[Epidemiology of malaria in the French Armed Forces]. / Épidémiologie du paludisme dans les armées françaises.

Because of the individual morbidity and lethality and the resulting collective incapacity, malaria has always been a risk for the Armed Forces in operation. The fight against malaria is a real public health plan carried out by the Armed Forces Health Service (SSA) for the benefit of the Forces. This plan has four main components: vector control, which targets larvae and adult mosquitoes of the genus Anopheles, personal vector protection, which limits human-vector contact, chemoprophylaxis, and early diagnosis and treatment of malaria.Since 2001, the epidemiology of malaria in the Armed Forces have suffered from large-scale epidemics during operational engagements in Côte d'Ivoire, Guyana and the Central African Republic. The start of a military operation is accompanied by strategic and logistical priorities that take precedence over prevention. In addition, the rigorous application of personal protection measures remains difficult and even more so in a combat situation.The development of urban malaria in Africa, the use of causal chemoprophylaxis, the alternative to "nothing but insecticides", and the development of efficient diagnostic tools allowing for early and adapted management are the challenges ahead for the SSA.

From Foodborne Disease Outbreak (FBDO) to Investigation: The Plant Toxin Trap, Brittany, France, 2018.

On 6 July 2018, the Center for Epidemiology and Public Health of the French Armed Forces was informed of an outbreak of acute gastroenteritis among customers of a dining facility at a military base in Brittany, France. A total of 200 patients were reported out of a population of 1700 (attack rate: 12%). The symptoms were mainly lower digestive tract disorders and occurred rapidly after lunch on 5 July (median incubation period: 3.3 h), suggesting a toxin-like pathogenic process. A case-control survey was carried out (92 cases and 113 controls). Statistical analysis pointed to the chili con carne served at lunch on 5 July as the very likely source of poisoning. Phytohaemagglutinin, a plant lectin, was found in the chili con carne at a concentration above the potentially toxic dose (400 HAU/gram). The raw kidney beans incorporated in the chili con carne presented a high haemagglutination activity (66,667 HAU/gram). They were undercooked, and the phytohaemagglutinin was not completely destroyed. FBDOs due to PHA are poorly documented. This study highlights the need to develop methods for routine testing of plant toxins in food matrices. Improved diagnostic capabilities would likely lead to better documentation, epidemiology, and prevention of food-borne illnesses caused by plant toxins.

Blister Beetle Dermatitis Outbreaks in Mali.

INTRODUCTION: Meloidae are distributed in temperate and arid regions but are also common in subtropical and tropical savannahs. These insects contain cantharidin, a vesicant substance that can cause poisoning by ingestion and dermatitis by direct contact. MATERIAL AND METHODS: We describe recurrent Meloidae-related dermatitis outbreaks and their health impact by analyzing medical consultation records and meteorological data. RESULTS: Between 2015 and 2019, dermatitis outbreaks took place at a French military base at the end of the rainy season, from July to August, with 100 cases reported in 2015, 74 in 2017, 100 in 2018, and 36 in 2019. In 2017, the incidence rate was 4.4% for the base's population. Initial medical consultations represented 31.5% of total medical care activity. Meloidae were identified as Cyaneolytta fryi. CONCLUSIONS: These outbreaks of burn-like lesions, although clinically benign, can place a considerable burden on the medical activity of health care facilities. The diagnosis of Meloidae dermatitis is exclusively anamnestic and clinical and requires reported contact with the insect. The treatment protocol is that of standard burn care, and the best preventive measure is to avoid bright white lights. Military personnel, foreign workers, and travelers venturing into the Sahel should be warned of the risks associated with these beetles.

Variation in Pyrethroid Resistance Phenotypes in Anopheles darlingi in an Area with Residual Malaria Transmission: Warning of Suspected Resistance in French Guiana.

Anopheles darlingi is the main vector of malaria in South America. In French Guiana, malaria transmission occurs inland and along the rivers with a regular reemergence in the lower Oyapock area. Control against malaria vectors includes indoor residual spraying of deltamethrin and the distribution of long-lasting impregnated bednets. In this context, the level of resistance to pyrethroids was monitored for 4 years using CDC bottle tests in An. darlingi populations. A loss of susceptibility to pyrethroids was recorded with 30-minute knock-down measured as low as 81%. However, no pyrethroid molecular resistance was found by sequencing a 170 base pair fragment of the S6 segment of domain II of the voltage-gated sodium channel gene. Fluctuation of resistance phenotypes may be influenced by the reintroduction of susceptible alleles from sylvatic populations or by other mechanisms of metabolic resistance.

Respiratory pathogens among ill pilgrims and the potential benefit of using point-of-care rapid molecular diagnostic tools during the Hajj.

We investigated respiratory pathogens among ill Hajj pilgrims from Marseille. We also discuss the potential role of point-of-care (POC) rapid molecular diagnostic tools for this purpose. Clinical data were collected using a standardised questionnaire. Influenza A and B viruses, human rhinovirus and human coronaviruses, Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae and Klebsiella pneumoniae were investigated using real-time PCR in respiratory samples obtained during travel, at the onset of symptoms. 207 participants were included. A cough, expectoration, rhinitis and a sore throat were the most frequent respiratory symptoms, followed by loss of voice and dyspnoea. 38.7% and 25.1% of pilgrims reported a fever and influenza-like symptoms, respectively. 59.4% pilgrims received antibiotics. Rhinovirus (40.6%) was the most frequent pathogen, followed by S. aureus (35.8%) and H. influenzae (30.4%). Virus and bacteria co-infections were identified in 28.5% of participants. 25.1% pilgrims who were positive for respiratory bacteria did not receive antibiotic treatment. In the context of the Hajj pilgrimage, it is important to detect infections that can be easily managed with appropriate treatment, and those that can affect prognosis, requiring hospitalisation. POC rapid molecular diagnostic tools could be used for patient management at small Hajj medical missions and to rationalise antibiotic consumption among Hajj pilgrims.

Role and Limits of COVID-19 Vaccines in the Delicate Transition from Pandemic Mitigation to Endemic Control.

The recent surge of COVID-19 related to the Omicron variant emergence has thrown a harsh light upon epidemic control in the near future. This should lead the scientific and medical community to question the long-term vaccine strategy for SARS-CoV-2 control. We provide here a critical point of view regarding the virological evolution, epidemiological aspects, and immunological drivers for COVID-19 control, including a vaccination strategy. Overall, we need more innovations in vaccine development to reduce the COVID-19 burden long term. The most adequate answer might be better cooperation between universities, biotech and pharmaceutical companies.

Cryptosporidiosis outbreaks linked to the public water supply in a military camp, France.

INTRODUCTION: Contaminated drinking and recreational waters account for most of the reported Cryptosporidium spp. exposures in high-income countries. In June 2017, two successive cryptosporidiosis outbreaks occurred among service members in a military training camp located in Southwest France. Several other gastroenteritis outbreaks were previously reported in this camp, all among trainees in the days following their arrival, without any causative pathogen identification. Epidemiological, microbiological and environmental investigations were carried out to explain theses outbreaks. MATERIAL AND METHODS: Syndromic diagnosis using multiplex PCR was used for stool testing. Water samples (100 L) were collected at 10 points of the drinking water installations and enumeration of Cryptosporidium oocysts performed. The identification of Cryptosporidium species was performed using real-time 18S SSU rRNA PCR and confirmed by GP60 sequencing. RESULTS: A total of 100 human cases were reported with a global attack rate of 27.8%. Cryptosporidium spp. was identified in 93% of stool samples with syndromic multiplex PCR. The entire drinking water network was contaminated with Cryptosporidium spp. The highest level of contamination was found in groundwater and in the water leaving the treatment plant, with >1,000 oocysts per 100 L. The same Cryptosporidium hominis isolate subtype IbA10G2 was identified in patients' stool and water samples. Several polluting activities were identified within the protection perimeters of the water resource. An additional ultrafiltration module was installed at the outlet of the water treatment plant. After several weeks, no Cryptosporidium oocysts were found in the public water supply. CONCLUSIONS: After successive and unexplained gastroenteritis outbreaks, this investigation confirmed a waterborne outbreak due to Cryptosporidium hominis subtype IbA10G2. Our study demonstrates the value of syndromic diagnosis for gastroenteritis outbreak investigation. Our results also highlight the importance of better assessing the microbiological risk associated with raw water and the need for sensitive and easy-to-implement tools for parasite detection.

Investigation of a COVID-19 outbreak on the Charles de Gaulle aircraft carrier, March to April 2020: a retrospective cohort study.

BackgroundSARS-CoV-2 emergence was a threat for armed forces. A COVID-19 outbreak occurred on the French aircraft carrier Charles de Gaulle from mid-March to mid-April 2020.AimTo understand how the virus was introduced, circulated then stopped circulation, risk factors for infection and severity, and effectiveness of preventive measures.MethodsWe considered the entire crew as a cohort and collected personal, clinical, biological, and epidemiological data. We performed viral genome sequencing and searched for SARS-CoV-2 in the environment.ResultsThe attack rate was 65% (1,148/1,767); 1,568 (89%) were included. The male:female ratio was 6.9, and median age was 29 years (IQR: 24-36). We examined four clinical profiles: asymptomatic (13.0%), non-specific symptomatic (8.1%), specific symptomatic (76.3%), and severe (i.e. requiring oxygen therapy, 2.6%). Active smoking was not associated with severe COVID-19; age and obesity were risk factors. The instantaneous reproduction rate (Rt) and viral sequencing suggested several introductions of the virus with 4 of 5 introduced strains from within France, with an acceleration of Rt when lifting preventive measures. Physical distancing prevented infection (adjusted OR: 0.55; 95% CI: 0.40-0.76). Transmission may have stopped when the proportion of infected personnel was large enough to prevent circulation (65%; 95% CI: 62-68).ConclusionNon-specific clinical pictures of COVID-19 delayed detection of the outbreak. The lack of an isolation ward made it difficult to manage transmission; the outbreak spread until a protective threshold was reached. Physical distancing was effective when applied. Early surveillance with adapted prevention measures should prevent such an outbreak.

COVID-19 outbreak among French firefighters, Marseille, France, 2020.

We investigated a COVID-19 outbreak at a fire station in Marseille, France. Confirmed cases were defined as individuals with positive SARS-CoV-2 reverse transcription (RT)-PCR and/or neutralising antibodies. All 85 firefighters at work during the outbreak period were included after questioning and sampled for RT-PCR and viral neutralisation assay. Twenty-three firefighters were confirmed positive, 19 of them were symptomatic, and four asymptomatic cases were confirmed by virus neutralisation. A total of 22 firefighters had specific neutralising antibodies against SARS-CoV-2. Neutralising antibodies were found in four asymptomatic and 18 symptomatic cases. Eleven symptomatic cases had high titres (≥ 1:80). The earliest detection of neutralising antibodies was 7 days after symptom onset, and 80% had neutralising antibodies 15 days after onset. One viral culture was positive 13 days after onset. The attack rate was 27%. We identified two introductions of the virus in this outbreak, through a presymptomatic and a paucisymptomatic case. Asymptomatic cases were not the source of a third generation of cases, although they worked without wearing a mask, indicating that asymptomatic cases did not play a significant role in this outbreak. Management and strategy based on early research of clinical signs associated with self-quarantine was effective.

Emergence of Indian lineage of ECSA chikungunya virus in Djibouti, 2019.

The chikungunya virus (CHIKV) originated from Africa and has spread worldwide. Since 2017, multiple chikungunya outbreaks have been reported in the Horn of Africa, without molecular characterization. In November 2019, an autochthonous acute chikungunya infection was diagnosed in a French patient living in Djibouti, marking the re-emergence of the virus in the country. The strain was isolated and fully sequenced. Phylogenetic analysis revealed that the Djiboutian strain belongs to the Indian lineage of the Eastern/Central/South African (ECSA) genotype. Two mutations highly increasing the virus's fitness in Aedes aegypti, the sole vector present in Djibouti city, were identified.

A COVID-19 outbreak on board ship: Analysis of the sociotechnical system of epidemiological management in the French Navy.

In late 2019, an epidemic of SARS-CoV-2 broke out in central China. Within a few months, this new virus had spread right across the globe, officially being classified as a pandemic on 11 March 2020. In France, which was also being affected by the virus, the government applied specific epidemiological management strategies and introduced unprecedented public health measures. This article describes the outbreak management system that was applied within the French military and, more specifically, analyzes an outbreak of COVID-19 that occurred on board a nuclear aircraft carrier. We applied the AcciMap systemic analysis approach to understand the course of events that led to the outbreak and identify the relevant human and organizational failures. Results highlight causal factors at several levels of the outbreak management system. They reveal problems with the benchmarks used for diagnosis and decision-making, and underscore the importance of good communication between different levels. We discuss ways of improving epidemiological management in military context.

Dynamics and genetic diversity of Haemophilus influenzae carriage among French pilgrims during the 2018 Hajj: A prospective cohort survey.

BACKGROUND: To investigate the genetic diversity of Haemophilus influenzae positive samples among French pilgrims attending the 2018 Hajj pilgrimage. METHOD: After screening by qPCR, multilocus sequence typing was performed for all H. influenzae-positive samples. The following housekeeping genes were amplified and assigned: adk, atpG, frdB, fucK, mdh, pgi and recA. RESULTS: 121 pilgrims were included. H. influenzae was positive in 35.5% pre-Hajj samples, 12.4% at day five post-arrival, 15.7% at day 12 post-arrival, and 43.0% post-Hajj. Of the 129 positive swabs for H. influenzae, only one sample at D12 was negative for all seven genes amplified by standard PCR. The adk, atpG, frdB, mdh, pgi, recA and fucK genes were positive in 123, 107, 122, 70, 127, 118 and 69 samples, respectively. One sequence of atpG and two of recA genes were not possible to assign. None of the sequences of fucK gene was successfully obtained. Consequently, a complete sequence type characterisation was not possible. Of the 128 obtained strains, 111 had distinct patterns of alleles. CONCLUSION: H. influenzae genotypes acquired were completely different from those present at pre-Hajj. We observed a great biodiversity and a lack of clonality of H. influenzae among French pilgrims during the 2018 Hajj. Further studies aiming at studying the genome of Hajj-acquired H. influenzae isolates are needed to define the clinical burden of H. influenzae infection during Hajj and to evaluate the potential interest of vaccination in Hajj pilgrims.

Identification of French Guiana anopheline mosquitoes by MALDI-TOF MS profiling using protein signatures from two body parts.

In French Guiana, the malaria, a parasitic infection transmitted by Anopheline mosquitoes, remains a disease of public health importance. To prevent malaria transmission, the main effective way remains Anopheles control. For an effective control, accurate Anopheles species identification is indispensable to distinguish malaria vectors from non-vectors. Although, morphological and molecular methods are largely used, an innovative tool, based on protein pattern comparisons, the Matrix Assisted Laser Desorption / Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) profiling, emerged this last decade for arthropod identification. However, the limited mosquito fauna diversity of reference MS spectra remains one of the main drawback for its large usage. The aim of the present study was then to create and to share reference MS spectra for the identification of French Guiana Anopheline species. A total of eight distinct Anopheles species, among which four are malaria vectors, were collected in 6 areas. To improve Anopheles identification, two body parts, legs and thoraxes, were independently submitted to MS for the creation of respective reference MS spectra database (DB). This study underlined that double checking by MS enhanced the Anopheles identification confidence and rate of reliable classification. The sharing of this reference MS spectra DB should make easier Anopheles species monitoring in endemic malaria area to help malaria vector control or elimination programs.

Capybara and Brush Cutter Involvement in Q Fever Outbreak in Remote Area of Amazon Rain Forest, French Guiana, 2014.

We investigated a Q fever outbreak that occurred in an isolated area of the Amazon Rain Forest in French Guiana in 2014. Capybara fecal samples were positive for Coxiella burnetii DNA. Being near brush cutters in use was associated with disease development. Capybaras are a putative reservoir for C. burnetii.

The challenging management of Rift Valley Fever in humans: literature review of the clinical disease and algorithm proposal.

Rift Valley Fever (RVF) is an emerging zoonotic arbovirus with a complex cycle of transmission that makes difficult the prediction of its expansion. Recent outbreaks outside Africa have led to rediscover the human disease but it remains poorly known. The wide spectrum of acute and delayed manifestations with potential unfavorable outcome much complicate the management of suspected cases and prediction of morbidity and mortality during an outbreak. We reviewed literature data on bio-clinical characteristics and treatments of RVF human illness. We identified gaps in the field and provided a practical algorithm to assist clinicians in the cases assessment, determination of setting of care and prolonged follow-up.

Environmental investigation of respiratory pathogens during the Hajj 2016 and 2018.

BACKGROUND: Respiratory tract infections are common in the context of the Hajj pilgrimage and respiratory pathogens can be transmitted via contact with contaminated surfaces. We sampled surfaces during the Hajj to detect the presence of respiratory bacteria and viruses. METHODS: Frequently touched surfaces at Mecca, Mina, Arafat and Medina were sampled. The common respiratory pathogens were tested by qPCR. RESULTS: 70/142 (49.3%) environmental samples collected were positive for at least one respiratory pathogen. Among the positive samples, Klebsiella pneumoniae was the bacterium most frequently tested positive (57.1%), followed by Streptococcus pneumoniae (12.9%), Staphylococcus aureus (10.0%) and Haemophilus influenzae (7.1%). 32.9% positive samples tested positive for rhinovirus and 1.4% for coronavirus. Surfaces with the highest rates of positive samples were kitchen tables (100%), water fountain faucet (73.3%) and edge of water coolers lid (84.6%). Samples collected in Mina were the most frequently contaminated with 68.8% being positive for at least one pathogen and 18.8% positive for a combination of multiple pathogens. CONCLUSION: These preliminary results indicate that respiratory pathogens are common in environmental surfaces from areas frequented by Hajj pilgrims. Further larger-scale studies are needed to better assess the possible role of environmental respiratory pathogens in respiratory infections in Hajj pilgrims.