The Mom’s Guide to Mosquitoes

With Zika, West Nile and other mosquito-borne illnesses dominating headlines around the world, fear and worry about the tiny creatures has grown. We asked Stanford Medicine Children’s Health doctors and local public health experts to share what pregnant women and parents really need to know about these diseases and if they had any tips for how parents can keep their families safe this summer.

Dr. George Han, Deputy Health Officer and Communicable Disease Controller, Santa Clara County, California

If I am a pregnant woman living in the United States, specifically the Bay Area, and I have not visited a Zika-impacted country, should I be worried about contracting the disease?

Your risk of getting Zika in the Bay Area is very low. In the summer months, mosquitoes that carry Zika (Aedes aegypti and Aedes albopictus) may come into the area, so it’s always a good idea to protect yourself from mosquito bites. (See below if your partner has traveled to a country with Zika.)

If I am pregnant and my partner has visited a Zika-impacted country, should I be worried about contracting Zika sexually?

Since Zika can be sexually transmitted, if your partner has traveled to a country with Zika and has shown symptoms of the disease, you should use condoms or abstain from sex for the duration of your pregnancy.

Should I get tested just to be sure?

Testing is only recommended if you have traveled to a country with Zika transmission or if your partner traveled to a country with Zika and has symptoms.

Are there other ways I can contract Zika?

Currently, the only known way to get Zika is through a bite from an infected mosquito and through sexual contact with someone who was bitten and has symptoms. Babies can get it from their moms before or during birth if their moms are infected.

Are certain types of mosquitoes more likely to bite pregnant woman?

No, pregnant women are not more likely to get bitten by certain mosquitos.

I live in San Jose, California. Do I really need to use bug repellent and wear long sleeves in the summer?

We recommend these precautions because it will not only protect you from Zika but can also protect you from other mosquito-borne diseases such as West Nile. (See below for other mosquito-protection recommendations.

Jagdip Powar, MD, OB/GYN, Women’s Health — Palo Alto, Stanford Medicine Children’s Health

What symptoms of mosquito-borne illnesses should a pregnant woman be aware of?

Common symptoms of mosquito-borne illness are a fever, flulike symptoms, a rash, joint and muscle pains, redness of the eyes, night sweats, headaches, confusion, muscle weakness and, in severe cases, seizures. Each disease has specific symptoms of its own, but many of the above symptoms are shared among the Zika virus, chikungunya virus, dengue fever, malaria, encephalitis and West Nile virus.

Is a repellent with DEET safe to use during my pregnancy? What brands do you recommend?

DEET is considered safe for use during pregnancy. Recommended products are Off! Deep Woods 8, Repel 100 and Sawyer Premium. Sawyer Picaridin, which contains picaridin, is also known to be effective as a mosquito repellent and is considered safe for use by pregnant women. Natural products containing citronella, cedar, peppermint, lemongrass and geranium may also be helpful to some extent. Consult the Environmental Protection Agency for a list of registered insect repellents with one of the following active ingredients: DEET, picaridin, IR3535 or oil of lemon eucalyptus (also known aspara-menthane-3,8-diol). A repellent that is EPA registered has been evaluated by the EPA for effectiveness. When used as directed, EPA-registered insect repellents are proven safe and effective, even for pregnant and breast-feeding moms.

Are there certain foods I should eat to avoid mosquito bites?

Garlic has been shown to repel mosquitoes, so if a pregnant patient does not mind smelling like an Italian restaurant, consuming garlic every day should help. Other foods that may help keep mosquitoes at bay are blueberries, apples, watermelons, cucumbers, cabbage and green peppers. On the flip side, it is important to avoid foods that are rich in salt and potassium. Also, cutting out all intake of alcohol will help prevent mosquito bites.

I’ve heard that vitamin B-1 repels mosquitoes; is this true?

Vitamin B-1 was thought to help prevent mosquito bites, but subsequent studies have not substantiated the claim. The consensus at this time is that it does not help.

Angelle Desiree LaBeaud , MD, Associate Professor of Pediatrics (Infectious Diseases) at Lucile Packard Children’s Hospital

Are mosquito-borne illnesses a danger to young children, or just to babies in utero?

Infections that are transmitted by mosquitoes can affect people of all ages. Some, such as dengue virus, are known to cause more severe illness in very young children. Others, like West Nile virus, tend to cause milder illness in children but more severe illness in adults. For many of these infections, we still need to do more research in order to learn how they affect different people, including children of different ages.

Every summer there is news in my town about the West Nile virus. Is West Nile a danger to pregnant women and children?

West Nile virus can infect people of all ages. Most people who are infected do not develop symptoms and are not even aware that they have been infected. The most commonly reported symptom is fever. However, West Nile can affect the brain and the nervous system, which can be fatal, particularly in the elderly. Pregnant women can be infected, but transmission to the fetus is rare, so we do not know whether West Nile affects the development of the fetus. Children infected with West Nile develop brain and nervous system disease less frequently than older adults.

Are there other mosquito-borne illnesses I should be aware of?

Mosquitoes transmit numerous infections around the world, including some of the viruses that we have been talking about, but they also transmit parasites like malaria. It is important to talk to your doctor before traveling so that you are aware of the types of infections that may be common in the part of the world where you’re going and can take precautions to prevent getting bitten. West Nile virus is transmitted throughout most of the United States, but another important virus that is spreading quickly throughout Latin America and the Caribbean is the chikungunya virus. This virus causes fever and debilitating arthritis that can last for years.

Is it safe to use repellent with DEET on my children?

Yes, DEET is very effective at repelling mosquitoes. DEET is safe to use on children and for moms breast-feeding their babies.. Look for repellents that contain at least 30 percent DEET; the higher the percentage, the longer it lasts. Thirty percent lasts about six hours. Make sure to follow the manufacturer’s directions and wash it off before bed. Because children often put their hands in their mouths or eyes, adults should apply repellent for them onto exposed areas of skin, avoiding the hands. In general, insect repellents should not be used on infants younger than 2 months old. Young infants can be protected from mosquito bites by draping mosquito netting over their carriers.

Denise Bonilla, Vector Control District Manager, Santa Clara County, California

I read that mosquitoes can breed in very little water. I have a bird bath and an inflatable play pool in my yard. Should I take them down?

There’s no need to take down bird baths or pools, but anything that holds water in your yard should either be dumped or drained weekly.

Does putting apple cider vinegar in standing water keep mosquitoes away?

It might, but dumping or draining standing water is a much better option. Mosquitofish can eat larval mosquitoes in permanent bodies of water like ornamental ponds and neglected pools. These fish can be requested from your local mosquito control agency.

What else can I do in my home and yard to keep mosquitoes away?

Turn pots and their saucers over, clear the yard of things that hold water, and dump and drain standing water weekly. Make sure you don’t have holes in your house’s doors and screens. If you are out at dusk or dawn, wear mosquito repellent.

Can animals get Zika and other vector illnesses?

There is no evidence right now that pets get Zika.