"Fatalities up to 60%," "Ineffective with various medications," "Classified as an 'urgent threat' by the CDC". "...... Recently, a series of overseas information as well as the news of 18 cases of super fungal infections diagnosed in China has become a hot spot in social media, a kind of ear candida known as "super fungus" has triggered a certain amount of public panic, and rapidly A "super fungus" called Candida otitis has sparked some public panic, quickly making its way to the top of the microblogging hotspot list and bringing the stock market's pharmaceutical sector to a halt.
Candida strains cultured in petri dishes (source: CDC website)?
What is the "super fungus"? Is it contagious?
"Superfungi," like "superbugs" which have been around before, are a general term for fungi that are resistant to a wide range of antibiotics. They pose a significant threat to human health because they are so resistant to current clinical antibiotics that they can escape extermination. Likewise, similar to "superbugs," the creation of superfungi is linked to the misuse of antibiotics in healthcare, which is why this Candida ear infection is highly prevalent in the ICU ward.
There are a large number of immunocompromised patients in ICU wards, and at the same time, there are a large number of antibiotics and sterilization drugs, making it difficult for ordinary pathogenic bacteria to survive and be eliminated, and drug-resistant "super fungi" have a competitive advantage, and naturally survived. Therefore, "super fungi" do have an advantage in drug resistance, but they often do not have any special advantage in their ability to spread, cause disease and survive in complex environments. Therefore, both "superbugs" and Candida auriculata are not inherently infectious diseases, and it is unlikely that they can cause a pandemic among the general population in an environment other than hospitals, as in the case of SARS or avian influenza. It is also one of the reasons why we, the general public, don't have to worry too much.
When did the "super fungus", Candida ear, come about?
The ear candida (Candida auris, C. auris) that is the subject of this outbreak was actually first reported in Japan in 2009. It was first discovered in secretions from the external ear canal of a Japanese patient, and despite its name, Candida auris can affect many other areas of the body, causing invasive infections such as bloodstream infections and wound infections. It can also be isolated from the respiratory tract, urine specimens and biliary fluids.?
The first reported case of Candida ear infection in China was identified from a bronchoalveolar lavage fluid of a woman with hypertension and nephrotic syndrome admitted to the People's Hospital of Peking University. Currently, Candida otitis, a multidrug-resistant fungus, is endemic in 12 states, including New York, New Jersey and Illinois. As of March 31, it has caused 613 infections across the United States, with a mortality rate of 30% to 60%, and nearly 50% or more of those infected die within 12 weeks.?
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Clinical cases of Candida reported by U.S. states as of February 28, 2019?
(Source: CDC website) ?
Meanwhile ear candida infections have been reported in more than 30 countries worldwide. There are currently 18 confirmed cases of clinical Candida ear infection in mainland China***.?
Countries reporting ear candida cases as of February 28, 2019 (source: CDC website)?
It is important to note that since Candida infections are common fungal infections in clinical healthcare settings, and ear candida is extremely difficult to recognize by traditional laboratory methods, it is likely to be missed. Retrospective studies of Candida strains have also found that the earliest known strain of Candida actually dates back to 1996 in South Korea. It is also likely that there were unrecognized cases of Candida ear infection before the first case of Candida ear infection was reported in China.
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Electron microscopic photographs of ear candida ?
(Source: Guanghua Huang's group, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences) ?
Outbreaks of ear candida have occurred in more than 30 countries, how much of a threat is it really?
1. Conditional pathogenicity: "riding the wave"?
To talk about the threat of ear candida, first we need to understand that ear candida belongs to the conditionally pathogenic bacteria. It exists in the human skin and mucous membranes, when the body's immunity is low can attack the body, causing opportunistic infections. Therefore, the chances of contracting ear candida are extremely low for the average person with normal immune function, but for immunocompromised critically ill patients in ICU wards, such infections are often fatal (up to 50% lethality in the 557 cases reported in the US, but it was also mentioned that since many of them suffered from other serious illnesses, it also increased the risk of their deaths. Thus it is uncertain whether patients with invasive ear infection are more likely to die than those with other invasive Candida infections).?
There is still a paucity of research on the specific pathogenesis of ear notions, and it is not yet clear how ear notions attack human cells. Unlike Candida albicans, which is currently the most common clinical infection of Candida, which invades cellular tissues by forming hyphae, this phenomenon has not been observed with ear candida. Although the exact pathogenesis remains unknown, the Centers for Disease Control mentions that any invasive infection with Candida can be fatal.?
As it stands now, critically ill patients who have been hospitalized in a healthcare facility for a long time and have a central venous catheter or other line or tube coming into their body are at the highest risk for ear candida infections, as this would greatly increase the likelihood of an ear candida invasion into their body.?
2. Multi-drug resistance: "no cure"? Little research has been done on the mechanisms of multidrug resistance in Candida ear.
Specifically, studies have estimated that up to 93% of clinical isolates have increased resistance to fluconazole, an azole commonly used to treat systemic Candida infections. Most alarmingly, some isolates have been reported to exhibit high levels of resistance to all three major antifungals (azoles, echinocandins, and polyenes), leaving no treatment options for this infection. In contrast, the U.S. Centers for Disease Control and Prevention summarizes data that more than 90% of isolates are resistant to one antifungal drug and at least 30% of strains are resistant to more than two classes of drugs. In addition, there are a few reports on Candida auriculata in China, and the results show that both drug-resistant and non-drug-resistant strains exist, with the predominance of fluconazole-resistant strains. Therefore, it is difficult to target treatment.?
Such a high level of multidrug resistance also contributes to the fact that ear candida has such a high lethality rate.?
3, clinically difficult to diagnose and identify: difficult to distinguish, easy to miss detection?
Because most of the patients infected with Candida ear are other critically ill patients, and the infection itself does not have obvious signs, which makes it difficult for healthcare organizations to determine the occurrence of Candida ear infection in the first place. Also, the similarity of the Candida ear phenotype to other types of yeast such as Candida albicans makes the current identification of Candida ear difficult, difficult to recognize using standard laboratory methods, and may be misidentified in the laboratory without specific techniques.?
The two main methods that can be used for effective identification are mass spectrometry and genome sequencing. According to Fang Wenjie, an attending dermatologist at Changzheng Hospital affiliated with the Naval Military Medical University, when a patient has an unexplained fever and medication is ineffective, clinicians will have the patient have blood drawn to test for a fungal infection. Blood samples to the laboratory, placed on a petri dish culture, after a period of time, there will be multiple colonies on the petri dish, then the doctor will select one or two colonies to do mass spectrometry analysis or a generation of gene sequencing to confirm the fungal species. However, due to the high cost of using the instrument, will not take all the colonies to be analyzed, whether to pick the "super fungus", is very dependent on the knowledge and experience of the test doctor, so it is likely to miss the test. Not only in the selection of colonies of the link is easy to miss, in the subsequent analysis phase, mass spectrometer analysis and genome sequencing of the high price, also makes many non-tertiary hospitals are not in a position to identify Candida ear.
4, strong vitality, the complete removal of the difficulty is extremely?
Candida can survive for a long time in different environments such as dry and wet surfaces, bedding, floors, sinks and patients' internal tissues, triggering infections in the blood, lungs, urinary tract, surface wounds, and ear canals, etc. It is particularly dangerous for patients who use medical aids (such as built-in catheters for urinary catheters, respiratory devices) who are hospitalized for long periods of time, in intensive care units, or who suffer from immune system disorders (eg. AIDS, diabetes, etc.) are particularly at risk.?
The U.S. New York Times had reported on April 6 that Mount Sinai Hospital in New York City found an elderly man infected with Candida ear when he underwent abdominal surgery last May. The old man eventually died after 90 days of isolation in the intensive care unit, while the deadly fungus stubbornly survived and took over the entire ward, for which the hospital carried out special disinfection of walls, beds, doors, sinks and telephones, and even removed part of the ceiling and floor. The strong resistance of Candida auriculata to many commonly used antiseptic drugs allows it to persist in the environment and is difficult to eradicate, so prevention efforts must be targeted to prevent the introduction of strains of the bacterial?
5, the geographical strains vary greatly?
The CDC sequenced the whole genome of Candida ear specimens from countries in East Asia, South Asia, Southern Africa and South America. Whole genome sequencing produces a detailed DNA fingerprint of the organism. They found that isolates within each region were very similar to each other, but isolates from each region were relatively different, with four distinct versions present and so different from each other that the researchers speculated that the strains had diverged thousands of years ago while emerging from harmless environmental strains to become drug-resistant pathogens in four different locales.?
The ear candida strain isolated from the first patient with ear candida infection reported in China was tested by Huang's research group, which found that, unlike the multi-drug resistance reported in other countries, the first Chinese strain of Candida auricularis was more sensitive to all the clinically used antifungal drugs. This also suggests that Candida is highly geographically diverse and that not all Candida strains are "super fungi," further reducing the potential threat posed by Candida.
But at the same time, Huang's group also noted that in follow-up experiments, when researchers used first-line antifungal drugs such as fluconazole for 48 hours or more, they induced resistance in Candida. This suggests that the resistance of Candida as a "super fungus" may have evolved as a result of the screening of environmental flora by the use of large amounts of antiseptics and antibiotics in the healthcare environment. The geographic variation of Candida otitis is increasing the need to tailor treatment regimens to different regions, which is also increasing its threat level.
The emergence of ear candida has significantly increased the economic burden on healthcare organizations?
The very low transmissibility of ear candida in the out-of-hospital setting and the very low infectivity of the average person with normal immunity makes it seem like it has nothing to do with us ordinary people, but I'm going to talk about the fact that it's likely to have another significant consequence: a significant increase in the cost of intensive care unit treatments in our healthcare organizations. This may not be very relevant to the average person, but it is a very serious concern for healthcare organizations.?
It was mentioned above that in order to remove ear candida from the wards at Mount Sinai Hospital in New York City, the hospital administration specially disinfected all corners of the hospital for this purpose, even removing parts of the ceiling and floor. This greatly increased the cost of maintaining the ICU.?
At the same time, in order to stop the spread of ear candida, even if there is a very small number of cases of ear candida infection, it is likely that isolation measures will need to be increased throughout the entire health care facility, which will likewise make the cost of manpower and medical equipment skyrocket.?
Finally, when a patient develops an infection of an unknown etiology, the possibility of being infected by ear candida, a multidrug-resistant pathogen, means that tens of dollars a day of generic antifungals may be ineffective, and faced with a critically ill patient in an ICU, the race-against-death healthcare worker has very little time to try different medications, which can force doctors to use newer, but at the same time more expensive, antibiotics first for treatment. All of these factors raise the cost of running the entire health care system, and it's the ICU patient and the entire health care system that ultimately pays the bill.
In fact, it's not just Candida, but every new "superbug" and "superfungus" that raises the burden on our entire healthcare system. The World Health Organization's then-director-general Margaret Chan noted on World Health Day 2011 that the development of drug resistance is a natural biological process, and with the daily use of medicines, this has to happen sooner or later. "However, misguided practices and flawed assumptions allow the inevitable development of resistance to occur much sooner." And irrational and inappropriate use of antimicrobials is the "main culprit" in the current development of resistant strains.?
The discovery and use of antibiotics has been called one of the greatest discoveries of the twentieth century, and has been hailed as a miracle of modern medicine, which has given mankind a decent weapon to fight pathogenic diseases. However, the misuse of antibiotics in healthcare and animal health, as well as in agriculture, is causing more and more antibiotics to lose their effectiveness, and the development of new antibiotics is becoming more and more expensive. The ongoing development of antibiotic resistance to a wide range of pathogens is threatening the lives of all of us, the safety of the environment, and the security of food and agricultural production. When the development of antibiotics cannot keep pace with the emergence of new resistant strains of bacteria, "druglessness" is likely to become a nightmare for most patients and healthcare workers.
What can we do in the face of increasingly frequent antibiotic resistance?
What can we do about the increasing frequency of antibiotic resistance?