Successful Transmammary Treatment of Babesia gibsoni Infection in Newborn Puppies after the Administration of Malarone®, Azithromycin, and Artesunate to a Lactating Dam.

Babesia gibsoni is a parasitic protozoan transmitted through tick bites and can cause severe disease in dogs. It can also be transmitted through direct contact with infected blood during dog fights, blood transfusions, and from dam to offspring during the perinatal period, resulting in stillborn or dead newborn puppies. This study aimed to determine the incidence of infection, the viability of newborn puppies, and the degree of B. gibsoni transmission from infected dam to offspring during pregnancy and lactation. Using PCR-based molecular methods, B. gibsoni infection in a pregnant American Pit Bull Terrier and her newborn puppies was confirmed. The incidence of B. gibsoni infection in the litter reached 75%. Out of eight puppies, six were infected with B. gibsoni, and one died. A therapeutic protocol comprising Malarone®, azithromycin, and artesunate was administered to a lactating B. gibsoni-positive bitch. By day 77 after birth, three out of five positive puppies showed negative PCR tests for B. gibsoni, indicating successful treatment through breast milk during nursing. In the two remaining positive puppies, therapy was started and parasitemia was successfully eliminated.

Amplicon Deep Sequencing Reveals Multiple Genetic Events Lead to Treatment Failure with Atovaquone-Proguanil in Plasmodium falciparum.

Atovaquone-proguanil (AP) is used as treatment for uncomplicated malaria, and as a chemoprophylactic agent against Plasmodium falciparum. Imported malaria remains one of the top causes of fever in Canadian returning travelers. Twelve sequential whole-blood samples before and after AP treatment failure were obtained from a patient diagnosed with P. falciparum malaria upon their return from Uganda and Sudan. Ultradeep sequencing was performed on the cytb, dhfr, and dhps markers of treatment resistance before and during the episode of recrudescence. Haplotyping profiles were generated using three different approaches: msp2-3D7 agarose and capillary electrophoresis, and cpmp using amplicon deep sequencing (ADS). A complexity of infection (COI) analysis was conducted. De novo cytb Y268C mutants strains were observed during an episode of recrudescence 17 days and 16 h after the initial malaria diagnosis and AP treatment initiation. No Y268C mutant reads were observed in any of the samples prior to the recrudescence. SNPs in the dhfr and dhps genes were observed upon initial presentation. The haplotyping profiles suggest multiple clones mutating under AP selection pressure (COI > 3). Significant differences in COI were observed by capillary electrophoresis and ADS compared to the agarose gel results. ADS using cpmp revealed the lowest haplotype variation across the longitudinal analysis. Our findings highlight the value of ultra-deep sequencing methods in the understanding of P. falciparum haplotype infection dynamics. Longitudinal samples should be analyzed in genotyping studies to increase the analytical sensitivity.

Tolerability of Atovaquone-Proguanil Application in Common Buzzard Nestlings.

Differences in drug tolerability among vertebrate groups and species can create substantial challenges for wildlife and ex situ conservation programmes. Knowledge of tolerance in the use of new drugs is, therefore, important to avoid severe toxicity in species, which are both commonly admitted in veterinary clinics and are of conservation concern. Antimalarial drugs have been developed for use in human medicine, but treatment with different agents has also long been used in avian medicine, as haemosporidian infections play a major role in many avian species. This study investigates the effects of the application of atovaquone-proguanil (Malarone®, GlaxoSmithKline) in common buzzards (Buteo buteo). The potential effects of treatment on body condition, growth rate, and chemical blood parameters of nestlings were assessed. All individuals survived the treatment, and no effects on body condition, growth rate, and chemical blood parameters were observed. Our results suggest the tolerability of Malarone® in common buzzards at a single dose of on average 11 mg/kg body weight. For its safe use, we recommend further studies to determine pharmacokinetics in different avian species as well as to assess the effects of repeated treatment.

Clinical Efficacy and Safety of Malarone®, Azithromycin and Artesunate Combination for Treatment of Babesia gibsoni in Naturally Infected Dogs.

Babesia gibsoni is a tick-borne protozoal blood parasite that may cause hemolytic anemia, thrombocytopenia, lethargy, and/or splenomegaly in dogs. Many drugs have been used in management of canine babesiosis such as monotherapy or combined treatment, including diminazene aceturate, imidocarb dipropionate, atovaquone, and antibiotics. This report examines the effectiveness and safety of Malarone®, azithromycin (AZM) and artesunate (ART) combination for the treatment of babesiosis in dogs naturally infected with Babesia gibsoni. Twelve American Pit Bull Terriers were included in the experiment. Examined dogs underwent clinical and laboratory analysis including hematology and biochemistry profile and serum protein electrophoresis. After diagnosis, the dogs received combined therapy with Malarone® (13.5 mg/kg PO q24 h), azithromycin (10 mg/kg PO q24 h) and artesunate (12.5 mg/kg PO q24 h) for 10 days. The combined treatment improved hematology and biochemical parameters to the reference range gradually during the first 14 days already, resulting in the stable values until day 56 after treatment. No clinically apparent adverse effects were reported during treatment and monitoring. No relapses of parasitemia were detected in control days 180, 360, 540 and 720 in all dogs. Results of the study indicate that the combined treatment leads to successful elimination of parasitemia in chronically infected dogs with B. gibsoni.

Selection of Cytochrome b Mutants Is Rare among Plasmodium falciparum Patients Failing Treatment with Atovaquone-Proguanil in Cambodia.

Atovaquone-proguanil remains effective against multidrug-resistant Plasmodium falciparum in Southeast Asia, but resistance is mediated by a single point mutation in cytochrome b (cytb) that can arise during treatment. Among 14 atovaquone-proguanil treatment failures in a clinical trial in Cambodia, only one recrudescence harbored the cytb mutation Y268C. Deep sequencing did not detect the mutation at baseline or in the first 3 days of treatment, suggesting that it arose de novo Further sequencing across cytb similarly found no low-frequency cytb mutations that were up-selected from baseline to recrudescence. Copy number amplification in dihydroorotate dehydrogenase (DHODH) and cytb as markers of atovaquone tolerance was also absent. Cytb mutation played a minor role in atovaquone-proguanil treatment failures in an active comparator clinical trial.

Malaria in the pregnant traveler.

Pregnant travelers face numerous risks, notably increased susceptibility to or severity of multiple infections, including malaria. Because pregnant women residing in areas non-endemic for malaria are unlikely to have protective immunity, travel to endemic areas poses risk of severe illness and pregnancy complications, such as low birthweight and fetal loss. If travel to malaria-endemic areas cannot be avoided, preventive measures are critical. However, malaria chemoprophylaxis in pregnancy can be challenging, since commonly used regimens have varying levels of safety data and national guidelines differ. Furthermore, although chloroquine and mefloquine have wide acceptance for use in pregnancy, regional malaria resistance and non-pregnancy contraindications limit their use. Mosquito repellents, including N,N-diethyl-m-toluamide (DEET) and permethrin treatment of clothing, are considered safe in pregnancy and important to prevent malaria as well as other arthropod-borne infections such as Zika virus infection. Pregnant travelers at risk for malaria exposure should be advised to seek medical attention immediately if any symptoms of illness, particularly fever, develop.

Malarone® induced pancreatitis and alopecia in a dog: a case report.

BACKGROUND: Malarone® is a drug used for the treatment of malaria in humans. This drug is also particularly effective in the treatment of canine Babesia gibsoni infections. Malarone® is rarely used in dogs, and its adverse effects have not been widely reported. Its mechanism of action is related to the inhibition of cytochrome b and electron transport in the cell. This is the first known report of the development of acute pancreatitis and alopecia in a dog following the administration of Malarone®. CASE PRESENTATION: A 3-year-old, intact, female Maltese was referred to our clinic with intermittent vomiting and sudden, generalized alopecia. Two months previously, the dog had been prescribed Malarone® for the treatment of a suspected B. gibsoni infection. The dog was evaluated using hematology, radiography, ultrasonography, a PCR for Babesia detection, and a canine pancreatic lipase immunoreactivity (cPLI) assay. The result of the PCR test was negative, whereas the cPLI assay yielded a positive result. Dermatologic examination revealed bacterial infection with hair cycle arrest. CONCLUSIONS: Based on these findings, drug-induced acute pancreatitis and alopecia with superficial pyoderma were diagnosed. Malarone® may induce severe adverse reactions in dogs. Therefore, careful monitoring for adverse effects is required when using Malarone® in dogs.

Failure of atovaquone-proguanil malaria chemoprophylaxis in a traveler to Ghana.

Clinical failure of Malarone™ chemoprophylaxis is extremely rare. We report a case of Plasmodium falciparum malaria in a returned traveler to Ghana who fully adhered to atovaquone-proguanil (Malarone™) chemoprophylaxis daily dosing, yet took the pills on an empty stomach. Screening of the P. falciparum isolate revealed triple codon mutation of Dhfr at positions 51, 59, and 108. Plasma drug levels of both atovaquone and proguanil revealed sub-therapeutic concentrations.

Phototoxic reaction associated with Malarone (atovaquone/proguanil) antimalarial prophylaxis.

Phototoxic reaction has not been reported previously as an adverse reaction to the combination of atovaquone and proguanil (AP) (Malarone) used for antimalarial prophylaxis and therapy. We report here a 32-year-old patient treated with AP who presented with clinical manifestations of photosensitivity. AP-induced phototoxicity in this patient was further supported by phototesting. Malarone is not known to photosensitize and render the skin more susceptible to severe sunburn-like reactions. That it may do so, as in this case, is of importance especially as this drug is used predominantly by those travelling to sunnier climes. A notification of potential phototoxic effects of AP should be published for the choice of prophylaxis made by tourists traveling in malarial areas.

Novel Mutation in Cytochrome B of Plasmodium falciparum in One of Two Atovaquone-Proguanil Treatment Failures in Travelers Returning From Same Site in Nigeria.

BACKGROUND: Atovaquone-proguanil (AP) is the most commonly used treatment for uncomplicated Plasmodium falciparum malaria in the United States. Apparent AP treatment failures were reported 7 months apart in 2 American travelers who stayed in the same compound for foreign workers in Rivers State, Nigeria. METHODS: We analyzed pretreatment (day 0) and day of failure samples from both travelers for mutations in the P falciparum cytochrome B (pfcytb) and dihydrofolate reductase (pfdhfr) genes associated with resistance to atovaquone and cycloguanil, the active metabolite of proguanil, respectively. We genotyped the parasites and sequenced their mitochondrial genomes. RESULTS: On day 0, both travelers had proguanil-resistant genotypes but atovaquone-sensitive cytb sequences. Day of failure samples exhibited mutations in cytb for both travelers. One traveler had the common Y268S mutation, whereas the other traveler had a previously unreported mutation, I258M. The travelers had unrelated parasite genotypes and different mitochondrial genomes. CONCLUSIONS: Despite the infections likely having been contracted in the same site, there is no evidence that the cases were related. The mutations likely arose independently during the acute infection or treatment. Our results highlight the importance of genotyping parasites and sequencing the full cytb and dhfr genes in AP failures to rule out transmission of AP-resistant strains and identify novel mechanisms of AP resistance.

The in vitro interactions and in vivo efficacy of atovaquone and proguanil against Babesia gibsoni infection in dogs.

In vitro interactions between atovaquone (ATV) and proguanil (PG) against Babesia gibsoni and the clinical efficacy of this combination therapy using Malarone(®) which is the antimalarial drug containing ATV and PG were evaluated. This combination showed synergism against uncloned wild-type and ATV-resistant B. gibsoni in vitro examinations using a modified fixed ratio method. Administration of Malarone(®) to experimentally B. gibsoni infected two dogs in chronic stage and three dogs in acute stage resulted in decrease in parasitemia, and clinical improvements were observed. However, all dogs showed relapse of parasitic infection with a single-nucleotide polymorphism in the cytchrome b gene (M121I). Some side effects were confirmed: self-limiting vomiting in two dogs and hyperphosphatasia in another dog. Mild increases in the levels of alanine aminotransferase were confirmed in two dogs. This is the first study to evaluate the interactions in vitro and the clinical efficacy of ATV and PG against canine B. gibsoni infection in dogs.

Assessment of acceptability and ease of use of atovaquone/proguanil medication in subjects undergoing malaria prophylaxis.

OBJECTIVE: International travelers from non-endemic areas are at high risk of contracting malaria due to their lack of immunity. Prevention is therefore of outmost importance and is achieved through effective and safe chemoprophylaxis, which reduces the risk of fatal disease. Among the various antimalarial drugs available, the synergistic combination of atovaquone and proguanil (A/P) (Malarone((R)); Glaxo-SmithKline) has proven a valuable option in terms of effective protection against chloroquine and multi-drug resistant falciparum malaria, safety, tolerability, and ease of use, thus favoring compliance. The purpose of the present study was to assess acceptability and ease of use of A/P chemoprophylaxis in a population of employees of the oil industry bound to malarious areas. Particular attention was paid to treatment adherence. METHODS: A survey was conducted on a sample of 700 employees on A/P chemoprophylaxis. Demographic data and specific information on A/P treatment were collected by means of a 16-item questionnaire administered immediately before departure. All questionnaires returned were then entered into a database and statistically analyzed. RESULTS: Both habitual and first-time travelers showed good adherence to A/P chemoprophylactic regimen. In general, only few adverse side-effects were reported, none of which were serious. Travelers with previous experience of other antimalarials stated A/P prophylaxis had proven advantageous due to fewer adverse reactions, better condition of administration, and better sense of protection compared with other available treatments.