Aeromedical Transfer of Patients with Viral Hemorrhagic Fever

Abstract

For >40 years, the British Royal Air Force has maintained an aeromedical evacuation facility, the Deployable Air Isolator Team (DAIT), to transport patients with possible or confirmed highly infectious diseases to the United Kingdom. Since 2012, the DAIT, a joint Department of Health and Ministry of Defence asset, has successfully transferred 1 case-patient with Crimean-Congo hemorrhagic fever, 5 case-patients with Ebola virus disease, and 5 case-patients with high-risk Ebola virus exposure. Currently, no UK-published guidelines exist on how to transfer such patients. Here we describe the DAIT procedures from collection at point of illness or exposure to delivery into a dedicated specialist center. We provide illustrations of the challenges faced and, where appropriate, the enhancements made to the process over time.

Keywords: Ebola virus; United Kingdom; aerospace medicine; aviation; hemorrhagic fever; infection control; patient isolation; patient transfer; viruses.

Figure 1

The Trexler Air Transport Isolator, a portable isolation facility used to transfer patients with serious infectious diseases. The sealed system is maintained under negative pressure by a HEPA-filtered ventilation system (red boxes, marked with white asterisk). Portable oxygen cylinders and tubing passed into the envelope through sealed delivery ports (black arrows) permit additional oxygenation of the patient. Additional ports allow cables for monitoring equipment and tubing for parenteral fluids or medication (white arrows). A half-suit on either side of the isolator (black asterisk) enables healthcare workers’ clinical access to the patient, and an additional half-suit can be fitted to the head of the patient for intubation (white arrowhead). Additional arm and glove ports along the side (black arrowheads) allow multiple workers to access the patient simultaneously. Two larger-bore disposable waste areas are available at the foot of the envelope (black star).

Figure 2

Dedicated road transport that can accommodate the Air Transport Isolator patient transport system, such as the Jumbulance shown, enables seamless end-to-end transfer from patient pickup to the destination facility.

Figure 3

A single Trexler Air Transport Isolator patient transport system ready for use on a Boeing C-17 Globemaster transport aircraft.

Figure 4

Demarcation of clean and dirty zones during use of the Trexler Air Transportable Isolator patient transport system on a Boeing C-17 Globemaster transport aircraft. A) Yellow lines clearly demarcate clean and dirty zones as required for transporting both confirmed and exposed viral hemorrhagic fever case-patients. B) For exposed patients, the demarcation zone should extend to a corridor leading to isolated toileting and comfort facilities.

Figure 5

Larger Trexler Air Transport Isolator patient transport systems enable care providers to access a patient via half-suits along the side of the patient; however, manual dexterity is severely impaired

Figure 6

The Deployable Air Isolator Team lead, a senior infection and prevention control nurse, is responsible for overseeing the preparation of the Air Transport Isolator patient transport system on the ground (A), the transfer of the patient into the isolator, and the safe transfer of the patient onto the aircraft by the main team while the reconnaissance team performs their decontamination drills (B).

Figure 7

Isolator–isolator transfer is the safest means of transfer for patients with serious infectious diseases and requires practice in dedicated training exercises, as shown.

Figure 8

Multiple Air Transportable Isolator patient transport systems on a single aircraft (Boeing C-17 Globemaster). A single isolator is set up for the confirmed viral hemorrhagic fever case-patient; 2 additional isolators (left, covered) are available for the 2 exposed patients should they deteriorate or become symptomatic in flight.