Breast density knowledge and willingness to delay treatment for pre-operative breast cancer imaging among women with a personal history of breast cancer.

BACKGROUND: Following a breast cancer diagnosis, it is uncertain whether women's breast density knowledge influences their willingness to undergo pre-operative imaging to detect additional cancer in their breasts. We evaluated women's breast density knowledge and their willingness to delay treatment for pre-operative testing. METHODS: We surveyed women identified in the Breast Cancer Surveillance Consortium aged ≥ 18 years, with first breast cancer diagnosed within the prior 6-18 months, who had at least one breast density measurement within the 5 years prior to their diagnosis. We assessed women's breast density knowledge and correlates of willingness to delay treatment for 6 or more weeks for pre-operative imaging via logistic regression. RESULTS: Survey participation was 28.3% (969/3,430). Seventy-two percent (469/647) of women with dense and 11% (34/322) with non-dense breasts correctly knew their density (p < 0.001); 69% (665/969) of all women knew dense breasts make it harder to detect cancers on a mammogram; and 29% (285/969) were willing to delay treatment ≥ 6 weeks to undergo pre-operative imaging. Willingness to delay treatment did not differ by self-reported density (OR:0.99 for non-dense vs. dense; 95%CI: 0.50-1.96). Treatment with chemotherapy was associated with less willingness to delay treatment (OR:0.67; 95%CI: 0.46-0.96). Having previously delayed breast cancer treatment more than 3 months was associated with an increased willingness to delay treatment for pre-operative imaging (OR:2.18; 95%CI: 1.26-3.77). CONCLUSIONS: Understanding of personal breast density was not associated with willingness to delay treatment 6 or more weeks for pre-operative imaging, but aspects of a woman's treatment experience were. CLINICALTRIALS: GOV : NCT02980848 registered December 2, 2016.

Broadband Data Forensics: Spatiotemporal Variations of the Download/Upload Speed Metric Commonly Used to Evaluate Potential Telehealth Accessibility.

Introduction: The complicated task of evaluating potential telehealth access begins with the metrics and supporting datasets that seek toevaluate the presence and durability of broadband connections in a community. Broadband download/upload speeds are one of the popular metrics used to measure potential telehealth access, which is critical to health equity. An understanding of the limitations of these measures is important for drawing conclusions about the reality of the digital divide in telehealth access. The objective of this study was to assess spatiotemporal variations in broadband download/upload speeds. Method: We analyzed a sample of data from the Speedtest Intelligence Portal provided through the Ookla for Good initiative. Results: We found that variation is inherent across the states of Vermont, New Hampshire, Louisiana, and Utah. Conclusions: The variation suggests that when single measures of download/upload speeds are used to evaluate telehealth accessibility they may be masking the true magnitude of the digital divide.

A Multilevel Primary Care Intervention to Improve Follow-Up of Overdue Abnormal Cancer Screening Test Results: A Cluster Randomized Clinical Trial.

Importance: Realizing the benefits of cancer screening requires testing of eligible individuals and processes to ensure follow-up of abnormal results. Objective: To test interventions to improve timely follow-up of overdue abnormal breast, cervical, colorectal, and lung cancer screening results. Design, Setting, and Participants: Pragmatic, cluster randomized clinical trial conducted at 44 primary care practices within 3 health networks in the US enrolling patients with at least 1 abnormal cancer screening test result not yet followed up between August 24, 2020, and December 13, 2021. Intervention: Automated algorithms developed using data from electronic health records (EHRs) recommended follow-up actions and times for abnormal screening results. Primary care practices were randomized in a 1:1:1:1 ratio to (1) usual care, (2) EHR reminders, (3) EHR reminders and outreach (a patient letter was sent at week 2 and a phone call at week 4), or (4) EHR reminders, outreach, and navigation (a patient letter was sent at week 2 and a navigator outreach phone call at week 4). Patients, physicians, and practices were unblinded to treatment assignment. Main Outcomes and Measures: The primary outcome was completion of recommended follow-up within 120 days of study enrollment. The secondary outcomes included completion of recommended follow-up within 240 days of enrollment and completion of recommended follow-up within 120 days and 240 days for specific cancer types and levels of risk. Results: Among 11 980 patients (median age, 60 years [IQR, 52-69 years]; 64.8% were women; 83.3% were White; and 15.4% were insured through Medicaid) with an abnormal cancer screening test result for colorectal cancer (8245 patients [69%]), cervical cancer (2596 patients [22%]), breast cancer (1005 patients [8%]), or lung cancer (134 patients [1%]) and abnormal test results categorized as low risk (6082 patients [51%]), medium risk (3712 patients [31%]), or high risk (2186 patients [18%]), the adjusted proportion who completed recommended follow-up within 120 days was 31.4% in the EHR reminders, outreach, and navigation group (n = 3455), 31.0% in the EHR reminders and outreach group (n = 2569), 22.7% in the EHR reminders group (n = 3254), and 22.9% in the usual care group (n = 2702) (adjusted absolute difference for comparison of EHR reminders, outreach, and navigation group vs usual care, 8.5% [95% CI, 4.8%-12.0%], P < .001). The secondary outcomes showed similar results for completion of recommended follow-up within 240 days and by subgroups for cancer type and level of risk for the abnormal screening result. Conclusions and Relevance: A multilevel primary care intervention that included EHR reminders and patient outreach with or without patient navigation improved timely follow-up of overdue abnormal cancer screening test results for breast, cervical, colorectal, and lung cancer. Trial Registration: ClinicalTrials.gov Identifier: NCT03979495.

Women's Breast Cancer Screening Confidence by Screening Modality and Breast Density: A Breast Cancer Surveillance Consortium Survey Study.

Objective: Little is known about women's confidence in their breast cancer screening. We sought to characterize breast cancer screening confidence by imaging modality and clinically assessed breast density. Materials and Methods: We undertook a cross-sectional survey of women ages 40-74 years who received digital mammography (DM), digital breast tomosynthesis (DBT), and/or breast magnetic resonance imaging (MRI) with a normal screening exam in the prior year. The main outcome was women's confidence (Very, Somewhat, A little, Not at all) in their breast cancer screening detecting any cancer. Multivariable logistic regression identified correlates of being very confident in breast cancer screening by screening modality group: Group 1) DM vs. DBT and Group 2) DM or DBT alone vs. with supplemental MRI. Results: Overall, 2329 of 7439 (31.3%) invitees participated, with 30%-61% being very confident in their screening across modality and density subgroups. Having dense versus nondense breasts was associated with lower odds of being very confident (Group 1: odds ratio [OR]: 0.58; 95% confidence interval [CI]: 0.46-0.79; Group 2: OR: 0.56; 95% CI: 0.40-0.79). There were no differences by modality within Group 1, but for Group 2, women undergoing MRI had higher odds of being very confident (OR: 1.69; 95% CI: 1.21-2.37). Other correlates of greater screening confidence were as follows: Group 1-being offered a screening test choice and cost not influencing modality received, and Group 2-decision satisfaction and worry. Conclusions: Women with dense breasts had lower screening confidence regardless of screening modality and those undergoing MRI had higher confidence regardless of density. The importance of informing women about screening options is underscored by observed associations between screening choice, decision satisfaction, and screening confidence. ClinicalTrials.gov: NCT02980848.

Primary Care Practitioner Perceptions on the Follow-up of Abnormal Cancer Screening Test Results.

Importance: Health care systems focus on delivering routine cancer screening to eligible individuals, yet little is known about the perceptions of primary care practitioners (PCPs) about barriers to timely follow-up of abnormal results. Objective: To describe PCP perceptions about factors associated with the follow-up of abnormal breast, cervical, colorectal, and lung cancer screening test results. Design, Setting, and Participants: Survey study of PCPs from 3 primary care practice networks in New England between February and October 2020, prior to participating in a randomized clinical trial to improve follow-up of abnormal cancer screening test results. Participants were physicians and advanced practice clinicians from participating practices. Main Outcomes and Measures: Self-reported process, attitudes, knowledge, and satisfaction about the follow-up of abnormal cancer screening test results. Results: Overall, 275 (56.7%) PCPs completed the survey (range by site, 34.9%-71.9%) with more female PCPs (61.8% [170 of 275]) and general internists (73.1% [201 of 275]); overall, 28,7% (79 of 275) were aged 40 to 49 years. Most PCPs felt responsible for managing abnormal cancer screening test results with the specific cancer type being the best factor (range, 63.6% [175 of 275] for breast to 81.1% [223 of 275] for lung; P < .001). The PCPs reported limited support for following up on overdue abnormal cancer screening test results. Standard processes such as automated reports, reminder letters, or outreach workers were infrequently reported. Major barriers to follow-up of abnormal cancer screening test results across all cancer types included limited electronic health record tools (range, 28.5% [75 of 263]-36.5%[96 of 263]), whereas 50% of PCPs felt that there were major social barriers to receiving care for abnormal cancer screening test results for colorectal cancer. Fewer than half reported being very satisfied with the process of managing abnormal cancer screening test results, with satisfaction being greatest for breast cancer (46.9% [127 of 271]) and lowest for cervical (21.8% [59 of 271]) and lung cancer (22.4% [60 of 268]). Conclusions and Relevance: In this survey study of PCPs, important deficiencies in systems for managing abnormal cancer screening test results were reported. These findings suggest a need for comprehensive organ-agnostic systems to promote timely follow-up of abnormal cancer screening results using a primary care-focused approach across the range of cancer screening tests.

Decision quality and regret with treatment decisions in women with breast cancer: Pre-operative breast MRI and breast density.

PURPOSE: We evaluated self-report of decision quality and regret with breast cancer surgical treatment by pre-operative breast MRI use in women recently diagnosed with breast cancer. METHODS: We conducted a survey with 957 women aged 18 + with stage 0-III breast cancer identified in the Breast Cancer Surveillance Consortium. Participants self-reported receipt of pre-operative breast MRI. Primary outcomes were process measures in the Breast Cancer Surgery Decision Quality Instrument (BCS-DQI) (continuous outcome) and Decision Regret Scale (dichotomized outcome as any/none). Generalized estimating equations with linear and logit link were used to estimate adjusted associations between breast MRI and primary outcomes. All analyses were also stratified by breast density. RESULTS: Survey participation rate was 27.9% (957/3430). Study population was primarily > 60 years, White, college educated, and diagnosed with early-stage breast cancer. Pre-operative breast MRI was reported in 46% of women. A higher proportion of women who were younger age (< 50 years), commercially insured, and self-detected their breast cancer reported pre-operative breast MRI use. In adjusted analysis, pre-operative breast MRI use compared with no use was associated with a small but statistically significantly higher decision quality scores (69.5 vs 64.7, p-value = 0.043). Decision regret did not significantly differ in women who reported pre-operative breast MRI use compared with no use (54.2% v. 48.7%, respectively, p-value = 0.11). Study results did not vary when stratified by breast density for either primary outcome. CONCLUSIONS AND RELEVANCE: Breast MRI use in the diagnostic work-up of breast cancer does not negatively alter women's perceptions of surgical treatment decisions in early survivorship. CLINICAL TRIALS REGISTRATION NUMBER: NCT03029286.

Breast Density Knowledge in a Screening Mammography Population Exposed to Density Notification.

OBJECTIVE: Women are increasingly informed about their breast density due to state density reporting laws. However, accuracy of personal breast density knowledge remains unclear. We compared self-reported with clinically assessed breast density and assessed knowledge of density implications and feelings about future screening. METHODS: From December 2017 to January 2020, we surveyed women aged 40 to 74 years without prior breast cancer, with a normal screening mammogram in the prior year, and ≥1 recorded breast density measures in four Breast Cancer Surveillance Consortium registries with density reporting laws. We measured agreement between self-reported and BI-RADS breast density categorized as "ever-dense" if heterogeneously or extremely dense within the past 5 years or "never-dense" otherwise, knowledge of dense breast implications, and feelings about future screening. RESULTS: Survey participation was 28% (1,528 of 5,408), and 59% (896 of 1,528) of participants had ever-dense breasts. Concordance between self-report versus clinical density was 76% (677 of 896) among women with ever-dense breasts and 14% (89 of 632) among women with never-dense breasts, and 34% (217 of 632) with never-dense breasts reported being told they had dense breasts. Desire for supplemental screening was more frequent among those who reported having dense breasts 29% (256 of 893) or asked to imagine having dense breasts 30% (152 of 513) versus those reporting nondense breasts 15% (15 of 102) (P = .003, P = .002, respectively). Women with never-dense breasts had 6.3-fold higher odds (95% confidence interval:3.39-11.80) of accurate knowledge in states reporting density to all compared to states reporting only to women with dense breasts. DISCUSSION: Standardized communications of breast density results to all women may increase density knowledge and are needed to support informed screening decisions.

10th Lorne Infection and Immunity Conference 2020.

The December 2020 issue contains a Special Feature on Infection and Immunity, featuring selected presentations from the 10th Lorne Infection and Immunity Conference. The breadth and excellence of science presented at this meeting is encompassed by the articles in this issue by Lamiable et al., Saunders et al. and Chua et al.

Does Omission of Ureteral Stents Increase Risk of Unplanned Return Visit? A Systematic Review and Meta-Analysis.

PURPOSE: Post-ureteroscopy ureteral stent omission remains controversial. Although omission is associated with reduced postoperative discomfort, concern remains for early obstruction. We performed a systematic review and meta-analysis of trials to compare the risk of unplanned visits with vs without a stent following ureteroscopy for nephrolithiasis. MATERIALS AND METHODS: Randomized, controlled trials and observational studies comparing post-ureteroscopic stent omission vs placement and reporting unplanned visits within 30 days were identified via a search of MEDLINE® (1946 to 2015), CENTRAL (Cochrane Central Register of Controlled Trials, 1898 to 2015), Embase® (1947 to 2015), ClinicalTrials.gov (1997 to 2015), AUA (American Urological Association) Annual Meeting abstracts (2011 to 2015) and reference lists of included articles as last updated in October 2015. Two reviewers independently extracted data and assessed methodological quality. ORs, RRs and weighted mean differences were calculated as appropriate for each outcome. RESULTS: Of the initial 1,992 studies 17 in a total of 1,943 participants met inclusion criteria. Unstented patients were significantly more likely to have an unplanned medical visit compared to those who received a post-ureteroscopy stent (OR 1.63, 95% CI 1.15-2.30). Unstented patients had shorter operative time (weighted mean difference -3.19 minutes, 95% CI -5.64--0.74) and were less likely to experience dysuria (RR 0.39, 95% CI 0.25-0.62). They were also less likely to experience postoperative infection (OR 0.89, 95% CI 0.59-1.33) and pain (OR 0.64, 95% CI 0.39-1.05), although these results were not significant. CONCLUSIONS: Stent omission is associated with an increased risk of unplanned medical visits despite reduced symptoms compared to those in stented patients. Patients and physicians should weigh these trade-offs when considering post-ureteroscopy stent placement.

Successful public health response to four cases of imported measles in Panama.

In Panama, the last endemic cases of measles occurred in 1995. In this paper, we report four cases of imported measles in three girls and one boy after they returned from a trip to Poland and Israel between 28 April and 11 May 2011. The etiologic diagnosis of the four cases was confirmed by detection of IgM antibodies against measles virus and positive polymerase chain reaction using measles-specific primers. All cases had genotype D4 with close genetic similarity to virus reported from Poland. Public health interventions included isolation of the cases in their homes and an extensive search for and vaccination of contacts of the four cases, regardless of their vaccination status. A nationwide vaccination campaign was also implemented after the first case was identified. A total of 70,950 measles vaccine doses were administered in Panama in the two months following the identification of these cases. In addition, 94,179 persons were confirmed to have their immunization schedule up-to-date and did not receive the vaccine. No secondary cases were detected in Panama in the following six months.

Simple, specific molecular typing of dengue virus isolates using one-step RT-PCR and restriction fragment length polymorphism.

A one-step RT-PCR and one-enzyme RFLP was used to detect and distinguish among flaviviruses, including the four serotypes of dengue and the St. Louis Encephalitis, West Nile and Yellow Fever viruses in cultured virus samples or acute-phase human serum. Using a previously described RT-PCR, but novel RFLP procedure, results are obtained in 24 h with basic PCR and electrophoresis equipment. There is 95% agreement between RT-PCR/RFLP results and those achieved by indirect immunofluorescence assays, and 100% agreement between RT-PCR/RFLP results and gene sequencing. This method is more rapid than tests of cytopathic effect based on virus isolation in tissue culture, and simpler than real-time PCR. It does not require specialized equipment, radioisotopes or computer analysis and is a method that can be applied widely in the developing world. It allows for prompt determination of whether a flavivirus is the cause of illness in a febrile patient, rapid identification of dengue serotypes in circulation, and improved patient management in cases where prior dengue exposure make dengue hemorrhagic fever or dengue shock syndrome a risk.

Molecular diagnosis of echovirus 30 as the etiological agent in an outbreak of aseptic meningitis in Panama: May-June 2008.

INTRODUCTION: Aseptic meningitis outbreaks are commonly caused by viral pathogens with enterovirus a common etiological agent. Between May and June of 2008, an outbreak of 173 cases of aseptic meningitis occurred in the Chiriqui Province of Panama. Molecular techniques were used to identify the etiological agent. METHODOLOGY: Cerebrospinal fluid (CSF) samples from 75 patients were received at the Gorgas Memorial Institute for Health Studies.  RNA extraction and one-step RT-PCR were performed on each sample to determine the presence of enterovirus.  Thirty-four samples which were positive for enterovirus were subject to group-specific PCR, sequencing, and phylogenetic analysis to identify the etiological agent of the outbreak. RESULTS: The CSF of 58 subjects was found positive for the enterovirus family using RT-PCR. Thirty-four samples were found to belong to the enterovirus B group. Phylogenetic analysis of four successfully sequenced samples revealed echovirus 30 as the etiological agent. CONCLUSION: Echovirus 30 is reported as the likely cause of an outbreak of aseptic meningitis in Panama, the first since the 1980s.

HIV transmitted drug resistance in adult and pediatric populations in Panama / Farmacorresistencia transmitida del VIH en poblaciones adultas y pediátricas en Panamá

Objetivo. Investigar la prevalencia de farmacorresistencia transmitida del VIH en adultos en Panamá mediante un estudio del umbral modificado de la Organización Mundial de la Salud (OMS) e investigar las tasas de resistencia inicial en lactantesseropositivos para el VIH en Panamá.Métodos. En el Instituto Conmemorativo Gorgas, en 47 adultos seropositivos al VIH se efectuó la genotipificación de las mutaciones asociadas con la farmacorresistencia transmitida en los genes de la transcriptasa inversa y la proteasa del VIH-1, según las directrices del estudio umbral de la OMS, modificadas para incluir a las personas ≤ 26 años de edad. Las tasas de prevalencia de las mutaciones farmacorresistentes contra tres clases de fármacos antirretroviral —inhibidores de la transcriptasa inversaanálogos de nucleósidos, inhibidores de la transcriptasa inversa no análogos de nucleósidos e inhibidores de la proteasa— se clasificaron en bajas (< 5,0%), moderadas (5,0%–15,0%) o altas (> 15,0%). También se llevó a cabo genotipificación y se calcularonlas tasas de prevalencia de las mutaciones causantes de farmacorresistencia en 25 lactantes.Resultados. En los adultos de Panamá la farmacorresistencia transmitida fue moderada: 6 de 47 adultos seropositivos para el VIH presentaron una o más mutacionesasociadas con farmacorresistencia transmitida. Las mutaciones farmacorresitentes de transmisión horizontal fueron moderadas para los inhibidores de la transcriptasainversa análogos de nucleósidos y los inhibidores de la transcriptasa inversa no análogos de nucleósidos, y bajas para los inhibidores de la proteasa. En Panamá la transmisiónvertical del VIH ha disminuido en el período 2002–2007, pero la prevalenciade la farmacorresistencia del VIH transmitida por vía vertical es moderada (12,0%) y está surgiendo como un problema debido a la cobertura antirretroviral incompletadurante el embarazo...

Objective. To investigate the prevalence of transmitted drug-resistant HIV among adults in Panama by using a modified World Health Organization Threshold Survey (WHO-TS) and to investigate rates of initial resistance among HIV-positive infants in Panama.Methods. At the Gorgas Memorial Institute, 47 HIV-positive adults were genotyped for mutations associated with transmitted drug resistance (TDR) in the reverse transcriptase andprotease genes of HIV-1, according to WHO-TS guidelines, modified to include patients ≤ 26 years old. Prevalence rates for drug-resistance mutations against three classes of antiretroviraldrugs—nucleoside analog reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), and protease inhibitors—were calculated as low (< 5.0%), moderate (5.0%–15.0%), and high (> 15.0%). Twenty-five infant patients were also genotyped and prevalence rates for drug-resistance mutations were calculated. Results. TDR among Panamanian adults was moderate: 6 of 47 HIV-positive adultsshowed one or more mutations associated with TDR. Horizontal TDR mutations were moderate for NRTIs and NNRTIs and low for protease inhibitors. Vertical transmission of HIV inPanama has decreased for 2002–2007, but vertical HIV TDR prevalence is moderate (12.0%) and is emerging as a problem due to incomplete antiretroviral coverage in pregnancy. Conclusions. The prevalence of HIV TDR indicated by this study, combined with knownrates of HIV infection in Panama, suggests more extensive surveys are needed to identify risk factors associated with transmission of HIV drug resistance. Specific WHO-TS guidelines for monitoring vertical transmission of drug-resistant HIV should be established.

Rocky Mountain spotted fever in Panama: a cluster description.

Rocky Mountain spotted fever (RMSF) is a tick-borne infection caused by Rickettsia rickettsii. We report a cluster of fatal cases of RMSF in 2007 in Panama, involving a pregnant woman and two children from the same family.  The woman presented with a fever followed by respiratory distress, maculopapular rash, and an eschar at the site from which a tick had been removed.  She died four days after disease onset.  This is the second published report of an eschar in a patient confirmed by PCR to be infected with R. rickettsii.  One month later, the children presented within days of one another with fever and rash and died three and four days after disease onset. The diagnosis was confirmed by immunohistochemistry, PCR and sequencing of the genes of R. rickettsii in tissues obtained at autopsy. 

HIV transmitted drug resistance in adult and pediatric populations in Panama.

OBJECTIVE: To investigate the prevalence of transmitted drug-resistant HIV among adults in Panama by using a modified World Health Organization Threshold Survey (WHO-TS) and to investigate rates of initial resistance among HIV-positive infants in Panama. METHODS: At the Gorgas Memorial Institute, 47 HIV-positive adults were genotyped for mutations associated with transmitted drug resistance (TDR) in the reverse transcriptase and protease genes of HIV-1, according to WHO-TS guidelines, modified to include patients ≤ 26 years old. Prevalence rates for drug-resistance mutations against three classes of antiretroviral drugs-nucleoside analog reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), and protease inhibitors-were calculated as low (< 5.0%), moderate (5.0%-15.0%), and high (> 15.0%). Twenty-five infant patients were also geno-typed and prevalence rates for drug-resistance mutations were calculated. RESULTS: TDR among Panamanian adults was moderate: 6 of 47 HIV-positive adults showed one or more mutations associated with TDR. Horizontal TDR mutations were moderate for NRTIs and NNRTIs and low for protease inhibitors. Vertical transmission of HIV in Panama has decreased for 2002-2007, but vertical HIV TDR prevalence is moderate (12.0%) and is emerging as a problem due to incomplete antiretroviral coverage in pregnancy. CONCLUSIONS: The prevalence of HIV TDR indicated by this study, combined with known rates of HIV infection in Panama, suggests more extensive surveys are needed to identify risk factors associated with transmission of HIV drug resistance. Specific WHO-TS guidelines for monitoring vertical transmission of drug-resistant HIV should be established.

Fasciola hepatica and Fasciola gigantica: cloning and characterisation of 70 kDa heat-shock proteins reveals variation in HSP70 gene expression between parasite species recovered from sheep.

Fasciola hepatica and Fasciola gigantica are trematode parasites responsible for fasciolosis, a disease of ruminant animals which is also increasingly recognised as a disease in humans. By biochemical and in silico methods, we have cloned and characterised the 70 kDa heat-shock proteins (HSP70s) of F. hepatica and F. gigantica. The nucleotide and protein sequences for HSP70 were found to be 98% and 99% identical between liver fluke species, respectively, and to encode conserved amino acid motifs that are of putative functional importance. Western blot analysis demonstrated that HSP70 proteins were expressed at a higher level in F. gigantica recovered from sheep relative to F. hepatica, but HSP70 was not detected in the excretory-secretory products of these liver fluke samples. Real-time reverse-transcriptase PCR analysis of HSP70 expression in parasites from sheep, but not cattle, showed HSP70 expression to be higher in F. gigantica than F. hepatica. These results suggest that hosts refractory to F. gigantica are associated with higher HSP70 expression by this parasite and that HSP70 expression may represent a biochemical marker of the stress response of F. gigantica.