Postmortem Testing Research Articles

The Limits of Test-Based Scrapie Eradication Programs in Goats

Small ruminant post-mortem testing programs were initially designed for monitoring the prevalence of prion disease. They are now considered as a potential alternative to genetic selection for eradicating/controlling classical scrapie at population level. If such policy should be implemented, its success would be crucially dependent on the efficiency of the surveillance system used to identify infected flocks. In this study, we first determined the performance of post-mortem classical scrapie detection in eight naturally affected goat herds (total n = 1961 animals) according to the age at culling. These results provided us with necessary parameters to estimate, through a Monte Carlo simulation model, the performance of scrapie detection in a commercial population. According to this model, whatever the number of tests performed, post mortem surveillance will have limited success in identifying infected herds. These data support the contention that scrapie eradication programs relying solely on post mortem testing in goats will probably fail. Considering the epidemiological and pathological similarities of scrapie in sheep and goats, the efficiency of scrapie surveillance in both species is likely to be similar.

Possible natural MCF-like disease in a domestic lamb in Scotland

Malignant catarrhal fever (MCF) is a severe and usually fatal disease of ungulates, including domestic cattle, deer, bison and, occasionally, pigs (Reid and Buxton 1984, Loken and others 1998, Schultheiss...

Multiple bee stings, peritumoral mast cell degranulation and anaphylaxis – Is there a relationship?

A case of a 58-year-old with fatal anaphylaxis due to multiple bee stings is reported. Supportive evidence for anaphylaxis included post-mortem serum tests, which demonstrated a markedly elevated tryptase level and increased sensitivity to bees on radioallergosorbent test (RAST). At autopsy a previously undiagnosed esophageal adenocarcinoma involving the gastroesophageal (GE) junction was also identified. Histology of the tumor demonstrated significant numbers of mast cells, many of which were degranulating. Increased numbers of mast cells, as in mastocytosis, are known to predispose to an allergic sensitivity to Hymenoptera. The finding of a significant peritumoral mast cell population with degranulating forms in this case, therefore, raises the possibility that death due to anaphylaxis was contributed to by mast cell proliferation in an occult esophageal carcinoma.

Comparative infectious serology testing of pre- and post-mortem blood samples from cornea donors

Defined serological blood tests of deceased cornea donors are required to minimize the risk of viral infections of a transplant recipient as much as possible. Haemolysis, autolysis and bacterial contamination, may produce significant changes of post-mortem blood samples, which may lead to false serological test results. Pre- and post-mortem findings from the same cornea donors of the University Tissue Bank of the Charité in the years 2004-2009 (n = 487) were retrospectively analyzed and compared. The test results from pre-mortem blood samples were defined as the reference for the post-mortem blood test. Of 487 cornea donors, there were a total of 21 cases (4.3%) with discrepancies between serological test results from pre- and post-mortem blood samples. Of these, 7 values referred to the HBsAg-testing, 3 to the anti-HBs-, 1 to the anti-HBcIgG + IgM-, 1 to the anti-HCV-, 4 to the anti-HIV 1/2- and 5 to the TPLA-findings. False negative results within post-mortem serology occurred in 4 of 487 cases (0.8%). False positive results within the post-mortem blood samples occurred at a much more frequent rate, with 17 of 487 cases (3.5%). Discrepancies between serological pre- and post-mortem blood tests occur mainly due to the use of non-validated test systems. Therefore, it seems reasonable to test pre- and post-mortem blood samples serologically, whenever possible, at the same time, regardless of the sample age. Positive results, regardless of the sample type, should always be retested with validated confirmation tests (e.g. NAT), in order to differentiate between false and true positive results.

A commentary on changing infant death rates and a plea to use sudden infant death syndrome as a cause of death

In his editorial entitled Changing Infant Death Rates— Diagnostic Shift, Success Story, Or Both, Byard concludes that changes in rates away from sudden infant death syndrome (SIDS) towards another cause of death (COD) are appropriate [1]. Improved death scene investigations and autopsies leading to increased awareness of potential dangers imposed by infant sleep sites have been instrumental to the diagnostic shift occurring in cases of sudden unexpected infant death. Given abundant supportive data accumulating over the past few years, we certainly agree. But where do we go from here in order to bring about greater consensus and accuracy in establishing CODs in these cases? Over the past four decades, the original definition of SIDS [2] has undergone several refinements focusing principally on mandating death scene investigations, circumstances of death, association with sleep, and certainty of the COD [3–5]. Yet, each subsequent iteration has remained exclusionary with respect to the COD and is encumbered with its own diagnostic dilemmas given the lack of a pathognomonic postmortem marker, incomplete death scene investigations, and limited postmortem examinations and ancillary testing as well as philosophical differences with and objections to the concept of SIDS itself among death certifiers [6]. As a result, other labels including sudden unexpected death in infancy (SUDI), sudden unexpected infant death (SUID), unclassified sudden infant death (USID), Undetermined, and Unascertained, have gained wider currency in an ever increasing proportion of these challenging cases. The choice between SIDS and these latter COD certifications now often centers on death scene findings that suggest an asphyxial risk to the sleeping infant. However, present investigative methods neither precisely quantify nor determine the certainty of its lethality in the absence of reliable postmortem evidence of its significance; hence the slippery slope of COD assignment. The present uncertainty in analyzing the circumstances of death in these cases is demonstrated in our recent study wherein five pathologists blinded to one another and using a classification scheme focused on the estimated risk of asphyxia at the death scene as described in the investigative reports assigned a COD to 117 sudden infant death cases including 83 cases with SIDS as the original COD [7]. The reviewers concluded that the death scene contributed to or actually caused death in 32–50 % of the entire case study group and in 40–59 % of the 83 SIDS cases. Among the 83 original SIDS cases, SIDS as the COD decreased by 55–69 % and another COD was considered plausible in 2–12 % of the cases. Although SIDS remains an exclusionary COD, its underlying elements and the mechanism of death as hypothesized in the triple risk hypothesis are being unraveled [8]. According to this hypothesis, ‘‘SIDS, or an important subset of SIDS, is due to abnormal brainstem mechanisms in the control of respiration, chemosensitivity, autonomic regulation, and/or arousal which impairs the infant’s response to life-threatening, but often occurring, stressors during sleep (e.g., hypoxia, hypercarbia, asphyxia, hyperthermia) and leads to sudden death in a vulnerable developmental period’’ [9]. Thus, according to this hypothesis, SIDS infants who are intrinsically vulnerable as a result of underlying pathology must be exposed simultaneously to risk factors, such as prone sleep position, during their physiologically unstable stage of development during sleep, before they will succumb. This period of H. F. Krous (&) Department of Pathology, Rady Children’s Hospital, 3020 Children’s Way, M5007, San Diego, CA 92123, USA e-mail: hkrous@rchsd.org

Six fatal cases of classical rabies virus without biting incidents, Iran 1990–2010

BackgroundRabies is an endemic fatal zoonotic disease, commonly transmitted to humans through contact (bites and scratches) with infected animals. ObjectivesDuring the years 1990–2010, six patients with the clinical symptoms of rabies (fever, tinnitus, buzzing, delirium and hydrophobia), with no history of a bite, were diagnosed by physicians in Iran. To obtain laboratory confirmation of rabies infection, different clinical specimens from each patient were sent to the World Health Organisation (WHO) Collaborating Center for Reference and Research on Rabies, Pasteur Institute of Iran.The first case was a 39-year-old male veterinary technician who entered his uncovered scratched hand into the mouth of a rabid bovine and became infected. Two years later, a herd of sheep being tended by a shepherd and his two sons were attacked by a rabid wolf. All three individuals were infected when they applied burnt thorny wool to the sheep's wounds as a bandage. Their hands were scratched and then infected through contact with the remaining saliva of the rabid wolf on the sheep's wounds. In 1994, two other human cases occurred through corneal transplantation from the same donor who had died with the clinical signs of food poisoning (according to his hospital record), which probably was a misdiagnosis of rabies infection. Study designThis is a case series study that describes human rabies cases without biting incidents. According to the WHO recommendation, human rabies cases are notifiable, therefore, in Iran, a rabies surveillance system has been established to follow these cases. During the last decade, six patients with no ‘history of a bite’ were hospitalised with growing symptoms of rabies. The data were collected from each patient by the physicians and transferred to the Ministry of Health and Medical Education of Iran, and to the WHO Collaborating Center for Reference and Research on Rabies, Pasteur Institute of Iran as the only testing laboratory. Thus, they came to the attention of the surveillance system. Ante-mortem diagnosis was performed on saliva, cerebrospinal fluid and blood samples that were collected from the first patient by the physicians. Fresh brain specimens from all patients were kept in a mixture of 50% glycerol in phosphate-buffered saline and transported on ice to the WHO Collaborating Center for Reference and Research on Rabies. ResultsFor the first patient, rabies virus was investigated in saliva using the rapid tissue cell inoculation test (RTCIT) and the mouse inoculation test (MIT). Anti-rabies antibodies in this patient's serum and cerebrospinal fluid (CSF) were examined using the mouse neutralisation test (MNT). Fresh brain specimens from all patients were examined using the fluorescence antibody test (FAT) as recommended by the WHO laboratory manual in rabies as the post-mortem diagnostic test for rabies. Rabies infection was confirmed in all of the deceased patients. Anti-rabies antibodies were identified only in one patient's serum specimen. Testing also showed that the rabies virus isolated was the classic rabies virus (serotype 1), which is widespread in Iran. ConclusionsPrevention and control of this fatal disease require a sensitive surveillance system to follow ‘suspected’ animal and human rabies cases thoroughly through the improved reporting system, which contains the history of exposure, clinical examinations, symptoms and laboratory results. This study describes some notable human rabies infections and their transmission modes to prevent occupational accidents.

Clinical and Pathological Findings of Fatal 2009–2010 Pandemic Influenza A (H1N1) Infection in Estonia

The aim of this study was to analyze all deaths from A(H1N1) in Estonia during the 2009-2010 epidemic to find out the reasons of high mortality and optimize management strategies for future influenza epidemics. MATERIAL AND METHODS. A retrospective review of medical records, autopsy reports, and reassessment of autopsy slides of all fatal cases of proven A(H1N1) influenza in Estonia from October 2009 to May 2010 was carried out. RESULTS. There were a total of 21 proven fatal cases (median age, 57 years); the population mortality rate of 1.56 per 100000 inhabitants was one of the highest in the world. Altogether, 18 of the 21 patients had known risk factors for influenza, and 3 patients were previously healthy children. Three decedents had received antiviral treatment, and none had been immunized. There were 19 decedents autopsied, with viral pneumonia (58%) being the most frequent pathological finding; 40% had evidence of bacterial superinfection. In 4 cases, influenza was not clinically suspected and was diagnosed postmortem. Influenza was the primary cause of death in 15 decedents, while in 9 cases, comorbidities played a significant role in fatal outcome. In the remaining 4 cases, another illness was considered the primary cause of death with influenza as an accompanying factor. CONCLUSIONS. High autopsy rate and liberal postmortem PCR testing enables the detection of additional A(H1N1) influenza cases, yet it might lead to overestimation of the population mortality rates, especially in a small population with low number of events. Increased vaccine coverage, vigilant diagnosing including wide PCR testing, and early more liberal use of antiviral medications during the influenza A(H1N1) epidemic may hold the potential of lowering population mortality.

Sudden death of neuromyelitis optica: A case report of clinical missed diagnosis

Deaths of clinical miss-diagnosed diseases are caused by various reasons. Similar symptoms shared by different diseases and the recent medical history could affect the judgement of clinicians sometimes, especially when the disease is unusually found. We present a case of sudden death in hospital. Patient was admitted with sudden visual loss and quadriplegia. He died suddenly without certain pathogenesis next day. The medical history showed he had head injury recently. The autopsy revealed scattered inflammatory demyelination in optic nerves and spinal cord. Postmortem serological testing showed positive result of neuromyelitis optica-IgG. Therefore, the cause of death is severe respiratory distress due to acute neuromyelitis optica.

Differential gene expression segregates cattle confirmed positive for bovine tuberculosis from antemortem tuberculosis test-false positive cattle originating from herds free of bovine tuberculosis.

Antemortem tests for bovine tuberculosis (bTB) currently used in the US measure cell-mediated immune responses against Mycobacterium bovis. Postmortem tests for bTB rely on observation of gross and histologic lesions of bTB, followed by bacterial isolation or molecular diagnostics. Cumulative data from the state of Michigan indicates that 98 to 99% of cattle that react positively in antemortem tests are not confirmed positive for bTB at postmortem examination. Understanding the fundamental differences in gene regulation between antemortem test-false positive cattle and cattle that have bTB may allow identification of molecular markers that can be exploited to better separate infected from noninfected cattle. An immunospecific cDNA microarray was used to identify altered gene expression (P ≤ 0.01) of 122 gene features between antemortem test-false positive cattle and bTB-infected cattle following a 4-hour stimulation of whole blood with tuberculin. Further analysis using quantitative real-time PCR assays validated altered expression of 8 genes that had differential power (adj P ≤ 0.05) to segregate cattle confirmed positive for bovine tuberculosis from antemortem tuberculosis test-false positive cattle originating from herds free of bovine tuberculosis.

Heart rate variability analysis in sheep affected by transmissible spongiform encephalopathies

BackgroundThe function of the autonomic nervous system can be assessed by determining heart rate variability (HRV), which is impaired in some brainstem diseases in humans. Transmissible spongiform encephalopathies (TSEs) in sheep are diseases characterised by accumulation of disease-associated prion protein in the brainstem, including nuclei of the parasympathetic nervous system. This study was undertaken to assess whether analysis of HRV can be used as an aid in the diagnosis of TSEs in clinically affected, naturally or experimentally infected sheep.FindingsWhen HRV indices were compared between 41 clinical TSE cases (18 sheep infected with scrapie and 23 sheep infected with bovine spongiform encephalopathy), 11 control sheep and six sheep reported as scrapie suspects or dosed with BSE brain homogenate, which were not confirmed as TSE cases by postmortem tests, no significant differences were found between the groups. Median heart rate was significantly different but only when sheep were grouped by gender: it was higher in female TSE cases than in control sheep and higher in female than castrated male ovine classical BSE cases.ConclusionsHRV analysis was not useful as a diagnostic aid for TSEs of sheep.

Sudden Death After Exercise in an Adolescent With Hemoglobin SE

Hemoglobin (Hb) S and Hb E are the most common variant hemoglobins, but because of the geographical separation of the areas where they are prevalent, the combination of the 2 is uncommon. Approximately 46 cases of hemoglobin SE compound heterozygosity have been reported. No deaths from the condition have been reported previously, whereas death after vigorous physical activity in individuals with sickle cell trait (hemoglobin AS) has been described in a few case reports. Here we report previously undiagnosed hemoglobinopathy SE in a 12-year-old American boy who collapsed during football practice and had a cardiac arrest on the field after a brief lucid interval. The autopsy was significant only for postmortem intravascular sickling. A postmortem hemoglobin electrophoresis test revealed 57% S, 34% E, and 1% F hemoglobins. The death is attributed to cardiac ischemia from functional vaso-occlusion by sickled erythrocytes.

Fatal Infectious Diseases during Pandemic (H1N1) 2009 Outbreak

To the Editor: Nonpandemic infectious diseases occur with usual incidence during pandemics even though clinical attention is often on the pandemic pathogen. Many of these other infectious diseases share similar clinical signs and symptoms and are sometimes fatal. During the outbreak of pandemic (H1N1) 2009, tissue specimens from case-patients with undiagnosed fatal respiratory illnesses were submitted to the Infectious Diseases Pathology Branch at the Centers for Disease Control and Prevention (Atlanta, Georgia, USA) for evaluation for pandemic (H1N1) 2009 virus infection (1). All respiratory tissue specimens from 450 case-patients received during April 29, 2009–May 5, 2010, were screened by the Centers for Disease Control and Prevention real-time reverse transcription PCR (rRT-PCR) protocol for detection and characterization of swine influenza virus (2). Of these, specimens from 250 (56%) tested negative for pandemic (H1N1) 2009 virus and had no other confirmatory or prior influenza testing. Of these case-patients whose specimens tested negative for pandemic (H1N1) 2009 virus, a total of 139 (56%) were male, and the median age was 30 years (range 8 days to 81 years). The median duration from onset of illness to death was 7 days (range 1–40 days). Of the 164 case-patients with available medical records, 127 (77%) had >1 underlying or preexisting medical condition. When compared with case-patients during the same time who had pandemic (H1N1) 2009 virus infection confirmed by rRT-PCR, case-patients who were not infected with pandemic (H1N1) 2009 virus were more likely to be young (<9 years of age; odds ratio [OR] 2.23, 95% confidence interval [CI] 1.38–3.61) and less likely to be obese (OR 0.6, 95% CI 0.36–0.92) or have asthma (OR 0.33, 95% CI 0.16–0.68). Fever, cough, and shortness of breath were less frequently reported in the case-patients without pandemic (H1N1) 2009. On the basis of the histopathologic features observed in the respiratory tissues of the case-patients who were not infected with pandemic (H1N1) 2009, along with their clinical and epidemiologic information, the specimens were further evaluated by using special histochemical stains, immunohistochemical tests, and molecular assays. At least l etiologic agent was identified in specimens from 69 (28%) of the 250 specimens (Table). Bacterial pathogens were identified for 44 case-patients; Staphylococcus aureus and Streptococcus pneumoniae were the most frequently identified. Immunohistochemical tests and PCRs found evidence of viral agents in samples from 26 case-patients. Most of these were seasonal or unsubtypeable influenza A viruses; in a smaller subset, other respiratory viruses were detected, including respiratory syncytial virus and adenovirus. Multiple fungal pathogens were detected in specimens from 2 case-patients. Table Infectious agents identified in tissue samples from case-patients without pandemic (H1N1) 2009 virus infection, United States, 2009 For many of the diseases caused by the pathogens subsequently identified, the clinical features are predominantly respiratory, and many nonspecific manifestations are similar to those of influenza. Nonetheless, >50% of the patients in this study who died of suspected influenza had negative test results for pandemic (H1N1) 2009 virus, and for >25% of these, other infectious causes were detected. Infections other than influenza should be considered during a pandemic and during an endemic influenza season to facilitate the diagnosis of illness and treatment of patients with complications or severe respiratory infections. Although we did not conduct a case–control study, these findings also support the results of other studies that previously reported the demographic characteristics of patients with pandemic influenza infections and the risk factors for severe or fatal pandemic influenza infections (3,4), especially with respect to obesity (5). Evaluation of tissues collected during autopsy from patients with a suspected infectious process can provide an etiologic diagnosis that was not available from routine premortem and postmortem testing. Other etiologic agents detected in this study included reportable disease agents (e.g., Rickettsia rickettsii, Legionella pneumophila, dengue virus), vaccine-preventable diseases (e.g., pneumococcal, meningococcal diseases), and zoonotic agents (Leptospira and Capnocytophaga spp.). These findings underscore the need for autopsies for diagnosing fatal infectious diseases (6). They also confirm the need for coordinated surveillance programs that identify deaths potentially attributable to infectious causes, including the unexplained deaths program (7) and medical examiner infectious diseases death surveillance program (8). Partnerships of medical examiners and pathologists with local, state, and federal public health departments are crucial for detecting and monitoring pandemic diseases and for assessing the scope and magnitude of infectious agents that continuously affect human populations (9). These infections often result in sudden or unexplained death; thus, a standardized approach to death investigations is recommended.

Time and frequency domain analysis of heart rate variability in cattle affected by bovine spongiform encephalopathy

BackgroundHeart rate variability (HRV) analysis is a method to assess the function of the autonomic nervous system. Brainstem nuclei that influence HRV are affected by vacuolar changes and accumulation of disease-associated prion protein (PrPd) in bovine spongiform encephalopathy (BSE) resulting in clinical signs suggestive of an increased parasympathetic tone. It was hypothesised that BSE in cattle causes changes in the autonomic nervous system; this was tested by comparing HRV indices derived from 1048 electrocardiograms, which were recorded from 51 naturally or experimentally infected cattle with BSE confirmed by postmortem tests, 321 clinical suspect cases or cattle inoculated with potentially infectious tissue without disease confirmation and 78 BSE-free control cattle.FindingsStatistically significant differences were found for low or high frequency power, their normalised values and ratio when the last recording prior to cull or repeated recordings were compared but only between male and female cattle of the three groups and not between groups of the same gender, even though BSE cases of each gender appeared to be more nervous during the recording. The same findings were made for heart rate, deviation from the mean RR interval and vasovagal tonus index when repeated recordings were compared. BSE cases with severe vacuolar changes in the parasympathetic nucleus of the vagus nerve had a significantly lower low:high frequency power ratio but not a lower heart rate than BSE cases with mild vacuolation, whereas severity of vacuolar changes in the solitary tract nucleus or intensity of PrPd accumulation in both nuclei did not appear to have any affect on either index. Abnormalities in the electrocardiogram were detected in 3% of the recordings irrespective of the BSE status; sinus arrhythmia was present in 93% of the remaining recordings.ConclusionsHRV analysis was not useful to distinguish BSE-positive from BSE-negative cattle grouped by gender, and HRV indices appeared to be mainly influenced by gender. There is agreement with earlier studies that vacuolar changes in the brainstem may be associated with an increased parasympathetic tone in BSE and that abnormalities in an electrocardiogram can be detected in cattle without evidence of heart disease.

Post-mortem examination and laboratory-based analysis for the diagnosis of bovine tuberculosis among dairy cattle in Ecuador

Veterinary inspection in slaughterhouses allows for the detection of macroscopic lesions reminiscent of bovine tuberculosis, but the presence of Mycobacterium bovis must be confirmed by laboratory methods. This study aimed at comparing the performances of the standard diagnostic tools used to identify M. bovis in tissue specimens sampled from suspicious animals. During a two years period, 1390 cattle were inspected at the Machachi abattoir in the Mejia canton – Ecuador. A total of 33 animals with granulomatous lesions were detected, representing 2.33% (16/687) and 2.42% (17/703) animals examined in 2007 and 2008, respectively. Ninety-four tissue specimens were sampled and screened for the presence of mycobacteria. Acid-fast bacilli were identified in one third of the suspicious cattle (11/33) and suggestive microscopic lesions in 27.3% (9/33) of the samples examined by direct microscopy and histopathology, respectively. Culturing on Stonebrink medium and 16S-rRNA-based polymerase chain reaction (PCR) yielded 36.4% (12/33) and 27.3% (9/33) of positives, respectively. Compared to culture, other diagnostic procedures displayed a lower sensitivity, with 56.5% for PCR, and 43.5% for direct microscopy and histopathology; however, the specificity was higher (94.4% for PCR and microscopy, and 97.2% for histopathology). We conclude that reliable post-mortem laboratory testing either requires the combination of a set of available diagnostic tools or necessitates the development of improved new-generation tools with better sensitivity and specificity characteristics.

Investigations following stillbirth – which tests are most useful and cost effective?

BackgroundThe RCOG guideline on the management of stillbirth recommends a variety of investigations to identify potential causes including: post-mortem (PM), placental histopathology and blood tests. There is little data regarding...

Study of the crystalline phase orientation in uniaxially stretched polypropylene by Raman spectroscopy: Validation and use of a time‐resolved measurement method

AbstractThis study proposes an experimental method to quantify the molecular orientation of the crystalline phase of isotactic polypropylene from polarized Raman spectroscopy measurements. The method is based on the intensity sensitivity of two Raman scattering bands located at 973 (C‐C stretching mode) and 998 cm−1 (CH3 rocking mode) to laser light polarization. The first part of this article is devoted to the validation of the method by comparing Raman and Wide Angle X‐ray Scattering (WAXS) results obtained on postmortem test samples uniaxially deformed at growing levels. Second, the method is applied to follow the molecular orientation in situ during a tensile test by combining a video‐controlled test machine and a Raman spectrometer. Postmortem results show a quantitative agreement between Raman and WAXS measurements. In situ results mainly evidence the ability of the Raman method to characterize molecular orientation in real‐time with less than 5 s time resolution. POLYM. ENG. SCI., 2011. ©2011 Society of Plastics Engineers .

Risk of Mycoplasma bovis transmission from contaminated sand bedding to naive dairy calves

The objective of this study was to evaluate the possible transmission of Mycoplasma bovis from positive sand bedding to naïve dairy calves. Twelve preweaned Holstein bull calves were blocked in pairs and randomly assigned as unexposed controls (n=6) bedded with control sand, or exposed calves (n=6) bedded with sand previously positive for M. bovis at a dairy farm. Bedding sand was cultured weekly. Nasal and ear swabs and sera were collected weekly, tracheal swabs were collected monthly, and by the end of the 105-d study, all calves were euthanized (n=10) or died (n=2). Sera were tested for M. bovis-specific antibody. Mycoplasma spp. culture was performed on nasal and ear swabs; culture and a PCR differentiating multiple Mycoplasma spp. were performed on postmortem samples of lung, retropharyngeal lymph node, and trachea from each calf. A complete necropsy also was performed. During 6 wk, mycoplasma concentration in exposed group sand was between 200 and 32,000 cfu/g. All 166 tracheal swabs, nasal and ear swabs, and postmortem tests from all calves were negative for mycoplasma. All 94 sera were negative for M. bovis-specific antibody. No gross pathology suggestive of mycoplasma disease was detected. The probability of mycoplasma detection, if an exposed calf had become infected 4 wk after exposure, ranged between 97 and 99% depending on time of exposure for individual calves. There was no evidence that sand bedding contaminated with M. bovis might serve as a source of transmission to naïve dairy calves.

Post-mortem vitreous sodium and chloride levels – a biochemical test for salt water drowning?

Deaths due to drowning, in both salt and fresh water, are quite frequently encountered in forensic pathology practise. A diagnosis of drowning may be made when other causes of death from trauma, drugs, natural disease, etc, have been excluded after a body is retrieved from water and examined. These types of cases can be difficult for the pathologist, especially when factors such as absence of witnesses to the event, prolonged immersion time, and/or decomposition occur. Post-mortem changes may significantly alter the integrity of the body and affect opinions relating to the cause and time of death. Eleven cases of salt water drowning are presented, where vitreous sodium and chloride levels have been tested for post-mortem. In 10 out of 11 cases, there was a statistically significant elevation of the sodium and chloride levels, in comparison with 35 case controls. It is proposed that post-mortem vitreous sodium and chloride testing could be used as an adjunct to the autopsy in the investigation of death from presumed salt water drowning. If the post-mortem vitreous sodium + chloride levels exceed 280–290 mmol/L, a cause of death from salt water drowning would appear quite likely, if circumstances surrounding the death and autopsy findings also suggest drowning as a likely cause of death.

Relationship between clinical signs and postmortem test status in cattle experimentally infected with the bovine spongiform encephalopathy agent

BackgroundVarious clinical protocols have been developed to aid in the clinical diagnosis of classical bovine spongiform encephalopathy (BSE), which is confirmed by postmortem examinations based on vacuolation and accumulation of disease-associated prion protein (PrPd) in the brain. The present study investigated the occurrence and progression of sixty selected clinical signs and behaviour combinations in 513 experimentally exposed cattle subsequently categorised postmortem as confirmed or unconfirmed BSE cases. Appropriate undosed or saline inoculated controls were examined similarly and the data analysed to explore the possible occurrence of BSE-specific clinical expression in animals unconfirmed by postmortem examinations.ResultsBased on the display of selected behavioural, sensory and locomotor changes, 20 (67%) orally dosed and 17 (77%) intracerebrally inoculated pathologically confirmed BSE cases and 21 (13%) orally dosed and 18 (6%) intracerebrally inoculated but unconfirmed cases were considered clinical BSE suspects. None of 103 controls showed significant signs and were all negative on diagnostic postmortem examinations. Signs indicative of BSE suspects, particularly over-reactivity and ataxia, were more frequently displayed in confirmed cases with vacuolar changes in the brain. The display of several BSE-associated signs over time, including repeated startle responses and nervousness, was significantly more frequent in confirmed BSE cases compared to controls, but these two signs were also significantly more frequent in orally dosed cattle unconfirmed by postmortem examinations.ConclusionsThe findings confirm that in experimentally infected cattle clinical abnormalities indicative of BSE are accompanied by vacuolar changes and PrPd accumulation in the brainstem. The presence of more frequently expressed signs in cases with vacuolar changes is consistent with this pathology representing a more advanced stage of disease. That BSE-like signs or sign combinations occur in inoculated animals that were not confirmed as BSE cases by postmortem examinations requires further study to investigate the potential causal relationship with prion disease.

Therapeutic complications in a patient with high‐risk acute lymphoblastic leukemia and undiagnosed hereditary hemochromatosis

Hereditary hemochromatosis (HH) is an autosomal-recessive disorder of iron metabolism that most commonly manifests in the fourth or fifth decade of life. Here, we describe a 14-year-old male who presented with high-risk acute lymphoblastic leukemia and previously undiagnosed HH. His treatment course was remarkable for significant therapeutic complications, including iron overload, hepatic failure, cardiac dysfunction, and death. Postmortem testing revealed homozygosity for the C282Y mutation, confirming the diagnosis of HH. Since HH mutations occur commonly in select populations, screening patients with leukemia for HH may better inform treatment decisions regarding chemotherapy, transfusions, and/or iron chelation therapy.