Pathfinder
Editor, Senior Moderator
Health protection – guidance
Zika virus
From
ublic Health England
...
Last updated:10 February 2016,
...
Clinical advice on Zika: assessing pregnant women following travel; symptoms, transmission (includes sexual transmission), epidemiology.
Contents
Zika is a mosquito-borne infection caused by Zika virus, a member of the genus flavivirus and family Flaviviridae. It was first isolated from a monkey in the Zika forest in Uganda in 1947.
As of 5 February 2016, PHE has defined countries with active Zika virus transmission as those with confirmed autochthonous (locally acquired) cases (vector borne transmission only) within the last 9 months. These are consistent with the list of countries provided by the European Centre for Disease Control (ECDC) and are:
Prior to 2015, Zika virus outbreaks occurred in areas of Africa, Southeast Asia, and the Pacific Islands.
As surveillance for Zika improves, further cases of Zika are expected to be reported in these regions and previously unaffected countries, particularly in south and central America and the Caribbean, where the Aedes mosquito vector is present.
Epidemiology
Zika virus was first discovered in Africa in the 1940s. The virus circulates in Africa and Asia in humans, animals and mosquitoes but prior to 2015 few outbreaks have been documented.
The first Zika outbreak reported outside Africa and Asia occurred on Yap Island in the Federated States of Micronesia in 2007. It was caused by the Asian strain of the virus. The same strain caused a subsequent outbreak in French Polynesia in 2013 and has since caused large outbreaks in other parts of the Pacific region including the first cases in the Americas on Easter Island (a Chilean island in the south east Pacific) in 2014.
In May 2015, the first locally-acquired confirmed case of Zika infection was reported in Brazil.
Zika in the UK
ZIKV does not occur naturally in the UK. However, as of 10 February 2016, a total of 7 cases have been diagnosed in UK travellers. [TABLE="width: 704, height: 1"]
[TR]
[/TR]
[TR]
[TD]Colombia[/TD]
[TD]-[/TD]
[TD]1[/TD]
[TD]2[/TD]
[TD]3[/TD]
[/TR]
[TR]
[TD]Cook Islands*[/TD]
[TD]1[/TD]
[TD]-[/TD]
[TD]-[/TD]
[TD]1[/TD]
[/TR]
[TR]
[TD]Cura?ao/Venezuela[/TD]
[TD]-[/TD]
[TD]-[/TD]
[TD]1[/TD]
[TD]1[/TD]
[/TR]
[TR]
[TD]Guyana/Suriname[/TD]
[TD]-[/TD]
[TD]1[/TD]
[TD]-[/TD]
[TD]1[/TD]
[/TR]
[TR]
[TD]Mexico/Venezuela[/TD]
[TD]-[/TD]
[TD]-[/TD]
[TD]1[/TD]
[TD]1[/TD]
[/TR]
[/TABLE]
* Not associated with current outbreak. Although cases have previously been reported in the Cook Islands, active transmission of Zika virus is not known to be ongoing.
Symptoms
The majority of people infected with Zika virus have no symptoms. For those with symptoms, Zika virus tends to cause a mild, short-lived (2 to 7 days) febrile disease. Typical symptoms include:
Serious complications and deaths from Zika are not common. However, recent increases in congenital anomalies (particularly microcephaly), Guillain-Barr? syndrome, and other neurological and autoimmune syndromes are being reported in areas where Zika outbreaks have occurred. The association of these illnesses with Zika virus is temporal and causality has yet to be proven, however evidence is accumulating. Further information about these findings is available from WHO.
Following an International Health Regulations (IHR) Emergency Committee (EC) meeting on 1 February 2016, it was declared that the recent cluster of microcephaly cases and other neurological disorders reported in Brazil, following a similar cluster in French Polynesia in 2014, constitutes a Public Health Emergency of International Concern (PHEIC).
In the absence of another explanation for these clusters, it was advised by the Emergency Committee (EC) that these clusters were possibly associated with the recent outbreaks of Zika virus. The World Health Organization (WHO) has issued temporary recommendations which include: improved surveillance and control of Zika in at risk countries, and measures for travellers and pregnant women.
Transmission
Zika virus is transmitted by the bite of an infected female Aedes mosquito, most commonly Aedes aegypti. Other species of Aedes mosquitoes may also have the potential to transmit this virus. The Aedes aegypti mosquito is not present in the UK and is unlikely to establish in the near future as the UK temperature is not consistently high enough for it to breed.
After an infected mosquito bites a human, the first symptoms of Zika can develop in 3 to 12 days but it can be shorter or longer in some people.
While almost all cases of Zika are acquired via mosquito bites, a small number of cases have occurred through sexual transmission, and there is increasing evidence of transmission from mother to fetus via the placenta.
Transmission of Zika via blood transfusion has been suspected in a small number of cases, and a study during the outbreak in French Polynesia detected Zika virus in 3% of blood donors who were asymptomatic at the time of donation. Measures to safeguard the UK blood supply are being implemented from 4 February 2016.
If a person acquires Zika abroad and becomes ill on their return to the UK, any public health risk to the wider population is negligible, as the mosquito that transmits the virus is not found in the UK.
Prevention and travel advice
There is currently no vaccine or drug to prevent Zika infection.
Aedes mosquitoes transmit Zika, as well as diseases such as chikungunya, dengue, and yellow fever. Aedes mosquitoes predominantly bite during the day, but especially during mid-morning and late afternoon to dusk (as opposed to mosquitoes that transmit malaria, which bite at night between dusk and dawn).
Travellers to regions where these diseases occur need to take insect bite avoidance measures during daytime and nighttime hours, to reduce the risk of infection with Zika and other mosquito borne diseases.
Leaflet: Mosquito bite avoidance for travellers
Use a good repellent containing N, N-diethylmetatoluamide (DEET) on exposed skin, together with light cover-up clothing. If you need sunscreen, apply repellent after sunscreen.
Zika has a possible association with congenital malformations. Travellers who are pregnant should consider avoiding travel to an area where active Zika transmission is being reported.
If travel is unavoidable, or they live in an area where active Zika transmission is being reported, they should take scrupulous measures to avoid mosquito bites during both daytime and night time hours (but especially during mid-morning and late afternoon to dusk, when the Aedes aegypti mosquito is most active).
Travellers who are planning to become pregnant, should discuss their travel plans with their healthcare provider to assess their risk of infection with Zika and receive advice on mosquito bite avoidance measures.
Up to date travel advice for countries reporting active Zika transmission is available from the National Travel Health
Network and Centre (NaTHNaC).
In areas affected by mosquito-borne diseases, control programmes rely on the elimination of mosquito breeding sites in the community by:
Almost all cases of Zika are acquired via mosquito bites.
A small number of cases of sexual transmission of Zika virus have been reported, and in a limited number of cases, the virus has been shown to be present in semen, although it is not yet known how long this can persist. The risk of sexual transmission of Zika virus is thought to be very low.
However, if a female partner is at risk of getting pregnant, or is already pregnant, condom use is advised for a male traveller:
Guidance for primary care
Guidance for primary care and clinicians has been jointly developed by PHE, Royal College of General Practitioners and the British Medical Association.
Zika virus infection: guidance for primary care
Zika and pregnancy
Interim algorithm for assessing pregnant women with a history of travel during pregnancy to areas with active Zika virus transmission.
Interim advice for health professionals
Zika virus briefing for midwives.
Women should be advised to avoid becoming pregnant while travelling in an area with active Zika virus transmission. On returning to the UK, they should avoid becoming pregnant for a further 28 days; this allows for a maximum 2-week incubation period (the time between exposure to an infection and the appearance of the first symptoms) and a 2-week viraemia (presence of virus in the bloodstream).
Diagnosis
Consider Zika virus infection among the differential diagnoses of patients with fever, or other symptoms suggestive of Zika virus infection, returning from countries with active Zika virus transmission (as listed above).
Clinicians should also consider in the differential diagnosis other travel-associated infections, including dengue and chikungunya virus infections, malaria, common infections not associated with travel, and non-infectious diseases.
Diagnostic testing is only indicated for a patient who
It is recommended that the following samples are obtained when testing is indicated:
RIPL provides medical and laboratory specialist services to the NHS and other healthcare providers for advice and diagnosis of a wide range of unusual bacterial and viral infections, including Zika virus infection.
This service is not available to the public.
Treatment
There is no specific antiviral treatment for Zika. Supportive nursing care and relief of symptoms are the standard treatment.
https://www.gov.uk/guidance/zika-virus
Zika virus
From
ublic Health England...
Last updated:10 February 2016,
...
Clinical advice on Zika: assessing pregnant women following travel; symptoms, transmission (includes sexual transmission), epidemiology.
Contents
- Countries with active Zika virus transmission
- Epidemiology
- Zika in the UK
- Symptoms
- Transmission
- Prevention and travel advice
- Guidance for primary care
- Zika and pregnancy
- Diagnosis
- Treatment
Zika is a mosquito-borne infection caused by Zika virus, a member of the genus flavivirus and family Flaviviridae. It was first isolated from a monkey in the Zika forest in Uganda in 1947.
- travel advice: see NaTHNaC current advice
- assessment of pregnant women following travel: see algorithm
- advice for those working in primary care: see primary care guidance
- deferral of blood donation: see NHS Blood and Transplant
- information for the public about Zika virus: see NHS Choices
- media enquiries: contact press office
As of 5 February 2016, PHE has defined countries with active Zika virus transmission as those with confirmed autochthonous (locally acquired) cases (vector borne transmission only) within the last 9 months. These are consistent with the list of countries provided by the European Centre for Disease Control (ECDC) and are:
- American Samoa
- Barbados
- Bolivia
- Brazil
- Cape Verde
- Colombia
- Costa Rica
- Cura?ao
- Dominican Republic
- Ecuador
- El Salvador
- Fiji
- French Guiana
- Guadeloupe
- Guatemala
- Guyana
- Haiti
- Honduras
- Jamaica
- Maldives
- Martinique
- Mexico
- New Caledonia
- Nicaragua
- Panama
- Paraguay
- Puerto Rico
- Saint Martin
- Samoa
- Solomon Islands
- Suriname
- Thailand
- Tonga
- US Virgin Islands
- Vanuatu
- Venezuela
Prior to 2015, Zika virus outbreaks occurred in areas of Africa, Southeast Asia, and the Pacific Islands.
As surveillance for Zika improves, further cases of Zika are expected to be reported in these regions and previously unaffected countries, particularly in south and central America and the Caribbean, where the Aedes mosquito vector is present.
Epidemiology
Zika virus was first discovered in Africa in the 1940s. The virus circulates in Africa and Asia in humans, animals and mosquitoes but prior to 2015 few outbreaks have been documented.
The first Zika outbreak reported outside Africa and Asia occurred on Yap Island in the Federated States of Micronesia in 2007. It was caused by the Asian strain of the virus. The same strain caused a subsequent outbreak in French Polynesia in 2013 and has since caused large outbreaks in other parts of the Pacific region including the first cases in the Americas on Easter Island (a Chilean island in the south east Pacific) in 2014.
In May 2015, the first locally-acquired confirmed case of Zika infection was reported in Brazil.
Zika in the UK
ZIKV does not occur naturally in the UK. However, as of 10 February 2016, a total of 7 cases have been diagnosed in UK travellers. [TABLE="width: 704, height: 1"]
[TR]
[/TR]
[TR]
[TD]Colombia[/TD]
[TD]-[/TD]
[TD]1[/TD]
[TD]2[/TD]
[TD]3[/TD]
[/TR]
[TR]
[TD]Cook Islands*[/TD]
[TD]1[/TD]
[TD]-[/TD]
[TD]-[/TD]
[TD]1[/TD]
[/TR]
[TR]
[TD]Cura?ao/Venezuela[/TD]
[TD]-[/TD]
[TD]-[/TD]
[TD]1[/TD]
[TD]1[/TD]
[/TR]
[TR]
[TD]Guyana/Suriname[/TD]
[TD]-[/TD]
[TD]1[/TD]
[TD]-[/TD]
[TD]1[/TD]
[/TR]
[TR]
[TD]Mexico/Venezuela[/TD]
[TD]-[/TD]
[TD]-[/TD]
[TD]1[/TD]
[TD]1[/TD]
[/TR]
[/TABLE]
* Not associated with current outbreak. Although cases have previously been reported in the Cook Islands, active transmission of Zika virus is not known to be ongoing.
Symptoms
The majority of people infected with Zika virus have no symptoms. For those with symptoms, Zika virus tends to cause a mild, short-lived (2 to 7 days) febrile disease. Typical symptoms include:
- a low-grade fever
- joint pain (with possible swelling mainly in the smaller joints of the hands and feet)
- rash, sometimes itchy
- conjunctivitis/red eyes
- headache
- muscle pain
- eye pain
Serious complications and deaths from Zika are not common. However, recent increases in congenital anomalies (particularly microcephaly), Guillain-Barr? syndrome, and other neurological and autoimmune syndromes are being reported in areas where Zika outbreaks have occurred. The association of these illnesses with Zika virus is temporal and causality has yet to be proven, however evidence is accumulating. Further information about these findings is available from WHO.
Following an International Health Regulations (IHR) Emergency Committee (EC) meeting on 1 February 2016, it was declared that the recent cluster of microcephaly cases and other neurological disorders reported in Brazil, following a similar cluster in French Polynesia in 2014, constitutes a Public Health Emergency of International Concern (PHEIC).
In the absence of another explanation for these clusters, it was advised by the Emergency Committee (EC) that these clusters were possibly associated with the recent outbreaks of Zika virus. The World Health Organization (WHO) has issued temporary recommendations which include: improved surveillance and control of Zika in at risk countries, and measures for travellers and pregnant women.
Transmission
Zika virus is transmitted by the bite of an infected female Aedes mosquito, most commonly Aedes aegypti. Other species of Aedes mosquitoes may also have the potential to transmit this virus. The Aedes aegypti mosquito is not present in the UK and is unlikely to establish in the near future as the UK temperature is not consistently high enough for it to breed.
After an infected mosquito bites a human, the first symptoms of Zika can develop in 3 to 12 days but it can be shorter or longer in some people.
While almost all cases of Zika are acquired via mosquito bites, a small number of cases have occurred through sexual transmission, and there is increasing evidence of transmission from mother to fetus via the placenta.
Transmission of Zika via blood transfusion has been suspected in a small number of cases, and a study during the outbreak in French Polynesia detected Zika virus in 3% of blood donors who were asymptomatic at the time of donation. Measures to safeguard the UK blood supply are being implemented from 4 February 2016.
If a person acquires Zika abroad and becomes ill on their return to the UK, any public health risk to the wider population is negligible, as the mosquito that transmits the virus is not found in the UK.
Prevention and travel advice
There is currently no vaccine or drug to prevent Zika infection.
Aedes mosquitoes transmit Zika, as well as diseases such as chikungunya, dengue, and yellow fever. Aedes mosquitoes predominantly bite during the day, but especially during mid-morning and late afternoon to dusk (as opposed to mosquitoes that transmit malaria, which bite at night between dusk and dawn).
Travellers to regions where these diseases occur need to take insect bite avoidance measures during daytime and nighttime hours, to reduce the risk of infection with Zika and other mosquito borne diseases.
Leaflet: Mosquito bite avoidance for travellers
Use a good repellent containing N, N-diethylmetatoluamide (DEET) on exposed skin, together with light cover-up clothing. If you need sunscreen, apply repellent after sunscreen.
Zika has a possible association with congenital malformations. Travellers who are pregnant should consider avoiding travel to an area where active Zika transmission is being reported.
If travel is unavoidable, or they live in an area where active Zika transmission is being reported, they should take scrupulous measures to avoid mosquito bites during both daytime and night time hours (but especially during mid-morning and late afternoon to dusk, when the Aedes aegypti mosquito is most active).
Travellers who are planning to become pregnant, should discuss their travel plans with their healthcare provider to assess their risk of infection with Zika and receive advice on mosquito bite avoidance measures.
Up to date travel advice for countries reporting active Zika transmission is available from the National Travel Health
Network and Centre (NaTHNaC).
In areas affected by mosquito-borne diseases, control programmes rely on the elimination of mosquito breeding sites in the community by:
- regular inspections
- spraying insecticide (particularly during an outbreak)
- educating local residents to regularly empty standing water and
- keeping outside areas free from waste items that can collect standing water
Almost all cases of Zika are acquired via mosquito bites.
A small number of cases of sexual transmission of Zika virus have been reported, and in a limited number of cases, the virus has been shown to be present in semen, although it is not yet known how long this can persist. The risk of sexual transmission of Zika virus is thought to be very low.
However, if a female partner is at risk of getting pregnant, or is already pregnant, condom use is advised for a male traveller:
- for 28 days after his return from an active Zika transmission area if he has not had any symptoms compatible with Zika virus infection
- for 6 months following recovery if a clinical illness compatible with Zika virus infection or laboratory confirmed Zika virus infection was reported
Guidance for primary care
Guidance for primary care and clinicians has been jointly developed by PHE, Royal College of General Practitioners and the British Medical Association.
Zika virus infection: guidance for primary care
Zika and pregnancy
Interim algorithm for assessing pregnant women with a history of travel during pregnancy to areas with active Zika virus transmission.
Interim advice for health professionals
Zika virus briefing for midwives.
Women should be advised to avoid becoming pregnant while travelling in an area with active Zika virus transmission. On returning to the UK, they should avoid becoming pregnant for a further 28 days; this allows for a maximum 2-week incubation period (the time between exposure to an infection and the appearance of the first symptoms) and a 2-week viraemia (presence of virus in the bloodstream).
Diagnosis
Consider Zika virus infection among the differential diagnoses of patients with fever, or other symptoms suggestive of Zika virus infection, returning from countries with active Zika virus transmission (as listed above).
Clinicians should also consider in the differential diagnosis other travel-associated infections, including dengue and chikungunya virus infections, malaria, common infections not associated with travel, and non-infectious diseases.
Diagnostic testing is only indicated for a patient who
- has travelled to or arrived from an area with active Zika virus transmission and
- within 2 weeks of return to the UK, presents with active symptoms at the time of assessment
It is recommended that the following samples are obtained when testing is indicated:
- non-pregnant patients: clotted ‘red top’ (plain) or ‘yellow top’ (serum separator) blood, and EDTA ‘purple top’ blood
- pregnant patients: clotted ‘red top’ (plain) or ‘yellow top’ (serum separator) blood, EDTA ‘purple top’ blood, and a small volume of urine without preservative
RIPL provides medical and laboratory specialist services to the NHS and other healthcare providers for advice and diagnosis of a wide range of unusual bacterial and viral infections, including Zika virus infection.
This service is not available to the public.
Treatment
There is no specific antiviral treatment for Zika. Supportive nursing care and relief of symptoms are the standard treatment.
https://www.gov.uk/guidance/zika-virus