Those who work or regularly practice outdoor activities, particularly in areas where there is tall vegetation - for example, farmers, shepherds, hunters, among many others - are at greater risk of being bitten by ticks. However, for safety, anyone who is in these environments, even for a short time, should take some precautions . These mainly concern clothing, the use of repellents, behavior while staying in risky places and a final inspection to make sure everything is ok. Clothing Choose clothing that does not leave exposed skin. For example, long sleeves, pants, hat, among others. Wear closed shoes and wear socks, preferably with the top placed over the pants. Choose light colored items to more easily identify the presence of ticks. Use insect repellent on exposed skin areas and clothing. Whenever possible, use existing trails to walk instead of areas with vegetation. Keep an eye out for ticks on your clothes. After staying in risky places, always carefully inspect your clothes and skin to ensure that ticks have not been brought home. Ticks are clearly visible to the naked eye: they look like small spiders, their color varies from reddish to brown or black, they can be around 2 mm long or reach much larger sizes. Always keep in mind that ticks prefer warmer and moister areas of the body where they go unnoticed. Therefore, always take a good look at the scalp, groin, armpits, skin folds, and navel . If an attached tick is detected, remove it. Using tweezers or protected fingers, grab the tick as close to the skin as possible, twist and pull to release it. Finally wash and disinfect the skin area. If you do not want to or if you think you cannot remove the tick, seek help to do so. Then, pay attention to: High fever, flu-like symptoms, the presence of a scab at the site of the tick bite, a blotchy rash on the skin or another symptom in the following days, for which there is no obvious explanation, which should prompt the search for medical care. Some more information about ticks Ticks are external parasites of many species of mammals and other vertebrates. They have their preferred hosts but can parasitize others; man is an accidental host. They do not live their entire lives parasitizing their hosts, they only do so at specific times. Throughout their life cycle, ticks go through several phases. For the metamorphosis from larva to nymph and from nymph to adult they need to ingest blood. To do this they search for suitable hosts. They have a developed sensory system that allows to stay closer to animal locations to find suitable hosts. Once attached to their hosts, they bite and feed on blood. The duration of blood meals is variable. It takes longer the more advanced the ticks are in their life cycle, it can be from several days, up to about 2 weeks. After the blood meal is over, the ticks leave their hosts and enter a less active phase, during which metamorphosis occurs to the next phase of their life cycle or death after laying of eggs, in the case of females. In the blood meal before laying, female ticks can increase their size by up to 100 times. Ticks have long lifespans and are very resistant, even in adverse environmental conditions. There are ticks all over the world. Most prefer hot, humid climates. In 2023, almost 900 species of ticks were identified , belonging to two main families. The Ixodidae family is the most important in terms of disease transmission. In Portugal there are 22 species of ticks that belong to the ixodid family, currently called hard-bodied ticks, which include the genera Dermacentor, Haemaphysalis, Hyalomma, Ixodes and Rhipicephalus . There are also 3 species of ticks from the second most important family, the Argasidae family, also called soft-bodied ticks . Most common species in Portugal According to REVIVE 2023 data, the tick species with the greatest impact on public health and most prevalent in Portugal are , according to their relative abundance: Rhipicephalus sanguineus – the most important one, represents around 75.6% and is distributed throughout the country. It is also known as the dog tick, as these are the main host. Adult ticks are most active between March and October and immature ticks in August. It survives easily in dry climates. A tick lays about 3-5 thousand eggs at once. Among the microorganisms that it can transmit are those that cause Mediterranean spotted fever . Ixodes ricinus – represents around 10.5% and is distributed throughout the country. Adult ticks are most active between October and April and immature ticks in the spring and summer. They prefer areas of high relative humidity. Females generally lay no more than 3 thousand eggs. It is the main vector of the bacteria that causes Lyme borreliosis . Dermacentor marginatum – represents around 4.2% and is distributed throughout the country. Adult ticks are most active between August and October and immature ticks are most active in August and September. It can transmit the bacteria Rickettsia slovaca . Hyalomma marginatum - represents around 2% and is distributed throughout the country. Adult ticks are most active between March and October and immature ticks form in the fall. It can transmit the Crimean-Congo hemorrhagic fever virus. Dermacentor reticulatus – represents around 1% and exists in the northern region of the country. Adult ticks are most active between March and October and immature ticks form in August. It can transmit the bacteria that cause Q fever . Hyalomma lusitanicum - represents around 0.7% and exists in the south of the country. Adult and immature ticks are most active between March and October. It has the ability to transmit the Crimean-Congo hemorrhagic fever virus and other bacteria of the genus Rickettsia. Tick-borne diseases Around 10% of tick species can transmit microorganisms – bacteria, viruses and others – that cause various diseases. In most cases, transmission is achieved through the inoculation of these microorganisms into the host when the tick bites to feed on blood, but there are other forms of transmission. The prolonged duration of tick blood meal favors the transmission of microorganisms to hosts when they are infected. Among the diseases that ticks can transmit, Mediterranean spotted fever and Lyme borreliosis are the most important in Portugal. However, cases of other tick-borne human infections have also been diagnosed: anaplasmosis, babesiosis, Q fever, tularemia, rickettsia-associated lymphangitis, tick-borne encephalitis, tick-borne lymphadenopathy, and Crimean-Congo hemorrhagic fever. Author : Saraiva da Cunha Sources REVIVE 2023 - Culicídeos, ixodídeos e flebótomos: Rede de Vigilância de Vetores / Centro de Estudos de Vetores e Doenças Infeciosas Doutor Francisco Cambournac. Lisboa: Instituto Nacional de Saúde Doutor Ricardo Jorge, IP, 2024. Núncio MS, Ales MJ. Doenças associadas a artrópodes vetores e roedores. Lisboa: INSA; 2019. Silva, MM, Santos S, Formosinho P. et al. Carraças associadas a patologias infeciosas em Portugal. Acta Med Port 2006; 19:39-48. Meet the infectious diseases clinical team from Hospital da Luz network. Our Health Guide contents have an information purpose, are intended for the general public and may not be up to date. They do not replace the information, opinion and individual advice of a doctor or other healthcare professional in their areas of expertise.
