{"id":569143,"date":"2025-11-21T19:09:33","date_gmt":"2025-11-21T22:09:33","guid":{"rendered":"https:\/\/revistapesquisa.fapesp.br\/?p=569143"},"modified":"2025-11-21T19:09:33","modified_gmt":"2025-11-21T22:09:33","slug":"number-of-scorpion-stings-increased-by-154-in-brazil-from-2014-to-2023","status":"publish","type":"post","link":"https:\/\/revistapesquisa.fapesp.br\/en\/number-of-scorpion-stings-increased-by-154-in-brazil-from-2014-to-2023\/","title":{"rendered":"Number of scorpion stings increased by 154% in Brazil from 2014 to 2023"},"content":{"rendered":"

In mid-May, residents of S\u00e3o Paulo\u2019s mid-upper class neighborhood of Perdizes, not used to encounters with scorpions, were alarmed by news of several accidents involving the arachnids. Scorpions are more frequently found in the city’s poorer peripheral areas, although they do occasionally appear in more central neighborhoods. Despite the initial scare, there are so far no signs that the S\u00e3o Paulo state capital is facing an invasion of the animals, which can enter houses and apartments through unprotected electrical conduits or water and sewage pipes. The S\u00e3o Paulo State Health Department\u2019s dashboard on accidents involving venomous animals shows there have been 161 scorpion stings in the city as of June 2025, compared to 426 in the entire previous year and 451 in 2023 (see graph below<\/em>). Over a longer time period, however, there has been a significant increase in recent decades in the total number of stings in the state capital, in the interior of the state, and nationwide.<\/p>\n

\u201cIn the past, you never heard of people being stung inside their homes. Now, it happens frequently. I myself have found scorpions in my house,\u201d says biomedical scientist Manuela Pucca, a professor at the School of Pharmaceutical Sciences at S\u00e3o Paulo State University (UNESP), Araraquara campus, where she lives. Pucca is the lead author of an article published in the journal Frontiers in Public Health<\/em><\/a> in May that shows the number of stings that occurred in different regions of Brazil between 2014 and 2023. The total number nationwide grew by 154% in the period. According to Ministry of Health data made available at the time the paper was written, the figure jumped from 67,000 in 2014 to 170,600 in 2023.<\/p>\n\n \n \n \n <\/picture>Alexandre Affonso\u2009\/ Pesquisa FAPESP<\/span>\n

The highest number of stings occurred in the two most populous regions of Brazil\u2014the Southeast, home to 84.8 million people, and the Northeast, with 54.6 million. In 2023, 84,500 and 57,600 cases were recorded in each region respectively, approximately one for every 1,000 inhabitants. With 30.2 million residents, the South region is proportionally the least affected, with one sting for every 4,000 people. Scientists suspect that the officially recorded numbers are likely only the visible part of a silent epidemic, since adults, when stung, do not usually seek health services (responsible for mandatory reporting), choosing to take care of themselves at home instead. \u201cScorpion stings are a neglected problem within the neglected diseases,\u201d says Pucca.<\/p>\n

With a slightly alarmist title that suggests Brazilian cities are being taken over by scorpions, the study also provides a projection of what could happen if nothing is done to change the conditions that are allowing the animals to proliferate. The total number of stings per year is forecast to continue to rise, reaching 274,300 cases in 2033 (see graph below<\/em>). \u201cAlthough the historical data are known, the projection exposes the problem very clearly,\u201d says biologist Gabriel Murayama of the Laboratory of Sensory Ecology and Arachnid Behavior (LESCA) at the University of S\u00e3o Paulo (USP), who is researching chemical and biological scorpion-control methods but did not participate in the study.<\/p>\n\n \n \n \n <\/picture>Alexandre Affonso\u2009\/ Pesquisa FAPESP<\/span>\n

In the Frontiers in Public Health<\/em> article, Pucca and five colleagues listed some of the reasons behind the increase in scorpion incidents, which included fast and unplanned urban growth (particularly in regions lacking in infrastructure); inadequate treatment and disposal of waste; a lack of basic sanitation; an absence of regular control actions in cities; and the occurrence of hotter summers and periods of heavy rain alternating with intense droughts, driven by climate change. \u201cThe increase in stings can also be partly attributed to the expansion and improvement of surveillance and reporting systems, especially in municipalities that have begun reporting data more systematically and regularly in recent years,\u201d says the researcher.<\/p>\n

The yellow scorpion (Tityus<\/em> serrulatus<\/em>) and the northeastern yellow scorpion (T. stigmurus<\/em>) are spreading across different regions of the country, possibly transported in the packaging of various goods. Native to regions with hot, dry climates, the two species have adapted to life in cities, where they easily establish new populations and appear to withstand the cold well. \u201cIn recent years, there have even been reports of accidents involving them in places with colder climates, such as Santa Catarina and Rio Grande do Sul,\u201d says Rog\u00e9rio Bertani, lead author of an article published in the journal Bioinvasions Records <\/em><\/a>in 2018, in which he described the 2012 arrival of T. stigmurus<\/em> in the city of S\u00e3o Paulo, probably brought in fruit boxes.<\/p>\n

The two scorpion species are considered invasive in some states. In S\u00e3o Paulo, they seem to have replaced the brown scorpion (T. bahiensis<\/em>), which lives in wetter environments near forests and was the most common in the city until the 1960s. In the Atlas escorpi\u00f4nico de S\u00e3o Paulo<\/em><\/a> (Scorpion atlas of S\u00e3o Paulo), published in 2024, biologist Sergio Cominato Ferraz of the city\u2019s Zoonosis Control Center and epidemiologist Francisco Chiaravalloti Neto of the USP School of Public Health reported that between 2013 and 2018, the yellow scorpion had been observed in 89 of the capital’s 96 administrative districts, while the northeastern yellow scorpion had been found in 64 and the brown scorpion in just four.<\/p>\n

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Rafael Sim\u00f5es \/ Butantan Institute Communications <\/span>Fluorescent compound in the exoskeleton makes scorpions glow when illuminated by black lightRafael Sim\u00f5es \/ Butantan Institute Communications <\/span><\/p><\/div>\n

Scorpions were among the first animals to occupy dry land. Paleontological records indicate that the first specimens appeared around 435 million years ago, when the world\u2019s continents were grouped into the supercontinent known as Gondwana. Of the approximately 2,500 species described worldwide, approximately 170 are found in Brazil. Four of them are considered to be of medical interest due to the serious health impacts they can cause: the three mentioned above and the Amazonian black scorpion (T. obscurus<\/em>).<\/p>\n

Scorpions have four pairs of legs, a pair of pincers, and a stinger at the end of their tail through which they inject venom, but they are smaller than most people think. Individuals of the first three species reach up to 7 centimeters (cm) in length, while the largest of them, the Amazonian black scorpion, can grow to 12 cm. \u201cScorpions are synanthropic animals, meaning they live near humans because they have adapted well to the urban environment, primarily because it provides water, food, shelter, and access,\u201d biologist Denise Maria Candido of the Arthropod Bioterium at the Butantan Institute told the Ag\u00eancia de Not\u00edcias do Estado de S. Paulo<\/em> news agency in February this year. \u201cThanks to these four conditions, they end up moving in, reproducing, and proliferating,\u201d she said.<\/p>\n

In Brazil, the most serious cases are associated with the yellow scorpion. With light yellow legs and tail and a darker body, the species is found in almost every state. One of the characteristics that helps it proliferate so easily is that it can reproduce asexually through parthenogenesis, when the egg produces another individual without needing to be fertilized\u2014males are rare and in some places nonexistent.<\/p>\n

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Rafael Sim\u00f5es \/ Butantan Institute Communications <\/span>Extraction of venom for the production of anti-scorpion-venom serumRafael Sim\u00f5es \/ Butantan Institute Communications <\/span><\/p><\/div>\n

The toxic compounds injected in the sting often cause local symptoms, such as pain, burning, tingling, and swelling, and systemic problems, such as headache, nausea, salivation, drowsiness, accelerated heart rate, body temperature drop or increase, and muscle spasms. More severe cases can result in shortness of breath, a significant drop in blood pressure, impaired blood circulation and lack of blood supply to organs, and even death.<\/p>\n

In the event of being stung, victims are advised to seek emergency medical attention as quickly as possible; although the death rate is low, some cases require hospitalization. A 2019 letter published in the journal Revista Brasileira de Medicina Tropical<\/em><\/a> by researchers from USP and the Butantan Institute, including Bertani, warned that 80% of deaths occur within 48 hours of a sting and that the chance of death depends on age.<\/p>\n

Children are most likely to die. Among children under the age of 10, there are 32 deaths for every 10,000 stings, more than three times higher than the rate observed in adolescents and adults (9 per 10,000).<\/p>\n

Because their bodies are smaller and heart rates naturally higher than adults\u2019, the scorpion’s toxins reach their central nervous system faster. \u201cThe symptoms are generally more severe in children because the blood-brain barrier, a structure that protects the brain and regulates the transfer of substances between the blood and the central nervous system, is not yet mature,\u201d says Eliane Candiani Arantes, a pharmacist and biochemist from USP\u2019s Ribeir\u00e3o Preto School of Pharmaceutical Sciences (FCFRP), coauthor of the paper published in Frontiers in Public Health<\/em>. \u201cNeurotoxins can therefore reach the nervous system very quickly and cause cerebral edema,\u201d she explains.<\/p>\n

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Rogerio Bertani \/ Butantan Institute<\/span>The brown Scorpion (T. bahiensis<\/em>), with a dark brown body, and the northeastern yellow scorpion (T. stigmurus<\/em>), with a dark marking on its backRogerio Bertani \/ Butantan Institute<\/span><\/p><\/div>\n

Not seeking care for children quickly enough increases the likelihood of hospitalization to deal with the changes in their bodies, according to an article published in the journal Toxicon<\/em> in April. In the study, a group led by pharmacist Edmarlon Girotto of the State University of Londrina (UEL) monitored the progress of 450 children aged under 12 who were stung by scorpions and treated at the Toxicological Information and Care Center (CIATOX) at the university\u2019s hospital between 2017 and 2022. Of these cases, 11% needed to receive anti-scorpion-venom serum and 8.4% had to be admitted to hospital. They were 11 times more likely to be hospitalized when the sting was inflicted by a yellow scorpion and 2.5 times more likely if they waited more than three hours before seeking treatment.<\/p>\n

The toxins, the authors write, cause changes to the circulation of sodium, potassium, and calcium ions in the cells of the nervous system, leading to what experts call an autonomic storm. The parasympathetic nervous system, which usually slows the heart rate and lowers blood pressure, is temporarily stimulated, followed by prolonged activation of the sympathetic nervous system, which is responsible for activating fight-or-flight responses and increasing heartbeat speed and intensity and blood pressure, in addition to facilitating breathing. \u201cAn autonomic storm makes fast treatment difficult because the patient may arrive at hospital with hypotension and then suddenly develop hypertension,\u201d says Arantes, from FCFRP-USP.<\/p>\n

Adults are not immune to the effects of the toxins and can also experience severe reactions, especially if they are elderly or have existing health problems. \u201cStings can be deadly to people with heart and lung problems because the main causes of death are heart problems and pulmonary edema [accumulation of fluid in the alveoli],\u201d explains Arantes.<\/p>\n

Anti-scorpion-venom serum produced at Butantan, S\u00e3o Paulo, and the Ezequiel Dias Foundation, Minas Gerais, is used to treat stings by the four species of the genus Tityus<\/em>. It is only kept in stock at some emergency departments and major hospitals. The Ministry of Health<\/a> provides a list of the major hospitals that treat accidents involving venomous animals in each city.<\/p>\n

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Butantan Institute Communications<\/span>Anti-scorpion-venom serum being packaged at the Butantan InstituteButantan Institute Communications<\/span><\/p><\/div>\n

The serum is only indicated for severe cases because it can cause allergic reactions\u2014although they are usually mild and can be managed with appropriate medication. These reactions occur because the serum is produced by injecting the scorpion venom into the blood of horses, then later collecting the blood and filtering the plasma (the liquid part) to extract antibodies for the scorpion toxins. \u201cHorse antibodies are not the same as human antibodies and are often recognized as foreign bodies in humans. When injected into humans, they can cause allergic reactions and even anaphylactic shock,\u201d explains Pucca, who is trying to produce a serum using biotechnology in a lab, without horses.<\/p>\n

Scorpions are predatory animals\u2014they generally hunt insects, spiders, and other arthropods\u2014and are most active at night. In nature, they hide among leaves, in the bark of trees, under stones or fallen branches, and in rock crevices or burrows. In cities, they are found in vacant lots, storm drains, gardens, and cemeteries. There are no effective chemical products on the market for scorpion control and little is known about the natural enemies of the species found in Brazil. \u201cStudies urgently need to be carried out to test control methods,\u201d says USP\u2019s Murayama.<\/p>\n

The best way to avoid the unwanted presence of scorpions is to keep houses and surrounding areas free of garbage and clutter, which can serve as shelter and a food source, and to seal cracks, doors, windows, drains, and plug sockets\u2014they can enter through the plumbing or electrical conduits (see chart below<\/em>). To avoid being stung, gloves and shoes should be worn when working outside or gardening. Shaking out clothes and inspecting the inside of shoes before putting them on is also advised. Scorpions do not generally attack humans. According to experts, their instinct when threatened is to flee. They usually only sting people when touched or stepped on. If you find one, do not try to pick it up, even if wearing gloves. Contact your city’s Animal Control Center (in the city of S\u00e3o Paulo, call 156, followed by option 2 and then option 3).<\/p>\n<\/div>

\n \n \n \n <\/picture>Alexandre Affonso \/ Pesquisa FAPESP<\/span><\/div>
\n

The story above was published with the title “Silent epidemic<\/strong>” in issue 353 of July\/2025.<\/p>\n

Scientific articles<\/strong>
\nPUCCA, M. B. et al<\/em>. Scorpions are taking over: The silent and escalating public health crisis in Brazil<\/a>. Frontiers in Public Health<\/strong>. May 7, 2025.
\nBERTANI, R. et al.<\/em> Alien scorpions in the Municipality of S\u00e3o Paulo, Brazil \u2013 Evidence of successful establishment of Tityus stigmurus<\/em> (Thorell, 1876) and first records of Broteochactas parvulus<\/em> (Pocock, 1897) and Jaguajir rochae<\/em> (Borelli, 1910)<\/a>. BioInvasions Records<\/strong>. 2018.
\nTORRES, P. P. Q. et al<\/em>. Scorpionism in Brazil: Exponential growth of accidents and deaths from scorpion stings<\/a>. Revista Brasileira de Medicina Tropical<\/strong>. May 16, 2019.
\nTONIN DOS SANTOS, R. H. et al<\/em>. Characterization of scorpion envenoming in children care for a poisoning control center<\/a>. Toxicon<\/strong>. Apr. 2025.<\/p>\n","protected":false},"excerpt":{"rendered":"The Southeast and Northeast regions were where the highest numbers of cases occurred","protected":false},"author":702,"featured_media":569148,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"footnotes":""},"categories":[159],"tags":[229,260],"coauthors":[3889],"class_list":["post-569143","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-science","tag-epidemiology","tag-public-health"],"acf":[],"_links":{"self":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts\/569143","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/users\/702"}],"replies":[{"embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/comments?post=569143"}],"version-history":[{"count":2,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts\/569143\/revisions"}],"predecessor-version":[{"id":569829,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts\/569143\/revisions\/569829"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/media\/569148"}],"wp:attachment":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/media?parent=569143"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/categories?post=569143"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/tags?post=569143"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/coauthors?post=569143"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}