Zika Virus InfectionLelete Holson-Patterson

RN, RM, Cert. Admin, Dip. HRM, BSc, MSc, Doctoral Candidate

2016

Situation Summary

1947- Zika Virus first isolated in the Zika Forest (Uganda) in a Rhesus Monkey

1952- Zika Virus first isolated in humans in Uganda, Tanzania

1968- Zika Virus detected in human samples in Nigeria

2013- Outbreak of Zika Virus in French Polynesia with 10,000 registered cases of which 70 were

severe cases including Guillian Barre’ syndrome, meningoencephalitis, leukopenia

2007- First major outbreak of Zika Virus on the island of Yap (Micronesia) with 185

suspected cases

2015- Zika Virus detected in New Caledonia and in the Cook Islands

May, 2015- confirmed transmission of Zika virus in Brazil

October, 2015, - Colombia health authorities confirmed transmission of Zika virus

December 1, 2015- 9 member states in the Americas confirmed circulation of Zika virus and

include Brazil, Chile, Colombia, El Salvador, Guatemala, Mexico, Paraguay, Suriname and

Venezuala

January, 2016- 20 Member States of the Americas including Haiti and Barbados

In October 2015, Brazilian health authorities reported an unusual increase in microcephaly cases

As of 30 November 2015, 1,248 cases of microcephaly have been reported in 14 states of Brazil.

Situation Summary

2000 2010 Nov. 20150

20

40

60

80

100

120

5.5/100,000 5.7/100,000

99.7/100,000

Prevalence of Microcephaly in Newborns in Brazil

On November 28, 2015, the Brazil Ministry of Health notified 3 deaths associated with Zika Virus infection.

The fatal cases were 2 adults and 1 newborn

Zika Virus Related Deaths

The first case was a male adult with history of lupus erythematosus, chronic use of corticosteroid drugs, rheumatoid arthritis and alcoholism who was admitted with suspected dengue fever

The second case was a 16 year old female The third case was a newborn

Zika Virus Related Deaths

This is a disease caused by the Zika virus (ZIKAV).

Very close phylogenetically to viruses such as dengue, yellow fever, Japanese encephalitis, or West Nile virus.

Zika Virus Infection

Zika Virus (ZIKAV)◦ An arbovirus the flavivirus genus (family

Flaviviridea)

Aetiology

The Zika virus is transmitted by the Aedes aegypti mosquitoes

Mode of Transmission

After an infected mosquito bite, the disease symptoms usually appear following an incubation period of 3-12 days

Incubation Period

Life Cycle

Life Cycle

Fever Non-purulent conjunctivitis Headache Myalgia Arthralgia Asthenia Maculopapular rash Oedema of the lower limbs

Common Clinical Features

Retro-orbital pain Anorexia Vomiting Diarrhoea Abdominal pain Mild Thrombocytopenia (laboratory findings) Mild Leucopenia (laboratory findings)

Less Common Clinical Features

Guillian Barre’ Meningoencephalitis Thrombocytopenia purpura

Severe Clinical Features

Microcephaly

Patients with rash or elevated temperature (> 37.2°C) with one or more of the following symptoms (not explained by other medical conditions):◦ Arthralgia or myalgia◦ Non-purulent conjunctivitis or conjunctival

hyperaemia◦ Headache or malaiseIn someone who resides in or has visited epidemic or endemic areas within 2 weeks prior to the onset of symptoms

Suspected Case (Preparedness Phase)

A suspected case with laboratory positive result for the specific detection of Zika virus

Confirmed Case

Algorithm for the Detection of Zika VirusZika suspected cases (Regarding

the symptoms and epidemic scenario)

Acute Phase(1-5 days after

symptoms arise)

Onset of symptoms vs

taking of samples

PositiveCHIK V

Confirmed

IgMDengue IgM ChikV

PositivePresumptive

ZIKA V

PositivePresumptive

DENGV

RT-PCR/NS4Dengue

Convalescent phase(> 6 days after symptom onset)

(Real Time) PCR-

CHIK V

PositiveDENV

Confirmed

NegativeConsider CHIK V

NegativeConsider

ZIkV(Real time)

PCR-ZikV

NegativeDiscard

PositiveZik V Confirmed

NegativeDiscarded

IgMZIKV

PositivePresumptiv

e CHIK VNegative

Consider ZIK V

Zika Fever is a Class 1 Notifiable disease and is notified on suspicion within 24 hours to the Parish Health Department and the National Epidemiology Unit, Ministry of Health

Cases (confirmed by laboratory testing) should also be notified as a Class 1 Notifiable disease to the Parish Health Department and the Epidemiology Unit, Ministry of Health

Class 1 Notifiable Disease

Samples for serology should be sent to the National Public Health Laboratory along with the completed CARPHA Laboratory form.

The following are the requirements for the sampling:◦ Type of sample: Serum- 4-5 mls. Of blood in a

plain red top tube Acute phase: Until 8 days after symptom onset Convalescent phase: 10-15 days after symptom

onset

Laboratory Testing for Zika

Keep refrigerated (2-8°C) if sample will be processed within 48 hours at the NPHL.

Keep frozen (-10 to -20°C) if sample will be processed after the first 48 hours

Maintain frozen (-70°C) if sample will be processed after one week

Conservation of the sample

Samples should be transported on ice or with ice packs to the National Public Health Laboratory once the Notification is made to the Parish Health Department

Transporting & Handling Samples

Nucleic Acid detection of Zika viral RNA using real time Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) performed on an “acute sample” collected during the first five (5) days of illness

Serological detection of anti-Zika IgM and IgG antibodies using Enzyme-Linked Immunosorbent Assay (ELISA) and immunofluorescence assays may be performed on blood samples collected 6 days after the onset of symptoms

Laboratory Tests

If the following is not included in the test request form, the sample cannot be referred and will be REJECTED:◦ Name of patient◦ Age of patient◦ Date of symptom onset◦ Date sample collected◦ Clinical features- full description◦ Clinical Tests Performed and Results◦ Pertinent Travel History

Samples

Dengue Chikungunya Malaria Leptospirosis Acute HIV infection Measles Rubella Rickettsial infections Epstein Barr Virus- Infectious mononucleosis

Differential Diagnosis

There is no vaccine or specific treatment for Zika Virus

It is important to differentiate Zika virus from other diseases

Cases of co-infection, Zika and Dengue, could occur

Compared with dengue, fever associated with Zika virus infection is more acute and shorter in duration

Case Management

Symptomatic Rest Acetaminophen to relieve fever Antihistamines to control pruritus Using aspirin is not advised due to the risk of

bleeding and the developing of Reye’s syndrome in children younger than 12 years of age

The use of NSAID is not advised as the clinical symptoms may be Dengue or Chikungunya.

Treatment

Increased oral fluids Patient isolation especially during the first

week of illness◦ Stay under mosquito net treated or without

insecticide◦ Stay in places with intact windows, doors and

screens◦ Staff who take care of these patients should

protect against mosquito bites using insect repellent (DEET, IR3535 or Icaridin) and wearing long sleeves and pants

Management

There is no evidence of any restriction of the use of these repellents by pregnant women if they are used in accordance with the instructions on the product label

Management

EVERYONE’S RESPONSIBILITY Eliminate breeding sites of the mosquitoes Identify areas of high risk transmission Select appropriate insecticide

Vector Control Measures

Stop the birth of Mosquitoes

Stop Mosquito from Biting you

Management

There is no evidence of any restriction of the use of these repellents by pregnant women if they are used in accordance with the instructions on the product label

References PAHO/WHO. (2016). Zika virus infection.

Thank You!!