Comparison of polymerase chain reaction with culture and enzyme immunoassay for diagnosis of pertussis

The risk for human infection with Lyme disease appears linked to the abundance of infected vector ticks, principally Ixodes dammini Spielman, Clifford, Piesman & Corwin, in the eastern United States. Habitat destruction by burning, although not well studied, has long been considered as an effective alternative to synthetic insecticides as a means of reducing tick populations. We evaluated the effect of a single spring burning of the woodland understory on the transmission risk of Lyme disease spirochetes (Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner) on Shelter Island, Long Island, NY. Following a burn in early April 1991, the abundance of nymphal I. dammini was 49% lower in the burned portion of a woodlot compared with the unburned portion. However, risk of encountering nymphs infected with B. burgdorferi remained similar in both burned and unburned woods. It is suggested that burning vegetation may disproportionately kill deer-derived rather than rodent-derived nymphs, significantly reducing tick abundance without affecting transmission risk.     

Gentamicin dosage in children with extensive burns

During the treatment of Gram-negative bacillary infections in severely burned children, it was noted that administration of standard dosages of gentamicin commonly produced inadequately low serum concentrations of the antibiotic. Pharmakokinetic studies demonstrated that mean peak serum gentamicin levels were significantly lower in 18 burned children as compared with peak serum levels in five unburned children. Furthermore, inadequately low peak serum levels (less than 3.0 mug/ml) were observed in 15 of 18 burned children and in only one unburned child. Clearance studies in two children suggested that the increased requirement for gentamicin can result from either loss of the antibiotic across burn wounds or increased urinary excretion. These studies indicate that the therapy of severe infections in children with major burns often requires administration of gentamicin at higher doses and more frequent intervals than usually employed.     

Temporal correlations between tick abundance and prevalence of ticks infected with Borrelia burgdorferi and increasing incidence of Lyme disease

The abundance of host-seeking Ixodes scapularis nymphs, the principal vector for the Lyme disease agent, Borrelia burgdorferi, in Old Lyme, Lyme, and East Haddam, Connecticut, was compared with the incidence of reported human Lyme disease in the 12-town area around the Connecticut River and the State of Connecticut for the period 1989 to 1996. Ticks were sampled from lawns and woodlands by dragging flannel over the vegetation and examined for the presence of B. burgdorferi by indirect fluorescent antibody staining. The infection rate of the nymphal ticks by B. burgdorferi during the 9-year period was 14.3% (of 3,866), ranging from 8.6% (1993) to 24.4% (1996). The incidence of Lyme disease was positively correlated with tick abundance in the 12 town area (r = 0.828) and the State of Connecticut (r = 0.741). An entomological risk index based upon the number of I. scapularis ticks infected by B. burgdorferi was highest in 1992, 1994, and 1996 and was highly correlated with the incidence of Lyme disease in Connecticut (r = 0.944). The number of Lyme disease cases has been influenced, in part, by annual changes in population densities of I. scapularis and, presumably, a corresponding change in the risk of contact with infected ticks. Based upon tick activity and spirochetal infection rates, epidemiologically based Lyme disease case reports on a regional scale appear to reflect real trends in disease.     

Implementing a computer-based mammography education project in a managed care setting

The authors evaluate the mortality of severely burned children hospitalized in the Intensive Care Unit, Prague Burns Centre from 1994 till 1997. There were hospitalized 345 children (aged 3 months-15 years, 1%-88% TBSA, mixed superficial and deep burns). No child died from burn shock during the early postburn period. Five children who died suffered deep burns greater than 50% of TBSA and at necropsy there were identified signs of multiple organ system failure which was related to infection.     

Reduction of progressive burn injury by a stable prostaglandin I2 analogue, beraprost sodium (Procylin): an experimental study in rats

Beraprost sodium is a chemically stable prostaglandin I2 analogue with antiplatelet and vasodilator actions. Burn injury causes thrombosis and vessel occlusion by increasing the blood viscosity and by thermal damage to the vascular network in the dermis. A vascular response also occurs in the uninjured dermis surrounding the site of injury. Diminished blood flow and spreading tissue oedema lead to progressive ischaemia and necrosis around the burn site (zone of stasis), with the final necrotic tissue area being larger than the initial one. If blood flow could be restored in the zone of stasis, secondary tissue damage would be minimized. In this study, we examined the effects of a prostaglandin I2 analogue, beraprost sodium (Procylin, Kaken Pharmaceutical Company, Tokyo, Japan) on burn injury in rats. Twenty male Sprague-Dawley rats weighing an average of 450 g were burned with a comb-shaped brass probe that produced a row of three burns measuring 10 x 30 mm each and two intervening unburned areas measuring 5 x 30 mm each. The rats were divided into two groups of 10 animals. One group received 0.015 mg of beraprost sodium intraperitoneally immediately after burn injury, while the control group received the same volume of saline. Skin blood flow was measured with a laser Doppler flowmeter, and the development of oedema as well as the area of necrotic tissue were also determined. The extent of skin necrosis and oedema were significantly reduced in the beraprost sodium-treated rats, and blood flow in the zone of stasis was increased. These findings demonstrate that prostaglandin I2 plays an important role in burn injury and that beraprost sodium can reduce secondary necrosis in the zone of stasis.     

Geographic risk for lyme disease and human granulocytic ehrlichiosis in southern New York state

Ixodes scapularis, the tick vector of Lyme disease and human granulocytic ehrlichiosis (HGE), is prevalent in much of southern New York state. The distribution of this species has increased, as have reported cases of both Lyme disease and HGE. The unreliability of case reports, however, demonstrates the need for tick and pathogen surveillance in order to accurately define areas of high risk. In this study, a total of 89,550 m2 at 34 study sites was drag sampled in 1995 and a total of 51,540 m2 at 40 sites was sampled in 1996 to determine tick and pathogen distribution in southern New York state. I. scapularis was collected from 90% of the sites sampled, and regionally, a 2.5-fold increase in nymphal abundance occurred from 1995 to 1996. I. scapularis individuals from all sites were infected with Borrelia burgdorferi in 1995, while an examination of ticks for both B. burgdorferi and the agent of HGE in 1996 confirmed that these organisms were present in all counties; the average coinfection rate was 1.9%. No correlation was found between estimated risk and reported cases of Lyme disease. The geographic disparity of risk observed among sites in this study underscores the need for vector and pathogen surveillance on a regional level. An entomologic risk index can help identify sites for targeted tick control efforts.     

Management of severe burns during the 1st 72 hours

Early and efficient management of severely burned patients facilitates outcome improvement. Pre-hospital care includes fluid loading with 2 mL.kg-1/% burn over the first six hours, sedation and analgesia, prevention of hypothermia and ventilatory support for either critically burned patients or facial, cervical or pulmonary burn injury. The transient stay in a general hospital before transfer to a burn centre allows extension of initial care, the critical investigation for associated injuries (intoxication, multiple trauma) and to perform initial local treatment with sterile coverage or vaseline gauze after a revised assessment of the burned skin area, and possibly escharotomies. The main aim of care in the burn centre is to control hypovolaemia and to obtain maximal tissue perfusion and oxygen delivery to burned tissues, as well as to healthy organs. To manage the burn shock (initially hypovolemic and later on hyperdynamic) catecholamines are often indicated when appropriate fluid loading remains insufficient. Mechanical ventilation is indicated in case of either a deep extensive burn over 60% of total body surface area, or facial and cervical burns or severe pulmonary burn injury from smoke inhalation, carbon monoxide intoxication, tracheobronchial thermal injury and blast injury. Because of the severity of burn-related pain, and the stimulus linked to intensive care, continuous sedation is usually required. Early surgical treatment such as escharotomies, excision and grafting, which cause significant pain as well as blood loss, and hydrotherapy, often require general anaesthesia. Burn injury can modify the volume of distribution and the pharmacokinetics of anaesthetic agents. Finally, chemical or electrical burn, radiation, associated CO intoxication or multiple trauma, as well as burn injury in infants, raise specific problems. With improvement in early intensive care, the survival rate of the most severely burned patients is obviously improving. New techniques in skin substitution will probably further improve the final outcome.     

Effects of the feeding process of Ixodes scapularis (Acari: Ixodidae) on embryonic development of its parasitoid, Ixodiphagus hookeri (Hymenoptera: Encyrtidae)

The chalcid wasp Ixodiphagus hookeri (Howard) is a parasitoid of several ixodid ticks including the blacklegged tick, Ixodes scapularis Say. We evaluated effects of the feeding process of nymphal I. scapularis on the embryonic development of I. hookeri. Potentially wasp-parasitized nymphal I. scapularis were collected on Prudence Island, RI. Subsamples of the questing nymph cohort were allowed to feed on laboratory white mice. Both the body length and the scutal length of ticks were measured individually for questing nymphs and for feeding nymphs that were removed from hosts at time intervals of 12, 24, 36, 48, and 72 h after attachment. The diameters of wasp eggs they contained were also measured for each designated time interval. There was a positive relationship between the mean scutal index (ratio between body length and scutal length) of ticks and the mean diameter of wasp eggs during 72 h of tick feeding (P < 0.05). Moreover, it appeared that within 24 h of tick attachment, the scutal index of ticks remained unchanged. However, after that period, the scutal index increased significantly (P < 0.05). Diameters of wasp eggs increased continuously during tick feeding and at 72 h after attachment, enclosed eggs and completely formed larvae were found in several ticks. We conclude that factors related to the feeding process of nymphal I. scapularis are necessary to initiate the embryonic development of wasps.     

Burn repetitions in Ghanaian children: prevalence, epidemiological characteristics and socioenvironmental factors

This paper reports the prevalence, epidemiological characteristics and socioenvironmental-factors for burn repetitions in Ghanaian children newborn to 5 years old using a population-based survey. Mothers of children identified in a survey with burn scars were interviewed to obtain information on each child's demographics and the burn event, among others. Burn repeaters were compared with non-repeaters (children burned just once). Of 630 children identified with burns, 20 (3.2 per cent) had been burned twice. This statistic is significantly lower than expected from the known burn prevalence of 6.1 per cent in the region (P < 0.01). Burn repeaters included nine (45 per cent) children aged 24-35 months, 11 (55 per cent) males, and 9 (45 per cent) rural residents. The mean time interval between repeat burns was 9.6 months. While different mechanisms caused the two burns in 14 children, six were burned by the same mechanism. None of the demographic and socioenvironmental variables examined was significantly associated with burn repetition. It is concluded that since burn repetitions are low and share similar epidemiological characteristics with first-time burns, prevention efforts need not address repeat burns separately from burns in general.     

Mortality determinants in massive pediatric burns. An analysis of 103 children with > or = 80% TBSA burns (> or = 70% full-thickness)

OBJECTIVE: Survivors and nonsurvivors among 103 consecutive pediatric patients with massive burns were compared in an effort to define the predictors of mortality in massively burned children. SUMMARY BACKGROUND DATA: Predictors of mortality in burns that are used commonly are age, burn size, and inhalation injury. In the past, burns over 80% of the body surface area that are mostly full-thickness often were considered fatal, especially in children and in the elderly. In the past 15 years, advances in burn treatment have increased rates of survival in those patients treated at specialized burn centers. The purpose of this study was to document the extent of improvement and to define the current predictors of mortality to further focus burn care. METHODS: Beginning in 1982, 103 children ages 6 months to 17 years with burns covering at least 80% of the body surface (70% full-thickness), were treated in the authors' institution by early excision and grafting and have been observed to determine outcome. The authors divided collected independent variables from the time of injury into temporally related groups and analyzed the data sequentially and cumulatively through univariate statistics and through pooled, cross-sectional multivariate logistic regression to determine which variables predict the probability of mortality. RESULTS: The mortality rate for this series of massively burned children was 33%. Lower age, larger burn size, presence of inhalation injury, delayed intravenous access, lower admission hematocrit, lower base deficit on admission, higher serum osmolarity at arrival to the authors' hospital, sepsis, inotropic support requirement, platelet count < 20,000, and ventilator dependency during the hospital course significantly predict increased mortality. CONCLUSIONS: The authors conclude that mortality has decreased in massively burned children to the extent that nearly all patients should be considered as candidates for survival, regardless of age, burn size, presence of inhalation injury, delay in resuscitation, or laboratory values on initial presentation. During the course of hospitalization, the development of sepsis and multiorgan failure is a harbinger of poor outcome, but the authors have encountered futile cases only rarely. The authors found that those patients who are most apt to die are the very young, those with limited donor sites, those who have inhalation injury, those with delays in resuscitation, and those with burn-associated sepsis or multiorgan failure.     

Fatal systemic mycotic infections in the burned child

Two cases of systemic phycomycotic burn wound infection occurred in severely burned children. Both patients, although treated aggressively, died after systemic colonization through the burn wound by fungi. Modern burn therapy has increased survival of many severely burned children but opportunistic fungal infection remains as an ominous threat. Early recognition, wide excision or amputation, and systemic antifungal agents comprise the current clinical armamentarium against systemic fungal invasion of burn wounds.     

Determining the duration of Ixodes scapularis (Acari: Ixodidae) attachment to tick-bite victims

The duration of tick attachment is one factor associated with risk for human infection caused by several tick-borne pathogens. We measured tick engorgement indices at known time intervals after tick attachment and used these indices to determine the length of time that ticks were attached to tick-bite victims in selected Rhode Island and Pennsylvania communities where the agents of Lyme disease and human babesiosis occur. The total body length and width as well as the length and width of the scutum were measured on nymphal and adult female Ixodes scapularis Say removed from laboratory animals at 0, 12, 24, 36, 48, 60, and 72 h after their attachment. Three engorgement indices were calculated at each time interval. In addition, engorgement indices measurements were recorded for 504 ticks submitted to a commercial laboratory for pathogen detection testing between 1990 and 1992. No detectable change was observed in the average engorgement indices for either nymphal or adult ticks between 0 and 24 h of attachment using any of the engorgement indices. After 24 h of tick attachment, all engorgement indices continuously increased: average indices for nymphs attached 36, 48, and 60 h were significantly different from those attached < or = 24 h and from each other. Similarly, average engorgement indices for adult ticks attached < or = 36 h were significantly different from those attached for 48 h or more. More than 60% of tick-bite victims removed adult ticks by 36 h of attachment, but only 10% found and removed the smaller nymphal ticks within the first 24 h of tick feeding. The duration of tick attachment may serve as a useful predictor of risk for acquiring various infections, such as Lyme disease and babesiosis, transmitted by I. scapularis. Regression equations developed herein correlate tick engorgement indices with duration of feeding. A table containing specific engorgement index prediction intervals calculated for both nymphs and adults will allow the practitioner or clinical laboratory to use easily measured tick engorgement indices to predict transmission risk by determining the duration of feeding by individual ticks.     

Reduced abundance of Ixodes scapularis (Acari: Ixodidae) with exclusion of deer by electric fencing

To assess the effect of deer exclusion on populations of Ixodes scapularis Say (formerly I. dammini Spielman, Clifford, Piesman & Corwin) in the northeastern United States, host-seeking ticks and ticks on white-footed mice, Peromyscus leucopus (Rafinesque), were monitored inside and outside a wooded, residential deer exclosure (approximately 3.5 ha) in Lyme, CT, in 1991 and 1992. Another deer exclosure was added in Lyme (approximately 7.4 ha) during 1992. Additional sample sites at other residences served as secondary controls. A seven-wire, slanted, high-tensile electric deer fence was used at both areas. Larvae of I. scapularis were 81.5% (1991) and 97.8% (1992) less abundant within the exclosure than immediately outside the deer exclosures. Nymphs of I. scapularis were 47.4% (1991) and 55.8% (1992) less abundant within the deer fence. The effect on adult ticks was mixed. No difference in tick abundance was seen at the 3.5-ha site. However, larvae, nymphs, and adults were 100, 83.8, and 74.1% less abundant, respectively, in plots at the 7.4-ha exclosure > or = 70 m from the deer fence and isolated from woodlands outside the fence by lawns, driveways, and buildings. The recovery of larvae and nymphs of I. scapularis from mice captured within the deer exclosures indicates that infestations of nymphs and adults are probably, at least in part, a result of the movement of these rodents. Based upon the number of nymphs per 100 m2 infected with Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner, the causal agent of Lyme disease, there were 73 and 82% fewer infected nymphs within the deer exclosures in 1992 in comparison with the number of infected ticks outside the fence and at the secondary control sites, respectively. The exclusion of deer in conjunction with other tick control strategies in large areas could substantially reduce populations of I. scapularis and the risk of acquiring Lyme disease.     

Catabolic hormones alone fail to reproduce the stress-induced efflux of amino acids

OBJECTIVE: To determine the impact of catabolic hormones on the pattern of amino acid efflux from human skeletal muscle during stress. DESIGN: Cohort analytical study. SETTING: Burn intensive care unit and clinical research facility at a university hospital. PATIENTS: Five patients with severe burns and five healthy volunteers of similar size and age. INTERVENTIONS AND MEASUREMENTS: The net balance of amino acids across the leg was determined in five healthy volunteers prior to and following a 2-hour infusion of the catabolic hormones epinephrine, cortisol, and glucagon into the femoral artery. These results were compared with amino acid net balance measurements in five severely burned patients. RESULTS: Hormonal simulation of stress in the normal volunteers increased glutamine efflux from the leg to an extent similar to that of the burn patients. Alanine efflux, however, was not affected by the hormonal infusion. Because alanine efflux constituted a major proportion of the total peripheral amino acid catabolism in the burn patients, there was significantly less total amino acid nitrogen loss from the healthy volunteers receiving the stress hormones. CONCLUSIONS: Catabolic hormones alone fail to reproduce the stress-induced pattern and quantity of amino acid efflux from human skeletal muscle. This discrepancy is largely due to an unresponsiveness of alanine to hormonally induced muscle protein catabolism.     

Cryopreserved cadaveric allografts for treatment of unexcised partial thickness flame burns: clinical experience with 12 patients

Partial thickness burns (PTB) usually heal within 3 weeks. Prevention of infection and desiccation of the wounds are crucial for optimal healing. Early tangential excision of the burn eschar and allografting prevent deepening of the burns, and are therefore advocated for treatment with the best functional and aesthetic results. For superficial partial thickness burns (SPTB) conservative use of topical antimicrobial agents with frequent dressing changes are implemented. We compared the conservative treatment for PTBs and SPTBs to grafting cryopreserved cadaveric allografts with no prior excision. Twelve patients with flame PTB areas were allografted after mechanical debridement without excision of the burn wounds. The allografts were cadaveric skin cryopreserved by programmed freezing and stored at -180 degrees C for 30-48 months. Matching burns for depth and area were treated with silver sulfadiazine (SSD) one to two times daily until healing or debridement and grafting were required. It was found that 80 per cent of the cryopreserved allografts adhered well and 76 per cent of the treated areas healed within 21 days, whereas only 40 per cent of the SSD-treated burns healed within 21 days. Partial thickness burns can be treated successfully with viable human allografts (cryopreserved cadaveric skin) with no prior surgical excision. The burn wounds heal well within 3 weeks. For deep partial thickness burns (DPTB) treatment with allografts has no advantage if they have not been previously excised.     

Burns during pregnancy: a gloomy outcome

The effect of burns on fetal and maternal survival is known to be detrimental. This prospective study describes the performance of pregnant burned patients who were managed and followed up for fetal and maternal outcomes at Ain Shams University's burn unit and Maternity Hospital during the period from October 1995 to September 1996. During the 12-month period, 27 pregnant burned patients were managed. Fetal and maternal mortality correlated with the total body surface area (TBSA) burned, the mortality rate being 63 per cent for both mothers and fetuses in the 25-50 per cent TBSA group. A fetal loss of 56 per cent with no maternal loss were recorded in the 15-25 per cent TBSA group. Experience in dealing with pregnant burned patients proves that early surgical excision and skin grafting, with timely termination of pregnancy are the best lines of treatment. Prevention or minimizing the effects of the burns may be achieved by proper education and guidance of the pregnant woman.     

Individual pharmacodynamics assessed by antilymphocyte action predicts clinical cyclosporine efficacy in psoriasis

The vector competence of 2 tick species, Ixodes ricinus (L.) and Ixodes scapularis Say, was determined and compared for 3 genospecies of Borrelia burgdorferi. The 3 genospecies of B. burgdorferi used in the following experiments were Borrelia burgdorferi sensu stricto (B-31 and B-31.D1 clone), Borrelia afzelii (strain Pgau. C3), and Borrelia garinii (strain VS286 and VSBP). Spirochetes from all 5 strains were inoculated intradermally into outbred mice; larval ticks of both species were subsequently fed on those mice and replete larvae were assayed for infection by culture in BSK-H media every 7 d for 4 wk. Infection frequencies in I. scapularis exposed to the 5 strains were as follows: B-31 (90%), B-31.D1 (83%), Pgau.C3 (87%), VS286 (10%), and VSBP (5%). The comparable infection frequencies for I. ricinus were B-31 (3%), B-31.D1 (3%), Pgau.C3 (90%), VS286 (5%), and VSBP (3%). Resultant nymphal I. scapularis successfully transmitted B-31, B-31,D1, Pgau.C3, and VS286 to outbred mice. I. ricinus nymphs transmitted Pgau.C3 and VS286. Both species failed to transmit strain VSBP.     

Molten metal burns: early treatment improves outcome

Molten metal burns have received relatively little attention in the surgical literature. We performed a retrospective chart review of 150 patients who sustained molten metal burns between 1972 and 1997. The injuries all occurred in male foundry workers, most commonly from molten aluminum (60%). The typical accident was that of a splatter spill, creating a full-thickness burn. The mean burn size was 2.3 per cent of the body surface area (range, 0.25-25%). The lower extremities were the most commonly injured areas (85%), yet 37 per cent of patients had multiple sites burned. Patients were often initially treated nonoperatively and then referred to a surgeon when the wound failed to heal. Hospitalization was necessary in 89 patients at a mean of 16 days after the injury, and 92 patients required an operation, most commonly excision of the wound with skin grafting. The mean length of hospital stay was 11.2 days, and mean absence from work was 72.6 days. Fifty-one patients treated by the burn surgeon within 2 weeks of injury had a mean length of disability significantly shorter than those referred late (53.5 vs. 83.4 days; P < 0.05). We believe that an underestimation of the severity of these burns often leads to a delay in correct therapy and extends disability.     

Occupational burns in Washington State, 1989-1993

Occupational burns cause significant morbidity in the United States each year; however, there are few studies that report industries or workplaces where workers are at an increased risk of burn injuries. Washington State's Department of Labor and Industries (L and I) computerized workers' compensation database was used to describe work-related burns over 5 years. From 1989 to 1993, L and I accepted 27,323 claims for occupational burns, 71.4% of them thermal burns and 26.8% chemical burns. The most common sources of injury were cooking oils (14%) and hot water/steam (13%). Workers involved in food preparation or food handling accounted for the highest proportion of injured workers (30%). Industries involved in the smelting, sintering, or refining of ore had the highest rate for thermal burns, with a rate of 15.0 burn injuries per 100 full-time equivalent workers per year, followed by paper, pulp, or wood fiber manufacturing, with a rate of 5.8, then roof work, with a rate of 4.3. Industries involved in hazardous waste landfill clean-up had the highest rate for chemical burns, with a rate of 4.9, followed by portable cleaning and washing, with a rate of 3.5, and paper, pulp, and wood fiber manufacturing, with a rate of 2.6. Further study is needed to identify work practices that result in burn injuries in order to decrease the incidence of this preventable occupational injury.     

Molecular and clinical study of 61 Angelman syndrome patients

This is the first study of of posttraumatic stress symptoms in parents (24 mothers and one father) of children with burns. The purpose of the study was to determine what factors relate to parental posttraumatic stress disorder (PTSD). Because the sample is all mothers, except for one father, the conclusions are about mothers. Through use of the Structured Clinical Interview for DSM-III-R, symptoms were determined as occurring from the time of the burn injury until 1 month before the interview (past), 1 month before the interview only (present), or from the date of the burn trauma up to and including 1 month before the interview (past and present). By Structural Clinical Interview criteria, 52% of the mothers had past PTSD, with four (31%) of those mothers having present PTSD symptoms. Eleven mothers and the one father reported neither past nor present PTSD. Multiple regression analysis revealed that larger burns were more strongly related to present PTSD symptoms than were proximity, social support, or perceived stress. Additional findings indicated that mothers with more than one child burned and those mothers who were burned themselves met diagnostic criteria for PTSD. Implications are that posttraumatic stress symptoms can be disruptive to a mother feeling capable of caring for her child with burns after the injury. Individual and group therapy during and after a child's hospitalization may be useful for mothers to reduce stress and to develop better coping skills.