Pre-Pandemic Cross-Reactive Immunity against SARS-CoV-2 among Central and West African Populations.

For more than two years after the emergence of COVID-19 (Coronavirus Disease-2019), significant regional differences in morbidity persist. These differences clearly show lower incidence rates in several regions of the African and Asian continents. The work reported here aimed to test the hypothesis of a pre-pandemic natural immunity acquired by some human populations in central and western Africa, which would, therefore, pose the hypothesis of an original antigenic sin with a virus antigenically close to the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2).

Evaluation of the application of national malaria treatment guidelines in private pharmacies in a rural area in the Democratic Republic of Congo.

In the Democratic Republic of the Congo, the first recourse in case of suspected malaria in the health system is the private pharmacy sector. This study was therefore designed to assess private provider adherence to national case management guidelines in Kimpese, a rural area of Central Kongo province. A descriptive cross-sectional survey of 103 pharmacies took place in March 2016.

Antimalarial Activity of Human Group IIA Secreted Phospholipase A in Relation to Enzymatic Hydrolysis of Oxidized Lipoproteins.

The level of human group IIA secreted phospholipase A (hGIIA sPLA) is increased in the plasma of malaria patients, but its role is unknown. In parasite culture with normal plasma, hGIIA is inactive against , contrasting with hGIIF, hGV, and hGX sPLAs, which readily hydrolyze plasma lipoproteins, release nonesterified fatty acids (NEFAs), and inhibit parasite growth. Here, we revisited the anti- activity of hGIIA under conditions closer to those of malaria physiopathology where lipoproteins are oxidized.

Design and synthesis of simplified speciophylline analogues and β-carbolines as active molecules against Plasmodium falciparum.

A structure-activity relationship study of active molecules against chloroquine-resistant Plasmodium falciparum K1 strain is reported. Structurally simplified analogues of antiplasmodial active alkaloids presented similar levels of activity as their corresponding natural products extracted from Guiera senegalensis and Mitragyna inermis with IC values on chloroquine-resistant P. falciparum K1 strain of up to 10.

Prevalence of Plasmodium falciparum parasites resistant to sulfadoxine/pyrimethamine in the Democratic Republic of the Congo: emergence of highly resistant pfdhfr/pfdhps alleles.

Background: In 2005, the Democratic Republic of the Congo (DRC) switched to artesunate/amodiaquine as the first-line antimalarial in response to increasing sulfadoxine/pyrimethamine resistance and adopted intermittent preventive treatment using sulfadoxine/pyrimethamine in pregnancy.

Objectives: To determine the prevalence of molecular markers of sulfadoxine/pyrimethamine resistance in southwestern DRC 10 years after the new policy was instituted.

Methods: From March 2014 to December 2015, blood samples were collected from symptomatic patients presenting to outpatient centres in urban and rural areas.

Access to artemisinin-based combination therapies and other anti-malarial drugs in Kinshasa.

Objective: Artemisinin-based combination therapies have been available since 2005 in the Democratic Republic of the Congo to treat malaria and to overcome the challenge of anti-malarial drug resistance as well as to improve access to effective treatments. The private sector is the primary distribution source for anti-malarial drugs and thus, has a key position among the supply chain actors for a rational and proper use of anti-malarial drugs. We aimed to assess access to nationally recommended anti-malarial drugs in private sector pharmacies of the capital-city of Kinshasa.

Development of sensitive direct chemiluminescent enzyme immunoassay for the determination of dihydroartemisinin in plasma.

Despite significant progress in prevention and therapy, malaria is still one of the world's leading major diseases due to its high morbidity and mortality. Recommended treatments by the World Health Organization include the use of artemisinin and artemisinin derivative-based combination therapies. To allow efficient patient monitoring during antimalarial therapy without the use of expensive apparatus, we developed a sensitive direct chemiluminescent enzyme immunoassay for the determination of dihydroartemisinin in biological fluids.

In vitro antiplasmodial activity of cepharanthine.

Background: New classes of anti-malarial drugs are needed to control the alarming Plasmodium falciparum resistance toward current anti-malarial therapy. The ethnopharmacological approach allows the discovery of original chemical structures from the vegetable biodiversity. Previous studies led to the selection of a bisbenzylisoquinoline, called cepharanthine and isolated from a Cambodian plant: Stephania rotunda.

Diversity of Anopheles mosquitoes in Binh Phuoc and Dak Nong Provinces of Vietnam and their relation to disease.

Background: Human malaria is still a burden in Dak Nong and Binh Phuoc Provinces in south-central Vietnam that border Cambodia. Several Anopheles species that transmit human malarial Plasmodium may also transmit Wuchereria bancrofti, the nematode that causes Bancroftian lymphatic filariasis. The objective of this study was to investigate the role of Anopheles species in the transmission of these two pathogens in the two highly malaria endemic provinces of Vietnam.

Ethnobotany, phytochemistry and pharmacology of Stephania rotunda Lour.

Ethnopharmacological Relevance: Stephania rotunda Lour. (Menispermaceae) is an important traditional medicinal plant that is grown in Southeast Asia. The stems, leaves, and tubers have been used in the Cambodian, Lao, Indian and Vietnamese folk medicine systems for years to treat a wide range of ailments, including asthma, headache, fever, and diarrhoea.

Quantitative analysis of cepharanthine in plasma based on semiautomatic microextraction by packed sorbent combined with liquid chromatography.

The spread of Plasmodium falciparum resistance toward most of the used drugs requires new antimalarial compounds. Taking advantage of the biodiversity, the ethnopharmacological approach opens the way for the discovery and the characterization of potent original molecules. Previous works led to the selection of a bisbenzylisoquinoline, cepharanthine, extracted from Stephania rotunda, which is mainly present in Cambodia.

In vitro and in vivo combination of cepharanthine with anti-malarial drugs.

Background: Stephania rotunda is used by traditional health practitioners in Southeast Asia to treat a wide range of diseases and particularly symptoms related to malaria. Cepharanthine (CEP) is an alkaloid isolated from this plant with potential innovative antiplasmodial activity. The analysis of interactions between antiplasmodial drugs is necessary to develop new drugs combinations to prevent de novo emergence of resistance.

A twenty-year follow-up of canine leishmaniosis in three military kennels in southeastern France.

Background: Canine leishmaniosis (CanL) is enzootic in southeastern France, and military working dogs (MWD) posted in this area are highly exposed. To assess the efficiency of prevention, we performed a serological and clinical follow-up of 80 MWD in the Var and Corsica regions during the 20-year period from 1993 to 2012. The systematic and specific prevention of CanL using a deltamethrin-impregnated collar (DMC) was implemented in 2002.

In vitro piperaquine susceptibility is not associated with the Plasmodium falciparum chloroquine resistance transporter gene.

Background: Dihydroartemisinin-piperaquine is a new ACT that is administered as single daily dose for three days and has been demonstrated to be tolerated and highly effective for the treatment of uncomplicated Plasmodium falciparum malaria. Piperaquine was used alone to replace chloroquine as the first-line treatment for uncomplicated malaria in China in response to increasing chloroquine resistance in the 1970s. However, the rapid emergence of piperaquine-resistant strains that resulted in the cessation of its use in China in the 1980s, suggests that there is cross-resistance between piperaquine and chloroquine.

Usefulness of a rapid immuno-migration test for the detection of canine monocytic ehrlichiosis in Africa.

A rapid immuno-migration test for the serological detection of canine monocytic ehrlichiosis, Witness® Ehrlichia (WE) (Zoetis, France), was evaluated in 528 serum samples from dogs living in endemic areas of West and East Africa: Senegal (N=208), Ivory Coast (N=7), Sudan (N=27), and Djibouti (N=286). Of these dogs, 200 were French military working dogs (MWD) temporarily residing in Africa. The WE test results were compared with those obtained by indirect immunofluorescence (IFA).

Taxonomic assessment of Anopheles crawfordi and An. dangi of the Hyrcanus Group of subgenus Anopheles in Vietnam.

Anopheles dangi, introduced as a new species of the Hyrcanus Group of subgenus Anopheles in an illustrated dichotomous key for the identification of the Anopheles mosquitoes of Vietnam published in 1987, was distinguished from Anopheles crawfordi based on the presence of a humeral pale spot on the base of the costal vein of the wing. However, this character has been known to occur occasionally in An. crawfordi.

A new, rapid and sensitive bioluminescence assay for drug screening on Leishmania.

We validated a new method, based on luciferine/luciferase bioluminescence, for drug screening on promastigotes of different Leishmania species. Results obtained with this new, rapid, reproducible, and reliable method are in good accordance with results obtained by the conventional MTT assay. This bioluminescence assay has a lower detection limit.

Longitudinal study assessing the return of chloroquine susceptibility of Plasmodium falciparum in isolates from travellers returning from West and Central Africa, 2000-2011.

Background: Chloroquine (CQ) was the main malaria therapy worldwide from the 1940s until the 1990s. Following the emergence of CQ-resistant Plasmodium falciparum, most African countries discontinued the use of CQ, and now promote artemisinin-based combination therapy as the first-line treatment. This change was generally initiated during the last decade in West and Central Africa.

Real-time PCR assay for discrimination of Plasmodium ovale curtisi and Plasmodium ovale wallikeri in the Ivory Coast and in the Comoros Islands.

Background: Plasmodium ovale is one of the five malaria species infecting humans. Recent data have shown that the name of this neglected species masks two distinct genotypes also called curtisi and wallikeri. Some authors show that these species could be sympatric.

Enhanced basophil reactivities during severe malaria and their relationship with the Plasmodium falciparum histamine-releasing factor translationally controlled tumor protein.

Recent studies suggest shared pathogenic pathways during malaria and allergy. Indeed, IgE, histamine, and the parasite-derived Plasmodium falciparum histamine-releasing factor translationally controlled tumor protein (PfTCTP) can be found at high levels in serum from patients experiencing malaria, but their relationship with basophil activation remains unknown. We recruited P.

Differential association of Plasmodium falciparum Na+/H+ exchanger polymorphism and quinine responses in field- and culture-adapted isolates of Plasmodium falciparum.

Plasmodium falciparum isolates with decreased susceptibility to quinine are increasingly being found in malaria patients. Mechanisms involved in this resistance are not yet understood. Several studies claim that alongside mutations in the Pfcrt and Pfmdr1 genes, the Pfnhe-1 Na(+)/H(+) exchanger polymorphism plays a role in decreasing susceptibility.

Proteomic analysis revealed alterations of the metabolism following salicylhydroxamic acid exposure.

Objectives: Although human respiratory metabolism is characterized by the mitochondrial electron transport chain, some organisms present a "branched respiratory chain." This branched pathway includes both a classical and an alternative respiratory chain. The latter involves an alternative oxidase.

Polymorphism of Plasmodium falciparum Na(+)/H(+) exchanger is indicative of a low in vitro quinine susceptibility in isolates from Viet Nam.

Background: The Plasmodium falciparum NA+/H+ exchanger (pfnhe1, gene PF13_0019) has recently been proposed to influence quinine (QN) susceptibility. However, its contribution to QN resistance seems to vary geographically depending on the genetic background of the parasites. Here, the role of this gene was investigated in in vitro QN susceptibility of isolates from Viet Nam.

Mefloquine for uncomplicated Plasmodium falciparum malaria in children.

Background: Children with uncomplicated Plasmodium falciparum imported malaria are treated with various antimalarial regimens including mefloquine depending on national guidelines. Little is known regarding mefloquine treatment efficacy in this setting.

Methods: In this prospective study, children 3 months to 16 years of age admitted in a tertiary hospital emergency ward in France with uncomplicated P.