Fatal Mastitis due to Group a Streptococcus: An Autopsy Case
Arisa Takeda1*, Marin Takaso1, Mami Nakamura1, Kenichi Mukaisho2, Masahito Hitosugi1
1Department of Legal Medicine, Shiga University of Medical Science, Otsu, Japan
2Education center for Medicine and Nursing, Shiga University of Medical Science, Otsu, Japan
*Corresponding authors: Arisa Takeda, Department of Legal Medicine, Shiga University of Medical Science, Tsukinowa, Seta, Otsu, Shiga 520-2192, Japan
Received Date: 16 March 2023
Accepted Date: 20 March 2023
Published Date: 22 March 2023
Citation: Takeda A, Takaso M, Nakamura M, Mukaisho K, Hitosugi M (2023) Fatal Mastitis due to Group a Streptococcus: An Autopsy Case. Ann Case Report. 8: 1230. DOI:https://doi.org/10.29011/2574-7754.101230
Abstract
Background: Severe infection by Streptococcus pyogenes, a type of group A Streptococcus (GAS), is uncommon but has a high fatality rate. We herein report the first autopsy case of mastitis due to GAS.
Case presentation: A healthy woman in her 40s died 3 days after complaining of severe right shoulder-to-chest pain. Forensic autopsy revealed a reddish-brown area with an irregular superficial abrasion extending from the neck to chest with thickened subcutaneous connective tissue. Microbiologically, the presence of GAS was identified from a blood culture collected at the time of autopsy. Histopathologically, numerous neutrophilic leukocyte and lymphocyte infiltrations were found around the mammary gland in the right breast. These changes were considered to indicate severe mastitis. The same infiltrations were observed in the liver and adrenal medulla. These findings were in accordance with systemic bacteraemia. Therefore, the patient was diagnosed with GAS-induced sepsis secondary to right mastitis. She was a non-lactating woman and had no lesions or risk factors related to GAS. This case illustrates that mastitis can lead to rapidly progressive GAS infection with a fatal outcome.
Conclusions: Early recognition of GAS infection and prompt initiation of supportive care with antibacterial therapy are required to prevent sudden death, even in patients with mastitis.
Keywords: Streptococcus Pyogenes; Group a Streptococcus; Fatal Mastitis; Bacteraemia due to GAS; Case Report
Introduction
Streptococcus pyogenes, a type of group A Streptococcus (GAS), is a β-haemolytic gram-positive coccus that often causes upper respiratory tract inflammation and skin/soft tissue infection. GAS is a known colonizer of the oropharynx, genital mucosa, rectum, and skin, and its carriage rate in healthy adults is estimated at <5% in the throat and 1% in the vagina and rectum [1]. Despite the rarity of severe GAS infection, such as that causing bacteraemia, cellulitis, puerperal sepsis, meningitis, necrotizing fasciitis, and septic arthritis, such infections are serious and have a high fatality rate. Invasive GAS disease is diagnosed when GAS is isolated from a normally sterile site, such as blood, subcutaneous tissues, surgical specimens, or bone [2]. According to previous studies, while the complication rate of invasive GAS disease shows remarkable consistency among industrialized nations (approximately 2 to 4 per 100,000 individuals), the fatality rate ranges from 8% to 19% [3,4]. The soft tissue is the most common site of invasive GAS infections, accounting for about half of all cases [3]. The most common skin and soft tissue infection sites are the extremities and perineum [4]. To the best of our knowledge, no reports have described fatal GAS infection of the soft tissue of the breast. We herein report a rare autopsy case of mastitis due to GAS.
Case Presentation
Overview
A woman in her 40s with no medical history except shoulder stiffness and low back pain developed right shoulder pain 3 days prior to her death. On the day of presentation, she was referred to an orthopaedist and was prescribed nonsteroidal anti-inflammatory drugs under the diagnosis of muscle strain. Soon after returning home, she fell asleep because of fatigue. The next day (2 days prior to her death), the pain had moved from her right shoulder to her right chest. Her husband confirmed that her right shoulder was red and swollen that night. The day before her death, she had developed severe shoulder to chest pain but went to work as usual. After returning home, she fell asleep with a cold pack on her chest because she was feverish with severe right shoulder-to-chest pain. At midnight, her husband heard her having a nightmare. At 6:00 AM the next morning, her husband found her dead on the bed. To determine the mechanisms and cause of death, a forensic autopsy was performed 27 hours after discovery of the body.
Autopsy findings
The woman’s height was 160.0 cm and weight was 56.2 kg. The surface of the body was light red, and purple-red post-mortem lucidity was observed on the back. No petechial haemorrhages were present on the oral mucosa or bilateral palpebral conjunctivae. A reddish brown area measuring 28.5 × 34.0 cm with an irregular superficial abrasion extended from the neck to the right shoulder and to the right chest (Figure 1). No marked injuries were noted externally. Internally, no subcutaneous or intermuscular haemorrhage was observed in the chest. No marked abnormality was found in the shoulder joint. The subcutaneous region around the shoulder showed no abnormalities except for mild enema. From immediately below the right breast to the centre of the chest (Figure 2), the subcutaneous connective tissue was thickened to 10.0 × 10.0 × 3.0 cm. A small amount of dark red soft coagulated blood was observed in the heart cavities. No injuries or abnormalities with the exception of congestion were found in the cerebrospinal regions or in the intrathoracic and abdominal organs.
Toxicological findings
No alcohol was detected in the cardiac blood or urine by gas chromatography. Urine drug screening tests with the INSTANT-VIEW® M-I immunoassay kit revealed no psychotropic or illicit drugs.
Microbiological findings
A bacterial culture was performed using the blood collected at the time of autopsy, and GAS was identified. No other bacteria or fungi were detected.
Histopathological findings
Numerous neutrophilic leukocyte and lymphocyte infiltrations were found around the mammary gland in the right breast (Figure 3). Immunohistochemical staining of the mammary gland tissue was performed to check for malignancy, and both p63 and CK5/6 were negative. These changes were considered to indicate severe mastitis. Marked neutrophilic leukocyte and lymphocyte infiltrations were also observed near Glisson’s capsule in the liver (Figure 4), and lymphocyte infiltration was found in the adrenal medulla (Figure 5). These findings were consistent with systemic bacteraemia.
Figure 1: A reddish brown area with an irregular superficial abrasion extended from the neck to the right shoulder and to the right chest.