Flooded areas are now faced with a second wallop of mold, mosquitoes

(Republished with permission from the St. Louis Post-Dispatch. This article originally ran in the Health & Fitness section on Monday, July 21, 2008)

By Dr. Indi Trehanand and Dr. H. James Wedner

The waters are receding, but the consequences of flooding in surrounding areas are only beginning to surface. These consequences are not just in physical and financial damage, but major indoor and outdoor health threats to children and their families.

A major outdoor health risk involves standing water, which serves as an excellent breeding ground for mosquitoes. Mosquitoes spread diseases such as West Nile virus to people.

Although no human cases of West Nile virus have been reported this year in Missouri or Illinois (as of mid-July), there have been instances in mosquitoes. This emphasizes the importance of protecting yourself and your family from West Nile virus and other mosquito-borne infections like California encephalitis, St. Louis encephalitis and western equine encephalitis.

The Centers for Disease Control and Prevention and local health departments recommend the following tips for limiting the spread of mosquito-borne infections:


Wear long-sleeve shirts, long pants and light colors when outdoors as much as possible when it’s not too hot, especially around dawn, dusk and early evening hours when mosquitoes bite the most. Place mosquito netting over infant carriers and strollers when you are outdoors with infants.


Products containing permethrin can be used on clothing and shoes but should not be used directly on skin. Products containing DEET are most effective for direct use on skin. Those products with a higher concentration of DEET will generally provide longer protection but there does not seem to be any benefit to concentrations above 50 percent. Apply DEET-containing repellents to exposed skin but avoid cuts, wounds or irritated skin. Do not spray directly onto the face, but instead spray on hands and apply sparingly to the face and around the ears. Do not apply to the eyes or mouth. Use just enough to lightly cover the skin and be sure to wash with soap and water after returning indoors.


At least once a week, drain standing water from garbage cans, flower pots, buckets, rain gutters, wading pools, toys, bird baths and tires. Look for “mosquito dunks” at home and garden stores to place in ponds or bird baths to prevent mosquitoes from breeding in these settings.


Help keep mosquitoes out of your home by installing or repairing screens in doorways and windows.


After the water recedes, the inside of damp homes and buildings are fertile ground for mold growth, which can cause allergic reactions and asthmatic symptoms in sensitive people.

Mold loves water. When a home or business is flooded, it can be difficult to dry it out quickly and completely, allowing mold a perfect place to grow. Drywall can also soak up water far above the water line and mold can hide under wallpaper, carpets and floorboards and in ceiling tiles, furniture and clothing.

Molds (and mildew, a type of mold) are fungi, which reproduce by releasing spores. Inhaling the spores can cause allergic reactions in some people. Symptoms of mold allergy include itchy, watery eyes; itchy, runny nose; headaches above and below the eyes; itchy ears and changes in hearing; itchy throat and palate; difficulty breathing; coughing; and shortness of breath. Mold spores also may trigger asthmatic reactions in people with asthma.

For those dealing with a flooded home or office, here are a few tips:

  • Dry things out quickly. Mold will grow almost immediately in wet conditions.
  • Cool it down. Mold likes warmth as well as humidity.
  • Remove wet materials. Wet drywall cannot be repaired and should be removed and replaced.
  • Clean anything that has been wet including clothing, which should be drycleaned. Throw away anything that cannot be thoroughly cleaned.
  • Consider hiring a professional to clean affected areas of the building with appropriate materials — often a solution of 10 percent bleach is used to disinfect areas.
  • If an allergist confirms that health symptoms stem from a reaction to mold, effective medical treatments include medications, which may include antihistamines or steroids. If necessary, immunotherapy, often known as “allergy shots” can allow your immune system to build up a tolerance to allergens, such as mold. But it is always important to make sure that the source of the reaction — the mold itself — is removed as soon as possible for the health of families in and around flood-affected areas.

Dr. Indi Trehan treats pediatric infectious diseases at St. Louis Children’s Hospital, and Dr. H. James Wedner is chief of the division of allergy and immunology at Washington University School of Medicine.

Copyright 2008 St. Louis Post-Dispatch, Inc.