A single co-administered dose of ivermectin (IVM) plus diethylcarbamazine (DEC) plus albendazole (ALB), or triple-drug therapy, was recently found to be more effective for clearing microfilariae (Mf) ...than standard DEC plus ALB currently used for mass drug administration programs for lymphatic filariasis (LF) outside of sub-Saharan Africa. Triple-drug therapy has not been previously tested in LF-uninfected individuals from Africa. This study evaluated the pharmacokinetics (PK), safety, and efficacy of triple-drug therapy in people with and without Wuchereria bancrofti infection in West Africa.
In this open-label cohort study, treatment-naïve microfilaremic (>50 mf/mL, n = 32) and uninfected (circulating filarial antigen negative, n = 24) adults residing in Agboville district, Côte d'Ivoire, were treated with a single dose of IVM plus DEC plus ALB, and evaluated for adverse events (AEs) until 7 days post treatment. Drug levels were assessed by liquid chromatography and mass spectrometry. Persons responsible for assessing AEs were blinded to participants' infection status.
There was no difference in AUC0-inf or Cmax between LF-infected and uninfected participants (P>0.05 for all comparisons). All subjects experienced mild AEs; 28% and 25% of infected and uninfected participants experienced grade 2 AEs, respectively. There were no severe or serious adverse events. Only fever (16 of 32 versus 4 of 24, P<0.001) and scrotal pain/swelling in males (6 of 20 versus 0 of 12, P = 0.025) were more frequent in infected than uninfected participants. All LF positive participants were amicrofilaremic at 7 days post-treatment and 27 of 31 (87%) remained amicrofilaremic 12 months after treatment.
Moderate to heavy W. bancrofti infection did not affect PK parameters for IVM, DEC or ALB following a single co-administered dose of these drugs compared to uninfected individuals. The drugs were well tolerated. This study confirmed the efficacy of the triple-drug therapy for clearing W. bancrofti Mf and has added important information to support the use of this regimen in LF elimination programs in areas of Africa without co-endemic onchocerciasis or loiasis.
ClinicalTrials.gov NCT02845713.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
African swine fever virus (ASFV) causes an acute hemorrhagic fever in domestic pigs, with high socioeconomic impact. No vaccine is available, limiting options for control. Although live attenuated ...ASFV can induce up to 100% protection against lethal challenge, little is known of the antigens which induce this protective response. To identify additional ASFV immunogenic and potentially protective antigens, we cloned 47 viral genes in individual plasmids for gene vaccination and in recombinant vaccinia viruses. These antigens were selected to include proteins with different functions and timing of expression. Pools of up to 22 antigens were delivered by DNA prime and recombinant vaccinia virus boost to groups of pigs. Responses of immune lymphocytes from pigs to individual recombinant proteins and to ASFV were measured by interferon gamma enzyme-linked immunosorbent spot (ELISpot) assays to identify a subset of the antigens that consistently induced the highest responses. All 47 antigens were then delivered to pigs by DNA prime and recombinant vaccinia virus boost, and pigs were challenged with a lethal dose of ASFV isolate Georgia 2007/1. Although pigs developed clinical and pathological signs consistent with acute ASFV, viral genome levels were significantly reduced in blood and several lymph tissues in those pigs immunized with vectors expressing ASFV antigens compared with the levels in control pigs.
The lack of a vaccine limits the options to control African swine fever. Advances have been made in the development of genetically modified live attenuated ASFV that can induce protection against challenge. However, there may be safety issues relating to the use of these in the field. There is little information about ASFV antigens that can induce a protective immune response against challenge. We carried out a large screen of 30% of ASFV antigens by delivering individual genes in different pools to pigs by DNA immunization prime and recombinant vaccinia virus boost. The responses in immunized pigs to these individual antigens were compared to identify the most immunogenic. Lethal challenge of pigs immunized with a pool of antigens resulted in reduced levels of virus in blood and lymph tissues compared to those in pigs immunized with control vectors. Novel immunogenic ASFV proteins have been identified for further testing as vaccine candidates.
Many countries will not reach elimination targets for lymphatic filariasis in 2020 using the two-drug treatment regimen (diethylcarbamazine citrate DEC and albendazole DA). A cluster-randomized, ...community-based safety study performed in Fiji, Haiti, India, Indonesia and Papua New Guinea tested the safety and efficacy of a new regimen of ivermectin, DEC and albendazole (IDA).
To assess acceptability of IDA and DA, a mixed methods study was embedded within this community-based safety study. The study objective was to assess the acceptability of IDA versus DA. Community surveys were performed in each country with randomly selected participants (>14 years) from the safety study participant list in both DA and IDA arms. In depth interviews (IDI) and focus group discussions (FGD) assessed acceptability-related themes. In 1919 individuals, distribution of sex, microfilariae (Mf) presence and circulating filarial antigenemia (CFA), adverse events (AE) and age were similar across arms. A composite acceptability score summed the values from nine indicators (range 9-36). The median (22.5) score indicated threshold of acceptability. There was no difference in scores for IDA and DA regimens. Mean acceptability scores across both treatment arms were: Fiji 33.7 (95% CI: 33.1-34.3); Papua New Guinea 32.9 (95% CI: 31.9-33.8); Indonesia 30.6 (95% CI: 29.8-31.3); Haiti 28.6 (95% CI: 27.8-29.4); India 26.8 (95% CI: 25.6-28) (P<0.001). AE, Mf or CFA were not associated with acceptability. Qualitative research (27 FGD; 42 IDI) highlighted professionalism and appreciation for AE support. No major concerns were detected about number of tablets. Increased uptake of LF treatment by individuals who had never complied with MDA was observed.
IDA and DA regimens for LF elimination were highly and equally acceptable in individuals participating in the community-based safety study in Fiji, Haiti, India, Indonesia, and Papua New Guinea. Country variation in acceptability was significant. Acceptability of the professionalism of the treatment delivery was highlighted.
Celotno besedilo
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Individuals residing in malaria-endemic regions acquire protective immunity after repeated infection with malaria parasites; however, mechanisms of protective immunity and their immune correlates are ...poorly understood. Blood-stage infection with Plasmodium vivax depends completely on interaction of P. vivax Duffy-binding protein (PvDBP) with the Duffy antigen on host erythrocytes. Here, we performed a prospective cohort treatment/reinfection study of children (5-14 years) residing in a P. vivax-endemic region of Papua New Guinea (PNG) in which children were cleared of blood-stage infection and then examined biweekly for reinfection for 25 weeks. To test the hypothesis that naturally acquired binding inhibitory antibodies (BIAbs) targeting PvDBP region II (PvDBPII) provide protection against P. vivax infection, we used a quantitative receptor-binding assay to distinguish between antibodies that merely recognize PvDBP and those that inhibit binding to Duffy. The presence of high-level BIAbs (>90% inhibition of PvDBPII-Duffy binding, n = 18) before treatment was associated with delayed time to P. vivax reinfection diagnosed by light microscopy (P = 0.02), 55% reduced risk of P. vivax reinfection (Hazard's ratio = 0.45, P = 0.04), and 48% reduction in geometric mean P. vivax parasitemia (P < 0.001) when compared with children with low-level BIAbs (n = 148). Further, we found that stable, high-level BIAbs displayed strain-transcending inhibition by reducing reinfection with similar efficiency of PNG P. vivax strains characterized by six diverse PvDBPII haplotypes. These observations demonstrate a functional correlate of protective immunity in vivo and provide support for developing a vaccine against P. vivax malaria based on PvDBPII.
Improved drug regimens are needed to accelerate elimination of lymphatic filariasis in Africa. This study determined whether a single co-administered dose of ivermectin plus diethylcarbamazine plus ...albendazole IDA is noninferior to standard 3 annual doses of ivermectin plus albendazole (IA) used in many LF-endemic areas of Africa.
Treatment-naive adults with Wuchereria bancrofti microfilaremia in Côte d'Ivoire were randomized to receive a single dose of IDA (n = 43) or 3 annual doses of IA (n = 52) in an open-label, single-blinded trial. The primary endpoint was the proportion of participants who were microfilaria (Mf) negative at 36 months. Secondary endpoints were Mf clearance at 6, 12, and 24 months; inactivation of adult worm nests; and safety.
At 36 months posttreatment with IDA, 18/33 (55%; 95% CI, 38-72%) cleared Mf versus 33/42 (79%; 67-91%) with IA (P = .045). At 6 and 12 months IDA was superior to IA in clearing Mf (89% 77-99% and 71% 56-85%), respectively, versus 34% (20-48%) and 26% (14-42%) (P < .001). IDA was equivalent to IA at 24 months (61% 45-77% vs 54% 38-72%; P = .53). IDA was superior to IA for inactivating adult worms at all time points. Both treatments were well tolerated, and there were no serious adverse events.
A single dose of IDA was superior to 2 doses of IA in reducing the overall Mf burden by 24 months. Reinfection may have contributed to the lack of sustained clearance of Mf with IDA.
NCT02974049.
Moxidectin (MOX) is a milbemycin endectocide recently approved by the U.S. FDA for the treatment of onchocerciasis in persons at least 12 years of age. MOX has been shown to have a good safety ...profile in recent clinical trials. The efficacy of MOX for the treatment of lymphatic filariasis (LF) and its potential use in mass drug administration protocols for the elimination of LF is currently under evaluation. In the context of a clinical trial, we investigated the pharmacokinetics and drug interactions of a combination of MOX plus albendazole (ALB) with or without diethylcarbamazine (DEC) compared to ivermectin (IVM) plus ALB with or without DEC in the following four different treatment arms: (I) IVM (0.2mg/kg) plus DEC (6 mg/kg) and ALB (400mg); (II) IVM plus ALB; (III) MOX (8 mg) plus DEC and ALB; and (IV) MOX plus ALB. Drug concentrations were determined using validated liquid chromatography-mass spectrometric methods. Pharmacokinetic parameters were determined using standard non-compartmental analysis methods. Statistical analysis was performed using JMP software. Fifty-eight of 164 study participants (53 men and five women) were included with ages ranging from 18 to 63 yrs (mean = 37). MOX apparent oral clearance (Cl/F) ranged from 0.7 to 10.8 L/hr with C.sub.max values ranging from 20.8 to 314.5 ng/mL. The mean (range) area under the curve (AUC).sub.0-infinity for MOX, 3405 ng*hr/mL (742-11376), and IVM 1906 ng*hr/mL (692-5900), varied over a ~15.3 and ~8.5-fold range, respectively. The geometric mean ratio for C.sub.max, AUC.sub.0-t, and AUC.sub.0-infinity were within the no-drug interaction range of 80-125% for all drugs. This indicates that the addition of MOX to ALB alone or ALB plus DEC for LF therapy did not alter the drug exposure of co-administered drugs compared to IVM combinations. Clinical Trial Registration: NCT04410406,
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Lymphatic filariasis (LF) is a neglected tropical disease caused by the filarial nematodes Wuchereria bancrofti, Brugia malayi and Brugia timori. The Global Program to Eliminate LF uses mass drug ...administration (MDA) of anti-filarial drugs that clear microfilariae (Mf) from blood to interrupt transmission by mosquitos. New diagnostic tools are needed to assess the impact of MDA on bancroftian filariasis, because available serologic tests can remain positive after successful treatment.
We identified Wb-bhp-1, which encodes a W. bancrofti homologue of BmR1, the B. malayi protein used in the Brugia Rapid antibody test for brugian filariasis. Wb-bhp-1 has a single exon that encodes a 16.3 kD protein (Wb-Bhp-1) with 45% amino acid identity to BmR1. Immunohistology shows that anti-Wb-Bhp-1 antibodies primarily bind to Mf. Plasma from 124 of 224 (55%) microfilaremic individuals had IgG4 antibodies to Wb-Bhp-1 by ELISA. Serologic reactivity to Wb-Bhp-1 varied widely with samples from different regions (sensitivity range 32-92%), with 77% sensitivity for 116 samples collected from microfilaremic individuals outside of sub-Saharan Africa. This variable sensitivity highlights the importance of validating new diagnostic tests for parasitic diseases with samples from different geographical regions. Individuals with higher Mf counts were more likely to have anti-Wb-Bhp-1 antibodies. Cross-reactivity was observed with a minority of plasma samples from people with onchocerciasis (17%) or loiasis (10%). We also identified, cloned and characterized BmR1 homologues from O. volvulus and L. loa that have 41% and 38% identity to BmR1, respectively. However, antibody assays with these antigens were not sensitive for onchocerciasis or loiasis.
Wb-Bhp-1 is a novel antigen that is useful for serologic diagnosis of bancroftian filariasis. Additional studies are needed to assess the value of this antigen for monitoring the success of filariasis elimination programs.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Substantial evidence indicates that antibodies to Plasmodium falciparum merozoite antigens play a role in protection from malaria, although the precise targets and mechanisms mediating immunity ...remain unclear. Different malaria antigens induce distinct immunoglobulin G (IgG) subclass responses, but the importance of different responses in protective immunity from malaria is not known and the factors determining subclass responses in vivo are poorly understood. We examined IgG and IgG subclass responses to the merozoite antigens MSP1-19 (the 19-kDa C-terminal region of merozoite surface protein 1), MSP2 (merozoite surface protein 2), and AMA-1 (apical membrane antigen 1), including different polymorphic variants of these antigens, in a longitudinal cohort of children in Papua New Guinea. IgG1 and IgG3 were the predominant subclasses of antibodies to each antigen, and all antibody responses increased in association with age and exposure without evidence of increasing polarization toward one subclass. The profiles of IgG subclasses differed somewhat for different alleles of MSP2 but not for different variants of AMA-1. Individuals did not appear to have a propensity to make a specific subclass response irrespective of the antigen. Instead, data suggest that subclass responses to each antigen are generated independently among individuals and that antigen properties, rather than host factors, are the major determinants of IgG subclass responses. High levels of AMA-1-specific IgG3 and MSP1-19-specific IgG1 were strongly predictive of a reduced risk of symptomatic malaria and high-density P. falciparum infections. However, no antibody response was significantly associated with protection from parasitization per se. Our findings have major implications for understanding human immunity and for malaria vaccine development and evaluation.
Unraveling the drivers controlling the response and adaptation of biological communities to environmental change, especially anthropogenic activities, is a central but poorly understood issue in ...ecology and evolution. Comparative genomics studies suggest that lateral gene transfer (LGT) is a major force driving microbial genome evolution, but its role in the evolution of microbial communities remains elusive. To delineate the importance of LGT in mediating the response of a groundwater microbial community to heavy metal contamination, representative Rhodanobacter reference genomes were sequenced and compared to shotgun metagenome sequences. 16S rRNA gene-based amplicon sequence analysis indicated that Rhodanobacter populations were highly abundant in contaminated wells with low pHs and high levels of nitrate and heavy metals but remained rare in the uncontaminated wells. Sequence comparisons revealed that multiple geochemically important genes, including genes encoding Fe(2+)/Pb(2+) permeases, most denitrification enzymes, and cytochrome c553, were native to Rhodanobacter and not subjected to LGT. In contrast, the Rhodanobacter pangenome contained a recombinational hot spot in which numerous metal resistance genes were subjected to LGT and/or duplication. In particular, Co(2+)/Zn(2+)/Cd(2+) efflux and mercuric resistance operon genes appeared to be highly mobile within Rhodanobacter populations. Evidence of multiple duplications of a mercuric resistance operon common to most Rhodanobacter strains was also observed. Collectively, our analyses indicated the importance of LGT during the evolution of groundwater microbial communities in response to heavy metal contamination, and a conceptual model was developed to display such adaptive evolutionary processes for explaining the extreme dominance of Rhodanobacter populations in the contaminated groundwater microbiome.
Lateral gene transfer (LGT), along with positive selection and gene duplication, are the three main mechanisms that drive adaptive evolution of microbial genomes and communities, but their relative importance is unclear. Some recent studies suggested that LGT is a major adaptive mechanism for microbial populations in response to changing environments, and hence, it could also be critical in shaping microbial community structure. However, direct evidence of LGT and its rates in extant natural microbial communities in response to changing environments is still lacking. Our results presented in this study provide explicit evidence that LGT played a crucial role in driving the evolution of a groundwater microbial community in response to extreme heavy metal contamination. It appears that acquisition of genes critical for survival, growth, and reproduction via LGT is the most rapid and effective way to enable microorganisms and associated microbial communities to quickly adapt to abrupt harsh environmental stresses.
Lymphatic filariasis has remained endemic in Fiji despite repeated mass drug administration using the well-established and safe combination of diethylcarbamazine and albendazole (DA) since 2002. In ...certain settings the addition of ivermectin to this combination (IDA) remains a safe strategy and is more efficacious. However, the safety has yet to be described in scabies and soil-transmitted helminth endemic settings like Fiji. Villages of Rotuma and Gau islands were randomised to either DA or IDA. Residents received weight-based treatment unblinded with standard exclusions. Participants were actively found and asked by a nurse about their health daily for the first two days and then asked to seek review for the next five days if unwell. Anyone with severe symptoms were reviewed by a doctor and any serious adverse event was reported to the Medical Monitor and Data Safety Monitoring Board. Of 3612 enrolled and eligible participants, 1216 were randomised to DA and 2396 to IDA. Age and sex in both groups were representative of the population. Over 99% (3598) of participants completed 7 days follow-up. Adverse events were reported by 600 participants (16.7%), distributed equally between treatment groups, with most graded as mild (93.2%). There were three serious adverse events, all judged not attributable to treatment by an independent medical monitor. Fatigue was the most common symptom reported by 8.5%, with headache, dizziness, nausea and arthralgia being the next four most common symptoms. Adverse events were more likely in participants with microfilaremia (43.2% versus 15.7%), but adverse event frequency was not related to the presence of scabies or soil-transmitted helminth infection. IDA has comparable safety to DA with the same frequency of adverse events experienced following community mass drug administration. The presence of co-endemic infections did not increase adverse events. IDA can be used in community programs where preventative chemotherapy is needed for control of lymphatic filariasis and other neglected tropical diseases.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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