Non-COVID-19 Viral Respiratory Tract Infection as Causes of Death amid the Pandemic: a Report of Two Autopsy Cases and Tips for Safe Practice

Autopsy practice is one of the most well-defined procedures in medicine, with strict safety instructions in place to protect medical personnel from infectious agents. However, for various reasons, these precautionary measures are often overlooked. Herein we report two autopsy cases of patients who died during the COVID-19 pandemic and the national state of emergency declared in Bulgaria. One patient was a 77-year-old female who had a medical history of a viral respiratory tract infection in February 2020 but had not undergone any test. She had multiple comorbidities including hypertension, cerebral and cardiovascular disease, and type 2 diabetes. The other patient was a 53-year-old female with morbid obesity with previous medical history of malignancy, hypertension, and type 2 diabetes. Both patients were tested for COVID-19 during the autopsy. Gross and histological findings in both patients showed respiratory tract viral infection with severe complications, incompatible with life. The first patient had serous desquamative tracheitis, hemorrhagic pneumonia, pericarditis, meningitis, and acute necrotizing encephalitis. The second patient had serous tracheitis, interstitial pneumonia, and diffuse alveolar damage and pneumocyte cytopathic effect, the alveolar septi had undergone a fibrotic change, with serous meningitis and non-necrotizing encephalitis also noted histologically. Autopsy-wise, it is always important, against the backdrop of an epidemic, to use full precautionary measures and exclude epidemic strands in cases where gross findings are suggestive of a viral infection.


INTRODUCTION
Autopsy practice is one of the most well-defined procedures in medicine, with strict safety instructions in place to protect the medical personnel from infectious agents. 1,2 However, due to different reasons, often these precautionary measures are overlooked. 1,2 This posed great difficulty in the novel coronavirus 2019 (COVID-19) pandemic, as most autopsy theatres were ill-equipped to perform autopsies of patients with respiratory viral infections. 3,4 Herein we report two autopsy cases of patients who died during the COVID-19 pandemic and the national state of emergency declared in Bulgaria.

CASE REPORT
Both patients were female, the one was 77 years old, and the other was 53 years old.
The first patient had a medical history of a viral respiratory tract infection in February 2020, but had not undergone any test. She had multiple comorbidities including hypertension, cerebral and cardiovascular disease, and type 2 diabetes. At admission to hospital, she presented with progressive neurological deficits and acute renal failure.
The second patient was morbidly obese and had a history of previous malignancy, hypertension, and type 2 diabetes. Current symptoms induced exacerbation of chronic respiratory failure; however, the patient died in the emergency department before proper investigations could be conducted.
Both autopsies were video documented in full. Due to the epidemiological data and the short hospital stay of both patients, a full infectious disease autopsy protocol was used. Both the pathologist and hall attendant were equipped with an N-95 respirator mask, respiratory helmet, and infectious disease suit with full-body protection. The autopsy theatre was well aerated with maximum air exchange being provided.
The thoracic section of the first patient revealed sero-desquamative tracheitis and hemorrhagic pneumonia located in the upper lobe of the right lung (Fig. 1). Based on the medi-cal history, gross characteristics of the respiratory system, and epidemiological data, a tracheal swab and blood sample were acquired for a quantitative real-time polymerase chain reaction (qRT-PCR) during the autopsy to test for COVID-19. The rest of the autopsy was uneventful apart from hypertension and atherosclerosis complications. A few hours after the autopsy the qRT-PCR results for COVID-19 came back negative.
Thoracic section of the second patient revealed serodesquamative tracheitis and a diffuse acute respiratory distress syndrome (ARDS) changes in both lungs (Fig. 3), with grossly detectable thromboembolism. A fast immunoglobulin (Ig) test was used during the autopsy, with both IgM and IgG being negative.
Histopathology from the collected specimens revealed serous tracheitis, interstitial pneumonia with hyaline membranes, multiple megakaryocytes and desquamation of the alveolar epithelium with cytopathic effect -some of the cells were enlarged with ground-glass opacity cytoplasm and an enlarged eccentric nucleus, whilst others were multinucleated, parts of the alveolar septi had undergone a fibrotic change (Fig. 4). Serous meningitis and non-necrotizing encephalitis were also noted histologically (Fig. 5).

DISCUSSION
Epidemiological data is always important when performing an autopsy, especially in cases where patients have had a very brief hospital stay, before death, or in cases where a viral disease was suggested but no test was performed. 2,5 In such cases, extreme precautions should be taken with the goal of both protecting the medical and non-medical hospital personnel and to properly identify any infectious agent to allow for more epidemiological data to be gathered. 5 It is also important to note that even despite the epidemiological data, non-prevalent viral agents can also be the cause of death, as in our two cases, where influenza viruses were considered to be the most probable cause for the diffuse changes. 5,6 Also worth noting is that the second case had pulmonary histology very close to some of the changes depicted in COVID-19 autopsies; however, even with the low-specificity of the rapid antibody test, without serology or qRT-PCR, the viral causative agent cannot be defined. 3