Paulo Vitor Portella Silveira

Aeromonas hydrophila soft-tissue infection as a complication of snake bite: report of three cases.

Aeromonas hydrophila soft-tissue infection has been associated with fish and reptile bites. There have bee three recent cases from Brazil of abscesses complicating snake bites in which A. hydrophila was isolated from the purulent exudates. One of the snakes responsible for the bites was a specimen of Bothrops moojeni, and the others were most probably also lance-headed vipers. These snakes have a local necrotizing, myotoxic, oedema-inducing venom that must have favoured the multiplication in the injured tissue of A. hydrophila strains, which were probably present in the mouth, fangs or venom of the snakes. The use of a tourniquet by two of the patients probably worsened the local envenoming, and contributed to the occurrence of soft-tissue infection. The patients had a good outcome after the abscesses were incised and drained, and after being treated with chloramphenicol. Chloramphenicol appears to be a good alternative for the empirical treatment of soft-tissue infection complicating snake bite in Brazil, because: it is active against the majority of the anaerobic and aerobic bacteria found in these abscesses, including A. hydrophila; it can be administered by the oral route; and its is inexpensive. Suitable alternatives are cotrimoxazole or fluoroquinolones, to which aeromonads are usually susceptible in vitro, associated with antibiotics, such as clindamycin and metronidazole, with an anti-anaerobic spectrum.

Philodryas patagoniensis bite and local envenoming

A 5-year-old boy bitten by a specimen of Philodryas patagoniensis, a colubrid snake currently classified as nonvenomous, developed signs of local envenoming characterized by swelling and warmth on the bitten limb. This is the first time that local envenoming following Philodryas patagoniensis bite is recognized. Based on the clinical findings and misidentification of the snake, the patient was treated as a victim of Bothrops bite, having received unnecessarily the specific antivenom. Educational efforts to make doctors and health workers capable to identify correctly venomous snakes are necessary, to avoid inappropriate indication of antivenom and decrease the risk of its potentially harmful untoward effects. Examination of the bite site can be useful to the differential diagnosis between pit viper and colubrid bites.

Non-venomous snake bite and snake bite without envenoming in a brazilian teaching hospital: analysis of 91 cases

A retrospective survey of 473 cases of snake bite admitted to a Brazilian teaching hospital from 1984 to 1990 revealed 91 cases of bite without envenoming and/or caused by non-venomous snakes. In 17 of these cases the snake was identified, and one patient was bitten by a snake-like reptile (Amphisbaena mertensii). In 43 cases diagnosis was made on clinical grounds (fang marks in the absence of signs of envenoming). The other 30 cases were of patients who complained of being bitten but who did not show any sign of envenoming or fang mark. Most cases occurred in men (66;73%), in the 10-19 years age group (26;29%), in the lower limbs (51/74;69%), between 6 A. M. and 2 P.M. (49;61%) and in the month of April (16;18%). One patient bitten by Philodryas olfersii developed severe local pain, swelling and redness at the site of the bite, with normal clotting time. The patient bitten by Drymarcon corais was misdiagnosed as being bitten by a snake of the genus Bothrops, was given the specific antivenom, and developed anaphylaxis. One patient bitten by Sibynomorphus mikanii presented prolonged clotting time, and was also given antivenom as a case of Bothrops bite. Correct identification of venomous snakes by physicians is necessary to provide correct treatment to victims of snake bite, avoiding unnecessary distress to the patient, and overprescription of antivenom, which may eventually cause severe untoward effects.

South American rattlesnake bite in a Brazilian teaching hospital. Clinical and epidemiological study of 87 cases, with analysis of factors predictive of renal failure

Records of 87 victims of rattlesnake bite who were admitted to a teaching in south-eastern Brazil from 1984 to 1990 were retrospectively examined. The patients came from 27 municipalities in 3 states. Most of the bites (47%) occurred between 10.00 h and 18.00 h and in April (13%). Identification of the snake was possible in only 17% of the cases, diagnosis being made on clinical grounds in the others. The lower limbs were the most common site of bite (85%). The median time interval between bite and receiving medical help was 3 h. Fang marks were observed in 47% of the cases, neurotoxic facies in 61%, and myalgia in 29%. Dark urine was reported in 40% of the cases. Clotting time was above 15 min in 53% of the tested cases. Use of a tourniquet before admission to hospital was reported 11 times. The mean dose of specific antivenom was 190 +/- 95.69 mg. The case fatality rate was 1%; 13 cases (18%) developed renal failure, 10 of whom needed dialysis. The chi 2 test for trend showed that both increased age and increased time interval between bite and medical help significantly increased the risk of renal failure (P < 0.02). Myalgia and neurotoxic facies were predictive of renal failure in patients older than 40 years (Fishers exact test, P < 0.002 and P < 0.02, respectively). There was no significant association between dark urine or prolonged clotting time and renal failure.

Occupational injuries with captive lance-headed vipers (Bothrops moojeni): experience from a snake farm in Brazil.

Summary We studied occupational injuries with captive lance‐headed vipers (Bothrops moojeni) that occurred in a snake farm in south‐eastern Brazil from February 1981 to May 1999. The risk of injury, taking into account 13 cases of snake‐associated injuries (12 of them snake bites) was 2.73 per 10000 person‐days of work, and 3.51 per 100000 venom extractions. Thirteen cases of injury occurred in seven workers, whereas 18 workers were never injured, suggesting that some individuals have a higher risk of injury than others perhaps due to lack of concentration or overconfidence. Eight episodes of occupational injuries occurring in four technicians, including a case of eye injury due to splashed venom during extraction, are reported. Assessment of whether envenoming occurred was facilitated by knowledge of the snake species and size, history of recent venom extraction and snake feeding, and examination of snake venom glands. Hypersensitivity reactions (anaphylaxis and serum sickness) to antivenom are a risk particularly to those workers who were bitten more than once and medicated previously. Antivenom therefore should not be administered to these individuals unless there is clear evidence that envenoming occurred or is likely to have occurred. Hypersensitivity to the venom is also a health concern for workers from snake farms.

Bite marks are useful for the differential diagnosis of snakebite in Brazil

OBJECTIVE To assess whether examination of the bite marks could be useful for the differential diagnosis between venomous and nonvenomous snakebite. DESIGN Assessment of the validityof the bite marks in the differential diagnosis betweenvenomous and nonvenomous snakebite in a series of patients prospectively recruited in a 32-month period. SETTING Teaching hospital in a southeastern Brazilian town. PATIENTS Forty-two victims of snakebite who brought the captured or dead snake for identification and who had recognizable bite marks. INTERVENTION Inspection of the bite site, recording the aspect of the marks either as isolated fang punctures or as multiple scratch-like teeth marks. RESULTS The presence of isolated fang marks, when related to venomous snakebite, had a sensitivity of 100%, a specificity of 56%, and a predictive value of 89%. The finding of multiple, scratch-like teeth marks had a predictive value of 100% when related to nonvenomous snake bite. CONCLUSIONS Examination of the bite marks showed to be useful for the differential diagnosis between venomous and nonvenomous snakebites in Brazil, which has implications for the option of empirical administration of antivenin to patients when the snake is not available for identification.

Lance-headed viper (Bothrops moojeni) bite wounding the eye

A 5-year-old girl was bitten in her left eye by a lance-headed viper identified as Bothrops moojeni, measuring 115 cm of length. There was severe facial swelling and left exophthalmus, and enucleation of the eye was necessary. The patient apparently had mild systemic envenoming, but local inflammatory signs and histological evidence of necrosis suggest that both the mechanical trauma and the local action of the venom had a role in the genesis of the eye lesion. It is arguable if the loss of the eye could be prevented even if the antivenom was administered earlier.

South American rattlesnake bite and soft-tissue infection: report of a case

The case of a man bitten by a South American rattlesnake (Crotalus durissus) and who developed an abscess at the site of the bite is reported. Abcesses are a rare complication of this type of envenoming, possibly due to the lack of a strong cytotoxic action of Crotalus durissus venom.

Scorpion sting on the penis.

A 58-year-old man was stung on the penis by a scorpion of the species Tityus serrulatus. The patient felt a severe sharp local pain that did not improve until he presented to the hospital 12 hours later. Block of the dorsal nerves of the penis with 1% lidocaine led to immediate relief of the pain. The aim of treatment of a Tityus scorpion sting on the penis, without systemic manifestations, should be concentrated on relief of the pain. Local or regional block with a local anesthetic is the treatment of choice. The use of the specific antivenom is recommended only for cases of systemic manifestations, particularly in children.

Botulism: considerations about eight cases occurred in Triângulo Mineiro, Minas Gerais, Brazil

Botulism constitutes a rare form of intoxication, particularly in our country. The only confirmed outbreak of this disease in Brazil occurred in the 50s in Rio Grande do Sul where nine persons acquired the disease after ingestion of home-canned fish. The present work reports an outbreak of type A botulism which occurred in eight members of the same family of whom seven contracted this food toxic infection after ingestion of home-canned pork. Two persons died and the others recovered after variable time of evolution. After eleven months a new case of botulism was diagnosed, but the source of this intoxication could not be found. The authors intend with this work to divulge the second confirmed outbreak of botulism in Brazil and to direct a special attention to ootulism clinical pictures, diagnostic and treatment pratically unknown in our country.