Outbreak of Cutaneous Leishmaniasis among military personnel in French Guiana, 2020: Clinical, phylogenetic, individual and environmental aspects

A review of skin disease in military soldiers: challenges and potential solutions

Introduction: Military soldiers comprised 1,195 million United States active-duty members and 778,000 reserve members in 9/2021. Soldiers are often exposed to drastic climates, environments, and living conditions which may make them more susceptible to cutaneous diseases.Methods: A PubMed search of studies published between 1/1/2002 - 8/30/2022, using MeSH terms: ((("Military Personnel"[Majr]) OR "Military Hygiene"[Majr])) OR "Military Medicine"[Majr]) AND "Skin Diseases"[Majr]), the reference lists of select articles, and other applicable sources were reviewed to identify articles on skin conditions affecting military soldiers and treatment options.Discussion: In this article, we review skin conditions that affect military soldiers in both the deployed and non-deployed settings including infectious diseases, arthropod associated diseases, sexually transmitted infections, ultraviolet radiation related skin disease, acne, diseases of hair and hair follicles, dermatitis, onychocryptosis, and conditions caused by extreme weather conditions and occupational exposures. We also discuss treatment options and prevention methods as they relate to military settings.Conclusion: Dermatological conditions can considerably impact soldiers' wellbeing and military performance, often lead to evacuation of military personnel, and are associated with high financial costs. Cutaneous disease is one of most common reasons for soldiers to seek medical care and may cause significant morbidity. Serving in the military often impacts and limits treatment options.

Clinical and immunological spectra of human cutaneous leishmaniasis in North Africa and French Guiana

Cutaneous leishmaniasis (CL) caused by infection with the parasite Leishmania exhibits a large spectrum of clinical manifestations ranging from single healing to severe chronic lesions with the manifestation of resistance or not to treatment. Depending on the specie and multiple environmental parameters, the evolution of lesions is determined by a complex interaction between parasite factors and the early immune responses triggered, including innate and adaptive mechanisms. Moreover, lesion resolution requires parasite control as well as modulation of the pathologic local inflammation responses and the initiation of wound healing responses. Here, we have summarized recent advances in understanding the in situ immune response to cutaneous leishmaniasis: i) in North Africa caused by Leishmania (L.) major, L. tropica, and L. infantum, which caused in most cases localized autoresolutives forms, and ii) in French Guiana resulting from L. guyanensis and L. braziliensis, two of the most prevalent strains that may induce potentially mucosal forms of the disease. This review will allow a better understanding of local immune parameters, including cellular and cytokines release in the lesion, that controls infection and/or protect against the pathogenesis in new world compared to old world CL.

Updated estimation of cutaneous leishmaniasis incubation period in French Guiana

BACKGROUND

The cutaneous leishmaniasis (CL) incubation period (IP) is defined as the time between parasite inoculation by sandfly bite and the onset of the first CL lesion. IP distribution is difficult to assess for CL because the date of exposure to an infectious bite cannot be accurately determined in endemic areas. IP current estimates for CL range from 14 days to several months with a median around 30-60 days, as established by a few previous studies in both New and Old Worlds.

METHODOLOGY

We estimated CL incubation period distribution using time-to-event models adapted to interval-censored data based on declared date of travels from symptomatic military personnel living in non-endemic areas that were exposed during their short stays in French Guiana (FG) between January 2001 and December 2021.

PRINCIPAL FINDINGS

A total of 180 patients were included, of which 176 were men (97.8%), with a median age of 26 years. When recorded, the parasite species was always Leishmania guyanensis (31/180, 17.2%). The main periods of CL diagnosis spread from November to January (84/180, 46.7%) and over March-April (54/180, 30.0%). The median IP was estimated at 26.2 days (95% Credible Level, 23.8-28.7 days) using a Bayesian accelerated failure-time regression model. Estimated IP did not exceed 62.1 days (95% CI, 56-69.8 days) in 95% of cases (95th percentile). Age, gender, lesion number, lesion evolution and infection date did not significantly modify the IP. However, disseminated CL was significantly associated with a 2.8-fold shortening of IP.

CONCLUSIONS

This work suggests that the CL IP distribution in French Guiana is shorter and more restricted than anticipated. As the incidence of CL in FG usually peaks in January and March, these findings suggest that patients are contaminated at the start of the rainy season.

Molecular Identification of Cutaneous Leishmaniasis Species in the Northcentral Iranian Province of Alborz: Is There a New Focus on Cutaneous Leishmaniasis in the Province?

Background

Cutaneous leishmaniasis (CL) is an endemic infection in the Middle East, including Iran that is also spreading to new foci. We aimed to determine the leishmaniasis species causing CL in Alborz province.

Methods

Overall, out of 55-suspected CL patients referred to health centers in Alborz Province, north central Iran in 2019, 40 patients had positive smear for CL based on optical microscopy. The internal transcribed spacer 1 (ITS1) of nuclear ribosomal DNA (rDNA) was amplified by PCR. Leishmania species were identified by PCR-restriction fragment length polymorphism (PCR-RFLP) using BshF I (Hae III) enzyme.

Results

Out of the 40 positive patients with CL, 34 cases (85%) had been caused by Leishmania (L) major and six (15%) by L. tropica. Fifteen patients had no history of traveling to the disease endemic areas, of which nine were Iranians. Skin lesions and scars caused by CL were mostly observed on the hands and face. Moreover, more than two skin lesions were observed in 22 cases (55%), all of which were infected with L. major. A single skin ulcer was seen in 18 (45%) of the CL patients.

Conclusion

Climate change, reduced rainfall, and demographic changes such as migration into Alborz Province and the increasing marginalization of the population and their entry to settle in new areas might have caused natural transmission of both L. tropica and L. major in this province.

Leishmania infantum infection after visiting southern Spain in patients on biological treatment; an observational, longitudinal, cohort study

BACKGROUND

Reports of leishmaniasis in immunosuppressed patients after visiting the Mediterranean Basin are becoming increasingly common. Still, awareness of the risk of infection and its clinical manifestations may be insufficient among healthcare professionals in the travellers' home countries.

METHODS

This observational, longitudinal study included 47 patients from Sweden with rheumatic disease and ongoing immunomodulatory treatment, who visited a rehabilitation centre in southern Spain where leishmaniasis is endemic. Patients were evaluated for clinical signs of leishmaniasis at baseline and after three years. Patients with leishmaniasis were followed for 4-5 years. The treatment outcome was assessed by clinical evaluation and determination of the cell-mediated immunological response to Leishmania by a whole blood cytokine release assay.

RESULTS

Seven patients (15%) were diagnosed with leishmaniasis. The median time from exposure to the onset of symptoms was 3 [1-17] months. The median delay between the onset of symptoms and treatment start was 9 [1-12] months. All patients with leishmaniasis responded well to treatment. Only one patient had a relapse, which occurred within the first year.

CONCLUSION

Healthcare professionals need to be aware of the increased risk of leishmaniasis for travellers who are immunosuppressed. Knowledge of the symptoms is crucial for a timely diagnosis and early treatment.

A Historical Review of Military Medical Strategies for Fighting Infectious Diseases: From Battlefields to Global Health

The environmental conditions generated by war and characterized by poverty, undernutrition, stress, difficult access to safe water and food as well as lack of environmental and personal hygiene favor the spread of many infectious diseases. Epidemic typhus, plague, malaria, cholera, typhoid fever, hepatitis, tetanus, and smallpox have nearly constantly accompanied wars, frequently deeply conditioning the outcome of battles/wars more than weapons and military strategy. At the end of the nineteenth century, with the birth of bacteriology, military medical researchers in Germany, the United Kingdom, and France were active in discovering the etiological agents of some diseases and in developing preventive vaccines. Emil von Behring, Ronald Ross and Charles Laveran, who were or served as military physicians, won the first, the second, and the seventh Nobel Prize for Physiology or Medicine for discovering passive anti-diphtheria/tetanus immunotherapy and for identifying mosquito Anopheline as a malaria vector and plasmodium as its etiological agent, respectively. Meanwhile, Major Walter Reed in the United States of America discovered the mosquito vector of yellow fever, thus paving the way for its prevention by vector control. In this work, the military relevance of some vaccine-preventable and non-vaccine-preventable infectious diseases, as well as of biological weapons, and the military contributions to their control will be described. Currently, the civil-military medical collaboration is getting closer and becoming interdependent, from research and development for the prevention of infectious diseases to disasters and emergencies management, as recently demonstrated in Ebola and Zika outbreaks and the COVID-19 pandemic, even with the high biocontainment aeromedical evacuation, in a sort of global health diplomacy.