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Anais Brasileiros de Dermatologia

Print version ISSN 0365-0596On-line version ISSN 1806-4841

An. Bras. Dermatol. vol.79 no.2 Rio de Janeiro Mar./Apr. 2004 



Cutaneous infections and injuries caused by traumatic and venomous animals which occurred in domestic and commercial aquariums in Brazil: a study of 18 cases and an overview of the theme*



Vidal Haddad Junior

Assistant Professor, Ph.D., Universidade Estadual Paulista (Sao Paulo State University) (Botucatu Faculty of Medicine and Sao Vicente Marine Biology Faculty), M.D., Vital Brazil Hospital (Butantan Institute)





BACKGROUND: Among the recreation activities that more they grew in the last years, the aquarism wins every day new followers in Brazil. Impelled by beautiful fish, plants and decoration objects, the habit involves problems, as infections and poisonings that happen after scratches, wounds and other traumas in animals or objects of the aquariums.
OBJECTIVES: This article points the animals and the clinical aspects frequently involved with these injuries, the skin infections found after traumas in aquariums and the therapeutic and preventive measures for control of the problem.
METHODS: A prospective study was accomplished for three years for the detection of injuries for animals and infections appeared after traumas in aquariums. These data served as base for epidemiologic, clinical and therapeutic studies.
RESULTS: IIn a study of 300 injuries for aquatic animals, poisonous animals in aquariums caused 12 or 4% of the total. Five bacterial infections and one fungic infection were identified after trauma in aquariums.
CONCLUSIONS: The injuries in domestic and commercial aquariums are relatively common and they can transmit infections and to cause wounds for poisonous or traumatic animals. The owners of aquariums rarely have information on these injuries. The authors supply the species of microorganisms and animals more frequently involved with skin injuries and the therapeutic and preventive measures appropriate to the handling of the problem.

Keywords: Brazil; wounds and injuries; infection; skin manifestations; fishes, poisonous.




The habit of rearing marine and freshwater animals in aquariums has grown exponentially in Brazil over the past few decades. In the meantime, relatively few notions have been publicized regarding the risks associated with this hobby. Handling animals and functional or decorative structures in commercial or domestic aquariums may cause traumas of varying intensity to the hands. The scratches and wounds may work as a point of entry for a whole series of complications, such as severe infections that arise due to the presence of bacteria and fungi in the waters and substrate of stones, shells and other ornamental material. Moreover, many animals acquired in aquarium shops may cause poisoning, skin diseases and diverse injuries to persons. Most shopkeepers and branch clerks have scant knowledge regarding the stingers, spicules and teeth of the most of these animals, which in turn increases the risk of injury.1

A) Infections

Bacterial infections may be caused by various species, including the same bacteria that cause infections on dry land, such as staphylococcus and streptococcus (occurring in most cases).2 It is important to bear in mind that small scratches or abrasions might suffice to cause severe infections that at times are life-threatening.2

Highly pathogenic bacteria may also be found in the "culture broth" characterizing aquarium waters. Among them, it is possible to isolate the following species: Pseudomonas, Clostridium perfringens and tetani (that cause gaseous gangrene and tetanus), Aeromonas hydrophila, found more in freshwater, and bacteria of the Vibrio genus, especially Vibrio vulnificus, which is common in seawater.3 Bacteria of the Aeromonas and Vibrio genuses are acquired from contact with water and may cause very severe infections. They arise through septicemias that are already in the premature phases of infection, which may cause organ and systemic failure, and death. These infections are most common in diabetic individuals or those with other diseases presenting with immunodeficiencies, though fortunately they are seldom observed.2 Erysipeloid is a cellulitis caused by Erysipelothrix rhusiopathiae, a gram-positive bacteria that rarely provokes systemic effects. Rarer infections are caused by Mycobacterium marinum, which provokes verrucous lesions, lymphangitis or difficult to heal ulcers at the localization of a small wound.2 Some infections caused by fungi may also be associated with traumas occurring in aquatic environments, such as sporotrichosis, a severe systemic mycosis.4

B) Venomous and traumatizing animals

In this category, there exist various injury-causing animals. Some are apparently inoffensive, such as anemones, corals or sea-urchins, and are used as ornaments in seawater aquariums. Anemones and corals are cnidarians and may cause skin diseases as severe as those provoked by jellyfishes and Portuguese man-of-war.1 At the localization, edema and erythema arise, and may persist for days. These injuries are very painful at the outset. Marine worms (polychaetes) may also cause similar injuries.1,2 Sea-urchins manipulated without due care may introduce their body spicules into human skin. Its removal is complicated, requiring exeresis performed at a hospital.5

Among poisonous fish, one must cite marine and freshwater catfishes (of the Pimelodidae and Ariidae families), featuring venomous stingers of which aquarists are not always aware.6 Freshwater stingrays are beautiful fish sold in large amounts in aquarium shops, and may cause one of the severest types of aquatic animal poisoning. Marine stingray maintained in domestic and commercial aquariums also cause serious injuries.1

At times, scorpionfishes (Scorpaenidae) can be seen in aquariums. The risks in handling such fish are obvious, given the severity of injuries for humans.8 Finally, the massive importing of lionfishes has brought about problems, with some injuries being treated at the Hospital Vital Brazil (Butantan Institute). The fish belongs to the Scorpaenidae family, and shares features with the scorpionfish of Brazil's costal regions.9 The long spicule of its dorsal fin perforates the skin and inoculates venom, which in turn incurs a great deal of pain for its victim, as well as edema and erythema.

Most injuries due to venomous animals occur as a result of carelessness or missing information about the animal chosen by the aquarist. All injuries by venomous fish cause erythema, edema and significant algic conditions. The most intense of the latter are injuries provoked by stingrays, scorpionfish and lionfish.1

Some fish may harm humans by biting or by traumatizing contact with other non-venomous body structures. Take the example of piranhas (Serrassalmidae) that a lot of people like to keep in their aquariums. They may cause severe injuries, including amputation of phalanges and fingers.1 Moray eels, whose sharp dental action joins up with a toxic saliva, causes intense pain for the victim. Sharp, knife-like blades emerge from the tails of surgeonfishes (Acanthuridaae), a family to which Tangs belongs. These were brought (to Brazil) in large quantities from the Pacific and Indian oceans. Finally, it is important to know that the dorsal fins of virtually all fish are sharp, and thus easily penetrate human skin. They may cause inflammation and bacterial and fungal infections.



The objectives of this paper are to assess the most common infectious cutaneous conditions and the amount of information available to domestic and commercial aquarium keepers who end up suffering from infections in the wake of traumas caused by aquarium animals, plants and decorative objects, or even the water. The study also seeks to assess the conditions observed in the poisoning caused by aquatic animals. From the collected data, minimal notions of care in handling animals or decorative materials, or in filling aquariums will be established. A standard of conduct for first-aid and hospital treatment will be determined. Such measures are evermore useful, though they remain relatively unknown for those who rear aquatic animals in aquariums.



In a three year period (from January 2000 to December 2002) injuries were observed and registered in persons with aquariums in their homes who gave accounts of associated infections and injuries caused by aquatic animals from the traumas suffered in the aquariums while cleaning the environment, feeding the animals or handling them. These patients were examined at the Hospital das Clínicas at the Botucatu Medical Faculty and at the Hospital Vital Brazil (Butanta Institute). Laboratory tests to confirm infectious etiology were always performed upon the appearance of infection signs and symbols, such as fever, sickness, local purulent secretion and extensive edema and erythema. Cultures for bacteria and fungi, and antibiogram were used. In injuries incurred from venomous or traumatizing animals, the diagnosis was provided through the help of the patient's account and the clinical picture shown.



Infections that were detected after aquarium traumas are described in chart 1. Six infections were detected in all, with five being of bacterial origin and one caused by fungus. In the roughly 300 injuries by marine and freshwater animals observed by the author over the three year period,1 12 arose in the wake of persons having had contact with aquarium animals. Fish and sea-urchins were the main agents responsible for these injuries. The severity of the condition varied in accordance with the causative species. The characteristics of these accidents are shown in chart 2.



All of the infections occurred in domestic aquariums and were not serious, though they were manifested by sickness, fever, local edema and erythema. In one case, blisters emerged over the erythematous and edematous plaques. Diagnosis of the patients was erysipelas by Staphylococcus aureus in five cases, which was confirmed by culture from the microorganism (Figure 1). The clinical examination showed the traumas functioning as ports of entry occurred within the aquarium water in 100% of samples, and always on the hands or fingers, predominantly on the right-hand side. Treatment was successfully carried out using cephalexin, the indication being 2 g daily taken orally for 10 days.



One of the patients showed infection by Sporothrix schenckii. This was characterized by a chronic ulcer on the right hand with nodular ascending lymphangitis, which emerged after the trauma provoked by the bones of a catfish in his aquarium (Figure 2). This clinical manifestation is often mixed up with swimming pool granuloma caused by Mycobacterium marinum, whose etiology is identical. In these cases, however, treatment of the sample resolved the lesions. The S. schenkii culture was negative, but the patient made use of itraconazole 100 mg daily for 28 days, from the first examination on, although without any definitive improvement of the lesions. The author reported an infection from the same fungus after a trauma caused by the dorsal fin of a fish,4 though not in an aquarium.



All patients lacked appropriate information as to the risks of contracting infectious processes while handling an aquarium--without exception. It thus reinforced the original idea for this study. Clinical pictures for bacteria of the Aeromonas, Pseudomonas, Vibrio or Clostridium genuses were not observed. This is compatible with the scarcity of such infections compared to streptococcal and staphylococcal infections.2

For each 1,000 patients treated at the emergency clinics of Brazil's coastal cities, one is caused by a marine animal.1 In the roughly 300 injuries caused by marine animals that were observed by the author from the beginning of 2000 till the end of 2002, 12 (4%) were caused by aquarium animals. The lionfish caused four injuries, corresponding to 1.33% of all injuries, or 33% of injury samples from aquarium animals (Figure 3). Lionfishes (Pterois volitans) are imported to Brazil in large numbers from the Indian and Pacific oceans due to their beauty, and are frequently seen in domestic aquariums. Rays also caused four injuries (1.33 of the total amount, or 33% of accidents by aquarium animals). Freshwater stingrays from the Potamotrygonidae family caused three injuries (Figure 4). These fish are sold a lot in aquarium shops, though with a typical lack of orientation required for raising these venomous animals safely at home. One case was provoked by a cownose ray (Rhinoptera bonasus) on a professional who was taking care of maintenance on one of the exhibition tanks in Guaruja, São Paulo (Figure 5).







Two cases (0.66% of the total, or 16.66% of injuries per aquarium animal) were caused by black sea-urchins (Echinometra lacunter) (Figure 6). One accident was due to a yellow moray eel (Gimnothorax ocellatus), and one to a freshwater catfish (mandijuba, or Pimelodus maculates). The latter case was the only injury caused by a freshwater fish (0.33% of the total, or 8.33% of aquarium-related accidents).



All of the wounds ached with greater or lesser intensity. The severest injuries, accompanied by physical indisposition, were caused by lionfish and rays. The victims suffered accidents when the aquariums were being cleaned or while handling animals for feeding or other care. Nine accidents occurred in domestic aquariums, two with aquarium shop clerks and one in an exhibition tank for large fish. Patients used treatments such as urine, injectable analgesic, or alcohol. Only one patient used hot water in which to immerse the injury site. Only half of the victims were aware of the risks posed by handling the animals, and of the type of precautions that must be taken when doing so.



All of the wounds occurred in aquariums. Needless to say, wounds must be carefully washed with water and soap. Fragments of fish stingers, stones, sand and other material from the wound must necessarily be withdrawn. An antiseptic, like alcohol or iodine, may be used after intensive washing. Small inflammations always occur in the wake of traumas from aquatic environments. But if erythema or edema does not disappear within a day or two, or if fever and indisposition appear, a cutaneous infection may be manifesting itself, as observed in the cases shown in this series.

Poisoning by aquatic animals is treated in various ways depending on the causative animal involved in the process. Injuries by corals, anemones and, more seldom, by jellyfish or 'Portuguese man-of-war', may be controlled by compresses or by immersing the affection in cold sea water (freshwater tends to let off nematocysts, i.e. the urticant cells of the tentacles aggravating the condition). Vinegar baths also help by neutralizing the venom. Sea-urchin spicules must be withdrawn in a hospital because they are brittle, and fragments remaining in the skin may lead to aching nodules that can only be healed by surgery. Wounds caused by venomous fish improve well by immersing the affected point in hot but tolerable water, since fish venom is unstable in heat and degenerates.1 These measures must always be applied when the pain is incompatible with the injury, which is an unequivocal sign of poisoning. Injuries provoked by catfish, marine catfish, scorpionfish, lionfish, moray eels, and freshwater and marine stingrays, must always be treated at the outset with hot water. They may later require medical assistance at a hospital. Traumatic wounds, like those caused by piranhas, surgeonfish or the dorsal fin of various fish must be treated with care by following the general measures already described in this study for wounds occurring within aquariums.

Finally, it is recommended that large rubber gloves be used when there is a need to introduce one's hands into an aquarium (whether it be a domestic one, or not), because even stones and ornamental objects may carry highly pathogenic bacteria. The use of nets is recommended for handling dangerous animal species. (In fact, nets should always be used whenever one has to deal with any aquatic animal). Poisoning is not common, but may occur if the necessary means are not taken and proper information on the animal is not made available to the aquarist. The aquarist must be aware that small cuts and scratches acquired within household aquariums pose a risk similar to those to which persons are exposed in Nature, if not a greater one. A small trauma must be treated with attention so as to avoid severe complications. q



The authors of this paper would like to express their thanks to Doctors João Luiz Costa Cardoso, Francisco Oscar Siqueira Franca and Silvio Alencar Marques for their assistance and allowing access to observing cases at the Hospital Vital Brazil ("Instituto Butantan").



1. Haddad Jr V. Atlas de animais aquáticos perigosos do Brasil: guia médico de identificação e tratamento (Atlas of Brazilian dangerous aquatic animals: a medical guide of diagnosis and treatment). São Paulo: Editora Roca, 2000: 145 pp.        [ Links ]

2. Thomas C, Scott S. All stings considered: first aid and medical treatment of Hawai'i's Marine Injuries. United States of America: University of Hawai'í's Press, 1997: 100-157.        [ Links ]

3. Millington JT, Wihelm P. Marine microbiology of Roca Alijos. J Wild Med 1983; 4: 384-390.        [ Links ]

4. Haddad Jr V, Miot HA, Camargo RMP, Chiaro A. Cutaneous sporotrichosis associated with a puncture in dorsal fin of a fish (Tilapia sp): report of a case. Medical Micology 2002; 40(4): 425-427.        [ Links ]

5. Haddad Jr V, Novaes SPMS, Miot HA, Zuccon A. Acidentes causados por ouriços-do-mar - eficácia da extração precoce das espículas na prevenção de complicações. An bras Dermatol 2002; 77(2): 123-128.        [ Links ]

6. Haddad Jr V, Gonzales MT. Acidentes provocados por mandis (Pimelodus sp): estudo clínico em uma comunidade de pescadores em Santa Maria da Serra (SP). Resumo. In: Anais do VI Simpósio da Sociedade Brasileira de Toxinologia, Março 15-18, 2000. São Pedro: 2000.        [ Links ]

7. Schiera A, Battifoglio ML, Scarabelli G, Crippa D. Stingray injury in a domestic aquarium. Int J Dermatol 2002; 41(1): 50-1.        [ Links ]

8. Haddad Jr V, Martins IA, Makyama HM. Injuries caused by scorpionfishes (Scorpaena plumieri Bloch, 1789 and Scorpaena brasiliensis Cuvier, 1829) in the Southwestern Atlantic Ocean (Brazilian coast): epidemiologic, clinic and therapeutic aspects of 23 stings in humans. Toxicon (In Press).        [ Links ]

9. Haddad Jr V, Cardoso JLC, França FOS, Hui FH, Malaque CMS. Acidentes por lionfishes (Pterois volitans): relato de dois casos observados no Hospital Vital Brazil (Instituto Butantan - SP). Resumo. In: Anais do LIII Congresso Brasileiro de Dermatologia, Setembro 5-9, 1998. Blumenau: 1998.        [ Links ]



Correspondence to
Vidal Haddad Junior
Departamento de Dermatologia e Radioterapia
Faculdade de Medicina de Botucatu
Caixa Postal 557
18618-000 Botucatu SP

Received in August, 01st of 2003
Approved by the Consultive Council and accepted for publication in February, 18th of 2004



* Work done at "Faculdade de Medicina de Botucatu - Universidade Estadual Paulista e no Hospital Vital Brazil, Instituto Butantan, São Paulo".

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