Effectiveness and safety of artemether-lumefantrine versus artesunate-amodiaquine for unsupervised treatment of uncomplicated falciparum malaria in patients of all age groups in Nanoro, Burkina Faso: a randomized open label trial

Background

Several studies have reported high efficacy and safety of artemisinin-based combination therapy (ACT) mostly under strict supervision of drug intake and limited to children less than 5 years of age. Patients over 5 years of age are usually not involved in such studies. Thus, the findings do not fully reflect the reality in the field. This study aimed to assess the effectiveness and safety of ACT in routine treatment of uncomplicated malaria among patients of all age groups in Nanoro, Burkina Faso.

Methods

A randomized open label trial comparing artesunate–amodiaquine (ASAQ) and artemether–lumefantrine (AL) was carried out from September 2010 to October 2012 at two primary health centres (Nanoro and Nazoanga) of Nanoro health district. A total of 680 patients were randomized to receive either ASAQ or AL without any distinction by age. Drug intake was not supervised as pertains in routine practice in the field. Patients or their parents/guardians were advised on the time and mode of administration for the 3 days treatment unobserved at home. Follow-up visits were performed on days 3, 7, 14, 21, and 28 to evaluate clinical and parasitological resolution of their malaria episode as well as adverse events. PCR genotyping of merozoite surface proteins 1 and 2 (msp-1, msp-2) was used to differentiate recrudescence and new infection.

Results

By day 28, the PCR corrected adequate clinical and parasitological response was 84.1 and 77.8 % respectively for ASAQ and AL. The cure rate was higher in older patients than in children under 5 years old. The risk of re-infection by day 28 was higher in AL treated patients compared with those receiving ASAQ (p < 0.00001). Both AL and ASAQ treatments were well tolerated.

Conclusion

This study shows a lowering of the efficacy when drug intake is not directly supervised. This is worrying as both rates are lower than the critical threshold of 90 % required by the WHO to recommend the use of an anti-malarial drug in a treatment policy.

Trial registration: NCT01232530

Ex vivo anti-malarial drug susceptibility of Plasmodium falciparum isolates from pregnant women in an area of highly seasonal transmission in Burkina Faso

Background

Ex vivo assays are usually carried out on parasite isolates collected from patients with uncomplicated Plasmodium falciparum malaria, from which pregnant women are usually excluded as they are often asymptomatic and with relatively low parasite densities. Nevertheless, P. falciparum parasites infecting pregnant women selectively sequester in the placenta and may have a different drug sensitivity profile compared to those infecting other patients. The drug sensitivity profile of P. falciparum isolates from infected pregnant women recruited in a treatment efficacy trial conducted in Burkina Faso was determined in an ex vivo study.

Methods

The study was conducted between October 2010 and December 2012. Plasmodium falciparum isolates were collected before treatment and at the time of any recurrent infection whose parasite density was at least 100/µl. A histidine-rich protein-2 assay was used to assess their susceptibility to a panel of seven anti-malarial drugs. The concentration of anti-malarial drug inhibiting 50% of the parasite maturation to schizonts (IC₅₀) for each drug was determined with the IC Estimator version 1.2.

Results

The prevalence of resistant isolates was 23.5% for chloroquine, 9.2% for mefloquine, 8.0% for monodesethylamodiaquine, and 4.4% for quinine. Dihydroartemisinin, mefloquine, lumefantrine, and monodesethylamodiaquine had the lowest mean IC₅₀ ranging between 1.1 and 1.5 nM respectively. The geometric mean IC₅₀ of the tested drugs did not differ between chloroquine-sensitive and resistant parasites, with the exception of quinine, for which the IC₅₀ was higher for chloroquine-resistant isolates. The pairwise comparison between the IC₅₀ of the tested drugs showed a positive and significant correlation between dihydroartemisinin and both mefloquine and chloroquine, between chloroquine and lumefantrine and between monodesethylamodiaquine and mefloquine.

Conclusion

These ex vivo results suggest that treatment with the currently available artemisinin-based combinations is efficacious for the treatment of malaria in pregnancy in Burkina Faso.

Trial registration

ClinicalTrials.gov ID: NCT00852423

Electronic supplementary material

The online version of this article (doi:10.1186/s12936-015-0769-1) contains supplementary material, which is available to authorized users.

Dynamic of plasmodium falciparum chloroquine resistance transporter gene Pfcrt K76T mutation five years after withdrawal of chloroquine in Burkina Faso

We investigated the evolution of Pfcrt K76T mutation five years after the withdrawal of chloroquine in Burkina Faso. A total of 675 clinical isolates collected from October 2010 to September 2012 were successfully genotyped. Single nucleotide polymorphism in Pfcrt (codon 76) gene was analyzed. The prevalence of resistant Pfcrt 76T allele was 20.55%. There was a progressive decrease of the proportion of mutant type pfcrt T76 from 2010 to 2012 (X2=5.508 p=0.0189). Our results suggest a progressive return of the wild type Pfcrt K76 in Burkina Faso but the prevalence of the mutants Pfcrt T76 still remains high.

Clinical signs and symptoms cannot reliably predict Plasmodium falciparum malaria infection in pregnant women living in an area of high seasonal transmission

Background

Malaria in pregnancy is a major public health problem in endemic countries. Though the signs and symptoms of malaria among pregnant women have been already described, clinical presentation may vary according to intensity of transmission and local perceptions. Therefore, determining common signs and symptoms among pregnant women with a malaria infection may be extremely useful to identify those in need of further investigation by rapid diagnostic test or microscopy.

Methods

Six hundred pregnant women attending the maternity clinic of Nanoro District Hospital, Burkina Faso were recruited, 200 with suspected clinical malaria and 400 as controls. Cases were matched with controls by gestational age and parity. Signs and symptoms were collected and a blood sample taken for rapid diagnostic test, microscopy and haemoglobin measurement. A multivariate model was used to assess the predictive value of signs and symptoms for malaria infection.

Results

The overall prevalence of malaria was 42.6% (256/600) while anaemia was found in 60.8% (365/600) of the women. Nearly half (49%) of the cases and 39.5% of the controls had a malaria infection (p = 0.03). The most common signs and symptoms among the cases were fever (36%,72/200), history of fever (29%,58/200) and headache (52%,104/200). The positive predictive value for fever was 53% (95% CI:41–64), history of fever 58% (95% CI:37–63) and headache 51% (95% CI:41–61).

Conclusion

Signs and symptoms suggestive of malaria are frequent among pregnant women living in areas of intense transmission. Common malaria symptoms are not strong predictors of infection. For a better management of malaria in pregnancy, active screening to detect and treat malaria infection early should be performed on all pregnant women attending a health facility.

Multiple populations of artemisinin-resistant Plasmodium falciparum in Cambodia

We describe an analysis of genome variation in 825 P. falciparum samples from Asia and Africa that identifies an unusual pattern of parasite population structure at the epicenter of artemisinin resistance in western Cambodia. Within this relatively small geographic area, we have discovered several distinct but apparently sympatric parasite subpopulations with extremely high levels of genetic differentiation. Of particular interest are three subpopulations, all associated with clinical resistance to artemisinin, which have skewed allele frequency spectra and high levels of haplotype homozygosity, indicative of founder effects and recent population expansion. We provide a catalog of SNPs that show high levels of differentiation in the artemisinin-resistant subpopulations, including codon variants in transporter proteins and DNA mismatch repair proteins. These data provide a population-level genetic framework for investigating the biological origins of artemisinin resistance and for defining molecular markers to assist in its elimination.

VarB: a variation browsing and analysis tool for variants derived from next-generation sequencing data

Summary: There is an immediate need for tools to both analyse and visualize in real-time single-nucleotide polymorphisms, insertions and deletions, and other structural variants from new sequence file formats. We have developed VarB software that can be used to visualize variant call format files in real time, as well as identify regions under balancing selection and informative markers to differentiate user-defined groups (e.g. populations). We demonstrate its utility using sequence data from 50 Plasmodium falciparum isolates comprising two different continents and confirm known signals from genomic regions that contain important antigenic and anti-malarial drug-resistance genes.

Availability and implementation: The C++-based software VarB and user manual are available from www.pathogenseq.org/varb.

Contact:taane.clark@lshtm.ac.uk

Analysis of Plasmodium falciparum diversity in natural infections by deep sequencing

Malaria elimination strategies require surveillance of the parasite population for genetic changes that demand a public health response, such as new forms of drug resistance. Here we describe methods for the large-scale analysis of genetic variation in Plasmodium falciparum by deep sequencing of parasite DNA obtained from the blood of patients with malaria, either directly or after short-term culture. Analysis of 86,158 exonic single nucleotide polymorphisms that passed genotyping quality control in 227 samples from Africa, Asia and Oceania provides genome-wide estimates of allele frequency distribution, population structure and linkage disequilibrium. By comparing the genetic diversity of individual infections with that of the local parasite population, we derive a metric of within-host diversity that is related to the level of inbreeding in the population. An open-access web application has been established for the exploration of regional differences in allele frequency and of highly differentiated loci in the P. falciparum genome.

An analysis of timing and frequency of malaria infection during pregnancy in relation to the risk of low birth weight, anaemia and perinatal mortality in Burkina Faso

BACKGROUND

A prospective study aiming at assessing the effect of adding a third dose sulphadoxine-pyrimethamine (SP) to the standard two-dose intermittent preventive treatment for pregnant women was carried out in Hounde, Burkina Faso, between March 2006 and July 2008. Pregnant women were identified as earlier as possible during pregnancy through a network of home visitors, referred to the health facilities for inclusion and followed up until delivery.

METHODS

Study participants were enrolled at antenatal care (ANC) visits and randomized to receive either two or three doses of SP at the appropriate time. Women were visited daily and a blood slide was collected when there was fever (body temperature > 37.5°C) or history of fever. Women were encouraged to attend ANC and deliver in the health centre, where the new-born was examined and weighed. The timing and frequency of malaria infection was analysed in relation to the risk of low birth weight, maternal anaemia and perinatal mortality.

RESULTS

Data on birth weight and haemoglobin were available for 1,034 women. The incidence of malaria infections was significantly lower in women having received three instead of two doses of SP. Occurrence of first malaria infection during the first or second trimester was associated with a higher risk of low birth weight: incidence rate ratios of 3.56 (p < 0.001) and 1.72 (p = 0.034), respectively. After adjusting for possible confounding factors, the risk remained significantly higher for the infection in the first trimester of pregnancy (adjusted incidence rate ratio = 2.07, p = 0.002). The risk of maternal anaemia and perinatal mortality was not associated with the timing of first malaria infection.

CONCLUSION

Malaria infection during first trimester of pregnancy is associated to a higher risk of low birth weight. Women should be encouraged to use long-lasting insecticidal nets before and throughout their pregnancy.

Approche socio-anthropologique de la dynamisation du réseau d'acteurs de prise en charge des malades tuberculeux au Burkina Faso

La tuberculose est une maladie chronique dont la prise en charge nécessite une approche multisectorielle: le social et le biomédical. Une étude socio-anthropologique retraçant les itinéraires thérapeutiques des malades a permis d'identifier les détenteurs d'enjeux dans la gestion de la maladie pour élaborer une « carte des acteurs » et encourager une interaction dynamique entre les membres. L'identification des acteurs clés et leur mise en réseau a permis d'entreprendre des actions contribuant à renforcer l'efficacité et l'efficience de la prise en charge des malades au Burkina Faso, par des actions collectives. Nous identifions ainsi des acteurs sociaux, alliés et confidents des malades; des acteurs biomédicaux, directement concernés par la prise en charge médicale de la maladie. A travers ces liens entre les acteurs, nous remarquons que les systèmes de santé sont caractérisés par des interactions sur fond d'incompréhension qui influence négativement la qualité des soins. La dynamisation du réseau d'acteurs a permis d'éprouver un mode de collaboration axé sur l'analyse collective des problèmes rencontrés par les prestataires de soins et les malades tuberculeux. Celle-ci a permis la mise en œuvre d'actions visant à améliorer la qualité de vie des malades. La dynamique de collaboration entre acteurs concernés par l'accès aux soins de santé a eu raison sur les situations problématiques qui entament les succès thérapeutiques et la qualité de vie des malades tuberculeux. (Global Health Promotion, 2009; 16 (1): pp. 72—80)

Newcastle disease virus in West Africa: new virulent strains identified in non-commercial farms

Forty-four Newcastle disease virus (NDV) strains, obtained between 2002 and 2007 from different poultry species in Nigeria, Niger, Burkina Faso and Cameroon, were phylogenetically analysed based on partial F sequences. Lineage 2 viruses were genetically identical or similar to the locally used LaSota vaccine strain and were mostly detected in commercial farms. Lineage 1, 3 and 4 strains were only sporadically found, and their origin was less clear. Twenty-one strains from backyard farms and live bird markets formed three new clusters within lineage 5, tentatively named 5f, 5g and 5h. All of these strains were predicted to be virulent based on their F protein cleavage site sequence. Minimal genetic distances between new and previously established sublineages ranged from 9.4 to 15.9%, and minimal distances between the new sublineages were 11.5 to 17.3%. Their high genetic diversity and their presence in three different Sub-Saharan countries suggest that these new sublineages represent the NDV variants indigenous to West Africa.

Major reduction of malaria morbidity with combined vitamin A and zinc supplementation in young children in Burkina Faso: a randomized double blind trial

Background

Vitamin A and zinc are crucial for normal immune function, and may play a synergistic role for reducing the risk of infection including malaria caused by Plasmodium falciparum.

Methods

A randomized, double-blind, placebo-controlled trial of a single dose of 200 000 IU of vitamin A with daily zinc supplementation was done in children of Sourkoudougou village, Burkina Faso. Children aged from 6 to 72 months were randomized to receive a single dose of 200 000 IU of vitamin A plus 10 mg elemental zinc, six days a week (n = 74) or placebo (n = 74) for a period of six months. Cross-sectional surveys were conducted at the beginning and the end of the study, and children were evaluated daily for fever. Microscopic examination of blood smear was done in the case of fever (temperature ≥37.5°C) for malaria parasite detection.

Results

At the end of the study we observed a significant decrease in the prevalence malaria in the supplemented group (34%) compared to the placebo group (3.5%) (p < 0.001). Malaria episodes were lower in the supplemented group (p = 0.029), with a 30.2% reduction of malaria cases (p = 0.025). Time to first malaria episode was longer in the supplemented group (p = 0.015). The supplemented group also had 22% fewer fever episodes than the placebo group (p = 0.030).

Conclusion

These results suggest that combined vitamin A plus zinc supplementation reduces the risk of fever and clinical malaria episodes among children, and thus may play a key role in malaria control strategies for children in Africa.

Molecular and antigenic evolution and geographical spread of H5N1 highly pathogenic avian influenza viruses in western Africa

In Africa, highly pathogenic avian influenza H5N1 virus was first detected in northern Nigeria and later also in other regions of the country. Since then, seven other African countries have reported H5N1 infections. This study reports a comparison of full-length genomic sequences of H5N1 isolates from seven chicken farms in Nigeria and chicken and hooded vultures in Burkina Faso with earlier H5N1 outbreaks worldwide. In addition, the antigenicity of Nigerian H5N1 isolates was compared with earlier strains. All African strains clustered within three sublineages denominated A (south-west Nigeria, Niger), B (south-west Nigeria, Egypt, Djibouti) and C (northern Nigeria, Burkina Faso, Sudan, Côte d'Ivoire), with distinct nucleotide and amino acid signatures and distinct geographical distributions within Africa. Probable non-African ancestors within the west Asian/Russian/European lineage distinct from the south-east Asian lineages were identified for each sublineage. All reported human cases in Africa were caused by sublineage B. Substitution rates were calculated on the basis of sequences from 11 strains from a single farm in south-west Nigeria. As H5N1 emerged essentially at the same time in the north and south-west of Nigeria, the substitution rates confirmed that the virus probably did not spread from the north to the south, given the observed sequence diversity, but that it entered the country via three independent introductions. The strains from Burkina Faso seemed to originate from northern Nigeria. At least two of the sublineages also circulated in Europe in 2006 as seen in Germany, further suggesting that the sublineages had already emerged outside of Africa and seemed to have followed the east African/west Asian and Black Sea/Mediterranean flyways of migratory birds.

[An action research network to improve the quality of tuberculosis care in West Africa]

BACKGROUND

Improvement in management systems for tuberculosis (TB) care is urgently needed in West Africa. In 2003, an experimental action research network began there, involving care providers, health system managers, and TB programme managers. Each project in all 6 countries used a "patient-centered" approach to improve tuberculosis case management.

METHODS

The research teams included care providers, district medical officers, anthropologists and TB programme managers. Each research team conducted its project for a one-year period and then assessed its results. The specific problems identified were low TB detection rates (Burkina Faso, Côte d'Ivoire and Niger) and poor compliance among patients receiving treatment, including their ensuing loss to follow-up (Benin, Mali and Senegal). Investigators concluded that these weaknesses were due to the lack of access to care (geographical, financial and cultural), the complexity of the care system and the low quality of care. Solutions for all 6 countries aimed at improving access to high-quality care.

RESULTS

One year after the experiment began, results varied from one country to another. In general, all participants understood the need to collaborate beyond national health systems because the problems from all 6 countries were quite similar. The research process led to better sharing of work between care providers and sometimes between care providers and TB patients. It provided participants with new concepts and a constant opportunity to implement them. These repeated meetings, however, keep care providers away from their offices.

CONCLUSION

The research would have improved case management and care more effectively had the teams taken into account the psychological and sociological need of TB patients. A new regional dynamic has begun and must be pursued to help improve health care systems.

Roles of specific Plasmodium falciparum mutations in resistance to amodiaquine and sulfadoxine-pyrimethamine in Burkina Faso

We evaluated associations between key polymorphisms in target genes and responses to treatment with sulfadoxine-pyrimethamine (SP) or amodiaquine (AQ) for uncomplicated Plasmodium falciparum malaria in Bobo-Dioulasso, Burkina Faso. Presence of the dihydrofolate reductase (dhfr) 108N or 59R mutations (but not dhfr 51I or dihydropteroate synthetase [dhps] 437G) and P. falciparum chloroquine resistance transporter (pfcrt) 76T or P. falciparum multidrug resistance 1 (pfmdr1) 86Y or 1246Y mutations (but not pfmdr1 184F) predicted recrudescence after treatment with SP and AQ, respectively. Treatment led to significant increases in the prevalence of the same mutations (except 1246Y) in new infections that presented after therapy. The dhfr 164L and dhps 540E mutations were not seen in any isolates. These results clarify the key roles of a small number of mutations in P. falciparum resistance to SP and AQ in west Africa.

Decentralising tuberculosis case management in two districts of Burkina Faso

SETTING

In West Africa, national tuberculosis programmes (NTPs) face many problems due to the low performance of health care delivery systems and patients' social and cultural environment.

OBJECTIVE

To improve the case management of TB in Burkina Faso.

DESIGN

Using the operational research process as a tool, TB case management was decentralised from the district hospital to eight primary health care centres in 2003.

RESULTS

Twelve months after decentralisation, the quality of case detection remained satisfactory. The delay between the identification of TB suspects with chronic cough and the confirmation of TB was reduced from 13 to 6 days. The detection rate of TB suspects during the study (30%) was twice as high as for 2001 and 2002 (15%). However, the detection rate for smear-positive TB cases decreased from 32.3% in 2001 and 2002 to 6.5% during the year of the study.

CONCLUSION

Sufficient time and commitment are essential to obtain a case management system that is decentralised and effective. Efforts therefore need to continue to obtain more information and better results.

Amodiaquine, sulfadoxine-pyrimethamine, and combination therapy for uncomplicated falciparum malaria: a randomized controlled trial from Burkina Faso

Increasing resistance to chloroquine necessitates the evaluation of other antimalarial therapies in Africa. We compared the efficacies of amodiaquine (AQ), sulfadoxine-pyrimethamine (SP), and AQ + SP for the treatment of uncomplicated falciparum malaria in a randomized trial of patients 6 months of age or older in Bobo-Dioulasso, Burkina Faso. Of the 944 patients enrolled, 829 (88%; 53% under 5 years of age) were assigned 28-day efficacy outcomes. For all regimens, early treatment failures were uncommon (< 2%). Considering all treatment failures based on WHO criteria, AQ + SP was most efficacious (failures in 4.2%), followed by SP (9.1%) and AQ (17.9%; P < 0.02 for all pairwise comparisons). Considering only clinical failures, relative efficacies were similar (failures in 2.1% with AQ + SP, 6.5% with SP, and 13.2% with AQ; P < 0.02 for all pairwise comparisons). The risk of recrudescence was lower with AQ + SP (2.1%) compared with SP (6.1%, P = 0.02) and AQ (8.1%, P = 0.001). Risks of new infection were lower with AQ + SP (2.1%) and SP (2.4%) compared with AQ (9.1%, P < 0.001 for both comparisons). No serious adverse events were seen. AQ + SP appears to offer a highly effective, inexpensive, and available therapy for the treatment of uncomplicated malaria in Burkina Faso.

First report of a kdr mutation in Anopheles arabiensis from Burkina Faso, West Africa

The leu-phe kdr mutation was detected in a specimen of Anopheles arabiensis during an extensive survey of pyrethroid resistance in An. gambiae s.l. in Burkina Faso. The detection of this mutation in An. arabiensis, which had so far been observed only in An. gambiae s.s., is important at both epidemiologic and fundamental levels. It can be useful to understand the history of this gene throughout the range of An. gambiae complex.

Natural swarming behaviour of the molecular M form of Anopheles gambiae

In Anopheles gambiae, as in most species of mosquitoes, mating is initiated in flight. The males aggregate in aerial swarms and conspecific females individually fly to these swarms where they mate with males. In this study, we investigated the swarming behaviour of A. gambiae and conducted 2 surveys in the rice field area of the Vallée du Kou in Burkina Faso in 1999 and 2002. A high number of anopheline mosquitoes were observed in this area and both molecular M and S forms of A. gambiae were found in sympatry. Swarms formed a few minutes after sunset in different places and no obvious markers were associated with their occurrence. However, swarms occurred close to cow herds generally in open flat areas, 2-3 m above the ground. Overall, 2829 anopheline mosquitoes were collected from 21 swarms composed primarily of males. A few specimens of Culex quinquefasciatus were collected from 3 swarms. Although both molecular M and S forms were found in sympatry in the village, swarms were composed almost exclusively of the molecular M form. This suggests that there are alternative swarming habits for both molecular M and S forms of A. gambiae in nature.

Chloroquine and sulphadoxine-pyrimethamine efficacy for uncomplicated malaria treatment and haematological recovery in children in Bobo-Dioulasso, Burkina Faso during a 3-year period 1998-2000

We determined the parasitological resistance and the clinical failure to chloroquine (CQ) and sulphadoxine-pyrimethamine (SP) by the WHO 14-day in vivo test over three consecutive years in 948 children aged 6-59 months with uncomplicated malaria attending four health centres in the province of Houet, Burkina Faso. Children were alternatively allocated to either CQ or SP. Packed cell volume (PCV) was measured at days 0 and 14. Parasitological resistance (RI, RII and RIII) to CQ was 18% (83 of 455) and to SP <1% (two of 308). Clinical failure with CQ was 12% (53 of 455) with no evidence of increase over time. Only one case of clinical failure was detected among the children treated with SP. The prevalence of anaemia (PCV <25%) was about 40% at day 0 and had decreased substantially by day 14 in both groups. However, in children treated with SP the prevalence of anaemia at day 14 was significantly lower than in those treated with CQ:RR = 3.15 (95% CI: 1.33-7.42, P = 0.008). CQ and SP are still efficacious for the treatment of uncomplicated malaria in children, at least in this area of Burkina Faso. However, the prevalences of CQ resistance reported from other areas of the country are worrying because of its potential spread. Regular surveillance of resistance to commonly used antimalarial drugs should continue.

[In vitro susceptibility of 232 isolates of Plasmodium falciparum to antimalarials in Burkina Faso (West Africa)]

Plasmodium falciparum in vitro susceptibility to chloroquine, quinine, mefloquine and halofantrine was investigated in patients living in Bobo-Dioulasso (Burkina Faso, West Africa). Our study was carried out from July to November 1997 at the Malaria Chemoresistance Reference Centre, Centre MurazIOCCGE. Inclusion criteria were: presence of a single infection by R falciparum with a parasite count > or =4000 infected red cells/mm3. The susceptibility to drugs was measured after an incubation period of 48 hours at 37 degrees C, under 5% CO2. (3H) Hypoxanthine was added to the medium to monitor parasite growth. 134 isolates of P. falciparum were tested against chloroquine; 24.6% (33/134) were resistant. We have also documented 11.2% (15/133) of resistant isolates to halofantrine. All the tested isolates were susceptible to quinine (n=135) and mefloquine (n=136). A significant positive correlation was found between the following IC50 values: chloroquine-quinine, quinine-mefloquine and mefloquine-halofantrine. Our study shows no significant increase of the prevalence of chloroquine-resistant strains of P. falciparum in our study area; as well as the persistence of resistance to halofantrine with regard to previous publications in the subject.

[Preliminary study of cutaneous leishmaniasis in the town of Ouagadougou from 1996 to 1998]

Since 1996, there have been reports of cases of cutaneous leishmaniasis in the town of Ouagadougou. The incidence has been on the rise but precise figures are not known. The object of the present study has been, first, to record cases of cutaneous leishmaniasis having occurred in private and public health centres in Ouagadougou from 1996 to 1998 and, second, to determine the progression of the disease in space and time. We wished also to confirm clinical cases in 1998 by parasitological examination, identify different clinical forms of the disease and map out cases in the town. We carried out a retrospective study from 1996 to 1998 and a prospective study in 1998. All cases recorded in this period in visited health centres were included. A total of 1845 cases of cutaneous leishmaniasis was identified, 50.3% of whom concerned women. The age of patients varied between 1 and 79 years for 356 patients, with a mean age of 26.7 years. Cases increased between 1996 and 1998 (1996 = 61 cases, 1997 = 552 cases, 1998 = 1218 cases). The months of highest incidence were August (13%), September (15%) and October (17%). Peripheral districts (28, 30, 29, 16, 15) in south-eastern areas of the town were the worst touched with 87% of cases. On average, patients seek care after 2 months of progression of the disease. The ulcero-crusted form (68.2%) was the most frequent clinical form observed for 327 patients, but almost half of the cases had more than one site of infection, (43.5%). Over half of the patients presented fewer than 10 lesions with an average of 6. The most common locations were on uncovered parts of the body, notably the superior (53%) and inferior limbs (49%). The parasite could be tested for by smear on 52 patients only in 1998 and 53.8% of cases tested were positive. Leishmania major, which is very prevalent in West Africa was identified in one patient. The vectors and main reservoirs of the parasite were not studied. Case management was generally incomplete; the most commonly prescribed drugs were antibiotics (70% of patients), but self-medication was frequent. Our recommendations after this preliminary study are: undertake multidisciplinary studies on cutaneous leishmaniasis in Ouagadougou in order to understand the local aetiology (vectors responsible for transmission, rodent and domestic animals involved in the epidemiological chain, parasite species); identify all other areas in the country where the disease is highly prevalent provide health care staff with a decisional algorithm and protocol therapy carry out and active control programme for cutaneous leishmaniasis in Burkina Faso.

[Malaria morbidity in adults living in urban Burkina Faso]

Urbanization in countries located in areas of endemic malaria can decrease the level of immunization and make malaria a more serious public health problem in adults. The purpose of this prospective study was to describe the clinical and parasitological features of malaria in adults in the city of Bobo Dioulasso in Burkina Faso. Study was carried out between July and November 1992 at the medical testing laboratory of the Muraz Center in 494 patients including 378 adults and 116 children under the age of 15 years. The parasitic index was 23% in adults as compared to 62% in children. There was not a significant difference in the parasitic index according to whether the place of residence was located in the city center or outlying suburbs. Parasite density ranged from 6 to 145,000 parasites per mm3 in adults as compared to 6 to 426,000 parasites per mm3 in children. Median parasitemia was 696 parasites per mm3 in adults as compared to 8800 per mm3 in children. The threshold of parasitemia for appearance of clinical symptoms was thus lower in adults than in children. Because of the poor positive predictive value of the main clinical features and the high incidence of self-treatment, microscopic examination is indispensable to confirm diagnosis of malaria. The results of this study indicate that urbanization in the city of Bobo Dioulasso has not significantly changed the level of immunization to malaria in adults.