Discussion

Previous data collection on clinical activity during UK military deployments has been laudable, but not integrated nor standardised nor used long-term.2–9 This study is also not standardised nor long-term, but has integrated the data collected by the ED, MED and PHC teams (for patients ‘bedded down’ under their care). This was difficult to achieve, but produces a much more representative result. For example, ED data alone would under-represent the burden of AGE (as these cases were not admitted through ED). Similarly, MED data alone would underestimate the burden of UNMUFI and malaria that was dealt with by ED and would also under-represent AGE and skew the causes of this, if the cases managed by PHC had been excluded. In future a single joint data set should be collected by all specialties to improve the transparency of results and make analysis simpler.

An integrated, standardised and long-term system for collecting useful clinical activity data is still required if the UK Ministry of Defence (MOD) is to improve its data collection and analysis regarding injuries and illnesses on military operations.13 Attempts are now being made to develop a ‘Medical Audit Form’ system that is robust and effective while not being overcomplicated or too onerous to use (for example, if it included almost every symptom, sign, result and treatment that patients may have for a wide range of diseases). The data required by clinicians are very different from those required for public health and command purposes, and so there is little point in trying to merge these systems while the former is still being developed.

The categorisation of cases for analysis remains a contentious issue. Categories based on patient symptoms or initial diagnosis would lack diagnostic accuracy, and so categories based on clinicians’ final diagnosis are preferable. However, further categorisation of cases based on systems such as the WHO International Classification of Diseases-10 is problematic (most gastrointestinal infections are classified under ‘Certain Infectious and Parasitic Diseases’ rather than ‘Diseases of the Digestive System’, but most respiratory infections are classified under ‘Diseases of the Respiratory System’). Further categorisation according to medical specialty and sub-specialty can also be contentious, and so we have used a combination of disease and specialty categories in this paper. Obviously, standardisation of the categories used would be highly desirable in future so that data from different deployments can be compared more easily.

As expected, the majority (96%) of clinical activity recorded in this study was performed by the ED, MED and PHC teams. During Op HERRICK in Afghanistan, the ED workload was reported as 23% battle injuries, 39% NBIs and 34% disease,14 whereas on Op TRENTON it was 0% battle injuries, 40% NBIs and 60% disease during this period. With an average of two ED clinical episodes per day, the first three months of Op TRENTON has not generated a high burden of emergency patient case load. That this case load has been entirely of a DNBI nature supports the assertion that this cohort warrants more consideration. The nature and relative proportions of the DNBI cases seen can be greatly instructive when defining clinical training priorities and continued clinical exposure, as well as informing future planning assumptions.

Military EM has for more than a decade focused on a major trauma narrative for EM training and made efforts to provide additional major trauma exposure and formal teaching beyond that required of civilian EM training and the Royal College of Emergency Medicine curriculum. That Op TRENTON represents one of a series of deployments of military EM in which DNBI has predominated suggests that a rebalancing of priorities should be discussed. Emergency physicians of all grades need to be mindful of a requirement to maintain competency in a broad range of domains that include infectious diseases and tropical medicine, clinical toxicology, and musculoskeletal presentations that are now mostly managed by nurse practitioners, and the ear, nose and throat (ENT) and ophthalmology presentations for which there is little alternative deployed source of expertise and experience. Achieving this will require specific training (eg. for example, the DMS courses in infectious diseases and tropical medicine, and in chemical-biological-radiological-nuclear medicine), plus appropriate clinical training and placements for military EM trainees and consultants.

For the MED cases managed by physicians, the main diagnostic groups were gastrointestinal tract diseases, UFIs and respiratory system diseases, which was similar to previous reports.2–8 The most common diagnoses were AGE, UNMUFI, malaria and respiratory tract infections, which was also similar to previous deployments.4–8 Other significant challenges for the physicians on Op TRENTON have included cases of atrial fibrillation, deep vein thrombosis, diabetes mellitus, psychosis following high-dose mefloquine treatment for malaria in UN personnel, probable viral hepatitis in UN personnel that could not be confirmed with the available laboratory tests and possible heat illness in a British soldier. Maintaining the acute and general medicine competencies needed to deal with such a range of cases is challenging for military physicians working in NHS hospitals, where sub-specialisation and direct admissions to sub-specialties are increasingly common.

The clinical management (including isolation) of AGE cases was optimised due to the availability of faeces PCR results, and the clinicians felt that this facility should be available on all deployments of this type. In practice, many patients were found to have PCR positive results for diarrhoeagenic E. coli in addition to other enteric pathogens, and so this test may be identifying carriage or sub-clinical infection rather than clinically significant infection. Improving the effectiveness and efficiency of treatment and avoiding excessive medication and associated adverse effects should reduce the number of days lost to this very common condition and so improve operational effectiveness (especially in a small deployment where some trades were represented by a single individual).

No fever study was conducted on this deployment, and so UFI cases were investigated according to standard operating procedures only. There were 15 UK cases of UNMUFI in ~200 personnel during this three-month period, which typically presented with arthralgia, myalgia, headache, rash, leucopaenia, lymphopaenia, thrombocytopaenia and low C-reactive protein (CRP) levels. The most likely cause is an arbovirus, but none has been identified despite a full range of serology tests performed at RIPL on cases who subsequently returned to the UK. Hence a prospective fever study should be performed in future (possibly using portable real-time devices for DNA and RNA sequencing) especially in view of the problems encountered with UFI on military deployments in recent years.12

This was a high-risk deployment for malaria as South Sudan has ~3500 malaria cases per 100 000 population per year,15 and the UN PoC camp at Bentiu (which was only 400 m away) has reported 4000–8000 confirmed cases in ~150 000 people per week during the rainy season from 2015 to 2017.16 There were 13 malaria cases who were newly diagnosed and treated at the MTF during this three-month period, of whom seven required intravenous artesunate initially and the remaining six were treated with oral Riamet alone, as per UK guidelines.17 Only two cases occurred in UK military personnel and another two military cases from South Sudan presented back in the UK during this period (Mark S Bailey, unpublished data, 2018) suggesting that the bite prevention, vector control and chemoprophylaxis (mostly with Malarone) measures employed were satisfactory. In contrast, malaria prevention measures appeared to be less well implemented in UN military and civilian personnel.18

The case mix seen over this three-month period suggests that clinical pre-deployment training and force generation of clinical staff for this deployment were appropriate. However, none of the nurses had clinical experience of working on an infectious diseases ward or with patients suffering from UFIs or malaria, which was a similar issue during Op GRITROCK in Sierra Leone from 2014 to 2015 (Mark S Bailey, unpublished data, 2015). The generally low level of clinical activity seen on this deployment will inevitably lead to debate about the ideal staffing for an L2H on a humanitarian mission such as this. However, it is the UN who decides staffing requirements for UN operations 19 20 and so any significant changes would need to be negotiated with them.

The fact that 146 (~73%) of ~200 UK military personnel were seen or admitted at the MTF compared with 140 (~7%) of ~2000 UN military and civilian personnel merits consideration. The rate for UK military personnel will have been increased due to a complete roulement of these troops in August 2017 and because their proximity to the MTF increased their access to it. However, this still seems like a high DNBI casualty rate overall and reminds us that force health protection can be especially challenging in the early stages of a deployment.

The UK DMS is only occasionally involved in providing secondary healthcare for humanitarian operations, and the demands of such deployments have varied significantly for Op HAVEN21 22 in Northern Iraq in 1991, Op GABRIEL23 in Rwanda in 1997, Op GRITROCK24 25 in Sierra Leone in 2014–2015 and now Op TRENTON in South Sudan from 2017. Hence there is a need to learn as much as possible in the early stages of this deployment by prompt publication of brief reports such as this, and we encourage other healthcare disciplines to share their experiences too.