Nosocomial transmission of necrotising fasciitis organisms from prepartum patient to healthcare worker

Abstract

Necrotising fasciitis is an aggressive skin and soft tissue infection requiring urgent surgical treatment, resuscitative efforts and intensive care management. We herein present a case of necrotising fasciitis with nosocomial transmission of causative organisms from patient to healthcare worker. Bacterial transmission from human to human despite personal protective equipment is quite rare, and with limited reports in the literature. The patient was also prepartum, representing to our knowledge, one of only a handful of cases of prepartum necrotising fasciitis. Recommendations to avoid healthcare worker transmission include wearing Association of the Advancement of Medical Instrumentation level 4 gowns during debridement, as well as eye protection and changing scrubs and showering between cases.

Background

Necrotising fasciitis (NF) is a potentially lethal skin and soft tissue infection (SSTI) that is characterised by rapid local invasion causing fulminant destruction of tissues and systemic unwellness. Group A Streptococcus (GAS) is the most common cause of NF. However, there are many different organisms that can be involved. Many polymicrobial cases have been documented. The incidence of NF is 0.3–15 cases per 100 000 population.¹ Prognosis is dependent on onset of treatment, which involves early and aggressive surgical debridement to remove necrotic tissue alongside empiric antibiotic therapy.¹ Transmission of GAS and other NF-causing organisms can occur through direct contact. However, NF is typically thought to be contracted through a break in the skin barrier or without a known source. Although very rare, there are reported case reports of surgical staff contracting GAS, and other infectious bacterial organisms from patients.

Herein, we present a case of nosocomial transmission of NF-causing bacteria from a patient to operating room (OR) staff member from a prepartum patient.

Although cases of nosocomial transmission of NF from patient to healthcare workers do exist,^2–7 these are few and rare occurrences. Individuals with severe NF infections typically have underlying risk factors that allow for more rapid spread of the bacteria, including diabetes, malnutrition, intravenous drug use and immunosuppression.⁸ Pregnancy creates an immunosuppressed state, which has been proposed to increase the likelihood of NF infection.^9–11 However, there have only been limited case reports of NF in pregnancy, and most of these are post partum.¹²

Case presentation

A woman in her mid-20s with visible signs of intravenous drug use, living in single room occupancy and socialised housing, was found unresponsive. She was visibly pregnant. She was tachycardic, tachypnoeic and hypotensive with a Glasgow Coma Scale score of 10. She had an unknown medical history. Her skin was pale, and her body was covered in sores, with a severe soft tissue infection with haemorrhagic bullae noted along the left lateral leg and buttock area (figure 1). This was concerning for NF. She was haemodynamically unstable and brought urgently to the nearest tertiary care centre. In hospital, she was intubated for airway protection and decreased level of consciousness. Central venous access was obtained.

Figure 1.

A woman presenting with severe necrotising infection of her left leg. The infection is circumferential (left). The leg is prepped in the operating room (right).

She had a severe anion gap metabolic acidosis with inadequate respiratory compensation (pH of 6.78). Her lactate was markedly elevated at 21 mmol/L. Prior to bringing her urgently to the OR for source control, she was given two amps of sodium bicarbonate. She was started on empiric triple antibiotic therapy consisting of vancomycin, piperacillin–tazobactam and clindamycin. She also received intravenous immunoglobulins for presumed toxic shock syndrome. The obstetrical and plastic surgery team were immediately involved in the case, with obstetrics confirming fetal demise by ultrasound. The patient was rapidly brought to the OR for immediate debridement, having been temporised and stabilised on vasopressors and blood transfusions, and resuscitated by the emergency and anaesthesia teams.

A circumferential leg debridement was performed on the left leg. Frank necrotic tissue and dishwater fluid was present and fascial biopsies were taken. The infection involved skin, and subcutaneous fat, extending down to the fascia in all three compartments in the upper leg. There was no frank muscle necrosis (figure 2). After the debridement, the patient’s vasopressor requirements were decreased from 50 to 25 mcg/min. Betadine-soaked Kerlix sponges were used to temporarily dress the wounds.

Figure 2.

Patient leg after initial debridement and featuring gown with contamination (left). The leg was at one point resting on the healthcare provider. Uterine closure after delivery of fetus (right).

Subsequently, obstetrics team performed an urgent caesarean section via a midline laparotomy incision and noted a pale and mottled uterus. Amniotic fluid samples were sent for cultures and sensitivity. The fetus was delivered and noted to be at least 32 weeks gestational age. Fetal demise was again confirmed. General surgery then examined the bowel contents and noted no areas of ischaemia or injury. The uterus was then closed but the abdomen was left open with a vacuum dressing, due to complications with ventilation.

The patient was then brought to the intensive care unit (ICU) in an unstable state. The patient developed respiratory failure with acute respiratory distress syndrome. She also developed renal failure and underwent continuous renal replacement therapy. The patient had periods of bradycardia, then pulseless electrical activity which led to cardiopulmonary resuscitation. Although the patient achieved a short-lived period of return of spontaneous circulation, her condition deteriorated despite maximal intervention, and she arrested again. Given the lack of improvement in her clinical picture despite resuscitative efforts and debridement, she was allowed to pass away peacefully.

During the care of this patient she had multiple cultures taken: her blood cultures grew GAS; her tissues grew GAS, methicillin-resistant Staphylococcus aureus (MRSA), methicillin-sensitive Staphylococcus aureus and Corynebacterium; the amniotic fluid grew GAS; her nares cultures grew MRSA; and her urine, sputum and fungus samples were all negative. The MRSA was sensitive to clindamycin, erythromycin and vancomycin. The GAS was pan-susceptible.

The healthcare team involved were wearing a combination of Association of the Advancement of Medical Instrumentation (AAMI) level 3 surgical gowns (figure 3). However, a member of the healthcare team developed 2 days of fever and a rash on his abdomen. He was diagnosed with an early stage of cellulitis and had a small abscess requiring an incision and drainage under local anaesthetic (figure 4). Cultures taken grew GAS and MRSA that genetically matched the cultures grown from the patient, by pulse-field gel electrophoresis (PFGE). This infection cleared after a prescription of cefazolin and clindamycin.

Figure 3.

Level 3 (left) versus level 4 (right) gowns.

Figure 4.

Healthcare worker with a small abdominal abscess and cellulitis requiring incision and drainage under local anaesthetic.

Outcome and follow-up

The patient died shortly after surgery. There was intrauterine fetal demise when the patient arrived in the emergency department.

Discussion

GAS can cause a variety of infections with severity ranging from the lethal necrotising SSTI including NF to cases of pharyngitis or pneumonia. GAS virulence and transmission seem to present in clusters, with cases in the community arriving at the hospital.¹³ However, due to the nature of NF, minimal resource is allocated determining whether two unrelated patients from the community have the same strain of bacteria.

This case is an overlap of two unique and rarely reported occurrences for NF, namely, NF in a prepartum patient, and nosocomial transmission leading to SSTI of a healthcare worker. To our knowledge, the case of nosocomial transmission of GAS from a pregnant patient to a member of the healthcare team is a novel occurrence.

NF in pregnancy

There have been several instances of NF in pregnant women. However, most of these cases occur post partum and were suspected to be the result of lacerations that occurred intrapartum.⁹ The incidence of NF in pregnancy is unknown, but some estimates between 1.1 and 3.8 per 100 000.⁹

In prepartum women, Nikolaou et al reported a case NF in a 15-year-old patient who was at 28 weeks gestation. Initial debridement for this patient was delayed due to belief that the patient was suffering from an abscess. On her fifth day postoperative, she continued to have premature contractions despite tocolytic therapy and delivered a boy who was immediately admitted to the neonatal ICU due to septicaemia, and died 48 hours later.¹⁴

McHenry et al reported a case series, with two post partum and one prepartum. The prepartum case was a 27-year-old pregnant woman, who presented with leg cellulitis and deterioration consistent with NF and requiring debridement.¹⁵ Nahas et al reported a case of NF and toxic shock syndrome in a prepartum 24-year-old with no other NF risk factors. This case had very good outcomes with full recoveries for the patient and for the fetus.¹⁶ This case supports the claim by that the immunocompromised state of pregnancy increases the risk of NF infection.⁹

Another successful case of prepartum GAS NF of the leg in 25-year-old previously healthy mother expecting twins was reported in 2017. She presented initially in early labour at over 35 weeks with a history of severe left leg pain and fever consistent with NF. The patient was successfully treated with antibiotics and debridement before an uneventful delivery of twins. One of the boys was noticed to have cellulitis of the right arm on delivery, which resolved with a course of intravenous antibiotics. The source of the cellulitis could not be definitively ascertained but it is believed to be caused by haematologic spread from the mother.¹⁷

Maternal patients in all these cases ultimately survived. Management of prepartum NF should be focused on stabilisation of the mother as this should provide stability to the fetus.¹⁶ There are some ICU considerations including avoiding permissive hypercapnia, limiting plateau pressures and no proning, especially in later pregnancy.^{14 16}

Nosocomial transmission of GAS to healthcare worker

The virulence factors of different strains of GAS and the portal of entry have influence on what infection the bacteria can cause. This allows for the infection to be transmitted through different sources and through different modes. GAS infections can be transmitted by several different mechanisms: direct contact, aerosolisation and respiratory droplets. Transmission of GAS from patients to healthcare workers has been reported, but most cases have resulted in pharyngitis or asymptomatic uncomplicated colonisation.⁷ For example, a respiratory therapist was diagnosed with GAS pneumonia, genetically identical to the patient, 6 days after being involved in the care of a patient with GAS NF.⁶

Even less commonly, only a handful of cases have been reported of nosocomial transmission from a patient to a healthcare worker causing an acquired SSTI.^{4 7} These usually require a skin breach, such as a scalpel laceration during a NF debridement,² or an accidental needle stick³ as previously reported in the New England Journal of Medicine.

The AAMI has four protection levels of surgical gowns. Level 3 surgical gowns provide moderate fluid protection and are used the most widely for surgical procedures. Level 4 surgical gowns have the highest fluid and microbial barrier, and are recommended for prolonged and fluid-intensive procedures. They are composed of poly material and undergo a series of stringent testing to ensure the gown is resistant to viral, bacterial and fluid penetration, abrasion and material breakdown and resistance to laser and ignition in key areas.

In a previous report, two healthcare workers, using unknown gown type, were involved in a surgical debridement of a GAS NF infection contracted GAS. One of the surgeons developed GAS pharyngitis, but it is unclear if it was from the patient as a throat culture was not obtained. The second surgeon noted soaking of his socks with blood and bodily fluid due to a lack of impervious boot covers, and he was not able to change his clothes and shower. On the eighth postoperative day, the second surgeon noticed erythema and swelling to his right foot, which had baseline tinea pedis. This surgeon had contracted GAS NF with associated toxic shock syndrome that required debridement and a short stay in the ICU. The isolates from the patient and the surgeon were identical by PFGE, indicating that they were genetically related. Both surgeons made full recoveries.⁷

Previous case reports of prepartum NF have not reported on whether amniotic cultures were done. The amniotic cultures that were done on our patient revealed GAS. However, it is difficult to ascertain whether this culture is a contaminant from the extensive GAS NF infection, or whether the infection had spread through direct or haematologic invasion. Based on the previous cases of NF in prepartum pregnant women, and subsequent cellulitis in the newborn,¹⁷ one can speculate either haematological spread or transmission during delivery. The fetus did not have mottling of the skin nor obvious cellulitis, indicating it was an acute and rapid death secondary to the maternal deterioration, and before the onset of a SSTI or cellulitis.

We present a case of direct transmission of GAS NF through contact with the blood and body fluid of a patient, causing an SSTI. Due to the nature of debridement surgeries and invasive GAS organisms, level 4 gowns are recommended and now routinely implemented in the local health authorities. If level 4 gowns are not available, or during emergent situations, surgeons should consider an impermeable layer, such as a plastic apron, to be worn underneath their regular sterile gowns. Other recommendations include the use eye protection, double gloving, potentially N95 masks and changing scrubs after the surgery is completed as well as showering between cases. This case report underscores the important of adequate and appropriate personal protective equipment according to the procedure at hand, and in the case of NF, the high possibility of bodily fluid exposure.

Learning points.

• Group A Streptococcus organisms can be transferred from patient to healthcare worker.

• Association of the Advancement of Medical Instrumentation level 4 gowns, eye protection and other personal protective equipment, as per institution protocol, are routinely recommended for healthcare workers directly in contact with patients with necrotising fasciitis (NF), especially when potential for exposure to bodily fluids and infected tissues is high.

• Prepartum NF cases are rare and some management changes include avoiding permissive hypercapnia, limiting plateau pressures and avoiding proning.