Failure of chloramphenicol prophylaxis to reduce the frequency of abscess formation as a complication of envenoming by Bothrops snakes in Brazil: a double-blind randomized controlled trial.

Bites by many species of venomous snake may result in local necrosis at, or extending from, the site of the bite. The use of prophylactic antibiotics to prevent infection as a complication of local necrotic envenoming is controversial. A double-blind randomized controlled trial was carried out to assess whether antibiotic therapy is effective in this situation. Two hundred and fifty-one patients, with proven envenoming by snakes of the genus Bothrops, admitted to two hospitals in Brazil, between 1990 and 1996, were randomized to receive either oral chloramphenicol (500 mg every six hours for five days) or placebo. One hundred and twenty-two of these patients received chloramphenicol (group 1) and 129 were given placebo (group 2). There were no significant differences between the groups at the time of admission. Necrosis developed in seven (5.7%) patients in group 1 and in five (3.9%) patients in group 2 (P>0.05) while abscesses occurred in six patients (4.9%) in group 1 and in six (4.7%) patients in group 2 (P>0.05). In conclusion, the use of orally-administered chloramphenicol for victims of Bothrops snake bite with signs of local envenoming on admission, is not effective for the prevention of local infections.

Atrioventricular pacemaker. Incidence and causes of reprogramming in long-term follow-up.

OBJECTIVE: To assess the incidence of problems requiring reprogramming of atrioventricular pacemakers in a long-term follow-up, and also the causes for this procedure. METHODS: During the period from May '98 to December '99, 657 patients were retrospectively studied, An actuarial curve for the event reprogramming of the stimulation mode was drawn. RESULTS: The follow-up period ranged from 12 to 178 months (mean = 81 months). Eighty-two (12.4%) patients underwent reprogramming of the stimulation mode as follows: 63 (9.5%) changed to VVI,(R/C); 10 (1.5%) changed to DVI,C; 6 (0.9%) changed to VDD,C; and 3 (0.5%) changed to DOO. The causes for the reprogramming were as follows: arrhythmia conducted by the pacemaker in 39 (37.6%) patients; loss of atrial sensitivity or capture, or both, in 39 (38.6%) patients; and microfracture of atrial electrode in 5 (4.9%) patients. The stimulation mode reprogramming free probability after 15 years was 58%. CONCLUSION: In a long-term follow-up, the atrioventricular pacemaker provided a low incidence of complications, a high probability of permanence in the DDD,C mode, and the most common cause of reprogramming was arrhythmia conducted by the pacemaker.

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

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 10,000 person-days of work, and 3.51 per 100,000 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.

Neurohumoral behavior in recipients of cardiac pacemakers controlled by a closed-loop autonomic nervous system-driven sensor.

The purpose of a sensor-driven pacing system is to physiologically correct chronotropic incompetence (CI). The aim of this study was to evaluate the changes in heart rate provided by a sympathetically driven pacemaker (PM) compared with normal sinus function (NSF). Nine men and six women (age 37-80 years) with AV block and a PM controlled by a closed-loop system were studied. Group I included eight patients with CI, and group II included seven patients with NSF. All patients underwent Valsalva maneuver and tilt table testing with measurements of plasma catecholamines and renin activity. Pacing was initially programmed in the DDDC mode at a lower rate (60 ppm) and upper rate limit (0.85 x [220 - age]), then in DDDR in group I and VVIR in group II. The second phase of the study consisted of nitroglycerin and phenylephrine infusions, and the third phase of physiological provocative maneuvers. The second and third phases were performed in three patients from each group with sensor activity On and Off. In group I, heart rate changed during tilt only in the DDDR mode. In group II, heart rate changes were comparable in both modes. Catecholamine levels in group I were higher during DDDC than during DDDR pacing (P < 0.05). In group I, heart rate did not change during phases II and IV of the Valsalva maneuver in the DDDC mode, but behaved nearly physiologically after sensor activation. A late and a paradoxical response to nitroglycerin was observed in groups I and II and to phenylephrine in group I. During physiological maneuvers, significantly greater variations in heart rate were observed during DDDR than during DDDC pacing. Sympathetic SDP provides physiological modulations of the heart rate were provided by a sympathetically driven pacing system in patients with AV block and CI.

Monoartrite de joelho como manifestação isolada de paracoccidioidomicose / Monoarthritis of the knee as an isolated manifestation of paracoccidioidomycosis

Artrite como manifestação isolada de paracoccidioidomicose, tem sido raramente descrita na literatura médica. O presente relato, descreve mulher de 46 anos de idade, com monoartrite crônica do joelho em tratamento com anti-inflamatórios não hormonais durante 4 anos, cujo diagnóstico definitivo foi obtido apenas por biópsia da membrana sinovial, que revelou uma inflamação crônica granulomatosa de tipo tuberculóide, com abundantes elementos leveduriformes do Paracoccidioides brasiliensis. A terapêutica específica (iniciada com ketoconazol e seguida por cotrimoxazol) levou à completa recuperação funcional da articulação acometida. Não se detectou a presença de outros sítios acometidos pela doença, apesar da utilização de vários métodos propedêuticos, incluindo tomografia axial computadorizada do tórax e abdome. Os autores chamam a atenção para a raridade do caso e discutem os possíveis fenômenos fisiopatológicos responsáveis por esta monoartrite fúngica.

Osteoarthritis in paracoccidioidomycosis has been rarely reported. The present case describes a 36-[quot ]year[quot ]-old woman, with chronic monoarthritis in the knee lasting 4 years. The diagnosis was achieved only after synovial biopsy, by anatomopathological examination showing granulomatous reaction with a large number of the characteristic [quot ]pilot wheel[quot ]Paracoccidioides brasiliensis yeast cells. Specific therapy, initially with ketoconazole and followed by cotrimoxazole led to complete functional recovery of the compromised joint. No other affected site was detected by various propaedeutic methods, including computed axial tomography of the thorax and abdomen. The authors emphasize the rarity of the case and discuss its possible pathophysiology.

[Monoarthritis of the knee as an isolated manifestation of paracoccidioidomycosis]. / Monoartrite de joelho como manifestação isolada de paracoccidioidomicose.

Osteoarthritis in paracoccidioidomycosis has been rarely reported. The present case describes a 36-"year"-old woman, with chronic monoarthritis in the knee lasting 4 years. The diagnosis was achieved only after synovial biopsy, by anatomopathological examination showing granulomatous reaction with a large number of the characteristic "pilot wheel"Paracoccidioides brasiliensis yeast cells. Specific therapy, initially with ketoconazole and followed by cotrimoxazole led to complete functional recovery of the compromised joint. No other affected site was detected by various propaedeutic methods, including computed axial tomography of the thorax and abdomen. The authors emphasize the rarity of the case and discuss its possible pathophysiology.

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.

Neurocysticercosis in Brazilian children: report of 10 cases.

In a 6-year period, ten cases of neurocysticercosis were diagnosed in children with ages ranging from 4 to 13 years, in a Brazilian teaching hospital. Most of the children presented epilepsy and/or raised intracranial pressure, but meningoencephalitis and psychotic reactions were also observed. The cerebrospinal fluid (CSF) cell count ranged from 1 to 52 cells per mm3, with pleocytosis in 6 cases, mostly by lymphocytes and eosinophils. Antibodies to Cysticercus cellulosae were detected in the CSF in all cases. A cranial radiograph was abnormal in 5 out of 6 cases, and a computed tomographic (CT) scan in 4 out of 8 cases. Stool examination was positive for ova and/or proglottids of Taenia sp in 4 out of the 10 cases. Seven patients were treated with either praziquantel or albendazole plus dexamethasone; there were no important side effects, and surgical treatment was required in no case. Neurocysticercosis must be included in the differential diagnosis of seizures, raised intracranial pressure, meningitis and psychotic reactions in children living in or having travelled to the tropics. The diagnosis can be suspected by the presence of eosinophils in the CSF, and confirmed by imaging methods such as CT scans and by immunological tests in the CSF.

Pathology of patients with Chagas' disease and acquired immunodeficiency syndrome.

The main pathologic findings in 23 patients with acquired immunodeficiency syndrome (AIDS) and Chagas' disease are reviewed; five are from our own experience and 18 from the literature. The presence of Trypanosoma cruzi parasites and/or T. cruzi antibodies in blood and cerebrospinal fluid was recorded and computerized tomograms of the brain were evaluated. Twenty (87%) of the 23 subjects developed severe, multifocal or diffuse meningoencephalitis with necrosis and hemorrhage associated with numerous tissue parasites. The second most severely affected site was the heart. Seven (30.4%) of the 23 cases had myocarditis on pathologic examination. It was acute in four patients, chronic in two, and simultaneously acute and chronic in one. Acute myocarditis and meningoencephalitis are interpreted as being caused by relapses of chronic T. cruzi infections. An AIDS permissive role is suggested for these conditions since immunologic defense against T. cruzi is mediated mainly by T lymphocytes, whose CD4 subpopulation is depleted in patients with this disease. Consequently, AIDS is a factor that may favor the reactivation of T. cruzi infections. The lesions reported in the association of Chagas' disease with AIDS were compared with those reported from patients without AIDS having fatal, acute, vector-transmitted infections, contaminated blood transfusions, or accidental exposures in the laboratory. For the latter three, meningoencephalitis is uncommon. Only immunosuppressed cases of Chagas' disease have been described as having a pseudotumoral presentation that shows expanding lesions with a mass effect in the cranial cavity that causes intracranial hypertension and simulates neoplasms (tumors such as gliomas, lymphomas, metastases, etc.).

Pig bite in Brazil: a case series from a teaching hospital.

A retrospective survey done from 1987 till 1990 revealed that 23 patients bitten by pigs sought medical help at a teaching hospital in Uberlândia, in southeastern Brazil. Most cases (21) were from Uberlândia. The cases were evenly distributed by month and by year; most of them (14/16; 87.5%) occurred between 7.00 a.m. and 7.00 p.m. The male to female ratio was 6.7:1. Age ranged from 6 to 73 (mean 38.95 +/- SD 22.06, median 36). The bites were more common on the upper limbs, particularly on the forearms. In 11 (47.8%) cases the injury was described as deep. In most cases where information was available the injury was related to capture, transport or immobilisation of the pig for slaughter. The following medical procedures were performed: local cleansing in 19(82.6%) cases, rabies vaccine (12; 52.2%), antirabies serum (2; 8.7%), suturing (6; 26.1%) and tetanus vaccine (12; 52.2%). There was no case of infection at the bite site, neither of rabies or tetanus. By our data, the annual incidence of pig bite in Uberlândia can be estimated to be about 1.5/100,000.

An outbreak of vampire bat bite in a Brazilian village.

An outbreak of 26 cases of vampire bat bite in one month in the rural area of Honorópolis, a Brazilian village, is reported. All patients were bitten during the night, when they were asleep, and most bites were on their toes. No complication attributed to the bite was reported. The patients were given prophylactic antirabies serum and rabies vaccine. Control of the outbreak was achieved by visiting bat roosting sites, smearing captured vampire bats (Desmodus rotundus) with a paste of 2% warfarin in vaseline, and releasing them. No case of human or animal rabies was diagnosed in a 5-month follow-up. A possible explanation for the outbreak of bat bite is that, because of man-induced environmental modifications in their habitats, vampire bats in Honorópolis now live in the peridomiciliar area, where people are more exposed to their bites. An alternative explanation is related to the use in cattle of a pyrethroid insecticide to control the horn fly, Haematobia irritans, as both events were temporally related. The insecticide could have had a repellent effect on bats, that then started to seek alternative food sources.

Randomized comparative trial of three antivenoms in the treatment of envenoming by lance-headed vipers (Bothrops jararaca) in São Paulo, Brazil.

In São Paulo City, Brazil, 121 patients with moderately severe envenoming by Bothrops snakes (principally B. jararaca) were randomized for treatment with Brazilian polyspecific Bothrops antivenoms: Instituto Butantan (39 patients), Instituto Vital Brazil (41), Fundação Ezequiel Dias (FUNED) (41). The initial dose was four ampoules (40 ml) in 89 patients with less severe envenoming and eight ampoules (80 ml) in 32 patients with more severe envenoming. A second dose of four ampoules was required in 20 patients. Patients receiving the three antivenoms were comparable in all respects before treatment. There were no deaths. The majority showed rapid clinical improvement, resolution of local envenoming, cessation of bleeding and restoration of blood coagulability. No differences in the efficacy of the three antivenoms were revealed by clinical or laboratory observations, including measures of haematological, haemostatic and biochemical abnormalities. Twelve patients developed abscesses (Butantan 1, Vital Brazil 6, FUNED 5) and seven developed local necrosis (3,1,3). Of 88 patients followed up 20-30 days after the bite 33 (37.5%) still had symptoms or signs of local envenoming, especially swelling. Early (anaphylactic) reactions were unexpectedly frequent after all three antivenoms but were significantly more frequent with Butantan (87%) than with Vital Brazil (37%) or FUNED (56%) antivenoms (p < 0.001). A possible explanation was the higher total protein content and percentage immunoglobulin of Butantan antivenom. The doses of antivenom recommended in Brazil and used in this study may be unnecessarily high, resulting in an unacceptably high incidence of reactions. Results of the study should prompt a critical re-evaluation of antivenom production techniques and dosage recommendations in Brazil.

Trypanosoma cruzi meningoencephalitis and myocarditis in a patient with acquired immunodeficiency syndrome.

We report the case of a 52-year-old male heterosexual patient with acquired immunodeficiency syndrome (AIDS) and reactivation of Chagas' disease manifested by meningoencephalitis and myocarditis, diagnosed post-mortem. Unexplained reactivation of Chagas' disease should be included among the diagnostic criteria of AIDS in human immunodeficiency virus positive patients. On the other hand, AIDS should be considered in the differential diagnosis of patients with unexplained reactivation of Chagas' disease.