Mucormicosis asociada a COVID-19: revisión de la literatura para odontólogos / COVID-19 associated mucormycosis: a literature review for dentists

La mucormicosis es una infección fúngica rara, con alta morbilidad y mortalidad. Se presenta principalmente en pa- cientes con diabetes mellitus no controlada, inmunocompro- metidos, con tratamiento crónicos con esteroides, entre otros. Actualmente, se cree que la pandemia de COVID-19 y los tratamientos con corticosteroides podrían estar implicados en el aumento de casos de esta micosis. Este hongo invade el sistema vascular, ocluyendo el flujo sanguíneo arterial y generando una rápida trombosis e isque- mia, lo que provoca la necrosis de los tejidos duros y blandos, con invasión rápida a los tejidos circundantes. Hay varias formas clínicas. En la cavidad bucal se presenta la variante rino-orbito-cerebral, que afecta el paladar en forma de lesión eritematosa o grisácea que puede progresar hacia la formación de una masa necrótica o ulceración con muy escaso sangrado de mucosa. Se manifiesta con síntomas típicos de una rinosinusitis con fiebre y dolor en las piezas dentarias superiores. El tratamiento consta de tres pilares fundamentales: el diagnóstico, un manejo adecuado de las comorbilidades y la combinación de las terapias antifúngica y quirúrgica. Desde el año 2020, la mucormicosis asociada a COVID-19 pasó a ser un evento de notificación obligatoria inmediata al Sistema Nacional de Vigilancia de la Salud (SNVS2.0) me- diante el Sistema Integrado de Información Sanitaria Argen- tina (SISA). Es importante destacar que se han reportado casos de mu- cormicosis luego de extracciones dentales; lo que impulsa a afianzar los conocimientos sobre esta enfermedad, extremar las medidas preventivas e incentivar el diagnóstico precoz en la atención odontológica, debido a la rapidez en la evolución de la patología (AU))

Mucormycosis is a rare fungal infection, with high mor- bidity and mortality. It occurs mainly in patients with uncon- trolled diabetes mellitus, immunocompromised, on chronic treatment with steroids, among others. Currently, it is believed that the COVID-19 pandemic and the corticosteroid treatments could be one of the causes of increased cases. This fungus invades the vascular system, occluding arteri- al blood flow and generating rapid thrombosis and ischemia, which causes necrosis of hard and soft tissues, with rapid in- vasion to the surrounding tissues. There are several clinical forms. In the oral cavity, the rhino-orbito-cerebral variant presents itself affecting the pal- ate in the form of an erythematous or grayish lesion that can progress towards the formation of a necrotic mass or ulcera- tion with very little mucosal bleeding. It manifests itself with typical symptoms of rhinosinusitis, with fever and pain in the upper teeth. The treatment consists of three fundamental pillars: diag- nosis, proper management of comorbidities and the combina- tion of antifungal and surgical therapies. Since 2020, COVID-19 associated mucormycosis became an event of mandatory immediate notification to the National Health Surveillance System (SNVS2.0,) through the Argentina Integrated Health Information System (SISA). It is important to emphasize that mucormycosis cases had been reported following tooth extractions, which drives to strengthen knowledge about this disease, extreme preventive measures and encourage early diagnosis in dental care, due to the speed of the evolution of the pathology (AU))

Seasonal clustering of sinopulmonary mucormycosis in patients with hematologic malignancies at a large comprehensive cancer center.

Background: Invasive Mucorales infections (IMI) lead to significant morbidity and mortality in immunocompromised hosts. The role of season and climatic conditions in case clustering of IMI remain poorly understood. Methods: Following detection of a cluster of sinopulmonary IMIs in patients with hematologic malignancies, we reviewed center-based medical records of all patients with IMIs and other invasive fungal infections (IFIs) between January of 2012 and August of 2015 to assess for case clustering in relation to seasonality. Results: A cluster of 7 patients were identified with sinopulmonary IMIs (Rhizopus microsporus/azygosporus, 6; Rhizomucor pusillus, 1) during a 3 month period between June and August of 2014. All patients died or were discharged to hospice. The cluster was managed with institution of standardized posaconazole prophylaxis to high-risk patients and patient use of N-95 masks when outside of protected areas on the inpatient service. Review of an earlier study period identified 11 patients with IMIs of varying species over the preceding 29 months without evidence of clustering. There were 9 total IMIs in the later study period (12 month post-initial cluster) with 5 additional cases in the summer months, again suggesting seasonal clustering. Extensive environmental sampling did not reveal a source of mold. Using local climatological data abstracted from National Centers for Environmental Information the clusters appeared to be associated with high temperatures and low precipitation. Conclusions: Sinopulmonary Mucorales clusters at our center had a seasonal variation which appeared to be related to temperature and precipitation. Given the significant mortality associated with IMIs, local climatic conditions may need to be considered when considering center specific fungal prevention and prophylaxis strategies for high-risk patients.

Bicarbonate correction of ketoacidosis alters host-pathogen interactions and alleviates mucormycosis.

Patients with diabetic ketoacidosis (DKA) are uniquely predisposed to mucormycosis, an angioinvasive fungal infection with high mortality. Previously, we demonstrated that Rhizopus invades the endothelium via binding of fungal CotH proteins to the host receptor GRP78. Here, we report that surface expression of GRP78 is increased in endothelial cells exposed to physiological concentrations of ß-hydroxy butyrate (BHB), glucose, and iron that are similar to those found in DKA patients. Additionally, expression of R. oryzae CotH was increased within hours of incubation with DKA-associated concentrations of BHB, glucose, and iron, augmenting the ability of R. oryzae to invade and subsequently damage endothelial cells in vitro. BHB exposure also increased fungal growth and attenuated R. oryzae neutrophil-mediated damage. Further, mice given BHB developed clinical acidosis and became extremely susceptible to mucormycosis, but not aspergillosis, while sodium bicarbonate reversed this susceptibility. BHB-related acidosis exerted a direct effect on both GRP78 and CotH expression, an effect not seen with lactic acidosis. However, BHB also indirectly compromised the ability of transferrin to chelate iron, as iron chelation combined with sodium bicarbonate completely protected endothelial cells from Rhizopus-mediated invasion and damage. Our results dissect the pathogenesis of mucormycosis during ketoacidosis and reinforce the importance of careful metabolic control of the acidosis to prevent and manage this infection.

Notes from the field: Fatal gastrointestinal mucormycosis in a premature infant associated with a contaminated dietary supplement--Connecticut, 2014.

In October 2014, a hospital in Connecticut notified CDC and the Connecticut Department of Public Health of a fatal case of gastrointestinal mucormycosis in a preterm infant. The infant, born at 29 weeks' gestation and weighing 1,400 grams (about 3 pounds), had developed signs and symptoms initially consistent with necrotizing enterocolitis approximately 1 week after birth. Exploratory laparotomy revealed complete ischemia of the gastrointestinal tract from the esophagus to the rectum; a portion of necrotic cecum was sent for microscopic examination. Following surgery, the infant developed multiple areas of vascular occlusion, including a large clot in the aorta, findings not usually associated with necrotizing enterocolitis. The infant died soon after. Histopathology results from the resected cecum revealed an angioinvasive fungal infection consistent with mucormycosis. Gastrointestinal mucormycosis is an extremely rare fungal infection caused by mold in the order Mucorales. It occurs predominantly in low birth weight infants, patients with diarrhea and malnutrition, and those receiving peritoneal dialysis; mortality is 85%. Local investigation revealed that the infant had received a dietary supplement, ABC Dophilus Powder, for 7 days, beginning on day 1 of life.

Intra-abdominal Rhizopus microsporus infection successfully treated by combined aggressive surgical, antifungal, and iron chelating therapy.

SUMMARY: Zygomycetes are widely distributed in the environment as inhabitants of soil and decaying matter. On rare occasions, these organisms can cause invasive infections in immunocompromised hosts. As zygomycetes are resistant to most conventional antifungal agents, its infection is often fatal. We report 2 cases of unusual intra-abdominal Rhizopus microsporus infection in children with acute leukemia as a result of an unprecedented outbreak due to oral intake of contaminated allopurinol tablets and ready-to-eat food items. Among the 2 patients, one of them survived after aggressive combined surgical, antifungal (AmBisome, Caspofungin, and Posaconazole) and iron chelation therapy.

Disseminated Rhizopus microsporus infection in a patient on oral corticosteroid treatment: a case report.

A 71-year-old male with mild steroid-induced hyperglycaemia was diagnosed with a lethal invasive Rhizopus microsporus infection. Disseminated zygomycosis is a rare entity and is most frequently found in neutropenic patients with haematological malignancies, post-transplants or in patients on deferoxamine therapy. Infection is characterised by tissue infarction and necrosis due to angioinvasive hyphae. Culture of Zygomycetes is necessary for species determination but histology is a must to prove the infection. Ante-mortem diagnosis and culture is challenging and therefore mortality approaches 100%. Apart from amphotericine B, most anti-fungals have no activity against Zygomycetes but posaconazole might offer new possibilities as a first-line agent. Timely diagnosis, rapid surgery of infected tissue, correction of underlying disorders and correct anti-fungal therapy might be life-saving. Due to the increasing use of potent immunosuppression, stem cell and organ transplants and possibly selection for Zygomycetes by prior treatment with broad-spectrum antifungal therapy, the incidence of zygomycosis is rising. Therefore, clinicians might encounter an increasing number of zygomycosis cases in the near future.

Intraabdominal zygomycosis caused by Syncephalastrum racemosum infection successfully treated with partial surgical debridement and high-dose amphotericin B lipid complex.

Invasive zygomycosis rarely complicates trauma. We describe the first recorded case of invasive infection of the anterior abdominal wall and omentum with the zygomycete Syncephalastrum racemosum, which was successfully treated with partial surgical debridement and amphotericin B lipid complex.

Infection due to Absidia corymbifera in a patient with a massive crush trauma of the foot.

We report the case of a patient with a massive crushing trauma of the right foot who developed a local infection due to Absidia corymbifera. Systemic and local antifungal therapy with ketoconazole associated with hyperbaric oxygen therapy (HBO) yielded a rapid clinical and microbiological resolution. Controlled clinical studies are warranted to further elucidate the potential utility of HBO/antifungal combination therapy.

Pulmonary mucormycosis in diabetic renal allograft recipients.

Renal allograft recipients are prone to opportunistic infections due to their need of immunosuppression to prevent rejection. Mucormycosis is a rare opportunistic infection caused by a fungi of the order Mucorales. Risk factors predisposing to this disease include prolonged neutropenia, chelation therapy for iron or aluminum overdose, diabetes, and patients who are immunosuppressed. Life-threatening infections can occur, as this fungi has the propensity to invade blood vessel endothelium, resulting in hematologic dissemination. Early diagnosis and prompt aggressive therapy is imperative to achieve an improved outcome. We present two cases of pulmonary mucormycosis in diabetic renal allograft recipients who were treated successfully with amphotericin B and surgical resection of the lesions with preservation of their allograft function. In this era of intensified immunosuppression, we may see an increased incidence of mucormycosis in our transplant population.

Indolent zygomycosis associated with deferoxamine chelation therapy.

This paper describes a 71-year-old man with myelodysplasia who required multiple transfusions and subsequent deferoxamine chelation therapy and who then developed indolent cutaneous and probable pulmonary infection with Rhizopus species. The patient did not have rapidly progressive infection as has been described in almost all previously reported deferoxamine-treated patients with zygomycosis. Amphotericin B therapy was successful in curing the infection.

Mucormycosis during deferoxamine therapy is a siderophore-mediated infection. In vitro and in vivo animal studies.

This study investigates the pathophysiology of mucormycosis caused by Rhizopus, which has been reported in 46 dialysis patients, while treated with deferoxamine (DFO). This drug aggravates mucormycosis, which we experimentally induced in guinea pigs and which lead to a shortened animal survival (P < or = 0.01). The drug's effect on Rhizopus is not mediated through the polymorphonuclear cells. Fe.DFO, the iron chelate of DFO, abolishes the fungistatic effect of serum on Rhizopus and increases the in vitro growth of the fungus (P < or = 0.0001). This effect is present at Fe.DFO concentrations > or = 0.01 microM, at which fungal uptake of radioiron from 55Fe.DFO is observed. A 1,000-fold higher concentration of iron citrate is required to achieve a similar rate of radioiron uptake and of in vitro growth stimulation as observed with Fe.DFO. These in vitro effects of Fe.DFO (1 microM) in serum on radioiron uptake and on growth stimulation are more striking for Rhizopus than for Aspergillus fumigatus and are practically absent for Candida albicans. For these three fungal species, the rates of radioiron uptake from 55Fe.DFO and of growth stimulation in the presence of Fe.DFO in serum are directly related (r = 0.886). These results underscore the major role of Fe.DFO in the pathogenesis of DFO-related mucormycosis. Pharmacokinetic changes in uremia lead to a prolonged accumulation of Fe.DFO after DFO administration, which helps explain the increased sensitivity of dialysis patients to DFO-related mucormycosis.

[A complication of local anesthesia during tooth extraction in children]. / Oslozhnenie mestnoi anestezii pri udalenii zubov u detei.

The authors describe a rare complication of local injection anesthesia, carried out in children for tooth removal: development of a specific granuloma due to Mucor and Nocardia mold fungi. The authors claim that the mycotic granuloma developed because of violation of the rules of asepsis, one of the possible violations being multiple use of disposable single-use syringes. No doubt, such complications can be easily prevented if asepsis regulations are strictly adhered to. The authors recommend the use of a separate sterile needle for every injection and treatment of the injection site with 1% iodine solution.