Hello, I'm Dr. Alice Barsoumian, and I'm an infectious disease physician. I'm here today to discuss one of the areas I am passionate about, and that's infection prevention in prolonged field care and austere settings. Being an infectious disease physician in the United States Air Force, I deal with infectious complications of people who were treated in field hospitals as they get repatriated back to my institution. But I've also been involved in outbreak investigations that have occurred at field hospitals, and dealing with these austere settings from a uniquely military standpoint is a great example that we can use to adapt to humanitarian and military crises for care of injured and critically ill personnel in austere and remote locations. The U.S. military has a lot of experience in this area, given the ongoing conflicts and previous recent conflicts, and there's a lot of robust lessons learned that we can use to take and adapt into these other situations. I have no financial relationships to disclose. I would like to discuss, however, that I will be talking about some off-label use of antibiotics later on in my talk, and that the context of this presentation reflect my own views and not those of the United States government. When we're talking about austere settings and prolonged field care, there is a lot of variation that can happen in terms of facilities and capabilities. On the right is an example of a low-volume combat support hospital in Iraq in 2019. This combat support hospital was relatively well-resourced in terms of personnel because it was low-volume in terms of patients. However, that can rapidly change. This particular location, being in a tent-based hospital, has the challenges of not being able to move beds and spacing, having patient tables close together, having non-wipable surfaces, not being able to mount infection prevention equipment to the walls, and other challenges that you would expect. However, I've been to many, quote, hardened facilities that have all the benefits of linoleum on the floor and drywall and plaster up on the walls and hoods and vents and all the things that you would expect, but still are considered austere due to where they are and the capabilities that they have. So what's in common? What is in common? What are you going to expect in terms of what defines an austere setting or involving a patient in prolonged field care? It's not really the facility. So these patients are going to have bad injuries and illnesses, an unpredictable supply chain, even if the facility looks pristine, potentially unreliable diagnostics, and that could be because the diagnostic capability for infections is not present or the experience to interpret them is not there. There could be aggressive or resistant bacterial organisms. Breakdown in habits is a big one, particularly when people are out of their element. Sometimes they revert back to more basic knowledge than the sophisticated knowledge of processes and procedures that they adhere to in the U.S. Fluctuations in patient volume and capacity to handle them are also challenges that you might have in austere settings. Sometimes you might get a mass casualty. Sometimes you might have a lot of people come in with a communicable illness. Variable expertise, because you don't know what the threat with the patients is going to be. Sometimes you don't have the right people on the team to manage it. And another defining feature of these settings would be a limited infrastructure for either escalation of care or de-escalation of care and discharging of the patients and downgrading of the patients. With that in mind, I'm going to discuss three main learning objectives. So infectious disease threats in prolonged field care, the identification of the best practices for infection control adapted to these austere settings, and then also discuss the risk and benefits for infection prophylaxis strategies for traumatic injuries. Certainly traumatic injuries won't be the only thing that you see in a humanitarian crisis or an austere field setting, but it is a hot topic and it's an area that you can really make impact on, so we will discuss that as well. Let's start with some of the threats. So here are the types of infectious disease threats in these settings. Endemic diseases, so these would be things like malaria, if you're providing care in a malarious area that requires ICU care. Multidrug-resistant organisms, their incidence is increasing worldwide and is a particular threat in distinct areas of the world. Also recall, multidrug-resistant organisms are frequently a complication of US-based ICU care as well, so all ICUs are at risk for multidrug-resistant organisms. Nosocomial infections are possible as well. When we're talking about prolonged field care, perhaps that patient can't be evacuated to a more stable scenario. Perhaps that patient has nowhere else to go. That patient's going to be in your ICU for a long time, and so they're going to be at risk for all of the nosocomial infections that they would be at risk at your institution down the street in big city USA. Outbreaks, outbreaks would be a nosocomial infection that is transmitted from person to person or the organism is transmitted to person to person who then develops an infection. And then traumatic wound infections, again, some of this will be one of the unique things about these types of crises, particularly after natural disasters. When you're trying to figure out what multidrug-resistant organisms are where, in the US, we have great surveillance systems and really have well-defined what we're worried about in each area of the country. Worldwide, that's a little bit more variable, but the WHO does have a global antimicrobial resistance use and surveillance system that does have some data coming from other countries that you can check out, and here is the link. This talk is going to focus mostly on these types of threats that are blocked here in this rectangle. I want to share an example of patients that had prolonged ICU care in an austere setting and hit all the box, nosocomial infections with ventilator-associated pneumonias, multidrug-resistant organisms. This was a field hospital outbreak I was involved in in 2020 and 2021. Had 15 patients and four deaths of multidrug-resistant Acineta baumannii, and so remember, that's an organism that's frequently carbapenem-resistant. And we have a complex surveillance network that we are able to recover these organisms and perform advanced genetic testing on them through some of the researches that we have, and we saw that there were three clusters of genetically linked isolates and implication of direct transfer from patient to patient in some of the situations with an intermediary in some of the other situations. This particular team was devastated by this outbreak. These 15 patients were all anticipated to survive their injuries. Most of these patients were wounded, and the four deaths were attributed to the Acineta bacter baumannii infection and not due to other causes. When they sampled their environment, they sent over 160 environmental samples back to labs in the United States, and they were unable to recover any of the organisms that were implicated in the outbreak. This is a printout of some of the susceptibility testing that was performed at a reference center, and as you can see, all of those R's are bad. So all of those drugs do not work for this organism. Of the drugs tested, only tigacycline and colistin had susceptibility for this organism, and there is increasing evidence of increased mortality when organisms, Acinetobacter in particular, is treated with colistin or with tigacycline. So these patients, just because it says S on paper, doesn't mean that the real world success is also susceptible or survivable. So as you can see, this is a great example of all of the risks that you have when you have these people in an austere location. Notably, this is the microbiologic data that we were able to receive from a reference laboratory. None of this was available at this particular site. They did not have the capability to test many of these drugs, and so oftentimes they were prescribing some of these drugs without ability to confirm that there was activity. That's something that you might run into, because some of this advanced drug susceptibility testing is not even performed in big-time hospitals in the United States. But this is not a time for us to despair and have doom and gloom. Throughout our repeated experience, we have been able to identify some best practices for infection prevention in the field, and I'd like to share them with you today. This should come as great relief. So the key principles and practices of field infection prevention and control are the same downrange, in an austere setting, in a field hospital, as they are in the United States. So the standards that we have with adaptations for the environment we're in are effective in the field, and they're familiar. It's going to be hand hygiene, it's going to be transmission-based precautions and cohorting of patients, and it's going to be the same bundles like ventilator-assisted pneumonia and central line bundles, perhaps adapted, that will save your patients' lives from infections downrange. Let's start with hand hygiene. Hand hygiene is the first and last lines of defense for your patients. Always wash hands between patients. If we don't find the reservoir of an infection, we can still interrupt transmission by washing our hands. When we have conducted outbreak investigations on-site at field hospitals over the years, we frequently reveal that the hand hygiene programs are unmonitored, there's no emphasis from the leadership, and hand hygiene stations are broken, empty, or unusable. Try and adapt to your situation. If you have sinks, that's great, but if you don't, gel's great too. If you have no soap or a mass casualty where you can't wash your hands between patients because of the tempo, you have to mitigate these threats and not ignore them. Those could include no soap, do wash only as opposed to wash with soap, or buy commercial soap instead of healthcare soap. These types of things are things that you're just going to have to assess and mitigate. Don't ignore the threat, mitigate the threat. On the screen, you'll see some pictures that I have seen at various field hospitals. This is actually the same field hospital at different iterations. On the left, you can see that the team is performing arts and crafts at the hand hygiene station, which shows a degradation of professionalism around hand hygiene. In the middle, you'll see a trash can obscuring the access to the hand hygiene station on a wall. This particular issue, anything that increases barriers to washing your hands will decrease your hand hygiene compliance. On the right, you kind of see a best practice. They were unable to get hand hygiene gel wall units refilled, so they taped hand hygiene stations to the beds. There's a variety of things you can do to adapt and mitigate to these threats. I really want you just to recognize washing your hands can end outbreaks, and the compliance doesn't even need to be that high. The one thing I'll say about compliance is that we have noticed poor compliance places that don't have a monitored program. I'd like to mention cohorting patients in two scenarios. Number one, cohorting patients in a humanitarian setting, you might have a lot of different persons responding to that natural disaster or a humanitarian crisis. And recall that people are colonized with organisms most prevalent in their country of residence. Try not to cross contaminate patients. This particular graph is from a study of looking at U.S. soldiers and non-U.S. personnel in field hospitals in Afghanistan, and you can see that U.S. personnel were largely colonized with Staph aureus, frequently MRSA, and the non-U.S. personnel were frequently colonized in this particular study with drug-resistant gram negatives. It's bad to share infections and organisms this way. Try and separate these patients. If you have difficulty separating patients in different wings of a hospital because you don't have different wings of a hospital, you can try having a row of beds, having patients on the left from one nationality, patients on the right from the other, or just having patient beds separated by empty beds in between them with hand hygiene stations on that empty bed. Those are all things I've seen that successful teams have used. You can also cohort patients based on symptoms, and this brings us into transmission-based precautions, and in general, you don't need to know what's causing a patient's illness to prevent the spread of disease in a hospital. You implement precautions based on symptoms, so diarrhea and purulent secretions from wounds are contact, respiratory are droplet, with or without contact if you think they may have a pandemic coronavirus or pandemic flu, airborne is for tuberculosis if you think that patient's at risk. If you have a fever with rash, that could be measles, that could be meningitis, that would be a reason for airborne precautions, and you can always add airborne plus contact if they have bleeding and you're concerned about a viral hemorrhagic fever. This is an example of one of my favorite studies that have come out from infection prevention at a combat hospital, and this is about ventilator-associated pneumonia and the VAP bundle that has been adapted to an austere setting with excellent outcomes. So this particular study occurred at a combat hospital in Iraq. They only had one sink per tent, no isolation rooms, minimal rooms between bed, non-wipable surfaces, and a high patient volume with 119 admits to the ICU a month. They also had to keep the doors open so they had cross-ventilation and temperatures were frequently above 100 degrees F in there. So very, very difficult. This particular team had an infectious disease physician assigned to the unit as an intensivist. Sometimes we see this in austere settings, of course, and when he arrived in May, he noticed that the VAP rate was 60 per 1,000 ventilator patient days. He implemented a VAP bundle. At the time, some of the features are going to look different than modern VAP bundles, but essentially placing hand gel at the bedside of each patient, enforcing hand hygiene, putting patients on contact precautions for those with known MDROs, elevating the head of bed, performing oral care, having sedation breaks and extubating patients the best they could, and reducing duration and spectrum of antibiotics. With his time there, he was able to decrease the ventilator-associated pneumonia rate in a high-ops tempo with no resources to about 10 per 1,000 ventilator patient days. At the time, the U.S. standard was 16. There's other published examples of the same thing being shown. Just like to show this to you to empower you and to make you see the power of continuing the things that we know work, even if you have to adapt them. So we, as the U.S. military infectious disease community, have seen a lot of outbreak investigations on hospital ships, in tent hospitals, in prolonged field care settings. And where do we see the most missteps? Poor recognition of the threat, perception of futility. We can't do it to U.S.-based standard of care, so why bother? There are words that we've heard and recorded many times, and low prioritization from leadership. We do not see missteps in the austere setting itself. So again, these are all things that we can adapt to in an austere setting, and it's the threat recognition and mitigation, understanding that it is not futile, and ensuring emphasis from leaders, and that includes thought leaders as well as actual assigned leaders. So I'd like to end with infection prophylaxis and traumatic wounds. So in a humanitarian crisis, you might see gunshot wounds, you might see combat injuries, you might see crush injuries, explosions, all kinds of things, and these wounds, because of the mechanism of injury, often get infected. I conceptualize three types of traumatic wound infection. So early bacterial infections, these have a high mortality. This is within the first 24 to 72 hours, and these kill patients, usually from group A strep, strep pyogenes, and clostridial gangrene. There's late infections of wounds, which are heterogeneous in terms of composition and organism, and frequently nosocomial, or onset is nosocomial. And then there's fungal infections. These are a bit more rare, and thank goodness, because these have a high morbidity and a mortality as well. And patients with blast injuries, crush injuries, tornado victims, and tsunami victims, anywhere that you have a mechanism of injury where you get vegetation and debris that contaminate the tissue planes, you're at risk. In the boxes, I have highlighted the areas in which there are prevention and empiric therapy strategies that are effective. Early bacterial infections, prevention strategies are very effective in decreasing these infections. We never see patients die of overwhelming group A strep sepsis and clostridial gangrene in the first 24 to 72 hours anymore. Fungal infections, while we don't have great historical data controls for this, expert opinion recommends empiric therapy for high-risk cases, and those would be the ones with the vegetation contaminating tissue planes that require massive transfusions or have high injury severity scores. In both of these cases, prevention and empiric therapy strategy is a combination of antimicrobials and aggressive debridement and delayed closure of wounds. And this combination of aggressive surgery and a short duration of antimicrobials is effective in really impacting these patients' lives. Early bacterial infection prophylaxis and trauma, there's a lot of different recommendations here. So there's the International Red Cross, different military organizations around the world will have different guidelines. The U.S. military guidelines have been published in peer-reviewed journals but are also accessible here through the Joint Trauma System clinical practice guidelines. And the bacterial prophylaxis is largely aimed at streptococcal species. So that will largely be cefazolin, and occasionally anaerobic coverage is recommended, and that's usually metronidazole. Alternates, if there's no access, no IV access, could include moxifloxacin orally or erdapenem, which can be given IV or intramuscularly. And most times this is for a very short duration. That's enough to really end the cycle of these infections. But there's a risk. Everything comes with a risk. Late wound infections are heterogeneous in organisms, nosocomial in onset, and we have not been able to prevent them effectively. We have been able to look at our U.S. military population data, and other countries have looked at them as well from operations OIF and OEF, and we have found that excess antibiotics do not prevent late wound infections, do not improve mortality, and do not improve morbidity. Excess antibiotics have also been shown to increase the risk of multidrug-resistant infections, and unfortunately, as you've seen, those can be fatal. I wanted to end with, you can do this. I know you can. I've seen it done. Wherever you go in the world, whatever it is, you can take the standards that you know very well, and you can adapt them for your situation. Any adaptation comes with a risk, but what you do is you mitigate a risk or accept the risk, not ignore the risk, and you can interrupt the cycle of infections and outbreaks. I mentioned we've done a lot of outbreak investigations on field hospitals in the U.S., in the U.K., and what we have found is that adhering to these practices interrupt them every time. Thank you.

infection prevention

prolonged field care

austere settings

limited resources

aggressive and resistant bacterial organisms

hand hygiene