Dog bites in children admitted to Pennsylvania trauma centers

Dog bites are a major public health problem in the pediatric population, requiring emergency treatment for wound repair and possible hospitalization in a trauma center. Data from the Pennsylvania Trauma Outcome Study were analyzed, and the records of 183 pediatric dog bite patients from 1990 to 1995 were evaluated. Dog bites were found to constitute a very small proportion of the total pediatric admissions to Pennsylvania trauma centers; however, the findings were similar to other reported studies.     

Conspecific aggression in the laboratory rat.

In 2 experiments, attacks by dominant colony males of a domesticated rat strain (Sprague-Dawley; N = 48) on conspecific strangers introduced into the colony included both a full range of threat displays and actual biting attack. These dominant males attacked and bit both anesthetized and unanesthetized strangers, but threat displays and bites to anesthetized rats were limited. Lesions resulting from these bites were nonrandomly distributed, with most damage to the head and upper back and very few bites to ventral surfaces. When introduced strangers were left in the colonies for several days, 66% were killed, indicating that domesticated rats are capable of lethal attacks on conspecifics without external provocation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bacteriologic analysis of infected dog and cat bites. Emergency Medicine Animal Bite Infection Study Group

BACKGROUND AND METHODS: To define better the bacteria responsible for infections of dog and cat bites, we conducted a prospective study at 18 emergency departments. To be eligible for enrollment, patients had to meet one of three major criteria for infection of a bite wound (fever, abscess, and lymphangitis) or four of five minor criteria (wound-associated erythema, tenderness at the wound site, swelling at the site, purulent drainage, and leukocytosis). Wound specimens were cultured for aerobic and anaerobic bacteria at a research microbiology laboratory and, in some cases, at local hospital laboratories. RESULTS: The infected wounds of 50 patients with dog bites and 57 patients with cat bites yielded a median of 5 bacterial isolates per culture (range, 0 to 16) at the reference laboratory. Significantly more isolates grew at the reference laboratory than at the local laboratories (median, 1; range, 0 to 5; P<0.001). Aerobes and anaerobes were isolated from 56 percent of the wounds, aerobes alone from 36 percent, and anaerobes alone from 1 percent; 7 percent of cultures had no growth. Pasteurella species were the most frequent isolates from both dog bites (50 percent) and cat bites (75 percent). Pasteurella canis was the most common isolate of dog bites, and Past. multocida subspecies multocida and septica were the most common isolates of cat bites. Other common aerobes included streptococci, staphylococci, moraxella, and neisseria. Common anaerobes included fusobacterium, bacteroides, porphyromonas, and prevotella. Isolates not previously identified as human pathogens included Reimerella anatipestifer from two cat bites and Bacteroides tectum, Prevotella heparinolytica, and several porphyromonas species from dog and cat bites. Erysipelothrix rhusiopathiae was isolated from two cat bites. Patients were most often treated with a combination of a beta-lactam antibiotic and a beta-lactamase inhibitor, which, on the basis of the microbiologic findings, was appropriate therapy. CONCLUSIONS: Infected dog and cat bites have a complex microbiologic mix that usually includes pasteurella species but may also include many other organisms not routinely identified by clinical microbiology laboratories and not previously recognized as bite-wound pathogens.     

A survey of snakebit in the Johannesburg area

Case records of persons with snakebite treated at the Johannesburg General Hospital and the Transvaal Memorial Children's Hospital during the 10-year period 1963-1972 were investigated. It was concluded that (i) snakebites were rare, since only 39 cases were recorded, none of which ended fatally; (ii) 86% of patients were men (mean age was 24 years); (iii) 80% of bites were on the hand and arm; (iv) 28% of patients had had previous snakebites; and (v) 60% of bites were 'illegitimate', i.e. they occurred in snake handlers. Apart from occasional bites by exotic snakes in collections, the venomous snakes responsible for the majority of bites were, in order; ringhals, puff adder, and burrowing adder. The first two snakes are common in the region, while amateur herpetologists are at particular risk of being bitten by burrowing adders because of the snake's ability to bite even when held by the back of the neck. Ringhals bites, although the most common, caused virtually no morbidity. Bites by other venomous snakes showed considerable variation in morbidity, suggesting that many different factors must be taken into account when the nature and effects of snakebite are assessed. Eighty-five per cent of snakes were positively identified, mostly by the snake fanciers they had bitten. This permitted specific treatment.     

Rhabdomyolysis in European viper bite

The case of a child who presented with severe rhabdomyolysis associated with renal failure after a viper bite is reported. Rhabdomyolysis is a serious complication resulting from systemic envenomation and is uncommon after viper bites in Europe. It may be due to oedema, myotoxic agents and haemorrhagic factors and may be responsible for two types of potentially fatal complications, i.e. acute renal failure and hyperkalaemia. The present case highlights the need to investigate routinely for rhabdomyolysis after viper bites. Antivenom therapy is recommended as soon as signs of envenomation are present, without waiting for the onset of complications.     

Maximizing constructivist learning from multimedia communications by minimizing cognitive load.

Students viewed an animation depicting either the process of lightning formation or how car brakes work and listened to a corresponding narration describing the steps. The entire animation and narration were presented at the same time (concurrent), the entire narration was presented before or after the entire animation (successive large bites), or short portions of the narration were presented before or after corresponding short portions of the animation for each successive portion of the presentation (successive small bites). Overall, the concurrent and successive small bites groups performed significantly better than the successive large bites groups on remembering the explanation in words (retention), generating solutions to transfer problems (transfer), and selecting verbal labels for elements in a line drawing (matching), but they did not differ significantly from each other. Results are consistent with a dual-process model of working memory in which learners are more likely to construct connections between words and corresponding pictures when they are held in working memory at the same time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Acute necrotizing cutaneous streptococcal infection following bites or scratch by dog or cat

INTRODUCTION: Domestic animal bites or scratches are quite frequent. Among banal bacteria isolated from infected bites or scratches, group A streptococcus seems to be frequently associated with severe infections. CASE REPORTS: Three cases of acute necrotizing cutaneous streptococcal infections, following cat or dog bite or scratch are reported. Twice, group A streptococcus was isolated from cutaneous swabs. In the third case, previous antibiotic therapy had sterilised bacteriological samples. Diagnosis was ascertained on the basis of clinical presentation and significant antistreptococcal antibodies elevation. Skin necrosis around the inoculation area was observed in the 3 cases. Cicatrisation required an average of two months under appropriate treatment. DISCUSSION: An evolution towards cutaneous necrosis localized to the initially injured area is common to these three cases. This peculiar evolution is worth to be known in order to choose an effective anti streptococcal antibiotherapy whenever domestic animals bites and scratches are to be treated.     

Transitional cell carcinoma of the ureteral stump 13 years after nephrectomy for benign disease

OBJECTIVE: To estimate the magnitude of the dog bite problem in the US. METHODS: Data on dog bites were gathered as part of a 1994 national telephone survey of 5,238 randomly dialed households. Data were weighted to provide national estimates. RESULTS: The weighted total number of dog bites was 4,494,083 (estimated incidence = 18/1,000 population); of these, 756,701 persons sustained bites necessitating medical attention (incidence rate = 3/1,000). Children had 3.2 times higher medically attended bite rates than adults (6.4/1,000 children v 2/1,000 adults). CONCLUSIONS: More attention and research needs to be devoted to the prevention of dog bites. Potential prevention strategies include: educational programs on canine behavior, especially directed at children; laws for regulating dangerous or vicious dogs; enhanced animal control programs; and educational programs regarding responsible dog ownership and training. Unfortunately, the relative or absolute effectiveness of any of these strategies has not been assessed. Continuing surveillance for dog bites will be needed if we are to better understand how to reduce the incidence of dog bites and evaluate prevention efforts.     

Experience with blackbrush affects ingestion of shrub live oak by goats

Generalization occurs when an animal responds to novel stimuli in much the same way it has responded to similar, familiar stimuli. Our objective was to determine whether goats generalized foraging skills from older growth blackbrush (Coleogyne ramosissima) to shrub live oak (Quercus turbinella). Blackbrush (OGBB) has small leaves that are difficult to ingest without the twigs, whereas shrub live oak (SLO) has larger leaves that can be ingested easily without twigs. In Yr 1, 6-mo-old goats and in Yr 2 18-mo-old goats were given experience browsing with OGBB for 0, 10, 20, or 30 d. They were next tested for 5 min/d for 2 d on OGBB, and then tested in the same way on SLO. The number of bites and bite rate increased significantly as goats of both ages gained experience browsing OGBB. Likewise, goats with more experience browsing OGBB took more bites during a 5-min period when foraging on SLO. Thus, goats generalized foraging skills from OGBB to SLO. Plant life form also affected the response of goats. Total intake, intake rate, and bite size were significantly higher for SLO than for OGBB. There was an interaction between level of experience and plant life form. The interaction occurred because goats with no experience browsing OGBB took more bites per 5 min of SLO than of OGBB, whereas goats with increasing levels of experience browsing OGBB generally took more bites of OGBB than of SLO. Controls took more bites per 5 min of SLO than of OGBB, because SLO leaves could be ingested (harvested and chewed) more easily than OGBB twigs.     

The Inventory of Functional Status-Dialysis: development and testing

Pet and wildlife populations are a potential source of various public health problems, and injuries and complications due to animal bites and scratches are the most obvious. As no population based data on the frequency of animal bites were available at a national level in Switzerland, a study was conducted by the Swiss Sentinel Surveillance Network. The objectives of this study were to estimate the incidence of medical consultations due to bite and scratch injuries in humans caused by vertebrate animals, to identify possible risk factors, and to assess bite management habits in primary health care. An annual bite and scratch incidence rate of 325 per 100,000 population was estimated. Consultations peaked during the summer months and geographical differences in the reported incidence were observed. Dogs accounted for more than 60% and cats for about 25% of all cases reported. Animal bites and scratches were frequent in persons under 20 years of age. In most ages, the incidence was higher among women than among men, but not in children under the age of ten years. The incidence of cat bites was especially high in adult women. Bites to the head and neck were most frequent in infants and young children and accounted for approximately one third of the reported cases in this age group. Patients sought medical care principally for primary wound care (52.0%) and for vaccination advice (29.6%). Rabies postexposure prophylaxis was initiated in 1.1% of patients. Wound infection was reported in 10.9% of cases, with cat bites/scratches being more often infected than injuries due to dogs. Hospitalization was reported in 0.3 % of patients. Data from the emergency department of two district hospitals showed that head and neck injuries were more frequent in out-patients and a higher proportion of persons presented with wound infections (14.1%). The hospitalization rate for emergency department visits was 4.7%. Animal bites and scratches are common events in Switzerland. They represent a public health issue of growing importance due to the steadily increasing pet population. A practice based sentinel surveillance system may be an appropriate tool to monitor national trends in animal bites and scratches.     

Envenoming and antivenom use in Australia

Australia has a diverse and rich venomous fauna, both terrestrial and marine, including some of the most venomous species in each class. Antivenom is the principal therapy for the majority of medically significant envenomings and is currently supplied through a single source, CSL, Melbourne. Cases of envenoming reported to Australian poisons information centers (PICs) are dominated by spiderbite and insect stings, respectively accounting for 53.7% and 39.3% of all bite/sting calls. Marine animal bites/stings/poisonings account for only 4% of PIC calls in this category, while snakebites account for a mere 3% (still at least 400 calls/yr). Because most PIC calls are from the public, not doctors/hospitals, snakebite in particular is under-represented. The author has recently reviewed antivenom usage in Australia. Snakebite affects between 1,000 to 3,000 people per year, with an average annual mortality of about 2 cases. Brown snakes (genus Pseudonaja) cause the majority of deaths (and bites), with tiger snakes (genus Notechis) and taipans (genus Oxyuranus) accounting for nearly all other fatalities. Up to 500 cases require snake antivenoms each year, the majority of cases coming from rural areas of Queensland, Western Australia, New South Wales and Victoria, these being the most populated states. The wide availability of snake venom detection kits has allowed specific antivenom to be used more often, rather than polyvalent antivenom, but the latter is still used in nearly 30% of cases, suggesting underutilization of venom detection. The issue of premedication prior to antivenom remains unresolved. Antivenom usage and complication data for 1995 and 1996 will be presented. Red back spider antivenom is the most commonly used antivenom, with reports of usage being greater than for all other antivenoms combined. It is reported as being therapeutically efficacious in 94% of cases, with a single ampoule being used in 76% of cases, 2 ampoules in 18% of cases, and 3 or more ampoules in 6% of cases. Clinical experience suggests only 20% of red back spider bites require antivenom therapy. It is likely that between 5-10,000 bites occur annually.     

Distribution and movement of infective-stage larvae of Dipetalonema viteae (Filarioidea) in the vector tick, Ornithodoros tartakowskyi (Argasidae)

To determine the behavior of Dipetalonema viteae in its tick vector, Ornithodoros tartakowskyi, the ticks were fed on jirds at successive intervals of 30 to 35 days after a single infective blood meal, and the number of larvae passing from the tick during each bite was determined by recovery of: 1) adult worms from the jirds' tissues; 2) larvae from skin snips taken at the feeding site immediately after the bite; and 3) larvae from serum and tissue after artificial feeding through a skin-membrane. All methods gave similar results. Ticks harboring few larvae released most of them (82%) during the first bite, and required only 2 bites to transmit all. Ticks with moderate or heavy infections required 3 or 4 bites to transfer all larvae. Factors which may explain this are: 1) relatively short duration of the bite of heavily infected ticks due to irritation and damage to the muscles of mouthparts and pharynx by the larvae; 2) resistance of the anterior alimentary tract to penetration by the larvae; and 3) retarding effects of crowding on development and migration of larvae. Aging of infection in the tick apparently did not influence the rate of transfer of larvae. Infection adversely affected the feeding and retarded the molting of young nymphs, but with the loss of larvae in successive bites the ability to suck blood was regained.     

Differentiation of bite force response in the rat.

Investigated differentiation of the bite force response by training 9 male rats to obtain water reinforcement by emitting bites with peak forces within 4 different bands of forces 500-gm wide. All Ss learned to bite with peak forces within each of the required bands, although the average maximum percentage of correct bites/session was only approximately 70%. Data are compared with those from studies of differentiation of the paw-press force response, and it is concluded that the differentiation process is similar in the 2 dissimilar response systems. Because of the generality of differentiation findings across motor systems, it is suggested that methods and results from studies of response differentiation might be used to increase the understanding of motor system function. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Wounds of the hand contaminated by human or animal saliva

A prospective and retrospective evaluation of 75 patients with hand wounds contaminated by human saliva (35) or animal saliva (40) demonstrates that a program of outpatient management can be sufficient for optimal care in many patients. This series challenges the proposition that hospitalization, radiographs, and surgical debridement are necessary for most such wounds. Sixty-seven per cent did not have surgical intervention and no complications resulted. Ninety-two per cent received antibiotics. Radiographs were obtained only when bony injury or entry into a joint was suspected. Delay in seeking treatment until obvious signs of infection or pain are present is common. Literature review details the anatomic factors important in the natural history and control of these infections, and the changes with respect to modes of treatment for these potentially dangerous wounds. The injury is caused by bites with the hand extended or, in fight-bite wounds, with the metacarpal-phalangeal and interphalangeal joints flexed, allowing deeper penetration and then sealing of the wound when the first is opened. Staphylococcus and Streptococcus are the organisms most frequently found in human bites, and in animal bites; Pasteurella multocida should be considered in dog and cat bites.     

Long-term analgesic reaction in attacked mice.

Four experiments were designed to characterize long-term analgesic (LTA) reaction in attacked mice. In Experiment 1 we showed that analgesic reaction in DBA/2 mice, induced by the stress of being attacked (30 or 50 bites), is reinstated upon reexposure to seven bites 24 hr later. The magnitude of the LTA response depended on the level of analgesia on Day 1 and was smaller than the original response. In Experiment 2 we showed that LTA was prevented by naloxone or beta-chlornaltrexamine given before exposure (50 bites) on Day 1. Results of Experiment 3 revealed that naloxone or beta-chlornaltrexamine injected before reexposure to seven bites on Day 2 antagonized LTA measured 10 min, but not 1 min, after reexposure. In Experiment 4 we showed that morphine substituted for being attacked on Day 1 failed to produce LTA. We concluded that pain inhibitory mechanisms remain in a state of increased readiness for at least 24 hr after attack stress and that activation of opioid systems is necessary but not sufficient to produce LTA, a response that is only partly sensitive to opioid antagonists. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Use of time-series analysis in infectious disease surveillance

This study evaluates the impact of rice fields in the city of Bouaké on anopheline fauna and malaria transmission. The Anopheles species represents between 11.4 to 39.2% of mosquitoes in the districts with rice fields and 5.2 to 47.8% in lowland districts with market-gardening. An. gambiae constitutes more than 98% of anopheline population in the city. In the lowland districts with market-gardening, biting rates of An. gambiae varied from 3650 to 6935 bites per man per year. Seasonal variations were correlated with rainfall. The mean annual parturity rate was 72% and the mean sporozoitic index 2%. Malaria transmission started at the beginning of the rainy season and attained its height during the second half of this season. Depending on the district, inhabitants were infected with 78 to 134 bites per year. The mean biting rate of An. gambiae in the districts with rice fields varied from 4745 to 22,630 bites per man per year. Seasonal variations were not correlated with rainfall, but with the growth of rice and the two annual cycles of rice cultivation. The parturity rates of the population of An. gambiae were low (46.2% to 57.2%), especially after rice transplantation. The mean infection rates were between 0.7 and 1.0%. The transmission period covered 7 to 11 months depending on the district with two annual peaks observed at the end of rice cultivation. Inhabitants were infected with 44 to 155 bites per year. Rice fields in Bouaké do not seem notably to have modified malaria transmission in the city.     

Trypanosoma cruzi: effect of immunization on the risk of vector-delivered infection in guinea pigs

The protective effect of experimental immunization was studied in guinea pigs exposed to vectorial infection by Trypanosoma cruzi. Immunized animals received an inoculum of live-attenuated T. cruzi epimastigotes into a granuloma previously induced by Freund's complete adjuvant in the hind footpad. Seven days later, a delayed-type hypersensitivity reaction was triggered by reinjection of the parasites in the front footpad. The animals were then placed in Triatoma infestans-colonized corrals and exposed to vectorial T. cruzi transmission of the parasite for up to 200 days. The effectiveness of this immunizing protocol was controlled in terms of the number of bites necessary for infection (NBNI) in immunized as compared with control animals. Periodic entomological census allowed for the determination of vector biting and infection rates and the calculation of NBNI. Although this measurement was quite variable between yards, an overall average of 4,973 bites was enough to infect a control guinea pig in 4 separate experiments. The corresponding figure for the experimental group was 21,307 bites, implying that immunized animals could resist a 4.28-fold increase (range: 1.99-8.32) in the number of vector bites before becoming infected.     

In vivo observation of the eating behavior of obese and nonobese subjects.

Patrons of a cafeteria were observed unobtrusively while eating an evening meal. Observers noted the occurrence of extraneous responses, counted bites and chews, and rated tension, mood, and food enjoyment. A pattern emerged for thin Ss: smaller bites, slower bites, more extraneous responses, more food left on plate, and less time spent at table after meal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Schedule-induced polydipsia: An artifact.

Conducted 6 experiments with 4 female rats in which they were allowed access to Noyes pellets for 1 hr/day with water freely available at all times. The food was presented either ad lib or in a lever-pressing situation on various interval schedules of reinforcement. The size of the individual reinforcements ("bites") was varied between experiments. Schedule-induced polydipsia was obtained when the S's meal consisted of a large number of very small bites. When the meal consisted of a smaller number of larger bites, polydipsia did not occur. The experiments collectively indicate that the amount of water consumed while eating is a function of the number of bites taken and independent of bite size or total food consumption. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Variability of impedivity in normal and pathological breast tissue

Bite wounds have a special position in traumatology because of their high complication rate compared to similar soft tissue wounds caused by other reasons. The authors report in a retrospective study about the results of 525 patients with bite wounds. In 98 (18.7%) cases the wounds were sutured primarily after surgical revision when there was no sign of infection. Antibiotic therapy (a combination of amoxicillin and clavulan acid) was given to 109 patients (20.8%) who had infected wounds or who were at greater risk for infection (e.g., extremely large wounds, large hematoma). Antibiograms were only made when the wounds had already been infected. The total infection rate came to 11.8%, with 5.2% infected facial bites, 11.3% lower extremity, 18.6% upper extremity and 18.8% hand bite wounds. The infection rate after primary suture was 10.2% (3.2% at the face, 18.8% at the upper extremity and 25% each in the hand and the lower extremity). The average time period from the trauma to the first medical treatment amounted to 11 h in the infected wounds and 2 h in the non-infected ones. Cat bites became infected in 37.5%, dog bites in 14.9%.