HIV and the necropsy

Infectious diseases and the role of needle biopsy post-mortem

Post-mortem examinations continue to play a crucial role in understanding the epidemiology and pathogenesis of infectious diseases. However, the perceived infection risk can preclude traditional, invasive, complete diagnostic autopsy. Post-mortem examination is especially important in emerging infectious diseases with potentially unknown infection risks, but rapid acquisition of good quality tissue samples is needed as part of the scientific and public health response. Needle biopsy post-mortem is a minimally invasive, rapid, closed-body autopsy technique that was originally developed to minimise the infection risk to practitioners. Since its inception, needle biopsy post-mortem has also been used as a technique to support complete diagnostic autopsy provision in poorly resourced regions and to facilitate post-mortem examinations in communities that might have religious or cultural objections to an invasive autopsy. This Review analyses the evolution and applicability of needle biopsy post-mortem in investigating endemic and emerging infectious diseases.

Risk of occupational infection in forensic workers: a review

The occupational risk of infection in forensic workers is a cause for concern, furthermore in the current context of the coronavirus disease-19 (COVID-19) pandemic. In order to characterize this risk, we performed an extended review of the literature on occupational infections occurring in forensic workers. Seventeen articles were included. Direct contamination by aerosolization was the main mode of transmission reported, with 17 cases of tuberculosis. Indirect contamination was described as the mode of transmission in 10 cases (five cases of blastomycosis, two cases of tuberculosis, two Streptococcus pyogenes, and one case of human immunodeficiency virus). In all the other included cases, the mode of transmission was unknown. For two of them, the information provided was sufficient to link them to occupational exposure (one case of toxoplasmosis, one case of tuberculosis). For the remaining 10 cases, the link was uncertain (six cases of tuberculosis, three of hepatitis B, and one of COVID-19). Even if there is probably significant under-declaration, the number of infections linked to an occupational risk in forensic workers is not alarming, thanks to effective preventive measures.

SARS-CoV-2 viral load and replication in postmortem examinations

We examined 29 autopsy cases (investigated between October 2020 and February 2021) whose postmortem swabs tested positive for SARS-CoV-2. Twenty-two of 29 cases died while hospitalized (H), while the remaining 7 cases were not hospitalized (NH). Since we included only cases in which the time since death was known (excluding unwitnessed NH deaths), the interval between death and postmortem swab(s) was registered, with a mean NH value of 5.50 days and a mean H value of 3.98 days. The mean age of NH was 65 years, while H were older (mean age: 73 years). Twenty-eight nasopharyngeal and 27 lungs postmortem swabs were obtained and real-time reverse transcriptase‒polymerase chain reaction assay for total and replicative SARS-CoV-2 RNA and mRNA detection was performed. Although the mean death-postmortem swabs interval was higher in NH than in H, the mean viral load of NH was higher than that of H (2.53 × 10¹¹ copies/mL vs 9.31 × 10⁸ copies/mL). In 13/29 cases (6 NH and 7 H), indicators of active replication were found. The relationship between the presence of replicative mRNA and death without hospitalization and that between the minimum cycle threshold value of SARS-CoV-2 RNA and the cycle threshold value of replicative SARS-CoV-2 mRNA were found to be statistically significant (with respective P values of 0.013 and 0.000). Therefore, especially in NH, full compliance with guidelines on biological safety in the autopsy room is essential, and no autopsy can be performed on infected cases in a structure that does not meet the established safety criteria.

A minimally invasive technique for the detection and analysis of pulmonary fat embolism: a feasibility study

We investigated the feasibility of postmortem percutaneous needle biopsy (PNB) for obtaining pulmonary samples adequate for the study of pulmonary fat embolism (PFE). Samples of both lungs were obtained from 26 cadavers via two different methods: (i) PNB and (ii) the double-edged knife technique, the gold standard at our institute. After water storage and Sudan III staining, six forensic pathologists independently examined all samples for the presence and severity of PFE. The results were compared and analyzed in each case regarding the vitality of the PFE and its relationship to the cause of death. The results showed that PFE was almost identically diagnosed and graded on the samples obtained via both methods. The discrepancies between the two techniques did not affect the diagnoses of vitality or cause of death related to PFE. This study demonstrates the feasibility of the PNB sampling method for the diagnosis and interpretation of PFE in the postmortem setting.

The spectrum of clinical and pathological manifestations of AIDS in a consecutive series of 236 autopsied cases in mumbai, India

The HIV epidemic in the Asian subcontinent has a significant impact on India. The AIDS associated pathology has not been well evaluated in a representative study hence very little is known about the spectrum of HIV/AIDS associated diseases in Indian subcontinent. To determine the important postmortem findings in HIV infected individuals in Mumbai, autopsy study was carried out. The patient population included patients with AIDS who died at the tertiary care hospital over a 20 year period from 1988 to 2007. A total of 236 (182; 77% males and 54; 23%) females) patients with AIDS were autopsied. The main risk factor for HIV transmission was heterosexual contact (226 patients; 96%) and 223/236 (94%) patients died of HIV-related diseases. Tuberculosis was the prime cause of death in 149 (63%) patients, followed by bacterial pneumonia 33 (14%), cryptococcosis 18 (8%), toxoplasmosis of brain 15 (6%), pneumocystis jiroveci (PCJ) 1 (0.5%) and Non-Hodgkin's lymphoma 7 (3%) cases. The major underlying pathologies are either preventable or treatable conditions. There is an urgent need for attention towards the diagnosis, issue of therapy, and care of HIV disease in developing countries. Reducing mortality in patients with AIDS from infections must be highest public health policy in India.

Autopsies in HIV: still identifying missed diagnoses

This study reviews the deaths and autopsies carried out over 23 years, 1983–2005, in a British Infection Unit in HIV patients. Of 115 HIV patients known to have died, we obtained data on 93%. Of this 80% were male, median age 38 (25–68) years; 83% were Caucasian; 12% Black African. Major risk factors were men who have sex with men, 52%; heterosexual in Africa, 17%; and injecting drug use, 8%. The commonest diagnosis pre- and post-autopsy diagnosis was pneumonia. Changes in diagnoses in the 38% who underwent autopsy were high (we requested autopsy in 50%). Primary diagnosis changed in 70%, and 36% of all opportunistic infections were missed. This included six of nine cytomegalovirus, all tuberculosis and 75% of Kaposi's sarcoma. Lymphoma was overdiagnosed. Thus, despite excellent resources, the majority of primary diagnoses were wrong, suggesting inadequacy of current diagnostics. To improve these and improve both epidemiological data and future management autopsy should be considered for all deaths.

Post-mortem tissue sampling using computed tomography guidance

PURPOSE

Currently, in forensic medicine cross-sectional imaging gains recognition and a wide use as a non-invasive examination approach. Today, computed tomography (CT) or magnetic resonance imaging that are available for patients are unable to provide tissue information on the cellular level in a non-invasive manner and also diatom detection, DNA, bacteriological, chemical toxicological and other specific tissue analyses are impossible using radiology. We hypothesised that post-mortem minimally invasive tissue sampling using needle biopsies under CT guidance might significantly enhance the potential of virtual autopsy. The purpose of this study was to test the use of a clinically approved biopsy needle for minimally invasive post-mortem sampling of tissue specimens under CT guidance.

MATERIAL AND METHODS

ACN III biopsy core needles 14 gauge x 160 mm with automatic pistol device were used on three bodies dedicated to research from the local anatomical institute. Tissue probes from the brain, heart, lung, liver, spleen, kidney and muscle tissue were obtained under CT fluoroscopy.

RESULTS

CT fluoroscopy enabled accurate placement of the needle within the organs and tissues. The needles allowed for sampling of tissue probes with a mean width of 1.7 mm (range 1.2-2 mm) and the maximal length of 20 mm at all locations. The obtained tissue specimens were of sufficient size and adequate quality for histological analysis.

CONCLUSION

Our results indicate that, similar to the clinical experience but in many more organs, the tissue specimens obtained using the clinically approved biopsy needle are of a sufficient size and adequate quality for a histological examination. We suggest that post-mortem biopsy using the ACN III needle under CT guidance may become a reliable method for targeted sampling of tissue probes of the body.

The autopsy: complete or not complete?

Less invasive or non-invasive alternatives to the complete autopsy have been sought for some time, and a range of methods, ranging from needle sampling to endoscopy to magnetic resonance imaging, have been considered. Evaluations of these methods are few and far between, but generally confirm the predictable conclusion that incomplete autopsies provide incomplete information. It is not difficult to envisage a situation whereby pressure for non-invasive autopsies will allow them to become prevalent, whether properly evaluated or not. However, used appropriately, non-invasive or less invasive autopsies may be valuable tools capable of answering specific questions in situations where it is not possible to perform a complete autopsy.

Health and safety at necropsy

The postmortem room is a source of potential hazards and risks, not only to the pathologist and anatomical pathology technician, but also to visitors to the mortuary and those handling the body after necropsy. Postmortem staff have a legal responsibility to make themselves aware of, and to minimise, these dangers. This review focuses specifically on those hazards and risks associated with the necropsy of infected patients, with foreign objects present in the body, and with bodies that have been contaminated by chemicals or radioactive sources.

Value of limited necropsy in HIV-positive patients

We performed limited autopsy with histological examination of tissue cores obtained percutaneously using the Tru-Cut needle and the Jamshidi trocar in 150 adult HIV-positive patients. Data were compared retrospectively with the antemortem clinical diagnosis. Eighty-one percent of the patients were male, and 78% were intravenous drug users. Specimens were obtained from the brain, liver, lung, bone marrow, and kidney of most patients. The main findings included liver cirrhosis in 22 cases (associated with HCV infection in 81%), Pneumocystis carinii pneumonia in 21, Cytomegalovirus (CMV) infection in 19, Mycobacterium avium-intracellulaire (MAI) infection in 17, bacterial pneumonia in 14, tuberculosis in 12, and lymphoma in 13 cases. Forty-six (30.6%) patients had at least one clinical diagnosis that was confirmed by autopsy, i.e., there was 40.6% agreement between pre- and postmortem findings. Forty-six (30.6%) patients had at least one clinical diagnosis that was not confirmed at autopsy, whereas 41 (27.3%) had at least one AIDS-related or unrelated disease that was not suspected clinically. The results obtained by limited autopsy are principally comparable to those achieved by full necropsy, with the advantages of decreasing the contagious risk, saving cost and time, including a rapid final diagnosis, and easily obtaining the consent for postmortem examination so that necropsy studies may be performed on a larger number of patients, thus contributing to a better understanding of the spectrum of HIV infection in our environment.

HIV-1 detection by nested PCR and viral culture in fresh or cryopreserved postmortem skin: potential implications for skin handling and allografting

AIMS

To date, the risk relating to the handling or allografting of human immunodeficiency virus type 1 (HIV-1) infected postmortem skin remains hypothetical. While blood screening for HIV antibodies is still the key safety procedure to detect HIV infected cadavers, false negative results are a concern. Conversely, false positive results may hamper the collection of skin allografts. Accordingly, viral culture was used to clarify skin infectivity and the nested polymerase chain reaction (PCR) was used to assess the reliability of skin PCR testing.

METHODS

Viral culture and nested PCR performed with gag and pol specific primers were investigated in cadaveric skin and blood from 12 HIV-1 infected patients. Samples were collected repeatedly between one and five days in seven patients. In most cases, analyses were performed on triplicate skin samples: fresh (n = 26); cryopreserved in 5% dimethylsulphoxide (n = 21), or cryopreserved in 30% glycerol (n = 26).

RESULTS

HIV was isolated in two of 26 cultures of fresh skin specimens (8%), seven of 47 cryopreserved skin specimens (15%), and eight of 26 blood specimens (31%). The nested PCR detected HIV-1 in all skin samples (n = 73), regardless of the postmortem interval or cryopreservation. In blood, a positive signal was found in eight of 12 patients but two of them had discordant results on successive samples.

CONCLUSIONS

These data suggest that nested PCR on postmortem skin samples can detect HIV more reliably than on blood. They also demonstrate the potential viral infectivity of fresh or stored skin postmortem samples in HIV infected patients. They underscore the need for caution during the handling of skin tissue from HIV infected cadavers and confirm the potential risk related to accidental allografting of HIV contaminated skin.

Comparison of magnetic resonance imaging with neuropathological findings in the diagnosis of HIV and CMV associated CNS disease in AIDS

OBJECTIVES

To compare the results of clinical assessment and MRI with neuropathological findings in the diagnosis of HIV and cytomegalovirus (CMV) associated CNS disease.

METHODS

A retrospective study of 35 patients infected with HIV who were examined at necropsy between four and 70 (median 20) days after neurological assessment and MRI.

RESULTS

Of the 35 patients, 19 had diffuse white matter hyperintensity on T2 weighted MRI, six of whom also had focal lesions. Nine other patients had focal white matter lesions and seven had changes in cortical atrophy only. Necropsy in the 19 with diffuse white matter hyperintensity showed HIV leukoencephalopathy (HIVLEP) with encephalitis in 10, CMV encephalitis in three, both HIVLEP/HIV encephalitis and CMV encephalitis in one, lymphoma in three, and non-specific inflammation in two. Necropsy in the 16 other patients without diffuse white matter hyperintensity showed CMV encephalitis in six, HIV encephalitis (without HIVLEP) in two, CMV encephalitis and HIVLEP/HIV encephalitis in one, non-HIV associated abnormalities in five, herpes simplex encephalitis in one, and lymphoma in one. CMV DNA was detected in CSF of five of seven patients with CMV encephalitis and in two of two with CMV associated polyradiculopathy but without CMV encephalitis. Diffuse white matter hyperintensity on MRI had a sensitivity of 100%, a specificity of 66.6%, and a positive predictive value of 58% for diagnosis of HIVLEP.

CONCLUSION

Diffuse white matter hyperintensity on MRI can be due to either HIV or CMV associated pathology or non-specific abnormalities.

The 'high-risk' neuropathological autopsy in AIDS and Creutzfeldt-Jakob disease: principles and practice

There is much current clinical, pathological and scientific interest in infective disorders of the central nervous system, particularly those associated with the human immunodeficiency virus (AIDS) and the transmissible human spongiform encephalopathies (Creutzfeldt-Jakob disease, Gerstmann-Sträussler-Scheinker syndrome and fatal familial insomnia). To investigate these disorders it is necessary to develop and follow procedures for performing autopsies on known or suspected cases which allow both diagnostic and research investigations to be carried out, while at the same time presenting minimal risk to pathologists, mortuary and laboratory technical staff. This article reviews the objectives for performing 'high-risk' autopsies, and summarizes current guidelines for autopsy procedures and laboratory tissue handling in light of extensive experience in the Neuropathology Laboratory, University of Edinburgh. Neuropathology has a leading role to play in diagnosis and research in this important field; the need for 'high-risk' autopsies is likely to increase into the next century.

Hospital-acquired tuberculosis

The resurgence of tuberculosis and the emergence of drug-resistant strains, coupled with a growing number of immunocompromised patients and a high proportion of susceptible health care workers, have increased our awareness of the possibility of hospital-acquired tuberculosis. Infection control guidelines which aim to prevent dissemination and inhalation of infectious particles include early diagnosis and isolation of infectious patients, particular care during procedures likely to increase the density of the organism in the environment, and regular surveillance of hospital staff.

What's new in managing health hazards in pathology departments

Health hazards related to activities performed in pathology departments have represented, in recent years, an increasing concern among pathologists and pathology technicians. The major occupational health problems encountered in pathology departments are reviewed. They include biological hazards (tuberculosis, hepatitis, HIV, other infectious diseases), chemical hazards (formaldehyde, xylene(s), aromatic amines, methacrylates, glutaraldehyde, latex) and physical hazards (cut injuries, accidental fires, radiation). Current data suggest that infections (particularly, tuberculosis and hepatitis) still represent the more relevant risk. Exposure to HIV and Creutzfeldt-Jakob agent may be highly harmful but containment measures have been proven to be effective. The actual adverse effects due to chemicals seem to be less alarming than was previously believed. Attaining a safe work environment is an inherent element of good quality assurance management. This task is largely a matter of information, education, organization and common sense. Well-designed premises, efficient equipment and well-trained personnel are the keys to preventing and minimizing hazardous exposures. In order to provide current information that may be used by pathology staff to implement the functional quality of the workplace, organizational and preventive measures are described.