Évaluation de la performance du test de diagnostic rapide du paludisme OnSite à Miandrivazo,Madagascar

The performance of the malaria rapid diagnostic test OnSite—for detecting pan specific pLDH and Plasmodium falciparum specific HRP2 — was assessed during the malaria transmission peak period in Miandrivazo, in the southwestern part of Madagascar from April 20 to May 6, 2010. At the laboratory, the quality control OnSite Malaria Rapid Test according to the WHO/TDR/FIND method demonstrated that the test had good sensitivity. Of the 218 OnSite tests performed at the Miandrivazo Primary Health Center on patients with fever or a recent history of fever, four (1.8%, 95% CI: 0.6–4.9%) were invalid. Ninety four (43,1%) cases of malaria were confirmed by microscopy, of which 90 were P. falciparum malaria and 4 Plasmodium vivax malaria. With a Cohen’s kappa coefficient of 0.94, the agreement between microscopy and OnSite is excellent. Compared with the rapid test CareStart? commonly used within the public health structures in Madagascar, the sensitivity and specificity of the OnSite test were 97.9% and 96.8%.     

Évaluation d’un test de diagnostic rapide et d’un microscope à fluorescence portable pour le diagnostic du paludisme à Cotonou (Bénin)

The aim of the study was to determine the accuracy of a rapid diagnostic test (SD Bioline Malaria Ag P.f/ Pan®) and fluorescent microscopy (CyScope®) in confirming presumptive malaria diagnosis in Cotonou. Thick blood smear was used as the reference technique for comparison. Testing was conducted on persons between the ages of 6 months and 70 years at two hospitals from June to October 2010. If malaria was suspected in the sample by the nurse based on clinical findings and sent to laboratory for confirmation, one thick smear, one rapid diagnostic test and one slide for the fluorescent microscopy were performed. All tests were read in hospital laboratories involved with the quality control of thick blood smear in the parasitology laboratory of National University Hospital of Cotonou. A total of 354 patients with clinical diagnosis of malaria were included. Malaria prevalence determined by thick smear, rapid diagnostic test and fluorescent microscopy was 22.8%, 25.4%, and 25.1% respectively. The sensitivity, specificity, positive and negative predictive values compared to the thick smears were 96.3, 95.6, 86.7, and 98.9% for rapid diagnostic test; and 97.5, 96.7, 89.8, and 99.27% for fluorescent microscopy. With these performances, these tests meet acceptability standards recommended by WHO for rapid tests (sensitivity > 95%). These two methods have advantages for the confirmation of malaria diagnosis in peripheral health structures that lack the resources to conduct diagnosis confirmation by the thick blood smear.     

Prévalence de Plasmodium falciparum, de l’anémie et des marqueurs moléculaires de la résistance à la chloroquine et à la sulfadoxine-pyrim éthamine chez les femmes accouchées à Fana, Mali

The aim of this study was to describe the malaria morbidity and the frequencies of molecular markers of resistance to chloroquine and sulfadoxine-pyrimethamine in pregnant women at delivery in Mali. Two hundred pregnant women have been included at the delivery clinic in Fana. The age group of 14–19 years was predominant. Fifty two per cent (52.3%: 104/200) were malaria slides positive in their peripheral blood and 15% (30/200) of the women carried parasite in their placenta. The prevalence rate of anemia was 44.5% (89/200). PCR technique was successfully performed on 16 paired samples. The frequency of the Pfcrt K76T mutants in Plasmodium falciparum infections in peripheral blood was 68.8% (11/16) and 100 % (16/16) in the placenta (p = 0.004). The frequency in peripheral blood of the DHFR N51I mutation was 12.5% (2/16) and 18.8% (3/16) in the placenta (p=0.12). The frequencies of the DHPS A437G mutants were similar in both sites 25% (4/16). No DHPS K540E and DHFR 164L mutations were found in the Fana pregnancy women samples.     

Le paludisme à <Emphasis Type="Italic">Plasmodium ovale wallikeri</Emphasis> et <Emphasis Type="Italic">Plasmodium ovale curtisi</Emphasis> au Sénégal en 2016

Recently in Senegal, a case of Plasmodium ovale malaria had led to a diagnostic difficulty due to the ignorance of this parasite and the neglect of it. The objective of this study was to actively investigate cases of P. ovale malaria that would be misdiagnosed in the health centre structures of Senegal. The study was conducted in three areas that reflect different epidemiological strata of malaria. Microscopy was performed by microscopy experts on suspected malaria patients. The results were validated by Rougemont real-time PCR. Positive P. ovale cases were genotyped by nested PCR targeting the potra gene. A total of 406 samples were taken. Microscopy of Giemsa stained thick and thin smears recorded 228 cases of Plasmodium falciparum (97%), 3 cases of Plasmodium malariae (1.3%), and 4 cases of P. ovale (1.7%). The cases of P. ovale observed at microscopy were confirmed by real-time PCR. Genotyping of P. ovale revealed 3 cases of P. ovale wallikeri and 1 case of P. ovale curtisi. The prevalence of P. ovale malaria remains low in Senegal. However, malaria microscopists should be trained to recognize non-falciparum species in order to avoid the diagnostic delays and unnecessary investigations. National malaria control program should consider those species for the better management of malaria control in the country. Simplified molecular methods like, loop-mediated isothermal amplification (LAMP) may be useful to better characterize the epidemiology of non-falciparum malaria.     

Evaluation du test de diagnostic rapide du paludisme OptiMal-IT® pLDH à la limite de la distribution de <Emphasis Type="Italic">Plasmodium falciparum</Emphasis> en Mauritanie

Performance of the malaria Rapid Diagnostic Test (RDT) OptiMal-IT® was evaluated in Mauritania where malaria is low and dependent on a short transmission season. Slide microscopy was considered as the reference method of diagnosis. Febrile patients with suspected malaria were recruited from six health facilities, 3 urban and 3 rural, during two periods (December 2011 to February 2012, and August 2012 to March 2013). Overall, 780 patients were sampled, with RDT and thick blood film microscopy results being obtained for 759 of them. Out of 774 slides examined, of which 200 were positive, P. falciparum and P. vivax mono-infections were detected in 63.5% (127) and 29.5% (59), while P. falciparum/P. vivax coinfections were detected in 7% (14). Both species were observed in all study sites, although in significantly different proportions. The proportions of thick blood film and OptiMal-IT® RDT positive individuals was 26.3% and 30.3% respectively. Sensitivity and specificity of OptiMal-IT® RDT were 89% [95% CI, 84.7-93.3] and 91.1% [88.6-93.4]. Positives and negative predictive values were 78.1% [72.2-83.7] and 95.9% [94.1-97.5]. These diagnostic values are similar to those generally reported elsewhere, and support the use of RDTs as the main diagnostic tool for malaria in Mauritanian health facilities. In the future, choice of RDTs to be used must take account of thermostability in a hot, dry environment and their ability to detect P. falciparum and P. vivax.     

Difficultés diagnostiques d’un exanthème fébrile d’étiologies différentes chez une même patiente tuberculeuse à Madagascar

This article illustrates the difficulties in the treatment of tuberculosis through the case of a patient with tuberculosis presenting with a haemophagocytic syndrome, severe drug hypersensitivity and a dissemination of the disease. A month after tuberculosis chemotherapy was started, Mrs. R.S, aged 45 years, presented with febrile exanthema, confusion, multiple lymph nodes enlargement/polyadenopathy, bi-cytopenia and a severe hepatic cytolysis. The haemophagocytic syndrome was confirmed by a myelogram and had shown a good response to the administration of methylprednisolone. Tuberculosis chemotherapy was stopped for a month and when resumed, there was a recurrence of the febrile exanthema without haematologic abnormalities but a moderate hepatic cytolysis. The association of haemophagocytic syndrome with tuberculosis is a rare occurrence. It was important to differentiate drug hypersensitivity and recurrence of haemophagocytic syndrome, as the sole treatment interruption was sufficient to heal the patient during the second febrile rash. Corticotherapy, discontinuation of tuberculostatic treatment and a very progressive reintroduction of antituberculosis drugs was successful though it caused the dissemination of the tuberculosis disease.