The accuracy of self-reported data concerning recent cannabis use in the French armed forces.

BACKGROUND: The aims were to evaluate the accuracy of self-report of past-month cannabis use in a representative sample of French military staff members and to evaluate the scale of the prevarication bias. METHOD: Data from three cross-sectional surveys conducted between 2005 and 2008 (n = 3493) were used. The characteristics of self-report (sensitivity, specificity, positive predictive value and negative predictive value) were computed using tetrahydrocannabinol detection in urine as the reference. RESULTS: The prevalence for past-month cannabis use was 16.1% and for positive testing was 13.4%. The discriminant power of self-report was good, with an area under the receiver operating characteristics curve 0.90. Specificity (94.5%) and negative predictive values (97.8%) were good, but sensitivity (85.7%) and positive predictive values (70.4%) were lower. The lowest sensitivity values were observed in the higher categories of personnel and in the Navy, which could reflect some prevarication in these sub-populations who might believe they were more exposed to sanctions if detected. CONCLUSIONS: Despite certain limitations of urine analysis as a reference, because of its poor detection of occasional users, our study is in favour of good accuracy of self-reported data on cannabis use, even among the military. However, our results, derived from a population study, do not enable any assumptions on the validity of self-reported data collected during individual testing procedures for the purpose of improving occupational safety.

Plasmodium vivax and Plasmodium falciparum infections in the Republic of Djibouti: evaluation of their prevalence and potential determinants.

BACKGROUND: Formerly known as a hypoendemic malaria country, the Republic of Djibouti declared the goal of pre-eliminating malaria in 2006. The aim of the present study was to evaluate the prevalence of Plasmodium falciparum, Plasmodium vivax and mixed infections in the Djiboutian population by using serological tools and to identify potential determinants of the disease and hotspots of malaria transmission within the country. METHODS: The prevalence of P. falciparum and P. vivax within the districts of the capital city and the rest of the Republic of Djibouti were assessed using 13 and 2 serological markers, respectively. The relationship between the immune humeral response to P. falciparum and P. vivax and variables such as age, gender, wealth status, urbanism, educational level, distance to rivers/lakes, living area, having fever in the last month, and staying in a malaria-endemic country more than one year was estimated and analysed by questionnaires administered to 1910 Djiboutians. Multivariate ordinal logistic regression models of the immune humeral response were obtained for P. falciparum and P. vivax. RESULTS: The P. falciparum and P. vivax seroprevalence rates were 31.5%, CI95% [29.4-33.7] and 17.5%, CI95% [15.8-19.3], respectively. Protective effects against P. falciparum and P. vivax were female gender, educational level, and never having visited a malaria-endemic area for more than one year. For P. falciparum only, a protective effect was observed for not having a fever in the last month, living more than 1.5 km away from lakes and rivers, and younger ages. CONCLUSIONS: This is the first study that assessed the seroprevalence of P. vivax in the Republic of Djibouti. It is necessary to improve knowledge of this pathogen in order to create an effective elimination programme. As supported by recent observations on the subject, the Republic of Djibouti has probably demonstrated a real decrease in the transmission of P. falciparum in the past seven years, which should encourage authorities to improve efforts toward elimination.

Plasmodium vivax Malaria among military personnel, French Guiana, 1998-2008.

We obtained health surveillance epidemiologic data on malaria among French military personnel deployed to French Guiana during 1998-2008. Incidence of Plasmodium vivax malaria increased and that of P. falciparum remained stable. This new epidemiologic situation has led to modification of malaria treatment for deployed military personnel.

Determinants of compliance with anti-vectorial protective measures among non-immune travellers during missions to tropical Africa.

BACKGROUND: The effectiveness of anti-vectorial malaria protective measures in travellers and expatriates is hampered by incorrect compliance. The objective of the present study was to identify the determinants of compliance with anti-vectorial protective measures (AVPMs) in this population that is particularly at risk because of their lack of immunity. METHODS: Compliance with wearing long clothing, sleeping under insecticide-impregnated bed nets (IIBNs) and using insect repellent was estimated and analysed by questionnaires administered to 2,205 French military travellers from 20 groups before and after short-term missions (approximately four months) in six tropical African countries (Senegal, Ivory Coast, Chad, Central African Republic, Gabon and Djibouti). For each AVPM, the association of "correct compliance" with individual and collective variables was investigated using random-effect mixed logistic regression models to take into account the clustered design of the study. RESULTS: The correct compliance rates were 48.6%, 50.6% and 18.5% for wearing long clothing, sleeping under bed nets and using repellents, respectively. Depending on the AVPM, correct compliance was significantly associated with the following factors: country, older than 24 years of age, management responsibilities, the perception of a personal malaria risk greater than that of other travellers, the occurrence of life events, early bedtime (i.e., before midnight), the type of stay (field operation compared to training), the absence of medical history of malaria, the absence of previous travel in malaria-endemic areas and the absence of tobacco consumption.There was no competition between compliance with the different AVPMs or between compliance with any AVPM and malaria chemoprophylaxis. CONCLUSION: Interventions aimed at improving compliance with AVPMs should target young people without management responsibilities who are scheduled for non-operational activities in countries with high risk of clinical malaria. Weak associations between compliance and history of clinical malaria or variables that pertain to threat perception suggest that cognition-based interventions referencing a "bad experience" with clinical malaria could have only a slight impact on the improvement of compliance. Further studies should focus on the cognitive and behavioural predictors of compliance with AVPMs.

Optical correction and quality of vision of the French soldiers stationed in the Republic of Djibouti in 2009.

To ensure vision readiness on the battlefield, the French military has been providing its soldiers with eyewear since World War I. A military refractive surgery program was initiated in 2008. A prospective questionnaire-based investigation on optical correction and quality of vision among active duty members with visual deficiencies stationed in Djibouti, Africa, was conducted in 2009. It revealed that 59.3% of the soldiers were wearing spectacles, 21.2% were wearing contact lenses--despite official recommendations--and 8.5% had undergone refractive surgery. Satisfaction rates were high with refractive surgery and contact lenses; 33.6% of eyeglass wearers were planning to have surgery. Eye dryness and night vision disturbances were the most reported symptoms following surgery. Military optical devices were under-prescribed before deployment. This suggests that additional and more effective studies on the use of military optical devices should be performed and policy supporting refractive surgery in military populations should be strengthened.

Determinants of compliance with malaria chemoprophylaxis among French soldiers during missions in inter-tropical Africa.

BACKGROUND: The effectiveness of malaria chemoprophylaxis is limited by the lack of compliance whose determinants are not well known. METHODS: The compliance with malaria chemoprophylaxis has been estimated and analysed by validated questionnaires administered before and after the short-term missions (about four months) in five tropical African countries of 2,093 French soldiers from 19 military companies involved in a prospective cohort study. "Correct compliance" was defined as "no missed doses" of daily drug intake during the entire mission and was analysed using multiple mixed-effect logistic regression model. RESULTS: The averaged prevalence rate of correct compliance was 46.2%, ranging from 9.6%to 76.6% according to the companies. Incorrect compliance was significantly associated with eveningness (p = 0.028), a medical history of clinical malaria (p < 0.001) and a perceived mosquito attractiveness inferior or superior to the others (p < 0.007). Correct compliance was significantly associated with the systematic use of protective measures against mosquito bites (p < 0.001), the type of military operations (combat vs. training activities, p < 0.001) and other individual factors (p < 0.05). CONCLUSIONS: The identification of circumstances and profiles of persons at higher risk of lack of compliance would pave the way to specifically targeted strategies aimed to improve compliance with malaria chemoprophylaxis and, therefore, its effectiveness.

Use of short message service (SMS) to improve malaria chemoprophylaxis compliance after returning from a malaria endemic area.

BACKGROUND: Malaria chemoprophylaxis compliance is suboptimal among French soldiers despite the availability of free malaria chemoprophylaxis and repeated health education before, during and after deployment to malaria endemic areas. METHODS: In 2007, a randomized controlled study was performed among a cohort of French soldiers returning from Côte d'Ivoire to assess the feasibility and acceptability of sending a daily short message service (SMS) reminder message via mobile device to remind soldiers to take their malaria chemoprophylaxis, and to assess the impact of the daily reminder SMS on chemoprophylaxis compliance. Malaria chemoprophylaxis consisted of a daily dose of 100 mg doxycycline monohydrate, which began upon arrival in Côte d'Ivoire and was to be continued for 28 days following return to France. Feasibility and acceptability were assessed by questionnaire. Cohort members were followed for a 28 day period, with compliance assessed by use of an electronic medication monitoring device, from which several indicators were developed: daily proportion of compliant individuals, average number of pills taken, and early discontinuation. RESULTS: Among 424 volunteers randomized to the study, 47.6% were assigned to the SMS group and 52.3% to the control group. Approximately 90% of subjects assigned to the SMS group received a daily SMS at midday during the study. Persons of the SMS group agreed more frequently that SMS reminders were very useful and that the device was not annoying. Compliance did not vary significantly between groups across the compliance indicators. CONCLUSION: SMS did not increase malaria chemoprophylaxis compliance above baseline, likely because the persons did not benefit from holidays after the return and stayed together. So the reminder by SMS was noted by all subjects of the study. Another study should be done to confirm these results on soldiers going on holidays from employment after return or with individual travellers.

Outbreak of malaria among policemen in French Guiana.

An outbreak of malaria occurred among 62 policemen following an operation against illegal gold panning in French Guiana. A retrospective cohort study was conducted. The objectives were to describe the outbreak and to identify factors related to the cases. The total number of initial cases was 37. Both Plasmodium falciparum and Plasmodium vivax were detected. Twenty-seven policemen presented with one to four recurrences. In bivariate analysis, factors related to malaria were a "medium to high" level of mosquito bites pollution at night, late washing in the evening and wearing a nonimpregnated Battle Dress Uniform (BDU). This investigation confirmed the low level of compliance with chemoprophylaxis among individuals on long-term assignment in French Guiana. Compliance with mosquito protection measures was satisfactory except for the use of impregnated BDU. Several recommendations were provided. Therefore, this outbreak reminds us that malaria remains a public health problem in French Guiana.

Assessment of the French National Health Insurance Information System as a tool for epidemiological surveillance of malaria.

OBJECTIVE: Epidemiological surveillance of malaria in France is based on a hospital laboratory sentinel surveillance network. There is no comprehensive population surveillance. The objective of this study was to assess the ability of the French National Health Insurance Information System to support nationwide malaria surveillance in continental France. MATERIALS AND METHODS: A case identification algorithm was built in a 2-step process. First, inclusion rules giving priority to sensitivity were defined. Then, based on data description, exclusion rules to increase specificity were applied. To validate our results, we compared them to data from the French National Reference Center for Malaria on case counts, distribution within subgroups, and disease onset date trends. RESULTS: We built a reusable automatized tool. From July 1, 2013, to June 30, 2014, we identified 4077 incident malaria cases that occurred in continental France. Our algorithm provided data for hospitalized patients, patients treated by private physicians, and outpatients for the entire population. Our results were similar to those of the National Reference Center for Malaria for each of the outcome criteria. DISCUSSION: We provided a reliable algorithm for implementing epidemiological surveillance of malaria based on the French National Health Insurance Information System. Our method allowed us to work on the entire population living in continental France, including subpopulations poorly covered by existing surveillance methods. CONCLUSION: Traditional epidemiological surveillance and the approach presented in this paper are complementary, but a formal validation framework for case identification algorithms is necessary.

Self-reporting compared to prospective surveillance to evaluate the incidence of diarrhea among French Army personnel deployed to N'djamena, Chad.

Self-reporting seems more appropriate than medical-based surveillance to estimate true incidence of diarrhea during deployment of military troops. Most soldiers self-reported multiple episodes, 42% leading to medical care, mainly the first episode, resulting in a threefold higher incidence. Mathematical models integrating self-reported data should better predict outbreaks during military deployments and define a more complete assessment of disease burden.

Malaria in the Republic of Djibouti, 1998-2009.

Historically, native populations in the Republic of Djibouti have experienced only low and unstable malaria transmission and intermittent epidemics. In recent years, efforts at malaria control have been aggressively pursued. This study was performed to inform revised malaria prevention recommendations for military service members and international travelers to the country. Laboratory-confirmed cases of malaria documented at large medical facilities and within military and civilian health care systems in the Republic of Djibouti from 1998 to 2009 were reviewed. In recent years, fewer than 5% of febrile cases among the three largest passive surveillance systems were laboratory-confirmed as malaria, and incidence of confirmed malaria was well below 1/1,000 persons/year. As efforts in the Republic of Djibouti progress toward elimination, and in conjunction with continued efforts at surveillance, emphasizing mosquito-avoidance measures and standby emergency treatment will become reasonable recommendations for malaria prevention.

Malaria outbreak among French army troops returning from the Ivory Coast.

In 2006, a French Army unit reported 39 malaria cases among service persons returning from Ivory Coast. Thirty, including three serious forms, occurred after the return to France. The risk of post-return malaria was higher than the risk in Ivory Coast. Half of the imported cases had stopped post-return chemoprophylaxis early.

Gastrointestinal illnesses among French forces deployed to Djibouti: French military health surveillance, 2005-2009.

Despite an increase in foreign tourism and in the numbers of foreign military personnel deployed to Djibouti, little is known about the risk of gastrointestinal illness in this country in eastern Africa. To assess risk and to describe common features of gastrointestinal illnesses, reports of illness derived from military health surveillance data collected during 2005-2009 among French service members deployed to Djibouti were reviewed. Diarrhea was the most common problem; it had an annual incidence ranging from 260 to 349 cases per 1,000 person-years. The risk was higher among soldiers deployed short-term (four months) than among soldiers deployed long-term (two years). This five-year review of French health surveillance data documents a significant burden of diarrhea among French soldiers in Djibouti. The identification of factors associated with risk may permit efficient targeting of interventions to reduce morbidity from gastrointestinal illness.

Chemoprophylaxis compliance in a French battalion after returning from malaria-endemic area.

Incidence of malaria is increasing in travelers and soldiers. In 2006, a survey was performed in a French battalion returning from a malaria-endemic area. According to the chemoprophylaxis plasma concentration and the individuals' reports, the noncompliance rates were high, respectively, 63.4 and 54.7%.

Circulation of Chikungunya virus in Gabon, 2006-2007.

This study reports the first isolation and partial genetic characterization of Chikungunya virus (CHIKV) from patients during a 2006-2007 dengue-like syndrome outbreak in Gabon. The isolated viruses were phylogenetically close to strains isolated in the Democratic Republic of the Congo 7 years ago and to strains isolated more recently in Cameroon. These results indicate a continuing circulation of a genetically stable CHIKV population during 7 years in Central Africa.