Insect spread illness reminder for pregnant travellers

Information and advice for pregnant women planning travel to countries with a risk of insect, mosquito and tick spread infections

A rise in insect, midge, mosquito and tick spread illnesses has been reported in many tropical and sub-tropical countries [1-3]. Catching a mosquito or insect spread infection abroad in pregnancy can put you at risk of serious illness and could cause complications for you and your unborn baby.

Taking precautions to avoid insect, mosquito and tick bites during the day and at night throughout your trip (including at airports) helps reduce your risk. Taking malaria prevention tablets (known as antimalarials), if recommended, helps protect both you and your baby.

While most travel is generally trouble free, any insect spread infection can be an issue in pregnancy. There are a number of infections we are particularly concerned about during travel for pregnant women, including malaria and Zika.

Malaria - is a parasitic infection spread by night biting mosquitoes and is a risk in many tropical countries. Malaria infection in pregnancy can cause severe illness, miscarriage and may increases your risk of dying of malaria.

Ideally, you should avoid visiting any malaria areas when you are pregnant, but if you have to travel, there are antimalarial tablets that are safe to take in pregnancy. It is very important you take the appropriate antimalarial tablets and know how to reduce your risk of infection by following good bite avoidance advice [4].

Zika - a virus spread by day-biting mosquitoes which is a risk in many tropical countries [5]. It usually causes a mild illness. However, Zika infection in pregnancy is linked to birth defects, including issues with brain development, small head size (microcephaly), hearing loss, eye problems and feeding difficulties [6].

Dengue - is a mosquito spread virus found in many tropical and sub-tropical countries, with outbreaks also reported in Europe [1]. Mosquitoes carrying dengue usually breed in urban areas and mostly bite during the day. Although dengue can cause a very unpleasant feverish illness, most people fully recover. However, a life-threatening complication called severe dengue can occur, and pregnancy increases the risk of this developing.

A live dengue vaccine, called Qdenga® is licensed in the UK, but this vaccine is not suitable for pregnant women. Please see our news item: Qdenga® dengue vaccine guidance for more information.

Oropouche virus disease - is spread mainly by midges, and occasionally mosquitoes, that bite around dawn and dusk in some tropical countries. It is not a risk in Europe. Infection can cause fever, chills, headache, joint pain, muscle aches, nausea, vomiting, rash, light sensitivity, dizziness and pain behind the eyes. Symptoms can reoccur, although most people will eventually fully recover.

ln 2024, possible mother-to-child transmission of this virus in pregnancy was reported in Brazil. This is currently under investigation [7, 8] and research is ongoing about Oropouche infection risk in pregnancy. Information will be updated once it becomes available [3, 7].

There are no vaccines or medicines to prevent infection with Oropouche virus. Infection can be avoided by not visiting countries reporting Oropouche outbreaks. If travel in pregnancy is unavoidable, risk can be reduced by following bite avoidance measures when visiting areas reporting this infection.

You can find more advice about insect, mosquito and tick spread infections at your destination in our: Country Information pages and Outbreak Surveillance section.

Advice for travellers

Before you go

If you are pregnant or planning a pregnancy, discuss your travel plans with your midwife and, if appropriate, your specialist doctor (obstetrician).

Book an appointment with your practice nurse, pharmacist or travel clinic (ideally four to six weeks before your trip) to discuss your travel plans.

Check your malaria risk with your health provider - if malaria is a risk at your destination, ask if you need antimalarials. Pregnant women are more susceptible to mosquito bites and so more at risk of malaria.

If you catch malaria when you are pregnant, you are more at risk of serious complications and possibly even death. You are also at increased risk of losing your baby (by miscarriage or stillbirth) and your baby could be born very underweight [4].

If your travel is essential, follow the 'ABCD' of malaria prevention:

• Awareness of risk
• Bite prevention
• Chemoprophylaxis (antimalarial tablets)
• Diagnose promptly and treat without delay [4]

As well as being aware of any insect spread risks at your destination, it is important to make sure you have all the recommended vaccines and are aware of other possible hazards.

You can find more information in our pregnancy factsheet.

If you are travelling at short notice, it's still very important to get advice; some vaccines can be given last minute, and malaria tablets (if needed) can be started on the day you travel.

If you are pregnant and planning to travel to a country with a Zika outbreak, you should discuss the suitability of travel and the potential risk that Zika virus may present at your destination with your health care provider.

Please see our Zika risk assessment for more information.

If you have to travel, make sure you are aware of all the current recommendations about Zika and check our website for country-specific advice and the outbreak surveillance database for current Zika outbreaks in the country you are visiting.

There is specific advice if you are travelling with a male partner, as sexual transmission of Zika is a risk.

The UK Health Security Agency has information about Zika and pregnancy, but discussing Zika with a travel health professional will help you understand your risks.

While you are away

Some vaccines may not be suitable in pregnancy or as effective. There are no vaccines or medicines to prevent many insect spread infections, such as Zika or Oropouche virus. The only way to try to prevent infection is avoid bites from insects, midges and mosquitoes as much as possible:

• Follow insect bite prevention advice carefully both during the day and at night; 50% DEET insect repellents are safe in pregnancy [9].
• Wearing protective clothes and sleeping under an insecticide treated mosquito net helps reduce your risk of insect and mosquito bites.
• If you have been prescribed antimalarial tablets, remember to take them as advised.
• Get urgent medical help from a local health professional if you have a fever, chills, flu-like symptoms or a rash while you are abroad.

Diagnosing falciparum malaria in pregnancy can be difficult, as malaria parasites may not be easy to see in blood samples via a microscope. This is because red blood cells infected with malaria parasites stick to blood vessels in the placenta, making them harder to spot.

When you return

If you are prescribed antimalarial tablets, remember to finish the course when you get home, even if you feel fine.

Get urgent medical advice if you have any symptoms such as fever, chills, headache, a rash or joint/muscle pain after travel abroad. This is especially important if you visited a country with a risk of malaria (even if you took antimalarials).

Remember to tell the health professional that you have travelled abroad and make sure you let them know all the countries you visited.

If you have visited a Zika risk area while pregnant, you should see your midwife or GP for advice when you return. This is even if you feel completely well and have not had any symptoms, as sometimes Zika infection can be very mild with no symptoms. They will advise if you need any assessments after your trip.

See the UK Health Security Agency's Zika virus: advice for women returning from areas with active transmission for more information.