[The contribution of biology laboratories to keep immunization recommendations up to date: the example of the Centre Pasteur of Cameroon in the fight against meningococcal meningitis in North-Cameroon]

The Centre Pasteur of Cameroon, Annex of Garoua, studied since 2007 méningococcus of meningitidis in the North of Cameroon. The serogroup A méningococcus completely seem to have disappeared with the profit from the serogroup W135 méningococcus. Current measurements of answers to an epidemic, based between others on reactive vaccination will have to take into account these new data to remain effective. Trivalent vaccine ACW135, placed at the disposal by WHO, should logically be able to be used in the event of epidemic, under reserve of an identification of the germ by a laboratory. The diffusion of the results of the circulation of serogroup W135 méningococcus supported vaccination by the tetravalent vaccine, but this one remains very expensive and, so held for a negligible minority of the population of North-Cameroon. It is part from now on of the recommendations to the travellers.

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.

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.

[European Center for Humanitarian Health (CESH). Providing operational know-how directly applicable in crisis situations]

Founded in 1997 at the initiative of Charles Mérieux, the European Center for Humanitarian Health Care (French acronym, CESH) is a Public Interest Organization comprising 7 members, i.e., Lyon 1 Claude Bernard University, Aix-Marseille II University of the Mediterranean, the Public Hospital System of Lyon, the Public Hospital System of Marseille, the French Army Health Corps, the Mérieux Foundation, and the National School of Veterinary Medicine in Lyon. The CESH is a multifunctional resource dedicated to providing education, information, and research in the field of humanitarian action. The objectives of the CESH's Educational Program are to increase awareness of the complexity of humanitarian action and teach the principles and methods necessary to integrate experienced teams already in the field. Courses including a three-week study program sanctioned by an Interuniversity Degree in Public Health and several 2-to-3-day training modules are open to all humanitarian actors including field workers and decision-makers, health-care professionals, and governmental or other administrative agents. Thanks to a diverse faculty with academic, humanitarian, training, civilian and military backgrounds and to a wide-ranging curriculum, the CESH helps to promote communication and to open up closed pathways of cooperation between the different groups involved in humanitarian action. The module entitled "Humanitarian Assistance and Civilian and Military Cooperation" exemplifies the effort of the CESH to generate collaborative behavior among civilian and military actors. The CESH's Research Program is aimed at providing practical tools for decision-making in the field. The web site of the CESH [http://cesh.univ-lyon1.fr] presents the mission and activities of the Center as well as information on course enrolment and humanitarian action.

[Conclusion: challenges and stakes in humanitarian action in the XXIth century]

The authors in the special issue devoted to humanitarian action use their own experience, analysis, and thought as a basis for identifying the challenges and stakes facing humanitarian action in the twenty-first century. They present their thoughts on the relevance of humanitarian intervention, on the need to combine emergency aid with development assistance, and on the development of governmental humanitarian action. In today's world there is a compelling obligation for communities with resources and means to undertake humanitarian action in the name of human dignity. Adopting a code of conduct, respecting minimal standards, and evaluating the outcome are now universally accepted principles, but the modalities of applying these principles are still subject to discussion especially with regard to standards and accreditation. The importance of adequate training and preparation for humanitarian action has also been established. Currently most humanitarian operations involve numerous actors from different organizations that may be national or international as well as governmental, intergovernmental, or non-governmental. A major portion of this issue is devoted to the relationship between military forces and humanitarian organizations. The need to coordinate action in the field is emphasized. Humanitarian actions are increasingly complex operations carried out in fast-changing situations by numerous players. As a result it has become more and more important that actors in the field know each other in order to work together efficiently and thus better reach their common goal of relieving and preventing human suffering in accordance with ethical principles.

Tolerability of doxycycline monohydrate salt vs. chloroquine-proguanil in malaria chemoprophylaxis

The resistance of Plasmodium falciparum to the chloroquine-proguanil association (C/P) as antimalarial chemoprophylaxis is becoming increasingly common in Africa. Daily oral doxycycline hyclate 100 mg is effective as malaria prophylaxis. But the hyclate salt's adverse effects combined with the capsule's galenic form are incompatible with good chemoprophylaxis compliance. We conducted a randomized group study of 522 French soldiers deployed in Gabon and Chad for 4 months to determine the tolerability of short-term malaria chemoprophylaxis with a 100-mg daily tablet of a monohydrate doxycycline salt compared with a daily C/P capsule. At days 7 and 120, compliance was better in the doxycycline group [respectively 98.5%vs. 73.9% (P < 0.001) and 90.5%vs. 74% (P < 0.001)]. No major event (evacuation, hospitalization) was related to the medications. Epigastralgia, diarrhoea, urticaria, mouth ulcers, sun sensitization and desquamation were significantly more frequent in the C/P group (P < 0.05). There was no statistical difference for malaria incidence, vertigo, nausea and hair loss. These results suggest that doxycycline monohydrate may be safely used in short-term malaria chemoprophylaxis. With the same efficacy as a hyclate doxycycline, doxycycline monohydrate could be a good chemoprophylaxis for short-term travellers at particular risk of C/P resistant P. falciparum malaria.

[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.

Malaria prophylaxis in the French armed forces: evolution of concepts

Malaria is still a serious public health problem in the world and control remains a major priority for the approximately 25.000 French troops deployed, mostly on permanent assignment, in malaria transmission regions. Epidemiological surveillance of malaria provides data necessary to assess morbidity, monitor changing patterns of Plasmodium falciparum drug-sensitivity, and evaluate the efficacy of malaria control measures. About 540 cases were observed in 1999 for an incidence of 4.1 p. 100 men. year. Since 1991, strong emphasis has been placed on prophylaxis. In addition to vector control measures and individual protection against mosquito bites (impregnated bednets, protective clothing, application of repellents, and indoor insecticide spraying), drug prophylaxis has been recommended using a combination of 100 mg of chloroquine and 200 mg of proguanil chlorhydrate (CQ + PG) in a single capsule manufactured by the French Health Army Service. Initially this policy led to a significant decrease in malaria cases among French soldiers. However the incidence of malaria rose in 1995 and 1996. This recrudescence was attributed to poor compliance with chemoprophylaxis and to the declining efficacy of the CQ + PG combination. In response to these problems, a new policy was implemented especially in countries where cycloguanil-resistant Plasmodium falciparum incidence rate is increasing. The new chemoprophylactic regimen calls for a personal prescription of mefloquine. Doxycycline monohydrate is used in case of mefloquine contra-indication or intolerance. Combination of CQ + PG delivered in a single capsule remains a suitable chemoprophylactic regimen in Sahel countries as well as Horn of Africa.

[Antimalarial chemoprophylaxis in the French army: development from 1986 to 2001]

In 1999, almost 25,000 French soldiers were deployed in malaria transmission areas. With an incidence of 4.5 p. 100 men.year, malaria infection remains a serious problem requiring priority status for control in military personnel. Epidemiological surveillance provides data necessary to assess morbidity due to malaria, monitor changing patterns of Plasmodium falciparum drug-sensitivity, and evaluate the efficacy of malaria control measures. In 1990, the French army replaced chemoprophylaxis using chloroquine alone with combination treatment using a single capsule containing 100 mg of chloroquine base and 200 mg of proguanil chlorhydrate. This measure in association with the use deltamethrine impregnated bed-nets led to a significant decrease in incidence. However a comeback was observed from 1993 to 1997. Since 1995, the effectiveness of the chloroquine-proguanil combination has diminished mainly in the stable malaria areas. In response to increasing Plasmodium falciparum resistance to chloroquine-proguanil chemoprophylaxis, it was necessary to find an alternative. Two studies carried out among French soldiers in Sub-Saharian Africa between 1996 and 1998 demonstrated that a daily dose 100 mg doxycycline was more effective than the chloroquine-proguanil combination. In addition the 1998 study showed that doxycycline monohydrate in the form of a multiparticle tablet was better tolerated. In 2001 four drugs are used for malaria chemoprophylaxis in the army personnel, i.e., chloroquine and proguanil in combination, mefloquine, and doxycycline, depending on location and duration of mission. The chloroquine-proguanil combination is used in countries with chloroquine-resistant strains, e.g., Chad and Senegal. Mefloquine and doxycycline are used in countries with chloroquine-resistant strains. Due to increasing resistance, it will be necessary to evaluate other drugs or antipaludian combinations.

[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.

[Malaria and travelers: protection and information]

With the increasing drug resistance of Plasmodium falciparum especially to agents used for chemoprophylaxis, every precaution must be taken to protect travelers from contracting malaria. Prevention of mosquito bites is a fundamental goal that can be achieved by a variety of means including pyrethrinoid-impregnated bed nets, insecticide strips, liquid vaporizers, repellents, insecticide-impregnated garments, and air-conditioning. There are no contraindications for vector control. Chemoprophylaxis depends of individual criteria as determined by clinical and laboratory examinations and on travel conditions (destination, season, duration of stay, and local living conditions). Stand-by medication should be prescribed for self-treatment of fever in areas where medical care is not readily available. Chemoprophylaxis must be continued after the traveler returns and medical attention should be sought if symptoms occur. To ensure proper compliance with preventive measures, pre-travel counseling is a mandatory and integral part of prevention. Information provided to travelers must be clear, reliable, and up-to-date.

[Malaria epidemic during a military-humanitarian mission in Africa]

A malaria epidemic broke out among French servicemen during a humanitarian military mission carried out in Central Africa in 1996. The purpose of this study was to determine compliance with drug prophylaxis for malaria by measuring blood levels of antimalarial drugs (combination treatment using chloroquine-proguanil or treatment with doxycycline) as well as to assess the conditions of vector control. The incidence density rate of malaria over a 60-day period was 3.1 cases per month per 100 men. Only reinforcement troops were affected. The risk of developing malaria was 5 times higher among new arrivals than in servicemen who had been in the zone for several months (95% CI relative risk = [2.9-7.8]). Type of prophylactic treatment had no effect on the incidence density rate. Study data showed that 40.2% of those treated for malaria were not in compliance with prophylactic treatment at the time of the malarial attack and that those who were in compliance with prophylaxis, i.e. the remaining 59.8%, presented a strain of plasmodium that was resistant to the prophylactic drugs at doses used. Findings also indicated the epidemic occurred mainly because operating conditions prevented implementation of proper vectorial control. The risk of epidemic could probably have been reduced by improving compliance with prophylactic treatment and changing standard vectorial control techniques, e.g. by using insecticide-treated uniforms.

[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.

[Current status of dengue virus infections. Epidemiologic and pathogenetic aspects]

The epidemiology of dengue fever is changing dramatically. The worldwide incidence is rising and clinical symptoms are worsening. Reports describing forms associated with hemorrhage or shock syndrome involving both children and adults are increasingly frequent in regions beyond Southeast Asia where the first cases were observed. Many mechanisms could be implicated in these changes including modifications of the virus, host, vector, or socioeconomic factors. Since no current model allows laboratory analysis of these mechanisms, observation of epidemics is still a major source of data. The findings of well conducted epidemiological studies allow not only assessment of morbidity and mortality in endemic areas and early detection of epidemic outbreaks but also evaluation of socioeconomic impact and effectiveness of control measures. Surveillance techniques must be chosen in function of prevailing local conditions. To ensure reliable results studies should be carried out in collaboration with an international network and a simple and accurate method of disease identification should be used.

Jail fever (epidemic typhus) outbreak in Burundi

We recently investigated a suspected outbreak of epidemic typhus in a jail in Burundi. We tested sera of nine patients by microimmunofluorescence for antibodies to Rickettsia prowazekii and Rickettsia typhi. We also amplified and sequenced from lice gene portions specific for two R. prowazekii proteins: the gene encoding for citrate synthase and the gene encoding for the rickettsial outer membrane protein. All patients exhibited antibodies specific for R. prowazekii. Specific gene sequences were amplified in two lice from one patient. The patients had typical clinical manifestations, and two died. Molecular techniques provided a convenient and reliable means of examining lice and confirming this outbreak. The jail-associated outbreak predates an extensive ongoing outbreak of louse-borne typhus in central eastern Africa after civil war and in refugee camps in Rwanda, Burundi (1), and Zaire.

[Malaria and febrile pathology of expatriates in Brazzaville in 1993]

Between January 1 and December 31, 1993, malaria was found in 22.6% of unexplained fever cases among expatriates in Brazzaville, i.e. 0.5% of all consulting physicians at the Medico-Social Centre of the Coopération française. There are three possible explanations for the small proportion of paludism infection among expatriates: the low density of anopheles in the city centre, living conditions that restrict possible man-vector contacts and use of chemoprophylaxis. Considering the risks of self-treatment which are not insignificant, the authors on the importance of taking into account these facts when treating cases of fever among European residents in Brazzaville.

[Drug sensitivity of Plasmodium falciparum in vivo and in vitro in Brazzaville (Congo)]

Various projects were launched in 1993 to monitor the chemosensitivity of Plasmodium falciparum in Congo. Resistance of 34 strains in Brazzaville to chloroquine, quinine and mefloquine and of 35 to halofantrine was investigated in an in vitro survey using an isotopic micro test. The resistance rates were 61.8, 14.7, 3.0 and 0.0% respectively. Thus, the chemoresistance which first appeared in 1990 is confirmed and is stable in the population. This finding was further confirmed by a parallel in vitro analysis of sensitivity to chloroquine in Brazzaville. A chloroquine monitoring network is now being established throughout the country based on simplified WHO tests of 100 asymptomatic schoolchildren conducted every six months. The first results in 1993, from three Southern regions indicate that parasites are found in 20 to 60% of cases seven days after a standard 3 day treatment with 25 mg/kg, according to the region. The results of in vitro and in vivo tests are very variable. Indeed, the value of such results for these tests for national monitoring is questionable: a more reliable system of identifying true therapeutic failures would be better suited.

[Epidemiological and control aspects of meningococcal meningitis epidemics in Africa]

Meningococcal meningitis epidemics are a major health problem in sub-saharan Africa where they account for thousands of deaths and cause morbidity in hundreds of thousands of people. Meningitis is caused by Neisseria meningitidis. In Africa, epidemic meningitis is primarily due to strains of serogroup A which are responsible for the largest and most recent epidemics. N. meningitidis serotype 4, serosubtype P1.9, clonal complex III-1 was introduced into Africa in 1987. Since then, epidemics spread through the Lapeyssonnie's meningitis belt to the south. Classically, the 6 months-30 years old age group is the group at highest risk of disease. Nevertheless, in recent epidemics caused by clonal complex III-1, high age-specific attack rate occurred in those aged 30 years and over. The objectives of epidemic control are the reduction of mortality and morbidity. Early detection of an emerging epidemic is based on the observation of an incidence rate above a cutoff value. Recently, the WHO has proposed a cutoff of 15 cases/100,000/week averaged over two weeks. Epidemic investigation must be as rapid as possible after detection. The different steps are: confirmation of the epidemic and the meningococcal aetiology, standard case definition and determination of the high risk population. During epidemics, in developing countries, simplified treatment protocols are justified and a single dose of long-acting chloramphenicol is a useful first-line treatment. The strategy most frequently used for the control of epidemics is mass vaccination after the start of the epidemic. This must be done as quickly as possible.(ABSTRACT TRUNCATED AT 250 WORDS)

Malaria and travelers--practical aspects

As international air travel becomes more and more common, we are witnessing an increase in the incidence of imported malaria caused by Plasmodium falciparum, a fatal variety resistant to antimalarial drugs. With the development of drug resistance, travelers can no longer rely on chemoprophylaxis alone for absolute protection against malaria; they need to take a number of complementary measures. The most important among these are steps to prevent mosquito bites (mosquito screens and nets impregnated with insecticide, insecticides and repellents in various formulations; nocturnal air-conditioning) which can be instituted anywhere. Chemoprophylaxis must be adapted in each case with regard to individual characteristics (laboratory and medical status), the drug used (contraindications, side effects) and the travel itinerary (departure date, places to be visited, duration of journey). The back-up treatment prescribed for a traveler before his departure is intended as cover in the event that the chemoprophylaxis used should prove to be ineffective. If people planning trips to malarious regions are to apply preventive measures, they have to be informed, aware and motivated. Information is an integral part of prevention. Objective, scientifically accurate information is provided by specialized centres and official bodies in the form of recommendations subject to regular updating. A recommendation of a nonmedical nature must be given by travel agents and tour operators, by airlines and shipping companies, embassies and consulates, and also by the media at peak periods of travel to the tropics. Information disseminated on this scale will produce the required degree of awareness, and the travelers targeted will then probably consult a doctor for the chemoprophylaxis they need.

[Effect of 2 vaccination strategies on developments during the epidemic of meningococcal A meningitis in N'Djamena (Chad) in 1988]

From February till May 1988, during an epidemic of group-A meningococcal disease, 4542 cases of meningitis were reported in N'Djamena, the capital of Chad (550,000 inhabitants). A first selective vaccination campaign was carried out between 5 and 14 March; 156,500 vaccine doses (polyvalent: group A and C: Institut Mérieux) were given using jet injectors. The target population for this first campaign consisted of groups such as school-children and the armed forces. As the epidemic continued, a mass vaccination campaign was implemented one month later between 8 and 14 April 1988; this was targeted at the whole population above 1 year of age, not previously immunized, and 266,738 doses of vaccine were injected. One week after the start of the second campaign, the number of reported cases fell sharply and, within four weeks, the epidemic was halted. The vaccination coverage rate, evaluated by a WHO cluster survey method in people above one year of age, was 95.5%. These results show (i) the failure of selective vaccination, restricted to only at-risk groups, to halt the epidemic; (ii) the efficacy of the mass vaccination campaign aimed at the whole population; and (iii) the feasibility in tropical Africa of such a mass campaign which must be carried out in a few days.

[Efficacy of radical treatment with halofantrine on the prevention of imported Plasmodium falciparum malaria]

We carried out in 1989 a non randomized comparative study in French army units which had been in Central Africa (Central African Republic and Gabon) for 4 months, in order to compare in 758 men on return from malaria areas the usual strategy of chemoprophylaxis with chloroquine and a radical cure by halofantrine (Halfan). Chloroquine was taken by 278 men (100 mg daily for 6 weeks after their return to France); the other 480 men were given two doses of 1,500 mg halofantrine on the third and on the tenth day after their return to France. In Africa both of the units were on chloroquine prophylaxis (100 mg daily for 4 months). The Plasmodium falciparum attack rates were, during a period of 5 months after the return to France, 0.2% in the halofantrine group (1/480) and 4.7% (13/228) in the chloroquine group (P < 10(-4)). The radical cure by halofantrine was more effective than chloroquine prophylaxis in preventing falciparum malaria on return from malaria areas.

[Comparative study of 3 bacteriological tests of cerebrospinal meningitis during the epidemiological period]

During an outbreak of group A meningococcal meningitis in Chad in 1988, a comparative study of three bacteriological techniques (direct microscopic examination, latex agglutination, and culture) was conducted with 120 samples of cerebrospinal fluid (CSF) for diagnosis. The results correlated well with cloudy or purulent CSF specimens. Direct microscopic examination was as good a diagnostic indicator as the other tests. The authors recommend using direct microscopic examination, which is easy to perform under field conditions and accurate enough for a rapid diagnosis of cerebrospinal meningitis during an epidemic. However, complete identification of the first cases in the epidemic is important in order to establish control measures as soon as possible.

Population genetics of abnormal haemoglobins in Burkina Faso, west Africa

The gene frequencies of haemoglobin A (HbA), HbS and HbC were studied in Burkina-Faso (BF) and in a neighbouring region of Niger, Ayorou. The frequency of HbS was higher in the Sahel region, (northern part of BF and Ayorou) than in the Savanna region. The reverse was true for the HbC gene. The major findings of this study are: (a) confirmation of a peak of HbC gene frequency in the central region of BF (Mossi plateau); (b) a possible negative correlation between the frequencies of HbS and HbC-Cavalli-Sforza and Bodmer have observed that this correlation is at a significantly different level from that expected because of the allelic relationship between HbS and HbC; (c) comparison with the data collected by Livingstone shows a modification in the fitness of the different genotypes in the last thirty years: AS individuals have a lower and AA and SS a higher fitness. Our data favour a partial selection relaxation in this region.

Blood glucose area under the curve. Methodological aspects

To specify the influence of methods used in estimating area under the curve (AUC) and the meaning of total and incremental AUC, 75 glycemic responses to a mixed meal were studied in 75 diabetic patients, 39 with insulin-dependent diabetes mellitus and 36 with non-insulin-dependent diabetes mellitus. AUC was integrated with five computerized methods: polynomial interpolation of third and fourth degree, trapezoidal rule, Simpson's integration, and cubic interpolatory splines. Although these methods gave significantly different results (P less than 0.001), a strong correlation was found between estimations of AUC with different methods (r greater than 0.99, P less than 0.001). In addition, variation between methods was less than or equal to 2%, whereas the coefficient of variation between subjects was 38%. Total AUC was strongly correlated with basal blood glucose value (r = 0.90, P less than 0.001), whereas incremental and positive AUC were not (r = 0.12 and 0.07, respectively, NS). Incremental and positive AUC were strongly correlated with glycemic rise (r = 0.89 and 0.93, respectively, P less than 0.001), whereas total AUC was only slightly so (r = 0.31, P less than 0.01). Incremental and positive AUC gave slightly but significantly different information on glucose response. These results suggest that variations related to the method used in estimating AUC are not clinically relevant and that a simple method such as trapezoidal rule can be used. Total AUC is a descriptive factor related to basal blood glucose value, whereas incremental and positive AUC more accurately describe glycemic response to foods.

[Chemosensibility of Plasmodium falciparum in Africa south of the Sahara: evaluation of two and a half years' research at the Tropical Medicine Institute of the Health Service of the French Armed Forces]

From March 1987 to June 1989, 194 isolates of Plasmodium falciparum were studied in vitro by the isotopic semi-microtest. 86.1% were resistant to chloroquine; 9.5% had a decrease of sensibility to quinine and 3.3% a decrease of sensibility to mefloquine. There was a positive correlation between I.C. 50 of the antimalarial drugs compared by pairs.

[The Quantitative Buffy Coat test (Q.B.C. test). Monofluo Kit Falciparum. Comparative value in the rapid diagnosis of malaria]

New emerging atypical forms of malaria, characterized by weak parasitemia, among peoples without premunition, back from Plasmodium falciparum resistant areas, make it necessary to use rapid, sensitive, reliable methods of parasitologic diagnosis. This work concerned two different populations: 394 expatriates back from a 4 months stage in endemic areas. 12 patients admitted for suspected of proved malaria. Authors have studied, by double blind method, versus thin film, two fluorescent techniques: a direct immunofluorescence, the Monofluo kit Falciparum of Diagnostic Pasteur. A nucleic acid fluorescence, on blood samples centrifuged in capillary tubes, the Q.B.C. test of Becton-Dickinson. Both methods seem of great interest for epidemiological surveys. The Q.B.C. test has showed more sensitivity than the thin film: it's rapidity of realisation indicates it for urgent diagnosis.

[Epidemiological value of graphic representation of the Tukey test]

The method of Tukey shows a graphic view of a distribution of data around its median. This graphic representation is simple, easy, pertinent and computer-compatible. It optimizes the description of distribution of data (normal or free distribution). Usable with small size samples, the Tukey test is not very powerful, but robust, and authorizes a comparison of two or more medians with a risk of 5%.

[Current quantitative approach to the splenic index in malaria: the median hypertrophied spleen]

The mean Hackett score is a commonly used index in malaria surveys. It is, however not suitable for comparing the distribution of hypertrophied spleens among small population samples, owing to the validity conditions of statistical tests. The authors suggest to use another index, the median Hackett score, which can be compared to the Tukey test. This test gives a graphical representation of hypertrophied spleen distribution, allowing for rapid and easy comparison. The lack of power of this test is compensated by its robustness (a consequence of its broad limits of validity), its graphical simplicity and its easy interpretation.

[Malaria morbidity in rural and urban areas in Senegal]

During September and November 1987, the authors surveyed the incidence of malaria fever in populations of a rural zone in Casamance and in adults as outpatients in an urban area. In these regions, the malaria is endemic with a recrudescence during the rainy season from July to October. In rural zone, 169 persons were examined. The malaria fevers represented 7.1% of the consultations and 23.3% of fevers. Differences were significantly observed between the parasitic densities of febrile and afebrile patients.

[Diagnostic difficulties and current clinical aspects of Plasmodium falciparum malaria upon returning from a chemoresistance area]

The incidence and clinical aspects of malaria in patients returning from chemoresistance areas were evaluated by means of two studies. The first one was a prospective study of 145 subjects back from a 4 months' stay in Gabon and who had complied with an appropriate chemoprophylaxis regimen. Twelve of these subjects were found to have particulate P. falciparum antigens on the 3rd day following their return. Spontaneous negativation of parasitaemia was observed in 10 cases, whereas 2 subjects were about to develop a malarial attack. Forty-five days after the return home, 5 new cases of malarial attack and 3 cases of anaemia had occurred, although none of these 8 patients had haematozoa on the 3rd day. In the second study 31 patients admitted to hospital in 1987 were reviewed. The following clinical syndromes were detected: malarial attacks with high parasitaemia in 6 cases, malarial attacks with low or undetectable parasitaemia in 5 cases, anaemia, thrombocytopenia or pancytopenia in 5 cases, and febrile alteration of the general condition in 3 cases. Two aspects of malaria were identified: "malaria infection" with a latent and asymptomatic parasitic infestation likely to disappear spontaneously or to turn into "malaria disease". The latter has protean manifestations, but bouts of fever with low parasitaemia and blood disorders are predominant.

[Reliability of clinical studies in the diagnosis of malaria fever in West African endemic areas]

We have studied 930 febrile cases in a savanna area of Burkina Faso. We have diagnosed malarial fevers according to the only clinical data in 333 cases and it was confirmed in 154 cases by parasitological study; for 597 cases a non malaria reason was given according to the only clinical data and it was confirmed in 507 cases by biological studies. On the whole the error rate was of 28% on the clinical examination alone and this proportion was equal or superior whatever the parasitological threshold was. The clinical examination is not allow by it self to diagnose a malaria fever case.