Personal Protective Equipment - A case for necessity driven innovation

Authored by Dhrupad Das; Co-authored by Nishchal Anand and Tanvi Jain

A Bit of History

Since the beginning of time, humans have undertaken endeavors which required specialized clothing to protect them from the hazards of the job. There is no doubt that our early ancestors fashioned specialized clothing from the materials available with them to serve specific functions. The plague doctors of sixteenth-century Europe had their own version of what we would today call medical protective clothing, complete with a face mask inspired by a bird’s face,  an ankle length overcoat made of waxed leather, gloves, boots, a wide-brimmed hat, and a sort of coverall, to top it all off. The beak of the bird faced mask contained dried flowers, herbs, and other aromatic material, in an early attempt to construct a respirator, meant to keep the plague at bay. It was believed that the plague spread through bad odor, called ‘miasma’. This was probably the first time the medical community used personal protective equipment (“PPE”) to shield them from a biological agent, which, unbeknownst to them, was a bacteria that spread through rats, called Yersinia pestis.

Today the field of protective clothing is a lot more evolved, with a much wider, much more nuanced understanding of materials and designs. We use PPE for a whole slew of purposes, some relatively new and modern, and others, antique. Today we have PPE that offers protection from radiation, chemicals, outer-space, flames and heat, electromagnetism, mechanical impact, and in the health care setting, from our old foe, pathogens.

PPE for Health Care Workers

Humans, throughout history have fought fierce wars with pathogens, and evidently, we still are. These pathogens spread diseases virulently, through air, through contact, through aerosol droplets in sneezes, or even respiration and have potentially deathly consequences for those who are unfortunate enough to be infected and also whose job it is to treat those infected patients. We’re talking here about health care workers (“HCWs”)

HCWs work in close quarters with infected patients, often for extended periods of time. They also collect test samples, conduct pathological tests, keep the quarantine areas sanitized, dispose of infected linen, towels, medical waste and even PPEs. One might argue that donning their PPE and heading into a quarantine zone is not unlike donning one’s armour and heading to the front to fight an armed and dangerous military enemy. The only difference is that for HCWs the enemy is invisible, innumerable, a master of technologies that are billions of years old, and their very existence occupies this grey area between living and non-living.

So, unsurprisingly, when the threat of COVID-19 became real and present, the Ministry of Health and Family Welfare, swung into action and identified various settings that it categorized as per the setting’s potential risk profile, which were low, medium and high. These categorizations formed part of it’s recommendations with respect to the rational use of PPE in it’s Novel Coronavirus Disease 2019 (COVID-19): Guidelines on rational use of Personal Protective Equipment. This made it clear that scores of individuals now required some form of protective equipment just to do their jobs safely. Chief amongst them were the HCWs.

How many Health Care Workers (“HCWs”) does India have? 

To understand the scale of those who may be potentially come into contact with patients infected with COVID19 within a healthcare setting, a good starting place is a recent study titled Size, composition and distribution of human resource for health in India: new estimates using National Sample Survey and Registry Data[1], which found that :-

The total size of health workforce estimated from the National Sample Survey (NSS) data is 3.8 million as of January 2016. The density of doctors and nurses and midwives per 10,000 population is 20.6 according to the NSS and 26.7 based on the registry data. More than 80% of doctors and 70% of nurses and midwives are employed in the private sector.

Now, granted, every one of these 3.8 million individuals may not be at high risk, but we quote this number to give a sense of the total population of HCWs in India. Those who work in emergency rooms, clinical laboratories, operating rooms, emergency wards, ICUs, among other like settings, would be most at risk of contracting COVID-19.

Some fatal statistics

A 2005 study titled Occupational Deaths among Healthcare Workers[2] noted that ‘experiences with severe acute respiratory syndrome and the US smallpox vaccination program have demonstrated the vulnerability of healthcare workers to occupationally acquired infectious diseases. However, despite acknowledgment of risk, the occupational death rate for healthcare workers is unknown... we estimate the annual death rate for healthcare workers from occupational events, including infection, is 17–57 per 1 million workers.'

Further, in a recent report by the Centre for Disease Control and Prevention (‘CDC”) titled Characteristics of Health Care Personnel with COVID-19 — United States, February 12–April 9, 2020 , the CDC put the number of HCWs infected with COVID-19 at a staggering 9,282, with 27 deaths. Unfortunately, this number might have risen substantially in the past month. China is not faring much better. The data from February of this year shows that 3387 HCWs were infected with COVID-19, resulting in 23 deaths.

The reason we use the United States and China as benchmarks is because they were/ are amongst the worst hit countries with some of the best healthcare facilities, which underscores not only the heroism of the HCWs in fighting a battle at great cost and risk, but also the important role proper and effective PPE plays, and will continue to play in this pandemic.

Know thy enemy

It goes by many names. It has been called the Plague of Justinian, Black Death, Smallpox, the Spanish flu, Ebola, AIDS, MERS, SARS, and now, we call it COVID-19. Many names for one, otherwise symbiotic vector, called pathogens, or as the technical papers call it ‘biological’ or ‘infectious’ agents. These agents are basically bacteria, fungi, viruses, prions, viruses, protozoa, and helminths (worms) – all different forms of micro-organisms. We’ll simply call them pathogens. These pathogens cause infectious diseases by first entering their hosts, us humans, and then replicating in their hosts. The infectious disease is basically a side effect of their replication process. It’s nothing personal, if that is of any comfort.

 But we should be clear, these pathogens are the black sheep of the microbial world. Most microbes are harmless, and many are even symbiotic. It will be fair to say that the human body will not be able to function without its resident microbes, who form in us our ‘microbiome’. In fact, these invisible life forms made and continue to make life possible on Earth. In 2018, it was discovered that microbial life present deep insider the Earth totals 15 to 23 Billion tonnes of carbon, this is hundreds of times more than humans in sheer weight. It turns out that some of these deep earth microbes exist on geological timelines and can be considered, well, immortal almost.

Microbes are everywhere. They are within and without us. It is estimated that human cells make up only 43% of the body's total cell count. The rest are microscopic colonists. Infact, if we look at the human genome, we find that the genes of our microbiome present essentially a second genome which augment the activity of our own. These co-dependencies highlight the symbiotic relationship that humans and microbes have. A very old, very healthy relationship – most of the time.

Interestingly, in H.G. Well’s ‘War of the Worlds’, published the same year as our antiquated Epidemic Diseases Act, 1897, the aliens that had invaded earth were not fought back or defeated by human ingenuity or grit, but rather by the microbes on earth, which the aliens had no immunity towards. This may well be the year that pathogens entered the global zeitgeist. 

To sum up, symbiotic microbes are great, pathogens, not so much. Symbiotic to whom and dangerous for whom are very pivotal questions, especially since microbes are ever evolving, mutating and are also capable of domestication, though often at some heavy (read herd immunity) costs. If you are quarantined in your house, wondering why and when will this all end, you have faced this reality first hand, and a global pandemic is, sadly, not just a risk vector in some consultancy’s risk analysis report anymore but a part of real everyday life now, a new normal. Scientist also warn us that the frequency of such pandemics may increase in the coming years and it is best to take our best learnings from the past and current pandemics and ensure we are better prepared as a species, as a nation, as a society and as a community to withstand whatever invisible challenge nature throws at us.

Elements of Transmission

Now we have a broad understanding of good microbes from bad. But how do these pathogens spread?

There are three things that a pathogen needs to complete its transmission cycle. There needs to be a source of infection, like an infected patient, contaminated clothes or surfaces, etc., a susceptible host (here, the HCW, with some form of exposure to the infectious microbe), and a mode of transmission (a way for the pathogen to travel from the source to the host). Once these three steps are complete, the susceptible host now becomes and source of infection, and the transmission process repeats. This is why we social-distance, wear masks, wash hands rigorously, and generally invoke the inner germaphobe in us.

The process of transmission is most likely to take place where all three links in the transmission chain are available, which unfortunately are hospitals or a clinics or other health care settings where infected patients receive care or are quarantined. In these settings, the patients are the source of infection, the HCWs are the susceptible hosts, and a pathogen has many ways to spread from the source to the host given the close proximity and frequent contact that is part of the job. Needless to say, transmission can and does take place outside such healthcare settings, but that’s a whole different story, which we are not delving into here.

To break this chain of transmission, the functions of PPE kits are employed. Sometimes it is enough to just wear gloves and a simple mask for personal protection. Other times, depending on the potential risk that exists to the HCW, a full body suit, complete with gloves, respirator, coveralls, face shields, etc., are required to be worn.

The PPE Kit as a protection system

It may be useful to think of the entire PPE kit as a complete protection system, and within this system -like in all other systems – there are elements which perform certain functions. If any of the elements fail, the system is compromised.

Broadly speaking, elements in this context include

1.      gloves,

2.      gowns or coveralls,

3.      aprons

4.      respirators,

5.      face shield,

6.      eye protection,

7.      head and shoe coverings.

Of all these elements that make up a PPE system, we are going to focus on gowns and coveralls, as they have the largest surface area and thus face the highest risk of contamination, after gloves.

Gowns and Coveralls

The World Health Organization, in 2016, released its rapid advice guidelines on Personal protective equipment for use in a filovirus disease outbreak. In this document, the WHO advised on the benefits and harms of double gloves, full face protection, head cover, impermeable coveralls, particulate respirators, and rubber boots as PPE, and compared their efficacy with alternative, less robust PPE, for health workers caring for patients with Ebola. 

In this guideline, the WHO made two design observation that we find relevant. Firstly, it noted that gowns were considered easier to put on and, to take off, making them safer when being removed, mainly because HCWs are more familiar with gowns than with coveralls. Secondly. It also noted that that heat stress was expected to be lower for gowns, than coveralls. The reason there is less heat stress in gowns is one-part design and one-part material.

The design of the gown makes it easier for body heat to escape. This is important to note because both WHO and MOHFW recognize that “coveralls and gowns are deemed equally acceptable as there is a lack of comparative evidence to show whether one is more effective than the other in reducing transmission to health workers.”

Further, heat stress can also be reduced by choosing the appropriate material for constructing the gowns or coveralls. The WHO notes that certain recommended materials like those that meets or exceeds ISO 16603 standards (that the MOHFW also recommends) are associated with lesser heat stress and more breathability, than those materials that meet or exceed ISO 16604 standards. Less heat stress and more breathability mean that such gowns and coveralls can be worn for longer and require less frequent changing. These too are important consideration for all stakeholders.

However, in an apparent contradiction, the Ministry of Health and Family Welfare, in their Novel Coronavirus Disease 2019 (COVID-19): Guidelines on rational use of Personal Protective Equipment on the one hand notes that gowns and coveralls offer the same level of protection against transmission of COVID-19, but on the other hand it distinguishes coveralls from gowns as coveralls on the basis of design, holding that coveralls typically provide 360-degree protection because they are designed to cover the whole body, including back and lower legs and sometimes head and feet as well and the design of medical/isolation gowns do not provide continuous whole-body protection (e.g., possible openings in the back, coverage to the mid-calf only). We have to admit, that this does make intuitive sense. The reason coveralls cause more heat stress is precisely because they are designed to keep all pathogens out, and consequently, keep all body heat in. How to balance heat versus protection is the real design and material challenge.

Gaps in Research and Regulation– Material, Fabrics and Design

Safety versus comfort

What we find from most of the available guidelines and regulations issued by various national and international institutions, is that they focus overwhelmingly on the protective functionality of the equipment, ensuring that the user of the PPE is safe above all else. This is very understandable and beyond reproach. However, a balance needs to be maintained, lest the very safety of the user of the PPE is compromised by bad design or inappropriate fabrics. In fact, this gap was identified by the WHO in their filovirus report noted above, where they pointed out that research with regard to the technical specifications for materials, fabrics and design of different PPE items was not adequate.

Safety and comfort ought to be the two overarching considerations that should weigh on the minds of regulators and manufacturers. When we speak of comfort, we mean thermal comfort and physical comfort associated with the fabric and design of such a gown or fabric. 

If the design and materials used to construct the gowns and coveralls cause discomfort to the wearer due to the issues like trapping too much heat - leading to exhaustion, or create an electro-static environment, or difficulty in putting on and taking off the gown or coverall, not only can the safety of the HCW be seriously compromised, but it will surely also have a direct bearing on the ability of HCWs to do their jobs, work efficiently and save lives. If we take the scale of our country, consider the number of healthcare workers who wear such PPE, the range of climactic conditions, urban and rural setting, certain basic design requirements can go a long way in aligning the intentions of the health care workers and their actual ability to carry out those intentions.

An environment that supports and encourages innovation in novel PPE designs and materials with the simple objective of balancing the safety and comfort requirements of the HCWs who will use the PPE can go a long way in increasing compliance, and safety of all involved.

The Ministry of Textiles may be one of the entities to take this cause forward, where it can encourage research and development into more novel materials, be they synthetic or natural, but most certainly a combination of the two. As on date, all gowns and coveralls used to keep pathogens like Ebola and COVID-19 are synthetic, which apart from being environmentally unsustainable from a manufacturing and disposal point of view, are also the root cause of the discomfort HCWs experience. As we have noted earlier, natural materials do not have particularly good barrier properties compared to synthetic materials. However, clever treatment of natural fibers or production of novel natural fibers using genetic/ CRISPR based interventions can be explored.

To reuse or not to reuse

In fact, design and material choices of PPE have a direct bearing on the duration of its usability. PPE can be either disposable or durable. Choosing durable versus disposable PPE would mostly come down to what the PPE is being used for, what do the regulations mandate and maybe even the philosophy of the purchaser of the PPE. Reusable PPE can be more environmentally sustainable when the environmental cost of production, transport and disposal are considered, all other metrics remaining the same. This may be an important consideration for hospitals and governments who want to signal a forward thinking and environmentally sustainable outlook.

It may be worth noting that AIIMS fearing a critical shortage of PPE, issued guidelines on how to re-use otherwise disposable PPE as an extraordinary last resort method. To help HCWs and hospitals re-use PPEs, IIT, Ropar has devised a technique to clean and sterilize PPE without causing any damage to them. Not to be outdone, a company out of Vadodara has claimed to have designed and manufactured reusable PPE Kits using novel materials. However, cost of these kits are high, though their repeated use and lack of bio-waste and compliance costs associated with the disposal of bio-waste may be sufficient incentive for early adopters to test these re-useable kits and iteratively improve them.

PPE Design Principles by the EU

In a very forward thinking and humanizing move, in 2016, the European Parliament passed Regulation (EU) 2016/425 on personal protective equipment, whereby they recognized the need for comfort and the role of design in achieving such comfort. Materials and textiles are one side of the story, smart design is another. 

The European Union went a step further than most when they set out the broad design considerations that are to be kept in mind by the manufacturers while designing their PPE kits. These Regulations though not restricted to the health care industry, hold sound design considerations that are worth keeping in mind when manufacturing PPE kits to be used by India’s HCWs in particular or all PPE users in general.

Some of the more relevant design principles that attempt to balance the PPE user’s needs for comfort, safety and efficiency have been extracted below:

1. the PPE must be designed and manufactured so that, in the foreseeable conditions of use for which it is intended, the user can perform the risk-related activity normally whilst enjoying appropriate protection of the highest level possible;
2. the optimum level of protection to be taken into account in the design is that beyond which the constraints imposed by the wearing of the PPE would prevent its effective use during the period of exposure to the risk or the normal performance of the activity;
3. the PPE must be designed and manufactured so as not to create risks or other nuisance factors under foreseeable conditions of use;
4. the materials of which the PPE is made, including any of their possible decomposition products, must not adversely affect the health or safety of users;
5. any part of the PPE that is in contact or is liable to come into contact with the user when the PPE is worn must be free of rough surfaces, sharp edges, sharp points and the like which could cause excessive irritation or injuries;
6. any impediment caused by PPE to the actions to be carried out, the postures to be adopted and sensory perceptions shall be minimized;
7. use of the PPE must not engender actions which might endanger the user;
8. PPE must be designed and manufactured in such a way as to facilitate its correct positioning on the user and to remain in place for the foreseeable period of use, bearing in mind ambient factors, the actions to be carried out and the postures to be adopted. For this purpose, it must be possible to adapt the PPE to fit the morphology of the user by all appropriate means, such as adequate adjustment and attachment systems or the provision of an adequate range of sizes;
9. PPE must be as light as possible without prejudicing its strength and effectiveness;
10. PPE must satisfy the specific additional requirements in order to provide adequate protection against the risks for which it is intended and PPE must be capable of withstanding environmental factors in the foreseeable conditions of use; and
11. PPE must be designed and manufactured in a way that perspiration resulting from use is minimized. Otherwise it must be equipped with means of absorbing perspiration.

PPE, Innovation and Patents

Besides regulatory bodies, private parties too have made attempts at striking a balance between comfort and protection when it comes to PPE. A recent series of innovations in designs and materials used in PPE were triggered by the spread of SARS, H1N1, MERS and Ebola. These innovations attempted to solve the problems noted above, specifically of enhanced safety, comfort and disposability of used materials. A few interesting and relevant innovations are discussed below:

Innovation in material - University of Tennessee Research Foundation, in the year 2004, applied for a patent (US 2005/0079379 A1) for a novel respirable fabric which can be used a barrier material for face masks. Besides ensuring adequate protection, the invention also claimed to provide enhanced thermal comfort to the user.   

In the year 2017, Avent, Inc. applied for a patent (WO 2017/184798 Al) for a “face mask having improved comfort through cooling of microclimate through use of a phase change material”. The invention claims to reduce the temperature of the of microclimate formed within the dead space of the mask by about 1°C to about 7°C after exhalation by the wearer and also improve upon the slash resistance which may be caused due to exhalation, coughing or sneezing.

Innovation in design - In the year 2007, an Italian inventor, conceptualized a new design (US 2009/0283096 A1) for the face mask claiming it to provide more comfort than existing face masks without compromising on its functionality and safety.

In the year 2015, Johns-Hopkins University applied for a patent (EP 3 039 977 A1) for an innovative design of a body suit or coverall for HCWs. The invention allows for a novel way of donning and doffing of the coverall with minimum contact thus minimizing the chances of infection. Sizing adjustments, sweat-wicking features, and vents were added to increase the comfort of the user and extend the time they can wear the PPE. Additional features included printed instructions in the suit, tabs for ease of removal, and several innovative safety concepts. The design of the PPE was also claimed to have an additional impact of improving healthcare workers’ relations with the community by rendering the appearance of PPE less intimidating (a departure from the grim reaper appearance of Bird Face!).

Let me care, not scare you (Source: EP 3 039 977 A1)

Innovation in manufacturing – Honeywell International Inc. applied for a patent (US 9,446,547 B2) in the year 2015 claiming a novel and cost-effective method of manufacturing nanofiber filtering material for disposable and reusable masks while remining in compliance with various regulatory standards with respect to PPEs. The invention also considers improvement in breathing resistance, solid or liquid aerosol penetration, as well as fit and comfort of the respirators.  

Opportunities for Indian manufacturers – The graver the challenge, the greater the opportunity. With the large resources, human and material, available in our country, it is time to make strides towards innovation in products and business models. It is the right time for Indian healthcare companies and manufacturers to invest in research and development, innovate with local resources and collaborate with foreign players to introduce innovative technologies into India.      

Conclusion

Pathogens and pandemics are as much a natural phenomenon as earthquakes or hurricanes or tsunamis. Only they last a lot longer, spread a lot further being non localized events. They are here to stay. This means that our ability as a species to fight pathogens is going to be critical, lest we suffer the evolutionary pressures from such pathogens as our not-so-far-ago-ancestors faced.

This is going to take great global co-operation and co-ordination, deep behavioral change at a global-societal level and series of small, deliberate and meaningful steps that collectively makes us all a little bit more secure. A big part of that challenge is to ensure out healthcare system is up to the task the next time such a novel virus spreads amongst our midst. Our health care system is only as good as our HCWs, who, as we are all aware, are the true heroes of this pandemic. The frontline is a dangerous place to be, and that is where they are, every day.

Finally, it is up to us, as people under their care to make sure that they are cared for. Not through empty words and gestures, which are easy, but by going back to the drawing board to achieve one simple aim, to make their armor better. Make it more secure, more comfortable, more effective. It will require many entities to collaborate - manufacturers, governments and regulators, the health care industry themselves. We will have to find new materials, new ways of arranging old materials, design innovations, technological solutions to age old problems. This is a place where necessity and duty, meet creativity and opportunity.

 Sources:

[1] Karan A, Negandhi H, Nair R, Sharma A, Tiwari R, Zodpey S. Size, composition and distribution of human resource for health in India: new estimates using National Sample Survey and Registry data. BMJ Open. 2019;9(4):e025979. Published 2019 May 27. doi:10.1136/bmjopen-2018-025979

[2] Sepkowitz KA, Eisenberg L. Occupational deaths among healthcare workers. Emerg Infect Dis. 2005 Jul;11(7):1003–1008