Use of multiplex PCR to rapidly diagnose febrile patients during a gastroenteritis outbreak among Ebola virus treatment unit workers

Infectious diseases in German military personnel after predominantly tropical deployments: a retrospective assessment over 13 years

OBJECTIVES

Military deployments to the tropics are associated with specific infection risks. To add to the available epidemiological information, infectious disease risks in German military personnel returning from predominantly tropical deployments were assessed.

METHODS

Since 2006, German soldiers returning from predominantly tropical deployments have been offered the opportunity of returnee screenings at the Department of Tropical Medicine and Infectious Diseases of the Bundeswehr Hospital Hamburg. Case files and diagnostic results recorded between 2006 and 2018 were retrospectively assessed to identify deployment-associated infectious disease risks.

RESULTS

Along with high enteric colonisation rates with apathogenic protozoa and resistant Enterobacteriaceae, direct or indirect proof of infections among the 764 assessed cases comprised Plasmodium spp (n=37), Giardia duodenalis (n=21), Schistosoma spp (n=14), Yersinia enterocolitica (n=5), Strongyloides stercoralis (n=3), Campylobacter jejuni (n=1), Leishmania spp (n=1) and Salmonella enterica (n=1), as well as latent infections with Mycobacterium tuberculosis complex (n=8). The infections were mainly imported from the African region and Eastern Mediterranean region and high proportions of cases lacked typical symptoms. Reported side effect rates of antimalarial chemoprophylaxis for mefloquine (n=121), atovaquone/proguanil (n=49) and doxycycline (n=6) were 36.3%, 19.3% and 11.8%, respectively, while non-compliance rates were 12.9%, 13.0% and 5.9%, respectively.

CONCLUSIONS

Considerable rates of infections with sometimes atypical or absent symptoms confirm a need for returnee screenings after tropical deployments. High reported side effect rates for mefloquine support its replacement by atovaquone/proguanil or doxycycline for antimalarial chemoprophylaxis.

Communicable diseases in humanitarian operations and disasters

Military organisations have battled communicable disease for millennia. They have pioneered disease prevention from the Crusades to the World Wars and continue to do so today. Predeployment vaccinations and chemoprophylaxis are effective in preventing communicable disease, as is reliable vector destruction and bite prevention, especially in the era of multidrug resistant organisms. These measures are unlikely to be fully possible in disasters, but reactive vaccination and efforts to reduce exposure to communicable disease should be a priority. Communicable diseases can be challenging to diagnose-the UK Defence Medical Services have become familiar with tools such as multiplex PCR and mass spectrometry. These have the potential to accurately identify organisms and sensitivity patterns in austere environments. Management of communicable diseases depends on accurate diagnosis and has a largely well-established evidence base but can be limited by a lack of resources and skills in an austere setting, therefore telemedicine can assist diagnosis and treatment of infections by projecting specialist skill. Systems such as EpiNATO2 are useful in monitoring diseases and identifying trends in order to establish control measures. Many of these tools and techniques are effective in austere environments and offer learning opportunities for those providing care in similar settings. Further research is ongoing into diagnostic tools as well as remote management.

Review of the role of gastrointestinal multiplex polymerase chain reaction in the management of diarrheal illness

Acute and chronic diarrheal illness secondary to gastrointestinal infection is a significant cause of morbidity and mortality around the world. A cornerstone of management includes prompt diagnosis and appropriate treatment of culprit pathogens. Timely diagnosis can improve patient care, assist in infection control, and prevent disease outbreaks. Historical methods of diagnosis include traditional culture methods and stool analysis. These are limited by long turnaround time and inability to simultaneously assess multiple pathogens. The advent of multiplexed nucleic acid amplification tests first began with the Food and Drug Administration-approved respiratory virus multiplex polymerase chain reaction (PCR) panel in 2009, followed by gastrointestinal infections in 2013, and neurological infections in 2014. We conducted a review of current literature pertaining to the clinical utility of a gastrointestinal multiplex PCR in management of acute and chronic diarrhea in patients. To date, seven platforms approved by the US Food and Drug Administration are used in detection of various bacterial, viral, and parasitic causative organisms for diagnosis of gastrointestinal infections. The sensitivity and specificity of each assay vary depending on the tested organism. Interpretation of a positive result has to be tailored to the clinical context. Further studies are required to establish the utility of gastrointestinal multiplex PCR from a cost-based perspective, whether specific enteropathogens such as Clostridioides difficile are better assessed with toxin gene detection and whether new parameters such as cycle threshold values can improve clinical application of test results.

Clinical Implications of Multiplex Pathogen Panels for the Diagnosis of Acute Viral Gastroenteritis

Acute gastroenteritis remains a significant cause of morbidity and mortality in both high- and low-resource settings. The development of nucleic acid-based testing has demonstrated that viruses are a common, yet often undetected, cause of acute gastroenteritis. The development of multiplex pathogen PCR panels makes it possible to detect these viral pathogens with greater sensitivity and rapidity than with previous methods. At present, there is insufficient evidence to recommend the routine use of these panels for the average patient with acute gastroenteritis. However, there are specific scenarios and patient populations, such as epidemiology/outbreak surveillance, antimicrobial stewardship, and the care of immunocompromised patients, where these tests could be clinically useful today. Further research on the effect of these syndromic panels on provider antibiotic prescribing behavior and patient length of stay will be necessary to know their ultimate role in clinical practice.

Clinical activity at the UK military level 2 hospital in Bentiu, South Sudan during Op TRENTON from June to September 2017

Introduction

Diseases and non-battle injuries (DNBIs) are common on UK military deployments, but the collection and analysis of clinically useful data on these remain a challenge. Standard medical returns do not provide adequate clinical information, and clinician-led approaches have been laudable, but not integrated nor standardised nor used long-term. Op TRENTON is a novel UK military humanitarian operation in support of the United Nations Mission in South Sudan, which included the deployment of UK military level 1 and level 2 medical treatment facilities at Bentiu to provide healthcare for UK and United Nations (UN) personnel.

Methods

A service evaluation of patient consultations and admissions at the UK military level 2 hospital was performed using two data sets collected by the emergency department (ED) and medicine (MED) teams.

Results

Over a three-month (13-week) period, 286 cases were seen, of which 51% were UK troops, 29% were UN civilians and 20% were UN troops. The ED team saw 175 cases (61%) and provided definitive care for 113 (40%), whereas the MED team saw and provided definitive care for 128 cases (45%). Overall, there were 75% with diseases and 25% with non-battle injuries. The most common diagnoses seen by the ED team were musculoskeletal injuries (17%), unidentified non-malarial undifferentiated febrile illness (UNMUFI) (17%), malaria (13%), chemical pneumonitis (13%) and wounds (8%). The most common diagnoses seen by the MED team were acute gastroenteritis (AGE) (56%), UNMUFI (12%) and malaria (9%). AGE was due to viruses (31%), diarrhoeagenic Escherichia coli (32%), other bacteria (6%) and protozoa (12%).

Conclusion

Data collection on DNBIs during the initial phase of this deployment was clinically useful and integrated between different departments. However, a standardised, long-term solution that is embedded into deployed healthcare is required. The clinical activity recorded here should be used for planning, training, service development and targeted research.