The Adjuvanted Recombinant Zoster Vaccine Confers Long-term Protection Against Herpes Zoster: Interim Results of an Extension Study of the Pivotal Phase III Clinical Trials (ZOE-50 and ZOE-70)

Background

This ongoing follow-up study evaluated the persistence of efficacy and immune responses for 6 additional years in adults vaccinated with the glycoprotein E (gE)-based adjuvanted recombinant zoster vaccine (RZV) at age ≥50 years in 2 pivotal efficacy trials (ZOE-50 and ZOE-70). The present interim analysis was performed after ≥2 additional years of follow-up (between 5.1 and 7.1 years [mean] post-vaccination) and includes partial data for year (Y) 8 post-vaccination.

Methods

Annual assessments were performed for efficacy against herpes zoster (HZ) from Y6 post-vaccination and for anti-gE antibody concentrations and gE-specific CD4[2+] T-cell (expressing ≥2 of 4 assessed activation markers) frequencies from Y5 post-vaccination.

Results

Of 7413 participants enrolled for the long-term efficacy assessment, 7277 (mean age at vaccination, 67.2 years), 813, and 108 were included in the cohorts evaluating efficacy, humoral immune responses, and cell-mediated immune responses, respectively. Efficacy of RZV against HZ through this interim analysis was 84.0% (95% confidence interval [CI], 75.9–89.8) from the start of this follow-up study and 90.9% (95% CI, 88.2–93.2) from vaccination in ZOE-50/70. Annual vaccine efficacy estimates were >84% for each year since vaccination and remained stable through this interim analysis. Anti-gE antibody geometric mean concentrations and median frequencies of gE-specific CD4[2+] T cells reached a plateau at approximately 6-fold above pre-vaccination levels.

Conclusions

Efficacy against HZ and immune responses to RZV remained high, suggesting that the clinical benefit of RZV in older adults is sustained for at least 7 years post-vaccination.

Clinical Trials Registration. NCT02723773.

Daclatasvir and sofosbuvir with ribavirin for 24 weeks in chronic hepatitis C genotype-3-infected patients with cirrhosis: a Phase III study (ALLY-3C)

BACKGROUND

Optimal treatment for patients with HCV genotype-3 infection and liver cirrhosis remains a medical priority. Daclatasvir+sofosbuvir and ribavirin is a recommended option for such patients, but clinical trial data are lacking for treatment >16 weeks.

METHODS

This was a single-arm, Phase III study of daclatasvir+sofosbuvir+ribavirin for 24 weeks in patients with compensated cirrhosis and HCV genotype-3 infection. The primary end point was sustained virological response at post-treatment week 12 (SVR12); the primary objective was to demonstrate statistical superiority to historical SVR12 data for 12 weeks' daclatasvir+sofosbuvir without ribavirin in genotype-3-infected patients with cirrhosis (95% CI lower bound >79.0%).

RESULTS

A total of 78 patients were treated (54 treatment-naive, 24 treatment-experienced including 8 with prior sofosbuvir exposure). SVR12 was achieved by 87% (68/78; 95% CI 77.7, 93.7%) of patients in the primary analysis of central laboratory data. One additional patient achieved SVR12 by local testing resulting in an overall SVR12 rate of 88% (95% CI 79.2, 94.6%) and the lower bound of the 95% CI above the historical threshold. SVR12 rates were 93% (50/54) for treatment-naive and 79% (19/24) for treatment-experienced patients. Of the nine non-SVR12 patients, four were lost to follow-up, two relapsed (both sofosbuvir-experienced), two had end-of-treatment virological failure and one discontinued early. There were no unexpected safety signals; only one patient discontinued for an adverse event.

CONCLUSIONS

Daclatasvir+sofosbuvir+ribavirin for 24 weeks was well tolerated and efficacious in HCV genotype-3-infected patients with compensated cirrhosis, with SVR12 outcomes comparable to previously reported outcomes in patients treated with this regimen for 12-16 weeks. ClinicalTrials.gov ID NCT02673489.

458. Diagnostic Accuracy and Management of Suspected Moderate to Severe Cellulitis Referred to an Infectious Diseases Outpatient Parenteral Antibiotic Clinic: A Prospective Cross-Sectional Study

Background

Moderate to severe cellulitis is a common reason for presentation to the emergency department and administration of intravenous antibiotics. Misdiagnosis of cellulitis occurs frequently as the disease can masquerade as a wide variety of noninfectious and infectious problems. There are currently no studies evaluating the impact of infectious diseases physicians on the diagnostic accuracy and management of cellulitis referred to an outpatient parenteral antibiotic clinic from the emergency department. The objective of this study was to quantify the prevalence of misdiagnosed moderate to severe cellulitis through an evaluation by an infectious diseases specialist, characterize the alternative diagnoses, and assess variables associated with misdiagnosis.

Methods

A prospective cross-sectional study of adults referred from emergency departments with presumed moderate to severe cellulitis to an outpatient parenteral antibiotic clinic staffed by infectious diseases specialists.

Results

301 consecutive patients with presumed cellulitis were evaluated over a 6-month period. A concurring diagnosis of cellulitis was found in 170 patients (56.5%), for a misdiagnosis rate of 43.5% (131/301). Table 1 summarizes the alternative diagnoses. Infectious conditions other than cellulitis were the most common (63/301; 20.9%), with abscess being present in 23 (7.6%) of patients. Fifty-two of 301 (17.3%) of the diagnoses were noninfectious and 16/301 (5.3%) patients had a dual diagnosis where minor cellulitis was present, but secondary to another, predomintating condition. The presence of stasis dermatitis (OR 6.62, P = 0.013) and a history of physical trauma (OR 1.76, P = 0.046) were associated with a misdiagnosis. 31.9% (107/335) of antibiotic regimens prescribed by emergency physicians were inappropriate or sub-optimal compared with 7.9% (22/280) of those ordered by infectious disease doctors.

Conclusion

Moderate to severe cellulitis was incorrectly diagnosed in nearly half of the patients referred for intravenous antibiotics and resulted in a high rate of unstewardly antimicrobial use. Infectious diseases physicians at an outpatient antibiotic clinic improved the diagnostic accuracy and management of this complicated condition.

Disclosures

All authors: No reported disclosures.

Spectrum of illness in migrants to Canada: sentinel surveillance through CanTravNet

BACKGROUND

Due to ongoing political instability and conflict in many parts of the world, migrants are increasingly seeking asylum and refuge in Canada.

METHODS

We examined demographic and travel correlates of illnesses among migrants to Canada to establish a detailed epidemiologic framework of this population for Canadian practitioners. Data on ill-returned Canadian travellers presenting to a CanTravNet site between 1 January 2015 and 31 December 2015 were analyzed.

RESULTS

During the study period, 2415 ill travellers and migrants presented to a CanTravNet site, and of those, 519 (21.5%) travelled for the purpose of migration. Sub-Saharan Africa (n = 160, 30.8%), southeast Asia (n = 84, 16.2%) and south central Asia (n = 75, 14.5%) were the most common source regions for migrants, while the top specific source countries, of 98 represented, were the Philippines (n = 45, 8.7%), China (n = 36, 6.9%) and Vietnam (n = 31, 6.0%). Compared with non-migrant travellers, migrants were more likely to have a pre-existing immunocompromising medical condition, such as HIV or diabetes mellitus (P < 0.0001), and to require inpatient management of their illness (P < 0.0001). Diagnoses such as tuberculosis (n = 263, 50.7%), hepatitis B and C (n = 78, 15%) and HIV (n = 11, 2.1%) were over-represented in the migrant population compared with non-migrant travellers (P < 0.0001). Most cases of tuberculosis in the migrant population (n = 263) were latent (82% [n = 216]); only 18% (n = 47) were active.

CONCLUSIONS

Compared with non-migrant travellers, migrants were more likely to present with a communicable infectious disease, such as tuberculosis, potentially complicated by an underlying immunosuppressing condition such as HIV. These differences highlight the divergent healthcare needs in the migrant population, and underscore the importance of surveillance programmes to understand their burden of illness. Intake programming should be adequately resourced to accommodate the medical needs of this vulnerable population of new Canadians.

Long-term follow-up of clinical trial patients treated for chronic HCV infection with daclatasvir-based regimens

BACKGROUND & AIMS

Daclatasvir has achieved high sustained virologic response (SVR) rates in diverse hepatitis C virus (HCV) populations. This study evaluated the long-term efficacy and safety of daclatasvir-based regimens administered during clinical studies.

METHODS

Patients enrolled within 6 months of parent study completion or protocol availability at the study sites. The primary objective was durability of SVR at follow-up Week 12 (SVR12). Secondary objectives included analysing HCV sequences in non-responders or responders who relapsed, and characterization of liver disease progression.

RESULTS

Between 24 February 2012 and 17 July 2015, this study enrolled and began following 1503 recipients of daclatasvir-based regimens (follow-up cut-off, 13 October 2015); 60% were male, 18% aged ≥65 years, 87% had genotype-1a (42%) or -1b (45%) infection, and 18% had cirrhosis. Median follow-up from parent study follow-up Week 12 was 111 (range, 11-246) weeks. 1329/1489 evaluable patients were SVR12 responders; 1316/1329 maintained SVR until their latest visit. Twelve responders relapsed by (n = 9) or after (n = 3) parent study follow-up Week 24; one was reinfected. Relapse occurred in 3/842 (0.4%) and 9/487 (2%) responders treated with interferon-free or interferon-containing regimens, respectively. Hepatic disease progression and new hepatocellular carcinoma were diagnosed in 15 and 23 patients, respectively. Among non-responders, emergent non-structural protein-5A (NS5A) and -3 (NS3) substitutions were replaced by wild-type sequences in 27/157 (17%) and 35/47 (74%) patients, respectively.

CONCLUSIONS

SVR12 was durable in 99% of recipients of daclatasvir-based regimens. Hepatic disease progression and new hepatocellular carcinoma were infrequent. Emergent NS5A substitutions persisted longer than NS3 substitutions among non-responders.

Surveillance report of Zika virus among Canadian travellers returning from the Americas

BACKGROUND

Widespread transmission of Zika virus in the Americas has occurred since late 2015. We examined demographic and travel-related characteristics of returned Canadian travellers with Zika infection acquired in the Americas to illuminate risk factors for acquisition and the clinical spectrum.

METHODS

We analyzed demographic and travel-related data for returned Canadian travellers who presented to a CanTravNet site between October 2015 and September 2016 for care of Zika virus acquired in the Americas. Data were collected with use of the GeoSentinel Surveillance Network data platform.

RESULTS

During the study period, 1118 travellers presented to a CanTravNet site after returning from the Americas, 41 (3.7%) of whom had Zika infection. Zika infection from the Americas was diagnosed at CanTravNet sites as often as dengue (n = 41) over the study period. In the first half of the study period, Zika virus burden was borne by people visiting friends and relatives in South America. In the latter half, coincident with the increased spread of Zika throughout the Caribbean and Central America, Zika virus occurred more often in tourists in the Caribbean. Forty (98%) of the travellers with Zika infection acquired it through probable mosquito exposure, and 1 had confirmed sexual acquisition. Congenital transmission occurred in 2 of 3 pregnancies. Two (5%) of those with Zika had symptoms resembling those of Guillain-Barré syndrome, 1 of whom also had Zika viral meningitis.

INTERPRETATION

Even in this small cohort, we observed the full clinical spectrum of acute Zika virus, including adverse fetal and neurologic outcomes. Our observations suggest that complications from Zika infection are underestimated by data arising exclusively from populations where Zika is endemic. Travellers should adhere to mosquito-avoidance measures and barrier protection during sexual activity.

Efficacy of the Herpes Zoster Subunit Vaccine in Adults 70 Years of Age or Older

BACKGROUND

A trial involving adults 50 years of age or older (ZOE-50) showed that the herpes zoster subunit vaccine (HZ/su) containing recombinant varicella-zoster virus glycoprotein E and the AS01B adjuvant system was associated with a risk of herpes zoster that was 97.2% lower than that associated with placebo. A second trial was performed concurrently at the same sites and examined the safety and efficacy of HZ/su in adults 70 years of age or older (ZOE-70).

METHODS

This randomized, placebo-controlled, phase 3 trial was conducted in 18 countries and involved adults 70 years of age or older. Participants received two doses of HZ/su or placebo (assigned in a 1:1 ratio) administered intramuscularly 2 months apart. Vaccine efficacy against herpes zoster and postherpetic neuralgia was assessed in participants from ZOE-70 and in participants pooled from ZOE-70 and ZOE-50.

RESULTS

In ZOE-70, 13,900 participants who could be evaluated (mean age, 75.6 years) received either HZ/su (6950 participants) or placebo (6950 participants). During a mean follow-up period of 3.7 years, herpes zoster occurred in 23 HZ/su recipients and in 223 placebo recipients (0.9 vs. 9.2 per 1000 person-years). Vaccine efficacy against herpes zoster was 89.8% (95% confidence interval [CI], 84.2 to 93.7; P<0.001) and was similar in participants 70 to 79 years of age (90.0%) and participants 80 years of age or older (89.1%). In pooled analyses of data from participants 70 years of age or older in ZOE-50 and ZOE-70 (16,596 participants), vaccine efficacy against herpes zoster was 91.3% (95% CI, 86.8 to 94.5; P<0.001), and vaccine efficacy against postherpetic neuralgia was 88.8% (95% CI, 68.7 to 97.1; P<0.001). Solicited reports of injection-site and systemic reactions within 7 days after injection were more frequent among HZ/su recipients than among placebo recipients (79.0% vs. 29.5%). Serious adverse events, potential immune-mediated diseases, and deaths occurred with similar frequencies in the two study groups.

CONCLUSIONS

In our trial, HZ/su was found to reduce the risks of herpes zoster and postherpetic neuralgia among adults 70 years of age or older. (Funded by GlaxoSmithKline Biologicals; ZOE-50 and ZOE-70 ClinicalTrials.gov numbers, NCT01165177 and NCT01165229 .).

Malaria in travellers returning or migrating to Canada: surveillance report from CanTravNet surveillance data, 2004-2014

BACKGROUND

Malaria remains the most common specific cause of fever in returned travellers and can be life-threatening. We examined demographic and travel correlates of malaria among Canadian travellers and immigrants to identify groups for targeted pretravel intervention.

METHODS

Descriptive data on ill returned Canadian travellers and immigrants presenting to a CanTravNet site between 2004 and 2014 with a diagnosis of malaria were analyzed. Data were collected using the GeoSentinel data platform. This network comprises 63 specialized travel and tropical medicine clinics, including 7 Canadian sites (Vancouver, Calgary, Toronto, Ottawa, Winnipeg and Montréal), that contribute anonymous, delinked, clinician- and questionnaire-based travel surveillance data on all ill travellers examined to a centralized Structure Query Language database.

RESULTS

During the study period, 20 345 travellers and immigrants were evaluated, and 93% had a travel-related diagnosis. Of these, 437 (2.1%) patients received 456 malaria diagnoses, the most common species being Plasmodium falciparum (n = 282, 61.8%). People travelling to visit friends and relatives were most well-represented (n = 169, 38.7%), followed by business travellers (n = 71, 16.2%). Sub-Saharan Africa was the most common source region, accounting for 341 (74.8%) malaria diagnoses, followed by South Central Asia (n = 55, 12%). Nigeria was the most well-represented source country, accounting for 41 cases (9.0%). India, a high-volume destination for Canadians, accounted for 40 cases (8.8%), 36 of which were caused by Plasmodium vivax. Of 456 malaria diagnoses, 26 (5.7%) were severe. Of 377 nonimmigrant travellers with malaria, 19.9% (n = 75) travelled for less than 2 weeks, and 7.2% (n = 27) travelled for less than 1 week.

INTERPRETATION

This analysis provides an epidemiologic framework for Canadian practitioners encountering prospective and returned travellers. It confirms the importance of preventive measures and surveillance associated with travel to sub-Saharan Africa and India, particularly by travellers visiting friends or relatives. Short-duration travel confers important malaria risk.

Efficacy and safety of ombitasvir/paritaprevir/r and dasabuvir compared to IFN-containing regimens in genotype 1 HCV patients: The MALACHITE-I/II trials

BACKGROUND & AIMS

Telaprevir plus pegylated interferon/ribavirin (TPV+PegIFN/RBV) remains a therapeutic option for chronic hepatitis C virus (HCV) genotype (GT) 1 infection in many regions. We conducted two open-label, phase IIIb trials comparing safety and efficacy of all-oral ombitasvir/paritaprevir/ritonavir and dasabuvir±ribavirin (OBV/PTV/r+DSV±RBV) and TPV+PegIFN/RBV.

METHODS

Treatment-naïve (MALACHITE-I) or PegIFN/RBV-experienced (MALACHITE-II) non-cirrhotic, chronic HCV GT1-infected patients were randomized to OBV/PTV/r+DSV+weight-based RBV, OBV/PTV/r+DSV (treatment-naïve, GT1b-infected patients only), or 12weeks of TPV+PegIFN+weight-based RBV and 12-36 additional weeks of PegIFN/RBV. The primary endpoint was sustained virologic response 12weeks post-treatment (SVR12). Patient-reported outcome questionnaires evaluated mental and physical health during the studies.

RESULTS

Three hundred eleven treatment-naïve and 148 treatment-experienced patients were randomized and dosed. Among treatment-naïve patients, SVR12 rates were 97% (67/69) and 82% (28/34), respectively, in OBV/PTV/r+DSV+RBV and TPV+PegIFN/RBV-treated GT1a-infected patients; SVR12 rates were 99% (83/84), 98% (81/83), and 78% (32/41) in OBV/PTV/r+DSV+RBV, OBV/PTV/r+DSV, and TPV+PegIFN/RBV-treated GT1b-infected patients. Among treatment-experienced patients, SVR12 rates were 99% (100/101) and 66% (31/47) with OBV/PTV/r+DSV+RBV and TPV+PegIFN/RBV. Mental and physical health were generally better with OBV/PTV/r+DSV±RBV than TPV+PegIFN/RBV. Rates of discontinuation due to adverse events (0-1% and 8-11%, respectively, p<0.05) and rates of hemoglobin decline to <10g/dl (0-4% and 34-47%, respectively, p<0.05) were lower for OBV/PTV/r+DSV±RBV than TPV+PegIFN/RBV.

CONCLUSIONS

Among non-cirrhotic, HCV GT1-infected patients, SVR12 rates were 97-99% with 12week, multi-targeted OBV/PTV/r+DSV±RBV regimens and 66-82% with 24-48 total weeks of TPV+PegIFN/RBV. OBV/PTV/r+DSV±RBV was associated with a generally better mental and physical health, more favorable tolerability, and lower rates of treatment discontinuation due to adverse events.

Daclatasvir plus peginterferon alfa and ribavirin for treatment-naive chronic hepatitis C genotype 1 or 4 infection: a randomised study

OBJECTIVE

To evaluate the safety and efficacy of daclatasvir, an HCV NS5A inhibitor with pangenotypic activity, administered with peginterferon-alfa-2a/ribavirin.

DESIGN

In this Phase 2b double-blind, placebo-controlled study, treatment-naive adults with HCV genotype 1 (N=365) or 4 (N=30) infection were randomly assigned (2:2:1) to daclatasvir 20 mg or 60 mg, or placebo once daily plus weekly peginterferon-alfa-2a and twice-daily ribavirin. Daclatasvir recipients achieving protocol-defined response (PDR; HCV-RNA<lower limit of quantitation at Week 4 and undetectable at Week 10) were rerandomised at Week 12 to continue daclatasvir/peginterferon-alfa-2a/ribavirin for 24 weeks total duration or to placebo/peginterferon-alfa-2a/ribavirin for another 12 weeks. Patients without PDR and placebo patients continued peginterferon-alfa/ribavirin through Week 48. Primary efficacy endpoints were undetectable HCV-RNA at Weeks 4 and 12 (extended rapid virologic response, eRVR) and at 24 weeks post-treatment (sustained virologic response, SVR24) among genotype 1-infected patients.

RESULTS

Overall, eRVR was achieved by 54.4% (80/147) of genotype 1-infected patients receiving daclatasvir 20 mg, 54.1% (79/146) receiving 60 mg versus 13.9% (10/72) receiving placebo. SVR24 was achieved among 87 (59.2%), 87 (59.6%), and 27 (37.5%) patients in these groups, respectively. Higher proportions of genotype 4-infected patients receiving daclatasvir 20 mg (66.7%; 8/12) or 60 mg (100.0%; 12/12) achieved SVR24 versus placebo (50.0%; 3/6). A majority of daclatasvir-treated patients achieved PDR and experienced less virologic failure and higher SVR24 rates with a shortened 24-week treatment duration. Adverse events occurred with similar frequency across all treatment groups.

CONCLUSIONS

The combination of daclatasvir/peginterferon-alfa/ribavirin was generally well tolerated and achieved higher SVR24 rates compared with placebo/peginterferon-alfa/ribavirin among patients infected with HCV genotype 1 or 4.

TRIAL REGISTRATION NUMBER

NCT01125189.

Daclatasvir in combination with asunaprevir and beclabuvir for hepatitis C virus genotype 1 infection with compensated cirrhosis

IMPORTANCE

Effective and well-tolerated, interferon-free regimens are needed for treatment of patients with chronic hepatitis C virus (HCV) infection and cirrhosis.

OBJECTIVE

All-oral therapy with daclatasvir (nonstructural protein 5A [NS5A] inhibitor), asunaprevir (NS3 protease inhibitor), and beclabuvir (nonnucleoside NS5B inhibitor), with or without ribavirin, was evaluated in patients with HCV genotype 1 infection and compensated cirrhosis.

DESIGN, SETTING, AND PARTICIPANTS

The UNITY-2 study was conducted between December 2013 and October 2014 at 49 outpatient sites in the United States, Canada, France, and Australia. Patients were treated for 12 weeks, with 24 weeks of follow-up after completion of treatment. Adult patients with cirrhosis were enrolled in 2 cohorts: HCV treatment-naive or HCV treatment-experienced. Statistical analyses were based on historical controls; there were no internal controls.

INTERVENTIONS

All patients received twice-daily treatment with the fixed-dose combination of daclatasvir (30 mg), asunaprevir (200 mg), and beclabuvir (75 mg). In addition, patients within each cohort were stratified according to HCV genotype 1 subtype (1a or 1b) and randomly assigned (1:1) to receive double-blinded weight-based ribavirin (1000-1200 mg/d) or matching placebo.

MAIN OUTCOMES AND MEASURES

Sustained virologic response at posttreatment week 12 (SVR12).

RESULTS

One hundred twelve patients in the treatment-naive group and 90 patients in the treatment-experienced group were treated and included in the analysis. Enrolled patients were 88% white with a median age of 58 years (treatment-naive group) or 60 years (treatment-experienced group); 74% had genotype 1a infection. SVR12 rates were 98% (97.5% CI, 88.9%-100%) for patients in the treatment-naive group and 93% (97.5% CI, 85.0%-100.0%) for those in the treatment-experienced group when ribavirin was included in the regimen. With the fixed-dose combination alone, response rates were 93% (97.5% CI, 85.4%-100.0%) for patients in the treatment-naive group and 87% (97.5% CI, 75.3%-98.0%) for those in the treatment-experienced group. Three serious adverse events were considered to be treatment related and there were 4 adverse event-related discontinuations. Treatment-emergent grade 3 or 4 alanine aminotransferase elevations were observed in 4 patients, of which 1 had concomitant total bilirubin elevation.

CONCLUSIONS AND RELEVANCE

In this open-label uncontrolled study, patients with chronic HCV genotype 1 infection and cirrhosis who received a 12-week oral fixed-dose regimen of daclatasvir, asunaprevir, and beclabuvir, with or without ribavirin, achieved high rates of SVR12.

Efficacy and safety of 12 weeks versus 18 weeks of treatment with grazoprevir (MK-5172) and elbasvir (MK-8742) with or without ribavirin for hepatitis C virus genotype 1 infection in previously untreated patients with cirrhosis and patients with previous null response with or without cirrhosis (C-WORTHY): a randomised, open-label phase 2 trial

BACKGROUND

There is a high medical need for an interferon-free, all-oral, short-duration therapy for hepatitis C virus (HCV) that is highly effective across diverse patient populations, including patients with cirrhosis or previous null response to pegylated interferon (peginterferon) plus ribavirin (PR-null responders). We aimed to assess the efficacy, safety, and effective treatment duration of grazoprevir (an HCV NS3/4A protease inhibitor) combined with elbasvir (an HCV NS5A inhibitor) with or without ribavirin in patients with HCV genotype 1 infection with baseline characteristics of poor response.

METHODS

The C-WORTHY trial is a randomised, open-label phase 2 trial of grazoprevir plus elbasvir with or without ribavirin; here we report findings for two cohorts of previously untreated patients with cirrhosis (cohort 1) and those with previous PR-null response with or without cirrhosis (cohort 2) enrolled in part B of the study. Eligible patients were adults aged 18 years or older with chronic HCV genotype 1 infection and HCV RNA concentrations of 10 000 IU/mL or higher in peripheral blood. We randomly assigned patients to receive grazoprevir (100 mg daily) and elbasvir (50 mg daily) with or without ribavirin for 12 or 18 weeks. Randomisation was done centrally with an interactive voice response system; patients and study investigators were masked to treatment duration up to week 12 but not to treatment allocation. The primary endpoint was the proportion of patients achieving HCV RNA less than 25 IU/mL at 12 weeks after end of treatment (SVR12), assessed by COBAS TaqMan version 2.0. This study is registered with ClinicalTrials.gov, number NCT01717326.

FINDINGS

We describe findings for 253 patients enrolled in cohort 1 (n=123) or cohort 2 (n=130). In cohort 1, we randomly assigned 60 patients to the 12-week regimen (31 with ribavirin and 29 with no ribavirin) and 63 to the 18-week regimen (32 with ribavirin and 31 with no ribavirin); in cohort 2, we randomly assigned 65 patients to the 12-week regimen (32 with ribavirin and 33 with no ribavirin) and 65 to the 18-week regimen (33 with ribavirin and 32 with no ribavirin. High SVR12 rates were achieved irrespective of the use of ribavirin or extension of the treatment duration from 12 to 18 weeks; SVR12 rates ranged from 90% (95% CI 74-98; 28/31; cohort 1, 12 weeks, ribavirin-containing) to 100% (95% CI 89-100; 33/33; cohort 2, 18 weeks, ribavirin-containing). Among patients treated for 12 weeks with grazoprevir plus elbasvir without ribavirin, 97% (95% CI 82-100, 28/29) of patients in cohort 1 and 91% (76-98, 30/33) of patients in cohort 2 achieved SVR12. Adverse events reported in more than 10% of patients were fatigue (66 patients, 26% [95% CI 21-32]), headache (58 patients, 23% [95% CI 18-29]), and asthenia (35 patients, 14% [95% CI 10-19]).

INTERPRETATION

Treatment with grazoprevir plus elbasvir, both with and without ribavirin and for both 12 and 18 weeks' treatment duration, showed high rates of efficacy in previously untreated patients with cirrhosis and previous PR-null responders with and without cirrhosis. These results support the phase 3 development of grazoprevir plus elbasvir.

FUNDING

Merck & Co, Inc.

Daclatasvir plus peginterferon and ribavirin is noninferior to peginterferon and ribavirin alone, and reduces the duration of treatment for HCV genotype 2 or 3 infection

BACKGROUND & AIMS

Twenty-four weeks of treatment with peginterferon and ribavirin for chronic hepatitis C virus (HCV) genotype 2 or 3 infection produces a sustained virologic response (SVR) in 70%-80% of patients. We performed a randomized, double-blind, phase 2b study to assess whether adding daclatasvir, a nonstructural protein 5A (NS5A) inhibitor that is active against these genotypes, improves efficacy and shortens therapy.

METHODS

Patients with HCV genotype 2 or 3 infection (n = 151), enrolled at research centers in North America, Europe, or Australia, were assigned randomly to groups given 12 or 16 weeks of daclatasvir (60 mg once daily), or 24 weeks of placebo, each combined with peginterferon alfa-2a and ribavirin. Treatment was extended to 24 weeks for recipients of daclatasvir who did not meet the criteria for early virologic response. The primary end point was SVR at 24 weeks after treatment (SVR24).

RESULTS

Baseline characteristics were similar among patients within each HCV genotype group. However, the 80 patients with HCV genotype 3, compared with the 71 patients with HCV genotype 2, were younger (mean age, 45 vs 53 y, respectively), and a larger proportion had cirrhosis (23% vs 1%, respectively). Among patients with HCV genotype 2 infection, an SVR24 was achieved by 83%, 83%, and 63% of those in the daclatasvir 12-week group, the daclatasvir 16-week group, or the placebo group, respectively; among patients with HCV genotype 3 infection, an SVR24 was achieved by 69%, 67%, and 59% of patients in these groups, respectively. Differences between genotypes largely were attributable to the higher frequency of post-treatment relapse among patients infected with HCV genotype 3. In both daclatasvir arms for both HCV genotypes, the lower bound of the 80% confidence interval of the difference in SVR24 rates between the daclatasvir and placebo arms was above -20%, establishing noninferiority. Safety findings were similar among groups, and were typical of those expected from peginterferon alfa and ribavirin therapy.

CONCLUSIONS

Twelve or 16 weeks of treatment with daclatasvir, in combination with peginterferon alfa-2a and ribavirin, is a well tolerated and effective therapy for patients with HCV genotype 2 or 3 infections. Daclatasvir-containing regimens could reduce the duration of therapy for these patients. Clinicaltrials.gov number: NCT01257204.

Longitudinal clinical findings and outcome among patients with Cryptococcus gattii infection in British Columbia

BACKGROUND

Cryptococcus gattii (Cg) infection emerged in British Columbia in 1999. A longitudinal, clinical description of patients has not been reported.

METHODS

Medical records were reviewed for Cg patients identified through surveillance (1999-2007). Risk factors for Cg mortality were explored using multivariate Cox regression; longitudinal patterns in serum cryptococcal antigen (SCrAg) titers and the probability of chest cryptococcomas over time were estimated using cubic B-splines in mixed-effects regression models.

RESULTS

Among 152 patients, 111 (73.0%) were culture confirmed. Isolated lung infection was present in 105 (69.1%) patients; 47 (30.9%) had central nervous system infection, with or without lung involvement. Malignancy was the provisional diagnosis in 64 (42.1%) patients. Underlying diseases were present in 91 (59.9%) patients; 23 (15.1%) were immunocompromised, and 23 (15.1%) had asymptomatic disease. There were only 2 (1.8%) culture positive relapses, both within 12 months of follow-up. The estimated median time to resolution of lung cryptococcomas and decline in SCrAg titer to <1:8 was 2.8 and 2.9 years, respectively. Cg-related and all-cause mortality among culture-confirmed cases at 12 months' follow-up was 23.3% and 27.2%, respectively. Cg-related mortality was associated with age >50 years (hazard ratio [HR], 15.6; 95% confidence interval [CI], 1.9-130.5) and immunocompromise (HR, 5.8; CI, 1.5-21.6). All Cg-related mortality occurred among culture-positive cases within 1 year of diagnosis.

CONCLUSIONS

Cryptococcomas and serum antigenemia were slow to resolve. However, late onset of failed therapy or relapse was uncommon, suggesting that delayed resolution of these findings does not require prolongation of treatment beyond that recommended by guidelines.

Dermatoses among returned Canadian travellers and immigrants: surveillance report based on CanTravNet data, 2009-2012

BACKGROUND

There is a lack of multicentre analyses of the spectrum of dermatologic illnesses acquired by Canadian travellers and immigrants. Our objective for this study was to provide a comprehensive, Canada-specific surveillance summary of travel-related dermatologic conditions in a cohort of returned Canadian travellers and immigrants.

METHODS

Data for Canadian travellers and immigrants with a primary dermatologic diagnosis presenting to CanTravNet sites between September 2009 and September 2012 were extracted and analyzed. Data were collected using the GeoSentinel data platform. This network comprises 56 specialized travel and tropical medicine clinics, including 6 Canadian sites (Vancouver, Calgary, Toronto, Ottawa and Montréal), that contribute anonymous, de-linked, clinician- and questionnaire-based travel surveillance data on all ill travellers examined to a centralized Structure Query Language database. Results were analyzed according to reason for most recent ravel: immigration (including refugee); tourism; business; missionary/volunteer/research and aid work; visiting friends and relatives; and other, which included students, military personnel and medical tourists.

RESULTS

During the study period, 6639 patients presented to CanTravNet sites across Canada and 1076 (16.2%) received a travel-related primary dermatologic diagnosis. Arthropod bites (n = 162, 21.5%), rash (n = 141, 18.7%), cutaneous larva migrans (n = 98, 13.0%), and skin and soft tissue infection (n = 92, 12.2%) were the most common dermatologic diagnoses or diagnostic bundles issued to returning Canadian tourists (n = 754, 70.1% of total sample). Patients travelling for the purpose of immigration (n = 63, 5.9%) were significantly more likely to require inpatient management of their dermatologic diagnoses (p < 0.001) than those travelling for other purposes.

INTERPRETATION

This analysis of surveillance data details the spectrum of travel-related dermatological conditions among returning Canadian travellers in this cohort, and provides an epidemiologic framework for Canadian physicians encountering these patients.

Efficacy and safety of 12 weeks versus 18 weeks of treatment with grazoprevir (MK-5172) and elbasvir (MK-8742) with or without ribavirin for hepatitis C virus genotype 1 infection in previously untreated patients with cirrhosis and patients with previous null response with or without cirrhosis (C-WORTHY): a randomised, open-label phase 2 trial

BACKGROUND

There is a high medical need for an interferon-free, all-oral, short-duration therapy for hepatitis C virus (HCV) that is highly effective across diverse patient populations, including patients with cirrhosis or previous null response to pegylated interferon (peginterferon) plus ribavirin (PR-null responders). We aimed to assess the efficacy, safety, and effective treatment duration of grazoprevir (an HCV NS3/4A protease inhibitor) combined with elbasvir (an HCV NS5A inhibitor) with or without ribavirin in patients with HCV genotype 1 infection with baseline characteristics of poor response.

METHODS

The C-WORTHY trial is a randomised, open-label phase 2 trial of grazoprevir plus elbasvir with or without ribavirin; here we report findings for two cohorts of previously untreated patients with cirrhosis (cohort 1) and those with previous PR-null response with or without cirrhosis (cohort 2) enrolled in part B of the study. Eligible patients were adults aged 18 years or older with chronic HCV genotype 1 infection and HCV RNA concentrations of 10 000 IU/mL or higher in peripheral blood. We randomly assigned patients to receive grazoprevir (100 mg daily) and elbasvir (50 mg daily) with or without ribavirin for 12 or 18 weeks. Randomisation was done centrally with an interactive voice response system; patients and study investigators were masked to treatment duration up to week 12 but not to treatment allocation. The primary endpoint was the proportion of patients achieving HCV RNA less than 25 IU/mL at 12 weeks after end of treatment (SVR12), assessed by COBAS TaqMan version 2.0. This study is registered with ClinicalTrials.gov, number NCT01717326.

FINDINGS

We describe findings for 253 patients enrolled in cohort 1 (n=123) or cohort 2 (n=130). In cohort 1, we randomly assigned 60 patients to the 12-week regimen (31 with ribavirin and 29 with no ribavirin) and 63 to the 18-week regimen (32 with ribavirin and 31 with no ribavirin); in cohort 2, we randomly assigned 65 patients to the 12-week regimen (32 with ribavirin and 33 with no ribavirin) and 65 to the 18-week regimen (33 with ribavirin and 32 with no ribavirin. High SVR12 rates were achieved irrespective of the use of ribavirin or extension of the treatment duration from 12 to 18 weeks; SVR12 rates ranged from 90% (95% CI 74-98; 28/31; cohort 1, 12 weeks, ribavirin-containing) to 100% (95% CI 89-100; 33/33; cohort 2, 18 weeks, ribavirin-containing). Among patients treated for 12 weeks with grazoprevir plus elbasvir without ribavirin, 97% (95% CI 82-100, 28/29) of patients in cohort 1 and 91% (76-98, 30/33) of patients in cohort 2 achieved SVR12. Adverse events reported in more than 10% of patients were fatigue (66 patients, 26% [95% CI 21-32]), headache (58 patients, 23% [95% CI 18-29]), and asthenia (35 patients, 14% [95% CI 10-19]).

INTERPRETATION

Treatment with grazoprevir plus elbasvir, both with and without ribavirin and for both 12 and 18 weeks' treatment duration, showed high rates of efficacy in previously untreated patients with cirrhosis and previous PR-null responders with and without cirrhosis. These results support the phase 3 development of grazoprevir plus elbasvir.

FUNDING

Merck & Co, Inc.

Travel-acquired infections in Canada: CanTravNet 2011-2012

BACKGROUND

Important gaps remain in our knowledge of the infectious diseases people acquire while travelling and the impact of pathogens imported by Canadian travellers.

OBJECTIVE

To provide a surveillance update of illness in a cohort of returned Canadian travellers and new immigrants.

METHODS

Data on returning Canadian travellers and new immigrants presenting to a CanTravNet site between September 2011 and September 2012 were extracted and analyzed by destination, presenting symptoms, common and emerging infectious diseases and disease severity.

RESULTS

During the study period, 2283 travellers and immigrants presented to a CanTravNet site, 88% (N=2004) of whom were assigned a travel-related diagnosis. Top three destinations for non-immigrant travellers were India (N=132), Mexico (N=103) and Cuba (N=89). Fifty-one cases of malaria were imported by ill returned travellers during the study period, 60% (N=30) of which were Plasmodium falciparum infections. Individuals travelling to visit friends and relatives accounted for 83% of enteric fever cases (15/18) and 41% of malaria cases (21/51). The requirement for inpatient management was over-represented among those with malaria compared to those without malaria (25% versus 2.8%; p<0.0001) and those travelling to visit friends and relatives versus those travelling for other reasons (12.1% versus 2.4%; p<0.0001). Nine new cases of HIV were diagnosed among the cohort, as well as one case of acute hepatitis B. Emerging infections among travellers included hepatitis E virus (N=6), chikungunya fever (N=4) and cutaneous leishmaniasis (N=16). Common chief complaints included gastrointestinal (N=804), dermatologic (N=440) and fever (N=287). Common specific causes of chief complaint of fever in the cohort were malaria (N=47/51 total cases), dengue fever (14/18 total cases), enteric fever (14/17 total cases) and influenza and influenza-like illness (15/21 total cases). Animal bites were the tenth most common diagnosis among tourist travellers.

INTERPRETATION

Our analysis of surveillance data on ill returned Canadian travellers provides a recent update to the spectrum of imported illness among travelling Canadians. Preventable travel-acquired illnesses and injuries in the cohort include malaria, enteric fever, HIV, hepatitis B, hepatitis A, influenza and animal bites. Strategies to improve uptake of preventive interventions such as malaria chemoprophylaxis, immunizations and arthropod/animal avoidance may be warranted.

Summary of recommendations for the diagnosis and treatment of malaria by the Committee to Advise on Tropical Medicine and Travel (CATMAT)

BACKGROUND

On behalf of the Public Health Agency of Canada, the Committee to Advise on Tropical Medicine and Travel (CATMAT) developed the Canadian Recommendations for the Prevention and Treatment of Malaria Among International Travellers for Canadian health care providers who are preparing patients for travel to malaria-endemic areas and treating travellers who have returned ill. These recommendations aim to achieve appropriate diagnosis and management of malaria, a disease that is still uncommon in Canada.

OBJECTIVE

To provide recommendations on the appropriate diagnosis and treatment of malaria.

METHODS

CATMAT reviewed all major sources of information on malaria diagnosis and treatment, as well as recent research and national and international epidemiological data, to tailor guidelines to the Canadian context. The evidence-based medicine recommendations were developed with associated rating scales for the strength and quality of the evidence.

RECOMMENDATIONS

Malarial management depends on rapid identification of the disease, as well as identification of the malaria species and level of parasitemia. Microscopic identification of blood samples is both rapid and accurate but can be done only by trained laboratory technicians. Rapid diagnostic tests are widely available, are simple to use and do not require specialized laboratory equipment or training; however, they do not provide the level of parasitemia and do require verification. Polymerase chain reaction (PCR), although still limited in availability, is emerging as the gold standard for high sensitivity and specificity in identifying the species.

Travel-acquired infections and illnesses in Canadians: surveillance report from CanTravNet surveillance data, 2009-2011

BACKGROUND

Important knowledge gaps exist in our understanding of migration medicine practice and the impact of pathogens imported by Canadian travellers. We present here a comprehensive, Canada-specific surveillance summary of illness in a cohort of returned Canadian travellers and new immigrants.

METHODS

We extracted and analyzed (using standard parametric and nonparametric techniques) data from the Canadian Travel Medicine Network (CanTravNet) database for ill returned Canadian travellers and new immigrants who presented to a Canadian GeoSentinel Surveillance Network site between September 2009 and September 2011.

RESULTS

During the study period, 4365 travellers and immigrants presented to a CanTravNet site, 3943 (90.3%) of whom were assigned a travel-related diagnosis. Among the 3115 non-immigrant travellers with a definitive travel-related diagnosis, arthropod bite (n = 127 [4.1%]), giardiasis (n = 91 [2.9%]), malaria (n = 77 [2.5%]), latent tuberculosis (n = 73 [2.3%]), and strongyloidiasis (n = 66 [2.1%]) were the most common specific etiologic diagnoses. Among the 828 immigrants with definitive travel-related diagnoses, the most frequent etiologies were latent tuberculosis (n = 229 [27.7%]), chronic hepatitis B (n = 182 [22.0%]), active tuberculosis (n = 97 [11.7%]), chronic hepatitis C (n = 89 [10.7%]), and strongyloidiasis (n = 41 [5.0%]). Potentially serious infections, such as dengue fever (61 cases) and enteric fever due to Salmonella enterica serotype Typhi or Paratyphi (36 cases), were common. Individuals travelling for the purpose of visiting friends and relatives (n = 500 [11.6% of those with known reason for travel]) were over-represented among those diagnosed with malaria and enteric fever, compared with other illnesses (for malaria 34/94 [36.2%] v. 466/4221 [11.0%]; for enteric fever, 17/36 [47.2%] v. 483/4279 [11.3%]) (both p < 0.001). For cases of malaria, there was also overrepresentation (compared with other illnesses) from business travellers (22/94 [23.4%] v. 337/4221 [8.0%]) and males (62/94 [66.0%] v. 1964/4269 [46.0%]) (both p < 0.001). Malaria was more likely than other illnesses to be acquired in sub-Saharan Africa (p < 0.001), whereas dengue was more likely than other illnesses to be imported from the Caribbean and South East Asia (both p = 0.003) and enteric fever from South Central Asia (24/36 [66.7%]) (p < 0.001).

INTERPRETATION

This analysis of surveillance data on ill returned Canadian travellers has detailed the spectrum of imported illness within this cohort. It provides an epidemiologic framework for Canadian practitioners encountering ill returned travellers. We have confirmed that travel to visit friends and relatives confers particularly high risks, which underscores the need to improve pretravel intervention for a population that is unlikely to seek specific pretravel advice. Potentially serious and fatal illnesses such as malaria and enteric fever were common, as were illnesses of public health importance, such as tuberculosis and hepatitis B.

Endemic institutional salmonellosis due to lactose-fermenting Salmonella newport in Nova Scotia

We report two outbreaks of salmonellosis due to lactose-fermenting Salmonella newport in a Halifax nursing home in August 1983 and July 1986 that we believe were related. The relative rarity of this serotype and other epidemiologic evidence suggest that the organism was endemic in the institution for at least 3 years. Persistent carriers as well as ill and convalescing patients presumably were responsible for propagation of the outbreak. We recommend adequate microbiologic follow-up of infected residents and implementation of surveillance and infection control measures for nursing homes and special care institutions.