Michele R.

Kadri:
• The main vector for dengue, yellow fever, and now the Zika virus is the Aedes aegypti
mosquito.
• There is no causal proof that pregnant women who are infected with the Zika virus
consequently have microcephalic babies, there is mounting correlational evidence in
support of this assertion.
1. First, the mothers giving birth to the babies with microcephaly lived in a region
where there had been a Zika virus outbreak;
2. More than 60 women who delivered microcephalic infants had reported to their
clinician that they experienced a rash during their pregnancy;
3. Two women whose foetuses were observed to have microcephaly had ZIKV
detected in their amniotic fluid and,
4. Examinations of infants who had died with malformed heads were similar to infants
who had died with microcephaly of mothers who were reported to have the Zika
virus.
• It can be found in urine, saliva, and amniotic fluid
• It was reported that nationwide there were 5280 cases of microcephaly and other
neurological disorders associated with ZIKV infection. Responding to these findings, the
Brazilian government has ordered mandatory PCR tests and made 250,000 test kits available
in 23 Central Public Laboratories.
• Children of mothers who are identified as potentially being infected by the Zika, should have
special attention throughout the first year of their life. During this period, it is possible that
other neurological symptoms, less severe than microcephaly, might appear. It is also
recommended that these children be followed later by a multidisciplinary team for possible
difficulties in speech and learning.
• Another issue affected by the ZIKA epidemic is pregnancy planning. A recommendation in
place is that women and their partners should wait until the second half of the year when
there are less Aedes aegypti mosquitoes to try to become pregnant. Another practical
recommendation is that Brazilians should use insect repellent and wear long-sleeved shirts
and long pants to avoid mosquito bites
• The biggest fight against Zika is to fight against sanitation with only 55 percent of
households are connected to sanitary sewer lines. Moreover, in the Northeast, the region
with the highest number of recent births with microcephaly, more than one quarter (26
percent) of households have open sewers
o The irregular distribution of drinking water in rural areas, or the periphery of large
cities, forces people to store water at home in a precarious way that ultimately
creates a breeding area for Aedes aegypti mosquitoes
• Three essential actions that must be taken to control and eventually eradicate the Zika virus
in Brazil:
1. Improve social and environmental conditions to eliminate mosquito breeding sites,
2. Fund research to expand knowledge about the disease and develop a vaccine, and
3. Provide health care and social support for those families who have children with
permanent special needs resulting from ZIKA infection.
Jacqui Thornton:
• Microcephaly is newly being referred to as Congenital Syndrome of Zika, with the condition
presenting more randomly than non-Zika microcephaly
• Repellent is very expensive and is sold out most of the time. N poor communities, NGO
World Vision Brazil has been providing free repellent, bed nets and advice to pregnant
women.
• Nursing staff believe that women of this age need to be more pragmatic and try to conceive
in the lowest risk season for mosquitoes which starts now, in Brazil winter.
• Primary care nurse play a leading role in identify Zika symptoms- a tell-tale red rash, fever
and pain in the joints in pregnant women- as midwives do not exist as a profession. In brazil
one GP works with one nurse and one assistant nurse to cover a population of 3.5-4000
people.
• Pregnant women who do have scans at hospital can usually have microcephaly detected in
their baby at 30 weeks.
• Children with microcephaly need to come back to hospital regularly. With nurses focussing
on the caring and teaching roles for mothers such as helping mothers feed their children, as
microcephaly babies commonly have reflux and swallowing problems.

Petersen, Jamieson, Powers and Honein:

• Zika virus is a flavivirus and is transmitted by the aedes mosquitoes, which can transmit the
virus from non-human primates to humans. Two types of aedes mosquitoes are A. aegypti
and A. albopictus. A. aegypti has a very high vectorial capacity meaning it is highly capable of
transmitting the virus and is most common.
o A. aegypti is the primary vector for Zika, dengue, chikungunya
• Zika virus remains hidden for nearly 70 years, however within the span of just 1 year, Zika
virus was introduced to Brazil from the Pacific Islands to the Americas.
• The 2007 outbreak of Zika on the islands of the State of Yap came as a huge shock.
o This outbreak was followed by an outbreak in French Polynesia in 2013 and 2014,
followed by further outbreaks in New Caledonia (2014), Easter Island (2014), Cook
Islands (2014), Samoa (2015) and American Samoa (2016).
o Prior to these outbreaks, only sporadic cases had occurred in the last 6 years. By
March 2016, the virus had spread to 33 countries in the Americas
• Transmission of Zika virus through a blood transfusion has yet to be reported.
• Sexual transmission to partners of returning male travellers who acquired Zika virus
infection abroad has been reported. With viral RNA, evident in very high numbers in the
sperm of male partners for up to 62 days after the onset of symptoms.
• Zika virus can be transmitted from mother to the fetus during pregnancy. Zika virus RNA has
been identified in the amniotic fluid of mothers whose foetuses had cerebral abnormalities
detected by ultrasound.
o RNA has been identified in the brain tissue and placentas of children who were born
with microcephaly and died soon after birth.
o Transmission through breast milk has not been documented, however, the
breastmilk of a women who became asymptomatic with the virus on the day of
delivery contained infective Zika virus particles.
• Fetal outcomes resulting from fetal Zika is still unknown or properly understood. However, it
is compared to rubella or cytomegalovirus (CMV).
o Rubella: has adverse fetal effects in up to 90% of infants in the first 10 weeks of
pregnancy, with decreasing effects and lower risk after week 18.
o CMV: risk of adverse fetal effects is highest during the first trimester, but the risk
persists in the second and third trimester, with some adverse fetal outcomes noted
in mothers after week 27.
• Microcephaly can occur because of fetal brain disruption sequence, a process in which
collapse of the fetal skull follow the destruction of fetal brain tissue. Other causes of
microcephaly include genetic syndromes, vascular disruption during brain development,
nutritional deficiencies, and exposure to toxins such as mercury.
o 35% of babies born with microcephaly had ocular abnormalities.
• Microcephaly can occur late during the second or even the third trimester. However, it has
the greatest risk in the first trimester. It is most common when mothers are infected
between weeks 7 to 13 but in some cases, can occur up to week 18.
• The finding of Zika RNA in amniotic fluid of foetuses, in infants with microcephaly and the
high rates of microcephaly among infants born to mothers with acute Zika infection provide
connect microcephaly to maternal Zika virus infection.
• The fetal abnormalities were detected by ultrasound in 29% of women with Zika.
o Early fetal loss and fetal death have been noted in women infected by the virus,
ranging between fetal loss in weeks 6 to weeks 32.
o In addition to microcephaly, other detected abnormalities include: an absent corpus
callosum, cerebral calcification, ventricular dilation, brain atrophy, abnormal
gyration, hydrops fetalis, intrauterine growth retardation.
• The intubation period of Zika is unknown, but is expected to be less than 1 week.
• Symptoms of Zika have only been evident in approx. 19% of infected people.
o Symptoms include: conjunctivitis, macular or papular rash, arthralgia/ arthritis,
fever, myalgia, headache, retro-orbital pain, oedema and vomiting.
o Other symptoms include: dull and metallic hearing, subcutaneous bleeding
• Zika virus has a very strong association with Guillian-Barre syndrome, with previously
infected people developing the syndrome.
• The CDC guidance has recommended that microcephaly be defined as an occipitofrontal
circumference below the third percentile for gestational age and sex.
• The detention of viral nucleic acid in serum provides a definitive diagnosis, however, in most
instances viremia is transient and diagnosis by RT-PCR has been most successful within 1
week after the onset of clinical illness.
o The cross reactivity of flavivirus antibodies presents major challenges for the
interpretation of serological test result. For example, recent Zika virus infection may
also evoke a positive MAC-ELISA result for dengue. This is particularly problematic in
areas in which dengue is endemic, where more than 90% of the population may
have had previous exposure to dengue and areas where dengue and Zika co-
circulate.
• Limited data suggests Zika virus RNA can be detected longer in urine than in serum, this is
unconfirmed.
• The virus is likely to have originated in East Africa and subsequently spread to West Afric and
then to Asia, resulting in distinct lineages
o All strains currently associated with the outbreak in the Americas are of the Asian
genotype. They are very similar to each other with a 99% nucleotide homology. This
similarity data suggests that any vaccine product developed would be protective
against all strains of Zika.
o Prevention and control measures include: avoiding mosquito bites, reducing sexual
transmission, and controlling the mosquito vector.
▪ Prevention in pregnant women focusses more on avoiding unnecessary
travel to areas of ongoing Zika virus transmission, avoiding unprotected sex
with partners who are at risk for Zika, using mosquito repellent, permethrin
treatment for clothes, bed nets, window screen and air condition.
▪ Application of larvicides and indoor residual spraying have been effective in
some settings.
Duffy et al:
• Zika virus is a flavivirus related to the west Nile, dengue and yellow fever viruses
• Until the 2007 outbreak in Micronesia, no transmission of Zika virus had been reported
outside of Africa and Asia. When patients were tested for dengue, patients all tested
positive, however, it was the insight and memory of physician who suspected the virus was
different, which lead to its investigation and reveal as Zika.
• The virus presents with an acute but generalised macular or papular rash, arthritis or
arthralgia, or non-purulent conjunctivitis.
• The number of cases peaked in late May and subsided in early July. The median age of
patients with confirmed or probable disease was 36 years (range, 1 to 76); 66 of these
patients (61%) were female.
o The median duration of rash was 6 days (range, 2 to 14), and that of arthralgia was
3.5 days (range, 1 to 14).
o Male participants were more likely than female participants to have IgM antibody
against Zika virus
• There are no environmental or behavioural risk factors for Zika
• Of the 1366 water-holding containers identified during the household survey, 587 were
infested with mosquito larvae or pupae; infested containers were found at 148 of the 170
households surveyed. Aedes hensilli was the predominant species identified and was present
in 489 of the water-holding containers. Thus, it is plausible that Aedes hensilli was a vector
of Zika virus transmission in this outbreak
• All 108 patients with confirmed or probable Zika virus disease had IgM antibody against Zika
virus and neutralizing antibodies.
• The attack rates of Zika virus disease detected by surveillance were higher among females
than males and among older persons than younger per- sons.
• The study did not find any recently ill residents who had travelled outside of Yap, but the
virus could have been imported by a person with undetected infection.