Prevention of mosquito and tick-borne diseases
Summer has arrived, and with it, countless possibilities for outdoor fun, whether we are going on vacation to the mountains, the seaside, or the delta, or simply enjoying a walk in the park or relaxing in the backyard. However, high temperatures are also a favorable time for the appearance of mosquitoes and ticks that can spoil these plans. In the rest of the article, you will learn about the main diseases transmitted by them, the symptoms and appropriate treatments, what the first aid is for insect bites, and how we can prevent them so we can enjoy a carefree summer.
Both mosquitoes and ticks are hematophagous insects. They ingest microorganisms responsible for diseases during a blood meal from an infected host (human or animal), which they then transmit to a new host after the pathogen has replicated. Once the insects have become infectious, they can transmit the pathogen for the rest of their lives during every new sting/bite. (*** (National Institute of Public Health), 2024)
Table of Contents
- General information about mosquitoes
- Diseases caused by mosquito bites – symptoms and treatment
- What to do in case of mosquito bites?
- How to prevent mosquito bites?
- General information about ticks
- Diseases caused by tick bites – symptoms and treatment
- What to do in case of tick bites?
- How to prevent tick bites?
- Bibliography
General information about mosquitoes
Mosquitoes (Culicidae) are dipterous insects present on all continents except Antarctica. There are three genera of clinical significance responsible for biting humans: Anopheles, Culex, and Aedes. (Mosquito Bites, 2021)
They are usually found near stagnant water, as these are favorable for completing their life cycle. Reproduction occurs through eggs with complete metamorphosis: egg→larva→pupa→adult, and incomplete: egg→larva→adult. Mosquitoes lay their eggs on the water surface. The male consumes plant juice and nectar, while the female feeds on the blood of mammals, birds, and humans, as she needs food for egg production. (Walrond, 2007)
The European Centre for Disease Prevention and Control (ECDC) has warned of an increased risk of mosquito-borne diseases in Europe. (***, Increasing risk of mosquito-borne diseases in EU/EEA following spread of Aedes species, 2023) Global warming caused by climate change favors the emergence of certain mosquito species responsible for spreading malaria and dengue fever in Europe. "Climate change-related droughts and floods can lead to greater virus transmission, with stored water providing additional mosquito breeding sites." – Professor Rachel Lowe (Barcelona Supercomputing Center) (Horton, 2024)
Diseases caused by mosquito bites – symptoms and treatment
In Europe, the 4 diseases that can be caused to humans by mosquito bites are infections with West Nile virus, Zika, Dengue (Dengue fever), and Chikungunya (Chikungunya fever). The West Nile virus is spread by mosquitoes of the Culex species, while the other infections are caused by Aedes species. Malaria and yellow fever are much more common in tropical parts of the world, being transmitted by the Anopheles mosquito in the first case and the Aedes aegypti mosquito in the second. (Mosquito Bites, 2021)
The reaction that appears after the sting is largely caused by toxins in the mosquito's saliva, which enter the human bloodstream. These have vasodilatory, anticoagulant, and antiplatelet properties. The result is the appearance of a pruritic papule. The mosquito becomes a vector for virus transmission after feeding on the blood of an infected animal or person, which it then transmits through its saliva. (Mosquito Bites, 2021)
| West Nile virus infection 1, 2 | Zika virus infection 3, 4 | Dengue virus infection (Dengue fever) 5, 6 | Chikungunya virus infection (Chikungunya fever) 7, 8 | |
| Symptoms | • No symptoms or: • Fever • Headache, muscle and joint pain • Nausea and vomiting • Swollen lymph nodes • Diarrhea • Pain behind the eyes • Sore throat • Skin rash (usually on the chest and back) • Requires urgent medical attention and hospitalization: high fever over 39.5°C, severe headache, stiff neck, muscle weakness, confusion, disorientation, seizures, paralysis • Serious complications: meningitis and encephalitis. In the worst case: coma |
• No symptoms or: • Mild fever • Headache, joint and muscle pain • Skin rashes • Conjunctivitis • If a pregnant person is infected: congenital abnormalities, including microcephaly or fetal death |
• No symptoms or: • Mild symptoms (cold-like) or severe: high fever (40°C), headache, muscle and joint pain, nausea, vomiting, pain behind the eyes, swollen glands, skin rashes • Severe form (Dengue hemorrhagic fever) can be lethal and requires hospitalization |
• High fever with sudden onset • Joint pain • Headache and muscle pain • Skin rashes • Fatigue Nausea • Red eyes • Joint swelling The disease is self-limiting, but joint pain can persist for a longer period • Complications are rare, but if they occur, they include damage to the eyes, heart, and nerves. |
| Incubation period | 2-6 days (sometimes up to 14 days) after the bite | 3-12 days after the bite. It is also transmitted sexually. | 4-10 days after the bite | 2-7 days after the bite |
| Treatment | • Symptomatic (avoid anti-inflammatories which can increase the risk of bleeding until Dengue virus infection is ruled out) • In case of severe neurological symptoms, these will be treated in the hospital by administering anticonvulsants, corticosteroids, intravenous fluids, oxygen |
• Symptomatic (avoid anti-inflammatories which can increase the risk of bleeding until Dengue virus infection is ruled out) • Rest and hydration |
• Symptomatic (avoid anti-inflammatories which can increase the risk of bleeding) and hydration • In severe cases, hospitalization with intravenous treatment and blood transfusions is necessary |
• Symptomatic (avoid anti-inflammatories which can increase the risk of bleeding until Dengue virus infection is ruled out) |
2 (***, West Nile Virus, 2023)
3 (Poland, Ovsyannikova, & Kennedy, 2019)
4 (***, Treatment of Zika, 2024)
5 (***, Dengue fever – symptoms&causes, 2022)
6 (***, Dengue fever – Diagnosis & treatment, 2022)
7 (Pritish K. Tosh, 2023)
8 (Symptoms, Diagnosis, & Treatment | Chikungunya Virus , 2024)
What to do in case of mosquito bites?
There are certain factors that can make mosquito bites more frequent: dark-colored clothing, perfume, body temperature, blood type, visiting regions with active diseases transmitted by them, time spent near stagnant water. (***, Mosquito Bites, 2021)
In case of a mosquito bite, it is recommended to wash the area with soap and water, and apply an ice pack for a few minutes to reduce swelling and itching. You can subsequently apply an antihistamine cream/gel, aloe vera, chamomile tea, or honey; in case of more intense allergic reactions, an oral antihistamine can be administered. Avoid scratching, as it can lead to infection of the area. (***, Mosquito Bites, 2021) In case of more severe symptoms (presented in the table above), consulting a doctor is recommended.
How to prevent mosquito bites?
It is recommended to eliminate any source of stagnant water around the home and remove household waste. Windows and doors of homes must have mosquito screens installed. Use mosquito repellent products inside the home as well (electric devices with liquid or capsules, coils, candles, or essential oils based on lavender, chrysanthemum, or eucalyptus).
Another method that can keep mosquitoes away is using a fan. They are attracted by carbon dioxide and other chemicals we release when we breathe. According to Melania Rose, a pest specialist at Nationwide Pest Control, fans can make it difficult for mosquitoes to detect these chemicals in the air, making them less able to find their target. (Slack, 2022)
Avoid or limit travel in areas with high vegetation, high humidity (forests, parks, stagnant water, etc.), and those with a high risk of infection. Dress appropriately with thicker long-sleeved shirts, long pants, and socks; use mosquito repellents with DEET (diethyltoluamide) or based on natural oils, such as Klinodiol anti-mosquito spray. For children, you can use anti-mosquito patches or an anti-mosquito bracelet (for those over three years old). Treat tents with repellents as well if you are sleeping in nature.
General information about ticks
Ticks (Ixodidae) are ectoparasites with a hematophagous and intermittent feeding mode, thus being important vectors for many pathogens, both in humans and in mammals, reptiles, and birds. (Ali, Mulenga, & Vaz, 2020) As temperatures rise, ticks become active.
Several species have been identified in our country. Among the four types of ticks found in Romania, according to the European Centre for Disease Control and Prevention (ECDC) (***, Tick maps, 2023), the most frequently encountered is Ixodes ricinus (the deer tick) (***, 2018).
They can be found in forests, meadow areas, and pastures, but also in semi-desert regions with dry climates or inside homes (the Rhipicephalus sanguineus species). (***, Prevention and control of tick-borne diseases in Europe, 2015)
The life cycle of ticks includes four stages of development: egg, larva, nymph, adult tick. In the last three stages, they can bite and transmit diseases. The risk is lower when the tick is detected and removed immediately. Thick snow can facilitate survival through winter, as they can adapt to temperatures below 0°C, and rising temperatures help accelerate their life cycle, which is otherwise completed in 2-3 years. (***, Small bites, big problems: tick-borne diseases in Europe, 2014)
Diseases caused by tick bites – symptoms and treatment
In Europe, the 4 diseases that can be caused to humans by tick bites are Lyme disease, tick-borne encephalitis (a serious infection of the brain and spinal cord), relapsing fever, and Crimean-Congo hemorrhagic fever. Allergic individuals may experience pain at the site of the bite, swelling, a burning sensation, and sometimes even difficulty breathing. (***, Prevention and control of tick-borne diseases in Europe, 2015) Ixodes ricinus is responsible for causing the first three diseases, being frequently observed in deciduous and mixed forests, requiring a humidity of at least 80% for replication, whereas in the case of Crimean-Congo hemorrhagic fever, Hyalomma marginatum is the culprit, being present in southern and eastern Europe. (***, Small bites, big problems: tick-borne diseases in Europe, 2014)
| Lyme disease(Borreliosis) | Tick-borne encephalitis | Relapsing fever | Crimean-Congo hemorrhagic fever | |
| Symptoms | • Circular reddish skin rash (around the bite, in 80-90% of cases), sometimes associated with a burning, stinging sensation • Fever, fatigue, headache. Untreated, it causes infections of the heart, liver, lungs, eyes, joints, and nervous system |
• Viremic phase (5 days): fever, fatigue, headache and muscle pain, nausea • Asymptomatic interval (7 days on average, can vary between 1-33 days) • Advanced phase presents symptoms similar to those of meningitis and requires hospitalization |
• Repeated episodes of fever higher than 39-40°C, headaches (lasting between 3 and 6 days), muscle and joint pain, nausea, intense asthenia • Splenomegaly, hepatomegaly, associated with jaundice, increased pulse, and blood pressure • Shorter and milder recurrences may appear after the first fever episode |
• Sudden onset of fever, headache, muscle, joint, and abdominal pain, and vomiting • Hemorrhagic manifestations (petechiae, ecchymoses) appearing on the skin and mucous membranes (nose, gastrointestinal system, uterus, urinary and respiratory tract), including at venous puncture sites • Possible necrotic hepatitis |
| Incubation period | Up to 30 days after the bite | 7 days on average (but can also occur between 3-28 days) after the bite | 3-18 days after the bite | 3-7 days (can vary between 1-13 days) after the bite |
| Treatment | • Antibiotic administration • Complications may appear after completing the treatment: post-treatment Lyme disease syndrome (asthenia, severe muscle and joint pain, headache), arthritis and joint pain, memory problems, numbness, tingling and stinging sensations in the limbs and face, stress, anxiety, and depression (due to the persistence of symptoms) |
• No treatment • Prior vaccination and taking protective measures are very important |
• Antibiotic administration (tetracycline or doxycycline). • If tetracycline is contraindicated, a macrolide may be prescribed. • Treatment can cause a Jarisch-Herxheimer reaction (acute febrile reaction) within two hours of treatment. |
• Supportive care, administration of platelets, fresh frozen plasma, and erythrocyte preparations • Oral ribavirin has been successful in some cases. Taking protective measures is very important |
What to do in case of tick bites?
As it is not painful, the bite often goes unnoticed. That is why a thorough check is important after you have been in places where ticks may exist. The entire body should be checked, paying greater attention to the underarm, groin, navel, leg, neck, and head areas (often, in children, they have been detected on the scalp, at the base of the hair – a magnifying glass is necessary). The bite has the appearance of a small dark bump with a scab that cannot be removed by brushing. (***, Prevention and control of tick-borne diseases in Europe, 2015)
If you notice a tick in your skin, it is important to act quickly and correctly as follows: disinfect the area with alcohol and use a pair of blunt-tipped tweezers (without a beak) to carefully grasp the tick's body as close to the skin as possible, pulling it out gently in one motion, without jerking or twisting. Do not grasp the head, as there is a risk that it may break and remain fixed in the skin. Do not apply heat or any other substance, as the tick may release its stomach contents, promoting the transmission of diseases.
Wrap it in a tissue and flush it down the toilet, then wash the area with soap and water and apply an antiseptic or disinfectant solution (rubbing alcohol, povidone-iodine). (***, Borreliosis (Lyme disease), 2014)
If after a few days you notice that the lesion is not healing or symptoms mentioned in the table above appear, even after a month from the bite, consult a doctor, providing them with all the necessary information related to it.
How can we prevent tick bites?
Avoid areas with thick and tall grass, dress appropriately (light-colored clothing that covers the skin – long sleeves, long pants, socks over pants, and boots/sneakers without holes), and use tick repellents with DEET (diethyl toluamide) or based on natural oils on areas that may come into contact with tick-infested zones (***, Leaflet for travellers on ticks, tickborne diseases and preventive measure, 2015), such as Klinodiol anti-mosquito and tick spray.
Another useful prevention option is vaccination, with the mention that this method only protects against tick-borne encephalitis. This is recommended for people who travel and remain for more than three weeks in a place where this disease is endemic. For high effectiveness, multiple doses are required.
It is important to reduce tall vegetation by mowing the grass or lawn, remove piles of dead leaves and fallen branches by burning them, and cover holes and cracks in houses. Periodically deparasitize pets and domestic animals.
Last but not least, use an insecticide to combat ticks, such as Aptanex forte (which is also effective against cockroaches, fleas, bed bugs, flies, ants, spiders, and other flying and crawling insects).
Therefore, preventing diseases transmitted by mosquitoes and ticks can primarily be achieved by using a repellent. It should not be applied near the eyes and mouth, over sunburns, cuts, wounds, or skin rashes, nor under clothing. Avoid inhaling it and do not apply it near flames. Always check the instructions, method of use, and contraindications mentioned on the product label. Once you enter the house, wash the areas where you applied the repellent with soap and water.
If you follow all these recommendations, you will enjoy a summer with outdoor activities without being bothered by mosquitoes and ticks.
Bibliography
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