa (Cape
Verde). In addition, more than 13 countries in the
Americas have reported sporadic Zika virus infections
indicating rapid geographic expansion of Zika virus.
5
6. DIAGNOSIS
Zika virus is diagnosed through PCR
(polymerase chain reaction) and virus
isolation from blood samples. Diagnosis by
serology can be difficult as the virus can
cross-react with other flaviviruses such as
dengue, West Nile and yellow fever.
6
7. PREVENTION
Mosquitoes and their breeding sites pose a significant
risk factor for Zika virus infection. Prevention and
control relies on reducing mosquitoes through source
reduction (removal and modification of breeding sites)
and reducing contact between mosquitoes and people.
This can be done by using insect repellent; wearing
clothes (preferably light-coloured) that cover as much of
the body as possible; using physical barriers such as
screens, closed doors and windows; and sleeping under
mosquito nets. It is also important to empty, clean or
cover containers that can hold water such as buckets,
flower pots or tyres, so that places where mosquitoes can
breed are removed. 7
8. • Special attention and help should be given to those who
may not be able to protect themselves adequately, such as
young children, the sick or elderly.
• During outbreaks, health authorities may advise that
spraying of insecticides be carried out. Insecticides
recommended by the WHO Pesticide Evaluation Scheme
may also be used as larvicides to treat relatively large
water containers.
• Travellers should take the basic precautions described
above to protect themselves from mosquito bites.
8
9. TREATMENT
Zika virus disease is usually relatively mild
and requires no specific treatment. People
sick with Zika virus should get plenty of rest,
drink enough fluids, and treat pain and fever
with common medicines. If symptoms
worsen, they should seek medical care and
advice. There is currently no vaccine
available.
Do not take aspirin and other non-steroidal
anti-inflammatory drugs.
9
10. ZIKA VIRUS IN PREGNANCY
Zika virus can be spread from a pregnant woman to
her unborn baby. There have been reports of a
serious birth defect of the brain called
microcephaly and other poor pregnancy outcomes in
babies of mothers who were infected with Zika virus
while pregnant. Knowledge of the link between Zika
and these outcomes is evolving, but until more is
known, CDC recommends special precautions for the
following groups:
Women who are pregnant (in any trimester):
• Consider postponing travel to any area where Zika
virus transmission is ongoing.
• If you must travel to one of these areas, talk to your
doctor first and strictly follow steps to prevent 10
11. 11
Women who are trying to become pregnant:
• Before you travel, talk to your doctor about your
plans to become pregnant and the risk of Zika virus
infection.
• Strictly follow steps to prevent mosquito bitesduring
your trip.
Specific areas where Zika virus transmission is
ongoing are often difficult to determine and are likely
to change over time. As more information becomes
available, this travel notice will be updated. Please
check back frequently for the most up-to-date
recommendations.
12. 12
What can travelers do to prevent Zika?
There is currently no vaccine to prevent or medicine to treat
Zika. Travelers can protect themselves by preventing
mosquito bites:
• Cover exposed skin by wearing long-sleeved shirts and long
pants.
• Use EPA-registered insect repellents containing DEET, picaridin,
oil of lemon eucalyptus (OLE), or IR3535. Always use as directed.
• Pregnant and breastfeeding women can use all EPA-registered
insect repellents, including DEET, according to the product label.
• Most repellents, including DEET, can be used on children aged >
2 months.
• Use permethrin-treated clothing and gear (such as boots, pants,
socks, and tents). You can buy pre-treated clothing and gear or
treat them yourself.
• Stay and sleep in screened-in or air-conditioned rooms.
13. 13
WHO RESPONSE
WHO is supporting countries to control Zika virus
disease through:
Define and prioritize research into Zika virus
disease by convening experts and partners.
Enhance surveillance of Zika virus and potential
complications.
Strengthen capacity in risk communication to help
countries meet their commitments under the
International Health Regulations.
Provide training on clinical management, diagnosis
and vector control including through a number of
WHO Collaborating Centres.
14. 14
• Strengthen the capacity of laboratories to detect
the virus.
• Support health authorities to implement vector
control strategies aimed at
reducing Aedes mosquito populations such as
providing larvicide to treat standing water sites
that cannot be treated in other ways, such as
cleaning, emptying, and covering them.
• Prepare recommendations for clinical care and
follow-up of people with Zika virus, in
collaboration with experts and other health
agencies.
15. VACCINE DEVELOPMENT
Work has begun towards developing a vaccine for Zika
virus, according to Anthony Fauci, director of the National
Institute of Allergy and Infectious Diseases. The researchers
at the Vaccine Research Center have extensive experience
from working with vaccines for other viruses such as West
Nile virus, chikungunya virus, and dengue fever. Nikos
Vasilakis of the Center for Biodefense and Emerging
Infectious Diseases predicted that it may take two years to
develop a vaccine, but 10 to 12 years may be needed
before an effective Zika virus vaccine is approved by
regulators for public use.
Bharat Biotech, a Hyderabad based Indian drug company
has claimed that they have developed a vaccine for Zika
virus, but they are in the process for approval to be released15
16. 16
• There is now a rush to develop a vaccine. Global
firms includingFrance’s Sanofi and Japan’s Takeda
have begun their own research. But Bharat Biotech
was the first company to file a patent for a Zika
vaccine, which is now in pre-clinical testing as the
firm prepares to test it on animals.
• It is not clear if and when Bharat’s vaccines will
reach the market. Animal testing is expected
to take about five months, and then they would
need to be tested on humans. The vaccine doesn’t
just need to be effective in trials; Indian regulatory
authorities also need to expedite the process, Ella
said. Passing through those stages could take
many years, but Ella is confident that, once
approved, Bharat Biotech can produce millions of
17. CDC GUIDELINES
The US Centers for Disease Control and Prevention (CDC)
has issued interim guidelines for the evaluation, testing, and
management of infants with possible congenital Zika virus
infection. The guidelines recommend Zika virus testing for
infants with microcephaly or intracranial calcifications who
were born to women who traveled to or resided in an area
with Zika virus transmission while pregnant and for infants
born to mothers with positive or inconclusive test results for
Zika virus infection. In these situations, the CDC
recommends:
Testing infant serum for Zika virus RNA, Zika virus
immunoglobulin M (IgM) and neutralizing antibodies, and
dengue virus IgM and neutralizing antibodies. The initial
sample should be collected either from the umbilical cord or
directly from the infant within 2 days of birth, if possible. 17
18. 18
• If cerebrospinal fluid is obtained for other studies, it
should also be tested for Zika virus RNA, Zika virus
IgM and neutralizing antibodies, and dengue virus
IgM and neutralizing antibodies.
• Histopathologic evaluation of the placenta and
umbilical cord with Zika virus immunohistochemical
staining on fixed tissue and Zika virus reverse
transcription-polymerase chain reaction on fixed
and frozen tissue may also be considered.
• If not already performed during pregnancy, test
mother's serum for Zika virus IgM and neutralizing
antibodies and dengue virus IgM and neutralizing
antibodies.
19. MICROCEPHALY
Microcephaly is a neurodevelopment
disorder where an infant’s head does not
develop normally and remains abnormally
small when compared to the heads of others
the same age and sex.
19
20. 20
• Microcephaly means “small head.” It is very similar
to and should not be confused with the word
microencephaly, which means “small brain.” The
skull size (and thus head size) is determined by
brain size, therefore a person with microcephaly is
guaranteed to have microencephaly as well.
22. HISTORY
Microcephaly was first noticed in children of
pregnant Japanese women who survived the
atomic bombings of Hiroshima and Nagasaki.
The radiation mutated the children.
Currently there is a heavy presence of
microcephalic children in Amish country in
Philadelphia
22
23. CAUSES
Microcephaly is the result of a mutation on
one of the six microcephalin genes. The most
common being the MCPH1gene.
Each gene corresponds to one of the three
common types of microcephaly:
Autosomal Dominant
Autosomal Recessive (most common)
X-Linked
23
25. CAUSES
There are two forms of microcephaly. They
are determined by when the mutation occurs.
If it is in the womb it is congenital onset
microcephaly. If it occurs after birth it is
postnatal onset microcephaly.
Microcephaly can either be inherited from
parents that carry the mutated gene or can
occur randomly due to a plethora of
disorders and environmental conditions.
25
26. SYMPTOMS
Microcephaly results in an abnormally small head size.
With this comes multiple symptoms:
Dwarfism
Delayed motor and speech functions
Mental retardation
Facial distortions
Seizures
Hyperactivity
Balance and coordination problems
Shortened life span
Limited mental capacity
Some people with microcephaly have grow up to have
normal intelligence.
26
27. CURE
There is no cure for microcephaly. It is
impossible without the technology to stimulate
nerve cell growth, which has yet to be
developed.
Current treatment focuses on mitigating the
effects of the symptoms of microcephaly.
If caught early on, speech therapy and physical
therapy may be able to mitigate the effects of motor
and speech dysfunction that is sure to ensue.
Medicine to treat hyperactivity has been developed.
Scientists have recently discovered that amino acid
therapy can significantly reduce the occurrence of
seizures.
27
28. PROGNOSIS FOR MICROCEPHALY
Prognosis for microcephaly varies and depends on
the presence of other existing medical conditions.
In general, life expectancy for children with
microcephaly is reduced and the chances for
attaining normal brain function is reduced.
28
29. KEY FACTS
Zika virus disease is caused by a virus
transmitted by Aedes mosquitoes.
People with Zika virus disease usually have a
mild fever, skin rash (exanthema) and
conjunctivitis. These symptoms normally last for
2-7 days.
There is no specific treatment or vaccine
currently available.
The best form of prevention is protection against
mosquito bites.
The virus is known to circulate in Africa, the
Americas, Asia and the Pacific.
29
30. REFERENCES
Sternberg, Steve (22 January 2016). "Vaccine Efforts Underway as Zika
Virus Spreads". US News & World Report. Retrieved 28 January 2016.
James Cook (27 January 2016). "Zika virus: US scientists say vaccine
'10 years away'—BBC News". BBC News. Retrieved 28 January 2016.
"Zika Travel Health Notices". www.cdc.gov. CDC. Retrieved24
January 2016.
"Microcephaly in Brazil potentially linked to the Zika virus epidemic,
ECDC assesses the risk". European Centre for Disease Prevention and
Control. Retrieved 18 January 2016.
CDC Issues Interim Guidance on Congenital Zika Virus Infection- CDC.
WHO fact sheet.
Expert comment on Zika virus outbreak in the Americas- London school
of hygiene and tropical medicine.
Lara C. Pullen, PhD; Zika Virus Spreading in Latin America, Raising
Concerns
Medscape News.
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