Franck Berger

Malaria transmission in Dakar: A two-year survey

BackgroundAccording to entomological studies conducted over the past 30 years, there was low malaria transmission in suburb of Dakar but little evidence of it in the downtown area. However; there was some evidence of local transmission based on reports of malaria among permanent residents. An entomological evaluation of malaria transmission was conducted from May 2005 to October 2006 in two areas of Dakar.MethodsMosquitoes were sampled by human landing collection during 34 nights in seven places in Bel-air area (238 person-nights) and during 24 nights in five places in Ouakam area (120 person-nights). Mosquitoes were identified morphologically and by molecular methods. The Plasmodium falciparum circumsporozoïte indexes were measured by ELISA, and the entomological inoculation rates (EIR) were calculated for both areas. Molecular assessments of pyrethroid knock down resistance (Kdr) and of insensitive acetylcholinesterase resistance were conducted.ResultsFrom May 2005 to October 2006, 4,117 and 797 Anopheles gambiae s.l. respectively were caught in Bel-air and Ouakam. Three members of the complex were present: Anopheles arabiensis (> 98%), Anopheles melas (< 1%) and An. gambiae s.s. molecular form M (< 1%). Infected mosquitoes were caught only during the wintering period between September and November in both places. In 2005 and 2006, annual EIRs were 9,5 and 4, respectively, in Bel-air and 3 and 3, respectively, in Ouakam. The proportion of host-seeking An. gambiae s.l. captured indoors were 17% and 51% in Bel air and Ouakam, respectively. Ace 1 mutations were not identified in both members of the An. gambiae complex. Kdr mutation frequency in An. arabiensis was 12% in Bel-air and 9% in Ouakam.ConclusionMalaria is transmitted in Dakar downtown area. Infected mosquitoes were caught in two subsequent years during the wintering period in two distant quarters of Dakar. These data agree with clinical data from a Senegalese military Hospital of Dakar (Hospital Principal) where most malaria cases occurred between October and December. It was the first detection of An. melas in Dakar.

Investigation on a pertussis outbreak in a military school: risk factors and approach to vaccine efficacy.

INTRODUCTION Pertussis (whooping cough) is a toxic bacterial infection caused mainly by Bordetella pertussis. In mid-January 2006, several cases of pertussis were diagnosed in a military boarding-school. An investigation was carried out at the end of January to identify the risk factors for infection and to evaluate the efficacy of vaccination. SUBJECTS AND METHODS Three definitions were used to distinguish the cases; confirmed biologically, confirmed epidemiologically and suspected cases. The risk factor study was carried out after the exclusion of suspect cases. Vaccine efficacy (VE) was evaluated from a case-control study where only biologically confirmed cases were included. For each case, five controls were matched according to age, sex and class. A logistic regression and a conditional logistic regression were performed for the risk factor study and vaccine efficacy, respectively. Statistical analysis was carried out using Stata 9.2 software. RESULTS A total of 206 cases were included, 17 of them biologically confirmed, 66 epidemiologically and 123 suspected cases. The attack rate was 17.8 per 100. Girls were 1.8 times more likely to catch pertussis (p=0.04), pupils in the first year of college, as well as those in high school were at 5 times greater risk of catching pertussis (p=0.008) than those in the second year of college. For pupils who benefited from at least 5 doses, the VE was at 80% when the last dose dated from less than 6 years earlier. DISCUSSION/CONCLUSION The attack rate observed in our study was similar to those normally seen during epidemics occurring within a community. Vaccine efficacy declined depending on the time lapse since the last vaccination. Since April 2008, the Public Health Authorities have planned to provide pertussis booster vaccinations for children aged 16-18 who missed those for 11-13-year-old, and for adults aged 26-27 and those who have not been vaccinated for more than 10 years.

Rabies Risk: Difficulties Encountered during Management of Grouped Cases of Bat Bites in 2 Isolated Villages in French Guiana

In French Guiana, from 1984 to 2011, 14 animal rabies cases and 1 human rabies case (2008) were diagnosed. In January 2011, vampire-bat attacks occurred in 2 isolated villages. In mid-January, a medical team from the Cayenne Centre for Anti-Rabies Treatment visited the sites to manage individuals potentially exposed to rabies and, in April, an anti-rabies vaccination campaign for dogs was conducted. Twenty individuals were bitten by bats in 1 month, most frequently on the feet. The median time to start management was 15 days. The complete Zagreb vaccination protocol (2 doses on day 0 and 1 dose on days 7 and 21) was administered to 16 patients, 12 also received specific immunoglobulins. The antibody titration was obtained for 12 patients (different from those who received immunoglobulins). The antibody titers were ≥0.5 EU/mL for all of them. The serology has not been implemented for the 12 patients who received immunoglobulins. Accidental destruction of a vampire-bat colony could be responsible for the attacks. The isolation and absence of sensitization of the populations were the main explanations for the management difficulties encountered. Sensitization programs should be conducted regularly.

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.

An approach for assessing effectiveness of a vaccination campaign against pertussis among young adults: The example of the French armed forces (2007–2012)

In 2011, we reported in this journal data arising from the surveillance of pertussis in the French armed forces from 2007 to 2009 and showed results consistent with the hypothesis of a shift of pertussis to young adults. Since military personnel are highly exposed due to their collective lifestyle, the military vaccination schedule was modified in 2008 according to national recommendations: A booster dose of inactivated diphtheria-tetanus-poliovirus vaccine combined with acellular pertussis vaccine (dTapIPV) was recommended in replacement of the usual dTIPV booster dose for military personnel who had not been vaccinated against pertussis in the previous 10 years. The aim of this work was to complete our previous analyses by adding the data from the period 2010e2012, to evaluate an eventual impact of these vaccination measures on the rates for pertussis in the French armed forces. The military epidemiological surveillance system covers all active duty personnel. The criteria for notification of pertussis include several case-definition parameters:

Medical Entomology: A Reemerging Field of Research to Better Understand Vector-Borne Infectious Diseases

In the last decade, the Chikungunya and Zika virus outbreaks have turned public attention to the possibility of the expansion of vector-borne infectious diseases worldwide. Medical entomology is focused on the study of arthropods involved in human health. We review here some of the research approaches taken by the medical entomology team of the University Hospital Institute (UHI) Méditerranée Infection of Marseille, France, with the support of recent or representative studies. We propose our approaches to technical innovations in arthropod identification and the detection of microorganisms in arthropods, the use of arthropods as epidemiological or diagnostic tools, entomological investigations around clinical cases or within specific populations, and how we have developed experimental models to decipher the interactions between arthropods, microorganisms, and humans.

Acute acoustic trauma in the French armed forces during 2007–2014

Context: Despite existing preventive measures, the number of acute acoustic trauma (AAT) cases reported to the French Military Epidemiological Surveillance System (MESS) remains high. Aims: The objective of this study was to describe AAT and the preventive measures already implemented. Subjects and Methods: We conducted a descriptive cross-sectional analysis of AAT using data from the MESS for the period 2007–2014. In addition, we reviewed the current prevention measures that exist in the French armed forces. Statistical Analysis Used: Comparisons between different incidence rates were made by Poisson and quasi-Poisson regression. Results: Between 2007 and 2014, 10,487 AAT cases were reported to the MESS, with a significant decrease in 2013 (P < 0.001). AAT incidence rates were the highest among those aged <25 years − 14.3 per 1000 person-years (PYs) (P < 0.001), and those in the army; with 8.1 per 1000 PYs (P < 0.001), and men had almost twice the risk of women (P < 0.001). AAT mainly occurred in training schools or at camps during exercises. The main prevention actions identified were the following: official regulations, education, making hearing protection devices (HPDs) available for all service members, and regular hearing monitoring. A working group has been set up and has proposed an informative chapter in the weapon handling instruction book, an AAT simulator, and a new HPD, the 3M® earplug, with an information brochure. Conclusions: AAT rates decreased from 2007 to 2014 in the French armed forces. Further analysis is needed to identify the underlying factors involved to improve the prevention actions proposed. The MESS and targeted surveys will assess the impact of the different prevention measures implemented.

Scabies among the French armed forces in 2015.

• Incidence of scabies among French armed forces was estimated at 11 cases per 10,000 person-years in 2015.