Ebola epidemic: medical and military technologies converge
By Dr Nicola Davies(eiet),
Medical and military technologies are being adapted to fight the spread of Ebola. What are these technologies? How will they help advance the diagnosis and treatment of this epidemic?
Since the first reported case of Ebola Hemorrhagic Fever - more commonly known as Ebola Virus Disease - in Guinea in the latter part of December 2013, the death toll has exceeded 8,000. More than 20,000 people have been diagnosed with the highly contagious disease, with confirmed cases of Ebola reaching the US, UK, Spain, France, Germany and Norway. Furthermore, the World Health Organization believes that the disease is not likely to be under control before mid-2015.
Volunteer personnel face numerous obstacles with the aid they are attempting to provide, including suspicion and superstition from local people, who are unaware of the danger Ebola poses to them. Diagnostic techniques have been costly and treatment facilities have been non-existent or ill-equipped to cope with an epidemic of this magnitude.
International efforts to control the spread of Ebola in Sierra Leone, Guinea and Liberia – the countries hardest hit by the epidemic – have been showing some promise. In particular, there have been a number of technologies created for medical or military purposes that can be repurposed and used in the fight against Ebola.
The traditional tests used to determine the presence of the Ebola virus are costly, slow and complicated. They require a high level of laboratory biosafety, highly trained staff and complicated technology. Mobile laboratories in West Africa have been forced to use the RT-PCR test (reverse-transcriptase polymerase chain reaction test), a six-hour procedure costing approximately $100 (£64) and requiring a full vial of blood. The longer it takes to confirm or dismiss a diagnosis, the longer it is before the patient can begin receiving treatment, and the higher the risk of more people becoming infected.
Cambridge Consultants and Diagnostics For All have collaborated – with funding from Massachusetts Life Sciences Center – to develop a handheld point-of-care device for diagnosing Ebola. The device, which is expected to be field-tested before July 2015, utilises single-use disposable cartridges costing less than $10 each. It takes approximately 45 minutes to complete the diagnostic process. The programme manager at Cambridge Consultants, David Chastain, says: “Simple, low-cost testing tools that require minimal training to use are becoming essential in developing countries where the virus outbreak is most severe. The combination of our systems design, mechanical engineering and human factors skills with Diagnostics For All’s vision and expertise in molecular diagnostics can help transform the way health workers provide point-of-care diagnosis – and subsequent treatment – in at-risk areas.”
Tracing the possible points of contact of those with a confirmed Ebola infection is crucial to containing and managing the spread of the virus. This is where the Nigerian polio eradication programme’s satellite-based GPS (Global Positioning System) monitoring has been effectively repurposed for Ebola prevention. The Ebola epidemic in Nigeria was stopped in its tracks by technology originally designed to map the distribution of the polio vaccination and prevent the transmission of wild poliovirus. When the first Nigerian case of Ebola was confirmed in July 2014, the polio surveillance system was immediately used to track down and monitor the 898 people who were at risk of contracting the disease. Of the 19 cases of Ebola confirmed in Nigeria, seven were fatal. The country was declared epidemic-free on 20 October 2014.
Containment is key
Treating those with Ebola is particularly challenging in rural areas that have no access to hospitals or clinics equipped to deal with the number of patients and levels of sterilisation required. Canadian company Design Shelter has provided a solution with its lightweight, portable facilities, originally used as field hospitals in Trinidad and Tobago, the Cayman Islands and the Bahamas. Design Shelter president Brad Matchung says: “Canada experiences diverse weather and temperature conditions, so our kit was designed to be easy to transport to remote locations, assemble quickly, and to provide superior thermal insulation protection in any weather condition in the -50°C to +50°C ambient temperature range. Our initial clients ranged from mining and exploration teams to forest firefighting crews.”
In 2003, Canada experienced an outbreak of SARS (Severe Acute Respiratory Syndrome), which prompted the development of rapid and remote healthcare structures as field hospitals. “We looked at our already excellent field shelters and modified the design to become more airtight, to allow interconnection between shelters and to incorporate ante-rooms between different pressurised environments,” Matchung explains. “Since SARS was an airborne infectious disease, we developed a specialised heating, ventilating and air-conditioning unit to control internal pressure inside the shelters as well as air filtration to allow neutral, positive or negative pressure environments inside our unique soft-walled shelter design,” he adds. Combined with a soft-walled thermal insulation product, internal air temperature and air pressure can be maintained precisely to be as good as, if not better than, typical brick and mortar hospital facilities, he says. Design Shelters are now typically used as pharmacies, laboratories and field surgical facilities in addition to generic hospital spaces for triage and treatment of patients.
Design Shelter field hospitals are said to be ideal for treating Ebola since they can be deployed anywhere. “In the case of infectious disease, it’s best to isolate the patients at the source, so deploying a Design Shelter to a remote community is simple enough to do. This prevents the sick from migrating to the larger centres for treatment, where they may infect many people along the route,” explains Matchung. “This was evident for Ebola in Africa.”
The primary modification that was required for use in treating Ebola was making the Design Shelters airtight for use with disinfection technology. “As a portable soft-walled structure, especially in a multi-shelter configuration environment, it’s very difficult to provide 100 per cent airtight control,” says Matchung. “That said, we were able to effectively redesign our floor solution to provide a level of airtightness that was adequate to make the disinfection technology applicable and effective,” he assures. “We also extensively tested our shelter construction materials for degradation caused by the disinfection technology. Special consideration was given to materials that wouldn’t degrade due to prolonged exposure to this cleaning technology. This has resulted in a completely unique approach to this solution and one which we feel is second to none in the industry.” The Design Shelters are now being delivered to Liberia for use as an Ebola field hospital.
Medizone is the disinfection and cleaning technology specialist that has partnered with Design Shelters to provide the AsepticSure technology to be used with portable field hospitals. “The beauty of the AsepticSure cleaning and disinfection technology is that it allows the interior of the shelters to be completely disinfected, allowing the same space to be used to treat multiple infected patients one after another,” says Matchung.
Dr Michael Shannon, president of Medizone International, says: “The AsepticSure system was originally designed for hospital disinfection; however, it was very quickly realised that the range of applications is only limited by the size of each machine.” The AsepticSure is a unique disinfection system which combines low concentrations of ozone and vaporised hydrogen peroxide to create a new, highly oxidative compound called ‘Trioxidane’. This can effectively destroy all known pathogens, whether they are viral, bacterial or fungal, as well as their spores.
“This compound has a very short half-life, which like ozone and peroxide rapidly degrades into water and oxygen. It meets all North American environmental safety standards, rendering each space treated perfectly safe for rapid re-use,” Shannon declares. This makes the system ideal for the treatment of Ebola in combination with the portable Design Shelters. “When the AsepticSure system is employed in a room or tent contaminated with the Ebola virus, the entire space will be filled with the vaporised gas to a level known through laboratory testing to be lethal for the virus,” says Shannon. “By using this approach, all exposed surfaces everywhere in that space will be decontaminated to a sterilisation standard of six logs or 99.9999 per cent kill. This level of efficacy is achieved regardless of the type of material contaminated, including textiles.”
The AsepticSure system is expected to prove very effective in decontaminating tented facilities ahead of the introduction of ‘suspected but unconfirmed’ new cases. It can also be used to decontaminate personal protective equipment prior to re-use and it can be useful in cleaning a facility before a move or storage.
An alternative disinfection solution has been developed by Xenex Disinfection Services. Dr Mark Stibich, co-founder and chief scientific officer of Xenex, says: “Xenex offers the fastest, safest, and most cost-effective method for the disinfection of healthcare facilities. Our germ-zapping robots use full-spectrum pulsed xenon ultraviolet light to destroy viruses, bacteria and bacterial spores in the patient environment without contact or chemicals. The robot works by pulsing xenon, an inert gas, at high intensity in a xenon ultraviolet flash-lamp. This produces ultraviolet C (UVC), which penetrates the cell walls of microorganisms. Their DNA is instantly fused so that they are unable to reproduce or mutate, effectively killing them on surfaces.”
Ebola is a non-enveloped virus that has been found to be particularly sensitive to UVC light, fusing the DNA and causing it to become inactive. “Our robots use xenon instead of toxic mercury to create the UV light,” explains Stibich. “Our patented technology is hundreds of times more intense than mercury UV systems, which enables our robots to disinfect healthcare facilities in a fraction of the time it takes for mercury bulb devices to disinfect rooms – a single robot can disinfect a typical patient room in just 5-10 minutes.”
Stibich says that the robots – while not yet in use in West Africa – are being used at Texas Health Presbyterian Dallas Hospital and the University of Nebraska Medical System. He adds: “We certainly hope the robots will be used to combat Ebola overseas. We have submitted proposals to the US Agency for International Development and Defense Threat Reduction Agency, and are waiting to hear back from them. We've also offered robots to several non-profit organisations for use in Africa.”
The trouble with treatment
Joining the battle against Ebola is Avon Rubber, a British company that manufactures military gas masks. The climate in the African countries worst hit by the disease is hot and humid, and medical personnel wearing full personal protective equipment (PPE) become quickly exhausted and dehydrated. Often, within 20 minutes they are rendered unable to aid their patients.
The Avon military gas mask allows troops to drink and keep cool while in protective gear, which would greatly assist the volunteers battling Ebola, allowing them to treat patients for longer. Minor adjustments to the design do need to be made however, such as changing black portions to white in order to make them appear less daunting to the people suffering from Ebola.
Another potential aid in the treatment of Ebola comes from researchers at John Hopkins University, who have designed a full PPE suit specifically for the fight against Ebola. This suit protects care workers from coming into contact with the virus, both during patient treatment and the removal of the suit. The suit is quicker and easier to take off and keeps volunteers cool in the hot West African climate. The cooling technology was originally developed for patients who were experiencing a cardiac arrest. The suit is still a prototype, but is expected to be ready for mass production by April 2015.
There is currently no known treatment for Ebola and patients are treated symptomatically, primarily through rehydration. Intellimedix, an Atlanta-based drug development and discovery company, has created a computational algorithm called FINDSITE. This identifies the proteins that drugs bind to in order to determine which genetic disorders the drugs can be repurposed for. By identifying Ebola proteins or the human proteins that the Ebola virus needs to live or multiply, approximately 50 drugs developed for genetic disorders and approved by the US Food and Drug Administration have been identified that can possibly be repurposed to treat Ebola. These drugs could prevent the virus from entering the cells or reproducing, and some may even effectively kill it.
As thousands of volunteers continue to fight tirelessly against the seemingly ever-present threat of Ebola in Africa, repurposed technology the world over has given the frontlines an edge that may stop the spread of the epidemic before it reaches pandemic proportions. The technology and its developers have also prepared the world for any future epidemics that may arise, providing a quick and thorough response plan that is sure to save thousands, if not millions, of lives