Antibiotic therapy and staphylococcal skin infections in a tropical malarial zone (Guyana). Practices in conventional and exceptional situations

A problem of community-acquired Staphylococcus aureus skin infections emerged in the French armed forces in 2004, in a malaria-endemic areas. The high incidence rate led us to evaluate military staff practices. This was a cross-sectional survey of doctors and nurses deployed as officers in French Guyana since 2006. The definition of skin and soft-tissue infection came from the criteria for epidemiological surveillance of the armed forces. We studied the management of antibiotic therapy and its related difficulties. In all, 47 officers responded. At the Military Medical Center (MMC), 23.4% of respondents routinely prescribed antibiotics, compared with 36.2% when stationed in the jungle (p<0.05%). Complication led 68.1 of staff to prescribe antibiotic prescriptions at the MMC, compared with 46.8% in the jungle (p<0.05%). Finally, 22.5% of those at MMC prescribed antibiotic coverage of surgical drainage, compared with 14.8% in the jungle (p<0.05%). Pristinamycin and fusidic acid were the preferred antibiotics. Two-thirds of the staff reported difficulties in jungle management. This first study indicates the need for an update of military medical recommendations. Personnel training must continue to enable them to provide appropriate aggressive management in the current endemic context.

Surveillance of adverse events following vaccination in the French armed forces, 2011-2012

OBJECTIVES

French military personnel are subject to a compulsory vaccination schedule. The aim of this study was to present the results of surveillance of vaccine adverse events (VAEs) reported from 2011 to 2012 in the French armed forces.

STUDY DESIGN

VAEs were surveyed among all French armed forces from 2011 to 2012 by the epidemiological departments of the military health service. For each case, a notification form providing patient and clinical information was provided.

METHODS

Case definitions were derived from the French drug safety guidelines. Three types of VAE were considered: non-serious, serious and unexpected. Incidence rates were calculated by relating VAEs to the number of vaccine doses delivered.

RESULTS

In total, 161 VAE cases were reported. The overall VAE reporting rate was 24.6 VAEs per 100,000 doses, and the serious VAE rate was 1.3 per 100,000 doses (nine cases). The serious VAEs included two cases of Guillain-Barré syndrome, one case of optic neuritis, one case of a meningeal-like syndrome, one case of rheumatoid purpura, one case of acute asthma and three cases of fainting. The highest rates of VAE were observed with the Bacille Calmette-Guérin vaccine (BCG) (482.3 per 100,000 doses), inactivated diphtheria-tetanus-poliovirus with acellular pertussis vaccine (dTap-IPV) (106.1 per 100,000 doses) and meningococcal quadrivalent glycoconjugate vaccine (MenACWY-CRM) (39.3 per 100,000 doses).

CONCLUSIONS

The global rates of VAE observed in 2011 and 2012 confirm the increase that has been observed since 2009 in the French armed forces, which could reflect improved practitioner awareness about VAEs and the use of certain vaccines added to the vaccination schedule recently (dTap-IPV in 2008 and MenACWY-CRM in 2010). VAEs appear to be relatively rare, particularly serious VAEs, which indicates acceptable tolerance of vaccines.

Chikungunya infection: self-reported rheumatic morbidity and impaired quality of life persist 6 years later

This study presents the 6-year follow-up of French gendarmes exposed to the chikungunya (CHIK) infection in 2006 on Reunion Island. The aim was to see to what extent the subjective health differences observed in 2008 (30 months after infection) between CHIK infected (CHIK+) and noninfected (CHIK-) gendarmes still persisted in 2012, and to investigate a possible return to a pre-CHIK health status for CHIK+ subjects. Gendarmes were contacted by mail in 2012 and asked to complete a self-questionnaire asking for morbidity, health care and medicines consumption since the last follow-up in 2008. Quality of life (QoL) after 6 years was evaluated using the SF-36 scale. In comparison with CHIK- subjects (n = 171), CHIK+ (n = 81) presented with higher rheumatic but also nonspecific morbidity such as headaches and fatigue associated with a large psychological impact, frequent depressive moods and social disabilities, leading to a significant impairment of the QoL and higher health care consumption. When restricted to CHIK+ subjects, comparing the data with that of 2008 showed persistent but decreasing self-reported rheumatic morbidity, and an increase over time of chronic discomfort (headache, fatigue) and depressive moods, resulting in no overall improvement in QoL. Despite possible cohort attrition bias, the comparability of CHIK+/CHIK- subjects allows the assumption of a long-term impact of CHIK infection with less chance of returning to a previous health status. Although these results may be specific to the 2006 virus strain, we recommend that public health strategies in the epidemic-prone countries include a response to the consequences of chronic post-CHIK disorders.

Malaria control strategies in French armed forces

Each year, 40,000 French soldiers deploy or travel through malaria-endemic areas. Despite the effective control measures that were successively implemented, malaria remains a public health concern in French armed forces with several important outbreaks and one lethal case every two years. This article describes the malaria control strategy in French armed forces which is based on three combined strategies: i) Anopheles vector control to prevent infection with the implementation of personal protection against vectors (PPAV) adapted to the field living conditions of the troops. ii) Chemoprophylaxis (CP) to prevent the disease based on prescription of effective and well tolerated doxycycline. iii) Management of cases through early diagnosis and appropriate treatment to prevent death. In isolated conditions in endemic areas, rapid diagnosis tests (RDT) are used as first-line tests by military doctors. Treatment of uncomplicated Plasmodium falciparum (P. falciparum) malaria is based either on the piperaquine tetraphosphate-dihydroartemisinin association since 2013, or on the atovaquone-proguanil association. First-line treatment of severe P. falciparum malaria is based on IV artesunate. These measures are associated with constant education of the military, epidemiological surveillance of malaria cases and monitoring of parasite chemosensitivity.

Adverse events following vaccination in the French armed forces: An overview of surveillance conducted from 2002 to 2010

Binary file ES_Abstracts_Final_ECDC.txt matches

Adverse events following vaccination in the French armed forces: An overview of surveillance conducted from 2002 to 2010

French military personnel are subject to a compulsory vaccination schedule. The aim of this study was to describe vaccine adverse events (VAE) reported from 2002 to 2010 in armed forces. VAE are routinely surveyed by the military Centre for epidemiology and public health. For each case, military practitioners fill a notification form, providing patient characteristics, clinical information and vaccines administered. For this study, VAE following influenza A(H1N1)pdm09 vaccination were excluded. Among the 473 cases retained, 442 (93%) corresponded to non-severe VAE,including local, regional and systemic events, while 31 corresponded to severe VAE, with two leading to significant disability. The global VAE reporting rate (RR) was 14.0 per 100,000 injections. While stationary from 2002 to 2008, the RR increased from 2009. The most important observations were a marked increase of VAE attributed to Bacillus Calmette-Guérin (BCG) vaccine from 2005 to 2008, a high RR observed with the inactivated diphtheria-tetanus (toxoids)-poliovirus vaccine combined with acellular pertussis vaccine (dTap-IPV) from 2008 and an increase in RR for seasonal influenza vaccine VAE in 2009. Our RR for severe VAE (1.1 VAEper 100,000) appears comparable with rates observed among United States civilians and military personnel. The increase observed from 2009 could be partly explained by the influenza A(H1N1)pdm09 pandemic which increased practitioner awareness towards VAE. In conclusion, the tolerance of the vaccines used in French armed forces appears acceptable.

Increase in reported adverse events following seasonal influenza vaccination among the French armed forces, 2008-2009: possible role of stimulated reporting and background cases of influenza-like infection

OBJECTIVES

In September 2009, an increase in seasonal influenza vaccine adverse events (VAE), compared with reports for previous years, was detected among the French armed forces in the setting of an extended immunization campaign. This work presents the results of this investigation.

STUDY DESIGN

VAE were surveyed among all French military personnel from 2008 to 2009 by Epidemiological Departments of the French Military Health Service. For each case, a notification form was completed, providing patient and clinical information.

METHODS

Case definitions were derived from the French drug vigilance guidelines. Three types of VAE were considered: non-serious, serious and unexpected. Incidence rates were calculated by relating VAE to the number of vaccine doses injected.

RESULTS

Forty-seven seasonal influenza VAE were reported in continental France: 18 in 2008 and 29 in 2009. The annual reporting rate was higher in 2009 (31.6 vs 16.6 VAE per 100,000 injections, respectively). The highest monthly incidence was observed in September 2009 (60.8 events per 100,000 injections). Two other peaks were observed in February 2008 and March 2009. The incidence in September 2009 was not significantly different from the incidences in February 2008 and March 2009. It was observed that incidence peaks occurred during influenza epidemic periods. One serious neurological VAE was observed.

CONCLUSIONS

The increase in seasonal influenza VAE in late 2009 mainly involved non-serious events, and could reflect stimulated reporting in the context of the A(H1N1)pdm09 pandemic. VAE reporting rates were highest during influenza epidemic periods, which could be explained by VAE being wrongly attributed to the vaccine when symptoms could reflect coincident background cases of viral infection.

Novel influenza A(H1N1) outbreak among French armed forces in 2009: results of Military Influenza Surveillance System

OBJECTIVES

An outbreak of novel A(H1N1) virus influenza, detected in Mexico in April 2009, spread worldwide in 9 weeks. The aim of this paper is to present the monitoring results of this influenza outbreak among French armed forces.

STUDY DESIGN

The period of monitoring by the Military Influenza Surveillance System (MISS) was 9 months, from May 2009 to April 2010.

METHODS

The main monitored events were acute respiratory infection (ARI), defined by oral temperature ≥38.5 °C and cough, and laboratory-confirmed influenza. Weekly incidence rates were calculated by relating cases to the number of servicepersons monitored.

RESULTS

In continental France, the incidence of ARI increased from September 2009, with a weekly maxima of 401 cases per 100,000 in early December 2009 according to MISS. Estimations of the incidence of consultations which could be related to novel A(H1N1) influenza ranged from 48 to 57 cases per 100,000.

CONCLUSIONS

The trends observed by MISS are compatible with French national estimations. The incidence of consultations which could be related to A(H1N1) influenza at the peak of the epidemic (194 cases per 100,000) was much lower than the national estimate (1321 cases per 100,000). This may be due to servicepersons who consulted in civilian facilities and were not monitored. Other explanations are the healthy worker effect and the younger age of the military population.

[Sexual exposure to HIV in the French armed forces between 2005 and 2007]

BACKGROUND

Non-occupational HIV exposure in the French forces has been placed under epidemiological surveillance since 2000. This surveillance programme provides an indirect indicator of risky sexual behaviour among military personnel.

PATIENTS AND METHODS

All cases of non-occupational exposures in French military personnel that meet the notification criteria, wherever they occur, are reported by a military physician, with data being collected from 2005 to 2007.

RESULTS

Between January 2005 and December 2007, 2241 cases of sexual exposure within the French forces were filed. The annual incidence was 214.3 per 100,000 with an average patient age of 26 years. Sexual exposures concerned men in 99.2% of cases and occurred overseas in 92.9% of cases. Partners were sex-workers in 66.7% of cases. Failure to use condoms adequately during sexual intercourse was reported in 15.5% of cases. In cases where condoms were used, exposure to HIV resulted either from condom rupture or slippage. Postexposure HIV prophylaxis was prescribed in 70.5% of cases.

DISCUSSION

The majority of cases of sexual exposure reported in the French armed forces involved high risk of HIV transmission. However, since the beginning of surveillance in 2000, no cases of HIV seroconversion have been reported following postexposure antiretroviral prophylaxis. The non-occupational postexposure prophylaxis strategy is not in question.

[Pathophysiological mechanisms of dengue fever: critical review of current concepts]

In the 20th century dengue fever became one of the leading causes of morbidity and mortality throughout the tropics. The dengue virus is an arbovirus transmitted by Aedes mosquitoes. There are four distinct serotypes of dengue arbovirus (DENV-1, 2, 3, 4). According to the World Health Organization, a person infected by one of the dengue viruses can develop symptoms ranging from the classical self-limiting form characterized by high temperature, headache, myalgia, and arthralgia to the severe, potentially fatal, form known as dengue shock syndrome. For over 40 years the main explanation for the pathogenesis of dengue has been based on the "antibody-dependent enhancement" (ADE) concept stating that enhancing antibodies acquired during a primary infection increase the number of infected cells, and thus the level of viremia, during secondary infection. However the severity of dengue is not limited to dengue shock syndrome and there are many cases that do not conform to the ADE concept. A meta-analysis could provide crucial information for resolving this controversy and open the way for development of a monovalent vaccine against the dengue virus as for the closely related yellow fever virus.

[Dengue virus infection in neotropical forest mammals: incidental hosts or potential reservoirs?]

The arboviral disease with the highest human incidence in South America is dengue fever. In French Guiana, where all four dengue serotypes, i.e., DENV-1, DENV-2, DENV-3 and DENV-4, are present, the disease is endemic with epidemic outbreaks. Though previous serological studies have suggested a sylvatic cycle, involvement of wild mammals in the dengue cycle in the neotropics has never been confirmed. The purpose of this study was to search for the presence of DENV in wild animals captured at two different sites between 2001 and 2007. About 10,000 trap/nights were performed leading to the capture of 464 non-flying mammals (rodents and marsupials). In addition, mistnests placed in the same zone yielded 152 bats. Reverse transcription-polymerase chain reaction amplification to detect infection by any of the four dengue serotypes demonstrated viral RNA in the livers and/or sera of 92 captured animals. Sequence analysis of amplification products revealed that the DENV-1, DENV-3 and DENV-4 serotypes were distinct from those circulating in humans at the same periods. Analysis for DENV-2 showed that some strains were divergent from concurrent human strains but that others were identical. The latter finding suggests that wild neotropical mammals living in periurban area can be infected by dengue virus strains circulating in humans. However, further investigation will be needed to determine if neotropical mammals are incidental hosts or potential reservoirs of dengue virus.

[Pertussis surveillance in French military forces in 2007]

OBJECTIVES

Pertussis surveillance in the French general population was stopped in 1986. Pertussis was added to the list of illnesses surveyed by the military epidemiological surveillance network because of outbreaks having occurred among French servicepersons and in military high schools. This study had for aim to report the results of the first year of surveillance.

DESIGN

Pertussis declaration criteria were those recommended in 2006 by the French council for public hygiene. The data concerning active military servicepersons was collected by physicians of all military medical units. An anonymous declaration form was used for data collection.

RESULTS

In 2007, 66 cases of pertussis were reported in the military forces, 10 of which were excluded after a negative biological test. The classification of the 56 included cases was: 46% biologically confirmed cases, 20% clinically confirmed cases, 14% suspected cases, and 6% epidemiologically confirmed cases. The incidence density rate was 16.3 cases for 100,000 servicepersons-years. Age under 20 was associated with a 4.6 fold higher risk to develop pertussis.

CONCLUSIONS

The high incidence rate observed in individuals under 20 years of age could reflect a shift of pertussis reservoir to young adults, as observed in industrialized countries after generalization of vaccination programs. However, several years of surveillance will be needed to confirm this hypothesis. Meanwhile, the military epidemiological network could constitute an important surveillance marker of pertussis among adults in France.

[Real time epidemiological surveillance within the armed forces: concepts, realities and prospects in France]

BACKGROUND

In 2002, the North Atlantic Treaty Organization took five initiatives in order to enhance the defence capacities against the massive destruction weapons, one of them concerned the development of an interoperable surveillance system, giving in real time some informations permitting early warning to the commanders. Thoughts in France to improve the military surveillance system, methodological constraints and first results are shown.

METHODS

Medical, technological, human and organisational aspects had to be taken into account to develop real time surveillance within the armed forces, and also specific military constraints. In order to evaluate the validity of its methodology, the "Institut de médecine tropicale du service de santé des armées" developed a prototype, set up in French Guyana and which took part in a second time at a multinational exercise.

RESULTS

The "surveillance spatiale des épidémies au sein des forces armées de Guyane" has been set up in 2004, formed by both a recording and an analysis networks. This system permits to provide in real time some dashboards directly operational for the commanders. The exhaustiveness rate has been evaluated at 104%, compared to the traditional surveillance. It permitted three times to detect outbreaks several weeks before the other systems. Some limits have been identified, as the use of personal digitalized assistants. The involvement in a multinational exercise showed the system's efficacy, by detecting two simulated outbreaks, but also its interoperability. In 2006, it has been decided to extend the concept by deploying its second generation within the French armed forces in Djibouti. The "alerte et surveillance en temps réel" disposal permitted to take into account multiple geographical localizations.

CONCLUSION

A real time surveillance system is an essential alarm disposal, however it is only an information tool within the complex activity of piloting the sanitary situation. It must be integrated within the whole situation expertise supports, represented also by medical intelligence, epidemiological investigations and prediction of the epidemiological phenomenon evolution.

Antimalarial remedies in French Guiana: a knowledge attitudes and practices study

A "knowledge attitudes and practices" study about malaria treatments was undertaken in French Guiana, along with an ethnopharmacological study. One hundred and seventeen people from five different groups and nationalities (Creole, Palikur, Galibi, Brazilian, and European) answered the questionnaire. The results were analysed using univariate and multivariate statistical analysis. First, we evaluated the overall knowledge about malaria from the interviewed people. According to bio-medical concepts, we noticed that they have a good knowledge of this illness. Secondly, we studied the treatment used by sick people during their last malaria attack. We demonstrated that, although bio-medical treatment is available in this area, people use both modern drugs and traditional remedies. Finally, preventive attitudes have been examined. One-third of the interviewed people drink regularly some herbal remedy to prevent febrile illnesses and malaria, thus displaying a strong concern about this disease. The ethnopharmacological study highlighted the frequent use of traditional remedies, along with their mode of preparation and administration. A total of 34 different species (both from flora and fauna) have been registered as antimalarial. Twenty-seven are used for curative purposes, 20 as preventive and 13 of them are used for both purposes. Quassia amara (Simaroubaceae) whose antimalarial activity has already been demonstrated was the species most frequently used as antimalarial for curative and preventive purposes.

Efficacy of permethrin-treated uniforms in combination with DEET topical repellent for protection of French military troops in Côte d'Ivoire

In 2000, 22,000 French military personnel were deployed overseas. The French military health service implemented a vector control strategy including personal protection by the use of permethrin preimpregnated battlefield uniforms (BFUs) and the application on the skin of a topical repellent (50% DEET). In 2000, French forces used an industrial process to impregnate cloth with permethrin by soaking it before cut-out of the BFU. A study was implemented in four experimental huts in Côte d'Ivoire to assess the field efficacy of the impregnated BFUs and their resistance to washing. Taking into account the systematic variations in each variable in the field and using a modeling based on logistic regression and discriminant analysis, this study showed that after 6 h without reapplication, the protective effects of the use of DEET as skin repellent was not significant, perhaps due to the high density of Anopheles mosquitoes during the night catching sessions and an average time of effective repellency of < 2 or 3 h in the field. The analysis also showed that the French process of industrial impregnation of permethrin of the BFU offered in 2000 some protection from mosquito bites but not enough to reduce significantly the incidence of malaria among nonimmune troops. No positive or negative interaction was noted when DEET and the impregnated BFUs were used together.

[Prevalence of hepatitis B and C virus, HTLV-1 and HIV in type B lymphoproliferative syndromes in Gabon]

B lymphoproliferative disorders (B-LPD) are the most frequent types of lymphoid malignancies encountered in Gabon where HCV, HBV, HTLV-I and HIV are highly prevalent and all known for lymphotropism. Prevalences of HBs Ag, antibodies to HCV, HTLV-I and HIV were compared in 40 patients (21 men, 19 women; 17 < age < 75 years) with newly diagnosed B-LPD (low grade lymphoma = 6, intermediate grade = 21, high grade = 8: chronic lymphocytic leukaemia = 5) and 160 age and sex-matched controls. None of the B-LPD patients had got transfusion or parenteral care from the onset of symptoms to the inclusion day. In the B-LPD group, 13 patients had HBs Ag and antibodies to HCV, HIV and HTLV-1 were detected in 11, 6 and 10 subjects. In monovariate analysis, HBs Ag, antibodies to HIV or HTLV-1 were risk factors for B-LPD but antibodies to HCV were not associated with such diseases. Multivariate analysis showed only a relationship between HBs Ag and B-LPD (OR = 3.86; IC: 1.11-13.48). In such patients, reactivation of B hepatitis by treatment of B-LBD may be an important concern. If a background poor immune system could explain both susceptibility to long standing virus carriage and lymphoma development, a participating action of the HBV in lymphomagenesis could not be excluded.

[Use of satellites for public health purposes in tropical areas]

The epidemiological hallmark of the new millennium has been the emergence or recrudescence of transmissible diseases with high epidemic potential. Disease tracking is becoming an increasingly global task requiring implementation of more and more sophisticated control strategies and facilities for sustainable development. A promising initiative involves the use of satellite technology to monitor and forecast the spread of disease. The Health Early Warning System (HEWS) was designed based on successful application of satellite data in food programs as well as in other areas (e.g. weather, farming and fishing). The HEWS integrates data from communications, remote-sensing and positioning satellites. The purpose of this review is to present the main studies containing satellite data on public health in tropical areas. Satellite data has allowed development of more reactive epidemiological tracking networks better suited to increasing population mobility, correlation of environmental factors (vegetation index, rainfall and ocean surface color) with human, animal and insect factors in epidemiological studies and assessment of the role of such factors in the development or reappearance of disease. Satellite technology holds great promise for more efficient management of public health problems in tropical areas.

[Epidemiologic surveillance of dengue fever in the French army from 1996 to 1999]

Dengue fever is a widespread disease that can occur outside tropical areas. Several thousand French military personnel are exposed to this infectious risk each year and exposure is expected to rise with the creation of a professional army and the increasing number of foreign missions. As a result, dengue fever has become a major priority for the Armed Services Health Corps (ASHC). A system of epidemiological surveillance based on the active participation of all military physicians has been designed by the ASHC to collect and analyze all data relevant to cases of dengue fever involving French military personnel stationed overseas or at home. The purpose of this study is to present data compiled for the period from 1996 to 1999. Analysis of these data demonstrated that the incidence of dengue fever peaked in 1997 due to epidemic outbreaks occurring in French Polynesia and Martinique. In response to these outbreaks control measures were adapted especially in regard to vector control. This study shows that the system of surveillance implemented by the ASHC is an effective but still perfectible tool.

[Disease vector control strategy in the French army]

Disease vector control is a major priority for the Medical Health Corps of the French Armed Forces which maintains around 23,000 troops in tropical areas and is involved in numerous military and humanitarian missions throughout the world. Control strategy includes both general and personal control measures. Personal control measures include wearing permetherin-impregnated combat uniforms, application of repellents to the skin, and use of deltamethrin-impregnated bednets. General measures are implemented in facilities and in the environment. Measures in facilities include not only physical deterrents such as screens on openings and air-conditioning but also application of chemical insecticides to walls, curtains, and screening. Environmental measures include control of larval deposits and elimination of potential breeding areas. Low-volume wide-area spraying of imagocides is a supplemental option used in case of disease outbreak. For units stationed in tropical areas, command and surveillance of vector control operations is under the responsibility of the mosquito control committee which includes personnel from the affected field unit. Strategies are chosen in function of local climate and operational conditions. The efficacy of vector control programs is assessed annually by reviewing the incidence in armed forces personnel of the main vector-transmitted diseases: malaria, dengue fever, and leishmaniasis. Documentation and training are dispensed to all units stationed in tropical areas. To ensure that knowledge of military physicians remains current, three courses on malaria control are offered each year at the Tropical Medicine Institute of the Armed Forces Health Corps (Le Pharo) in Marseille. Field research conducted in collaboration with military or civilian organizations independent of the Armed Services Health Corps makes it possible to keep chiefs of staff informed of state-of-the art vector control measures adapted to use by personnel on assignment or mission in tropical areas.

Plasma concentrations of sVCAM-1 and severity of dengue infections

Adhesion molecules are essential for the immune response. They are involved in the regulation of cell-to-cell contact, thereby enabling leukocytes to communicate. Circulating forms of adhesion molecules are found in the serum of healthy individuals. Raised levels have been associated with disease severity in HCV and other infections and thus appear to be good markers of endothelial damage. The levels of soluble Vascular Cell Adhesion Molecule-1 (sVCAM-1) and of sP and sL-selectin in the plasma of children hospitalised for dengue in French Polynesia were monitored. Studies from the 1996/1997 dengue-2 outbreak, showed that levels of sVCAM-1 increase steadily during the febrile period, peak on day 7, and then decline relatively rapidly. Disregarding the time frame within the febrile period, sVCAM-1 levels were always higher compared to controls. There was a significant association between sVCAM-1 levels and dengue haemorrhagic fever, a severe manifestation of dengue virus infection characterised by plasma leakage. No association was apparent between sVCAM-1 levels and primary vs. secondary dengue virus infections. Levels of sP-selectin and sL-selectin were significantly higher in primary compared with secondary infection but were not different in patients presenting with plasma leakage. Lastly, sVCAM-1 levels were significantly higher in an outbreak of severe disease in 1989/1990 (dengue-3) when compared to a non-severe outbreak in 1988/1989 (dengue-1) and a mild outbreak in 1996/1997 (dengue-2). The results suggested that levels of sVCAM-1 production might prove to be a useful marker in the management of severe dengue.

[Imported dengue hemorrhagic fever: aprops of 1 case presenting with signs of acute alithiasic cholecystitis]

Dengue is prevalent in all subtropical areas. Hemorrhagic forms of the disease were first described in southeast Asia but have now been observed on several continents. Travelers are at risk for infection and the likelihood of imported dengue has grown in relation to volume of air traffic. In developed countries, dengue usually presents in the benign form, but sudden aggravation is always possible. The purpose of this report is to describe a case of imported dengue hemorrhagic fever associated with abdominal pain in a traveler returning from Asia. Radiological findings were suggestive of nonlithiasic cholecystitis. Similar ultrasound feature have been reported by pediatric groups during dengue outbreaks in Asia. Previous findings have shown that bladder involvement is a predictive sign of severe disease and impending shock. Surgery is contraindicated in these patients. Close clinical and laboratory surveillance is necessary due to the high risk of aggravation. The pathogenesis of this severe life-threatening form of the disease is unclear. A possible explanation is involvement of a more virulent strain of virus. Dengue should always be considered after malaria in the differential diagnosis of returning travelers patients presenting fever.

Prospective study of the duration and magnitude of viraemia in children hospitalised during the 1996-1997 dengue-2 outbreak in French Polynesia

The magnitude and duration of viraemia in children admitted to the hospital with dengue was studied during a dengue 2 outbreak in French Polynesia in 1996-1997. Forty-nine patients from whom at least 3 plasma samples were available were included in the study. Based on analysis of IgG-ELISA and haemagglutination inhibition assay, 21 of these were primary and 28 were secondary infections. According to World Health Organization criteria, 42 were dengue fever and 7 were dengue haemorrhagic fever. Virus was detectable by reverse transcription-PCR in all patients for at least the first 3 days of the onset of fever, but was never detected after the 6th day (mean duration = 4.4 days). Plasma virus titers ranged from 1.7-5.6 Log(10) TCID(50)/ml. A significant difference was not observed in the magnitude and duration of viraemia in patients with primary versus secondary infections. The severity of the illness, however, was correlated with both criteria.

[Evidence of risk factors for condom breakage among French military personnel stationed overseas]

The French Army Medical Service has been distributing free condoms to overseas personnel since 1989. An epidemiologic study conducted in Cambodia showed that the rate of condom failure during protected sex was 16.3 p. 100. In view this high failure rate, a study to evaluate safety guidelines for condom use was deemed necessary. This report describes the results of an inquiry designed to identify risk factors for condom breakage. The study population included 124 servicemen stationed overseas who consulted an army physician following condom failure. An anonymous questionnaire was completed by the physician with the informed consent of the patient. Data was analyzed by multiple correspondence analysis. Anogenital intercourse and alcohol abuse were the main risk factors for condom failure. Oral sex before penetration, carrying the condom in the pocket, and improper application by the sex partner were also risk factors for failure. The major finding of this study was that 64 of the 124 (51.6 p. 100) denied any sexual activity or improper handling that might have led to condom breakage. Although condoms are still indispensable for prevention sexually transmitted diseases, the results of this study show that they do not provide absolute protection. Health care officials should inform the public as to the risk factors for breakage of latex condoms.

Association of D2 dopamine receptor and alcohol dehydrogenase 2 genes with Polynesian alcoholics

Alleles of the D2 dopamine receptor (DRD2) and the alcohol dehydrogenase 2 (ADH2) genes were determined in 69 French Polynesian alcoholic patients and 57 controls matched for racial origin. Three racial groups were studied: pure Polynesians (PP), Polynesians mixed with Caucasian (PCA) ancestry and Polynesians mixed with Chinese (PCH) ancestry. DRD2 A1 allele frequencies in the alcoholics compared to their controls in these groups were: PP,.26 vs.32 (P =. 69); PCA,.44 vs.35 (P =.46); PCH,.40 vs 0.39 (P =.88). ADH2 1 allele frequencies in alcoholics compared to their controls groups were: PP, .56 vs.62 (P =.66); PCA,.75 vs.56 (P =.09); PCH,.78 vs.32 (P =.009). In the PCA group, the combination of the DRD2 A1 genotypes and the ADH2 1 homozygotes was strongly associated with alcoholism (P =. 0027). This preliminary study shows the importance of ascertaining racial ancestry in molecular genetic association studies. Moreover, it suggests that a combination of genes are involved in susceptibility to the development of alcoholism.

Dengue: an evaluation of dengue severity in French Polynesia based on an analysis of 403 laboratory-confirmed cases

We conducted a retrospective study of 403 laboratory-confirmed dengue cases hospitalized in Tahiti between August 1989 and March 1997. According to standard WHO criteria, 337 of these cases were dengue fever (DF) and 64 were dengue haemorrhagic fever (DHF). Of the 10 fatal cases, 6 were DF and 4 were DHF. As an alternative, we used a correspondence analysis procedure to define dengue severity based on basic clinical and biological criteria for which we assigned a severity score, and then selected the 50 most severe cases from this analysis. Of the latter, 17 patients had been classified as DF and 33 as DHF by the WHO criteria. From this analysis, haemorrhages and decreased platelets counts associated with hepatic disorders are the main criteria associated with the severe dengue cases. Thus in our study population, the WHO classification does not account for the overall severity of dengue; hepatic failure should be considered as a specific severe form of dengue since plasma leakage, which is the pathophysiological hallmark of DHF, is only one of the pathogenic mechanisms leading to severity.

Filarial antibody responses in Wuchereria bancrofti transmission area are related to parasitological but not clinical status

In Wuchereria bancrofti transmission areas, three groups of individuals have been identified, according to the presence or absence of microfilariae or adult worm derived molecules in the blood compartment. These groups likely reflect individuals with different permissivity/resistance to the complete development of W. bancrofti cycle. The profile of filarial-specific immunoglobulins was analysed in W. bancrofti-exposed individuals in French Polynesia, according to the presence or absence of microfilariae (Mf) and adult worms, measured by Og4C3 circulating antigen. Individuals harbouring adult worms, have higher filarial-specific IgG4 but lower IgG3 and IgE levels, than adult worm-free individuals, independently of the presence of Mf. Low filarial-specific IgG1 and IgG2 levels were associated with the presence of Mf but independent of the presence/absence of adult worms. The filarial antibody responses were associated with the parasitological status of individuals but not with clinical symptoms such as hydroceles or limb lymphangitis or elephantiasis. The reduction of filarial-specific immunoglobulin levels was higher after treatment with diethylcarbamazine, than ivermectin, which likely reflects the better effect of the former on W. bancrofti adult worms. However, reduction of antibody levels was also observed in Mf-and adult worm-negative individuals. This could be due to the overall reduction of W. bancrofti transmission in the island where this study took place.

Changing clinical and biological manifestations of dengue during the dengue-2 epidemic in French Polynesia in 1996/97--description and analysis in a prospective study

In August 1996 dengue-2 virus was detected in French Polynesia for the first time since 1976. A prospective study was conducted from November 1996 to April 1997. Each time one of 7 physicians suspected dengue, the patient was enrolled and epidemiological, clinical and biological data were recorded. Dengue diagnosis was confirmed by virus isolation and IgM detection. The aims of this study were to find clinical and biological predictive factors constituting a specific profile of dengue (DF) and dengue haemorrhagic fever (DHF/DSS) and to assess the possibility of diagnosing dengue at primary health care level using clinical criteria and basic laboratory parameters. Of 298 clinically suspect cases, 196 (66%) were confirmed as dengue. The association of macular rash, pruritus, low platelet count and leukopenia was statistically predictive of dengue but not clinically, since these four signs occur in many other viral infections. As the prevalence of clinical and biological manifestations varied over time in our study, a specific profile useful for dengue diagnosis cannot be defined. With six cases of DHF, the morbidity of this dengue-2 outbreak was very low despite the sequential infection scheme DEN-3/DEN-2. The clinical expression of dengue could depend on a specific virus strain circulating in a specific population in a particular place, with varying virulence over time.

Possible dengue sequential infection: dengue spread in a neighbourhood during the 1996/97 dengue-2 epidemic in French Polynesia

A DEN-2 epidemic occurred in French Polynesia from August 1996 to April 1997 after 7 years of DEN-3 circulation. The susceptible population constituted all expatriates and Polynesians under 21. In August 1996, two successive DEN-2 cases occurred in Teroma, a Tahitian neighbourhood close to the international airport of Tahiti. A serological prospective study of persons < 21 years living in Teroma was conducted. The study population was bled in September 1996, October 1996 and June 1997. Analysis of dengue spread in Teroma confirmed that dengue transmission occurs primarily in the house, thus vector control campaigns should incorporate focal insecticide spraying and systematic daily use of insecticide in houses. The evolution in time of the disease demonstrated that among a susceptible population, prevalence and incidence rates are related to the time of exposure, and consequently to age. Comparison of dengue incidence or dengue prevalence between populations therefore requires adjusted age rates. Most studies did not adjust for age, leading to the conclusion that DHF is more frequent during secondary than during primary dengue infection. Prospective studies taking into account the time of dengue exposure are necessary to confirm the sequential infection hypothesis.

Plasma levels of tumour necrosis factor alpha and transforming growth factor beta-1 in children with dengue 2 virus infection in French Polynesia

The pathogenesis of dengue haemorrhagic fever (DHF) is not well understood. In the absence of predictive clinical or biological criteria, the management of DHF patients remains difficult. The role played by cytokines in the occurrence of DHF has been suggested by several authors. In this study, we determined the plasma levels of tumour necrosis factor alpha (TNF alpha) and transforming growth factor beta-1 (TGF beta-1) in 52 children with laboratory-confirmed dengue virus infection admitted to hospital during the recent dengue 2 outbreak in French Polynesia. Thirty-three children were classified as having dengue fever (DF) and 19 as DHF. The plasma of both DF and DHF patients contained similar levels of TNF alpha. By contrast, plasma obtained from children with DHF had significantly higher levels of TGF beta-1 than plasma from children with DF, especially from days 1 to 3 after the onset of fever.

Implication of macrophage inflammatory protein-1alpha in the inhibition of human haematopoietic progenitor growth by dengue virus

The mechanisms were investigated of haematopoietic progenitor growth inhibition, observed after in vitro infection of cord blood mononuclear cells (CBMNC) by a clinical isolate of dengue 3 (29-56DSS). The level of virus replication was not different when CBMNC were inoculated with 29-56DSS compared with a prototype strain of dengue 3 (H-87) which had no inhibitory effect. An inhibitory effect was also observed when cell-free and heat-inactivated supernatants from 29-56DSS cultures, but not from H-87 cultures, were added to cultures of normal CBMNC, suggesting an indirect mechanism via the release of soluble suppressive factor(s). Macrophage inflammatory protein-1alpha (MIP-1alpha) was detected at a significantly higher level in 29-56DSS cultures than in controls. Blocking experiments with anti-MIP-1alpha antibody demonstrated that the inhibitory effect was related at least partly to high MIP-1alpha levels. To our knowledge, this is the first report suggesting an indirect effect of dengue infection on haematopoiesis mediated by a suppressive cytokine.

[The specific epidemiological surveillance of dengue: the method and its importance since the dengue-2 epidemic in French Polynesia in 1996]

Dengue fever is present in tropical and subtropical regions and its geographical extension and the simultaneous increase of its mortality are worrisome. In endemic or epidemic countries, the aim of dengue-specific epidemiological surveillance is to confirm as soon as possible the circulation of a new viral dengue serotype, i.e. the beginning of an epidemic. The efficiency of the control strategy is improved by an earlier epidemic alert. In French Polynesia, dengue-3 virus circulated since 1989 at low level and, in May 1996, a specific epidemiological surveillance was undertaken because of the threat of a dengue-4 epidemic. From each suspected dengue case reported by 18 Polynesian physicians located in the Société Islands, a blood sample was taken for virological assay and clinical data were reported. Between May and November 1996, the virology unit of the Institut Malardé isolated 21 viruses (2 dengue-3 and 19 dengue-2) from 302 suspected cases. The dengue-specific epidemiological surveillance confirmed that dengue-2 virus was circulating and reduced the time of the epidemiological alert by 2 or 3 months compared to previous epidemics. Taking into account the day of illness, a logistic regression undertaken on the clinical data showed that the absence of cough was the only predictive sign of dengue diagnosis. The performance of this dengue-specific epidemiological surveillance system led us to consider its implementation in all concerned countries. A collaboration with international reference laboratories could be a solution for the developing countries.

[Evaluation of the completeness of the epidemiological surveillance systems for malaria by the Capture-recapture system in the French armies in l994]

The Capture-recapture method has been utilized to evaluate the annual incidence of malaria in the French armies in 1994 on the basis of the incidence derived from two regulatory systems, passive and exhaustive, of epidemiological surveillance: the Recueil et l'Exploitation des Données Epidémiologiques des Armées (REDEA) and the Surveillance Epidémiologique du Paladisme (SESP) system. Cases of malaria found by REDEA and SESP in 1994 rose to 480 and 424 respectively. Two hundred and thirty-eight cases were found by both systems. After validating the conditions for the application of the Capture-recapture method (in particular, having verified that the results from REDEA and SESP were probably independent), its utilization allowed us to evaluate the incidence of malaria in the French army in 1994 at 854 cases. The calculated exhaustivity values for REDEA and SESP were 56.2 and 49.6% respectively; 22% of cases were missed by both systems. The exhaustivity values of SESP and REDEA estimated in our study were comparable to those obtained by the Capture-recapture method applied in another legal inquiry into the passive and exhaustive epidemiological surveillance of meningitis and meningococcosis in France in 1989 and 1990. These results show that it is difficult to evaluate the epidemiological importance of a sickness on the results of passive and exhaustive surveillance alone. In 1995, a new system of surveillance was established in the army: a better conducted and more motivated retro-informative system, linked to a better education of medical officers in epidemiological surveillance permitted an improvement in the completeness of the results in the armies.