Bed bugs in France

Bed bugs have been making headlines in France due to numerous infestation cases, although they do not present a real danger to human health. They are found in furniture, carpets, and suitcases around the world.

Mosquitoes as a health threat

According to Molly Keck, an entomologist specializing in parasite control at Texas A&M AgriLife, "the most deadly animal in the world is the mosquito." Insects can carry pathogens such as bacteria, nematodes, protozoa, and viruses that can transmit to humans diseases that are difficult to diagnose.

Symptoms and diagnosis

Many of these conditions, such as dengue and Lyme disease, can begin with vague symptoms such as headaches, fatigue or fever, and the marks of bites or bites are not always apparent. These symptoms can make diagnosis difficult, especially in travelers unfamiliar with the local diseases.

Local treatment for travelers

When you fall ill while traveling, it is understandable to want to return home immediately to get treatment. However, according to William Spangler, an emergency physician and global medical director of the insurance company AIG Travel, "it is probably preferable to be treated locally, where health professionals know the endemic disease and know how to treat it."

Preparation before travel

Before traveling, consider visiting a travel medicine clinic, which will be able to recommend appropriate medications and vaccines for the different risks of your destination. In the meantime, here are some tips to help you avoid some of the most common parasites in the world.

Avoiding bed bugs

Bed bugs, species Cimex lectularius (common bed bug) and Cimex hemipterus (tropical bed bug), are found in furniture, carpets and suitcases around the world. Although they can carry viruses, bed bugs rarely transmit pathogens to humans.

Symptoms of bed bug bites

Their bites are painless; the itchy bumps are actually an allergic reaction that can appear up to nine days after the bite. "The bites can only be treated with antihistamines, and the relief will be limited," states Spangler.

Preventing bed bug infestations

To avoid bringing bed bugs home, place your bags in the hotel bathtub, where they cannot climb, and inspect the bed by pulling up the sheets and mattress cover. If you see bed bugs the size of an apple seed, brownish in color, pale yellow eggs or blood spots, "ask for another room that is not in contact with the one where you are staying."

Travelers' precautions

Bed bugs prefer fabric luggage over plastic or metal ones, and it is easier to spot them on light colors if you search with your phone's flashlight. If the temperature is low when you return home, store your suitcase outside for 80 hours if the temperature is below 0°C, or wash your clothes in hot water and dry them in a high-temperature dryer.

Mosquitoes and their diseases

Mosquitoes of the genus Aedes transmit chikungunya, dengue, yellow fever and the Zika virus; those of the genus Culex cause West Nile fever; and those of the genus Anopheles spread malaria. They are found everywhere in the world, except Iceland and Antarctica.

Mosquito-borne diseases

"Mosquito-borne diseases kill about a million people worldwide each year," reveals Spangler. These insects are responsible for 200 million cases of malaria annually, with about 625,000 deaths, and 100 to 400 million cases of dengue, with about 40,000 deaths.

Dengue and climate change

Although 80% of dengue infections are asymptomatic, this disease is sometimes called "breakbone fever" due to the particularly intense pain it can cause. The people most affected are those living in countries where mosquitoes carry diseases, but travelers are not immune either.

Expanding mosquito territories

Climate change is also expanding the territory of mosquitoes: although metropolitan France is not affected so far, the United States, for example, experienced locally acquired malaria cases in 2023. The World Health Organization (WHO) warns that this decade, dengue will become a major threat in more regions of Europe and the United States.

Vaccines and prevention

A second malaria vaccine has also been approved by the WHO at the beginning of October: this one, as well as a limited-use dengue vaccine, are promising for the future of the fight against these diseases. However, the most effective remains to do everything possible to avoid being bitten.

Preventing mosquito bites

To do this, use an insect repellent containing picaridin or DEET and wear long pants and sleeves, ideally treated with permethrin. Sleep with a mosquito net, but know that new research is challenging old theories according to which malaria-causing mosquitoes only bite at night.

New research on mosquito behavior

A study conducted in 2022 showed that 20 to 30% of Anopheles mosquito bites occur during the day. This means that prevention measures should be taken throughout the day, not just at night.

Tiny biting flies

Approximately 4,000 species of the family Ceratopogonidae are found around the world, especially near coasts, lakes and rivers, except the Antarctic and Arctic regions. These insects, which can measure 0.8 to 3 millimeters, are a type of fly known by several names depending on the regions of the world.

Biting flies and their impact

These insects are annoying, but relatively harmless (although they can spread rare diseases such as Oropouche fever in French Guiana, Central America and South America). Keck notes that "the real [Ceratopogonidae] are actually very easy to recognize, because their bite is painful."

Protecting against biting flies

Some people have an even more painful allergic reaction, which is generally characterized by redness and itching. Insecticides, even if they contain DEET, offer only limited protection. To protect yourself from bites, wear long sleeves and pants (even more effective if you tuck them into your socks). Hats with fine mesh can also protect your face.

Ticks and their habitats

Ixodidae (hard ticks) and Argasidae (soft ticks) are found in grassy and brushy areas, even in cities, on all continents except Antarctica, and in all American states except Alaska. These eight-legged arthropods are technically arachnids.

Tick behavior and bites

Ticks cannot fly or jump, but some wait at the ends of shrubs on frequented paths to climb onto people (or pets) who pass nearby. When they feed, ticks attach by planting a barbed harpoon into the skin of their host. It is therefore difficult to remove them, and they sometimes need a day or two to finish their meal.

Tick-borne diseases

Tick bites, generally painless, often go unnoticed or are mistaken for mosquito bites. "Various species of ticks carry different infectious pathogens," explains Lin H. Chen, president of the International Society of Travel Medicine.

Lyme disease in France

Each year, approximately 25,000 to 68,000 cases of Lyme disease (or Lyme borreliosis) are diagnosed in France; and the annual incidence rate has been increasing since 2009. Ticks can also transmit less common diseases, such as Crimean-Congo hemorrhagic fever, rickettsioses or tick-borne encephalitis.

Preventing tick bites

Travelers wishing to engage in many outdoor activities in Europe and Asia are more exposed to the risk of tick-borne encephalitis and can therefore consider getting vaccinated. "A number of repellents with some effectiveness are available for purchase," states Spangler, "but in areas particularly prone to ticks, it is recommended to minimize skin exposure as much as possible."

Post-exposure precautions

By wearing good shoes, long pants and long sleeves. If you return from a walk near tall grass or other foliage, inspect your entire body for ticks. It is possible to spot one on your clothes (or even on your skin) before they attach. Taking a shower within two hours of your outing can also help eliminate ticks that have not yet attached.

Parasitic worms and infections

Schistosomes (Schistosoma) and hookworms (Ancylostoma duodenale and Necator americanus) are found in tropical and subtropical countries, especially where sanitary conditions are poor, including on beaches where dogs and cats roam freely.

Avoiding parasitic infections

Although cases of infection by parasitic worms are rare among travelers, it is still important to do everything possible to avoid them. Symptoms can be minor (stomach pain) or severe (epileptic seizures). The worms or their eggs can, for example, be ingested during meals, especially in undercooked meat or unwashed vegetables.

Environmental exposure risks

This can lead to trichinosis (caused by roundworms), a cestode infection, or even impressive cases such as that of a live worm removed from a patient's brain in Australia. Children are also likely to spread oxyuriasis, especially if they do not wash their hands properly after using the toilet.

Precautions against worm infections

When traveling, be mindful of "environmental exposures, such as when you wade in fresh water" that presents "potential risks of schistosomiasis and leptospirosis," and when you walk barefoot on contaminated soil and sand with hookworms or strongyloides, explains Chen.

Global impact of parasitic diseases

Worldwide, approximately 230 million people are affected by schistosomiasis (also known as bilharziasis) and 200,000 people die from it each year, mainly, but not exclusively, in Africa. According to the CDC, the only parasitic disease more devastating than schistosomiasis is malaria.

Preventing worm infections

Schistosomes reproduce in freshwater snails, found to date in 78 countries, and spread mainly through the urine or feces of infected individuals. The parasite can survive for 48 hours after leaving the snail and can penetrate human skin when it comes into contact with contaminated water.

Foot hygiene and prevention

Poor hygiene conditions can also favor infections by the plant of the feet, especially through the soil and sand where cats and dogs defecate. Keeping shoes on is the best way to avoid worm larvae such as hookworms and trichinella, as well as the lesions, diarrhea, anemia and rectal prolapse they can cause.

Treatment for parasitic infections

Prescribed medications are effective in the fight against many worms, provided the diagnosis is correct.