Seroconversion for cytomegalovirus infection in a cohort of pregnant women in Québec, 2010-2013.

Cytomegalovirus (CMV) is the leading cause of congenital infection and non-genetic sensorineural hearing loss in children. There are no recent data on the incidence of CMV infection during pregnancy in Canada. This present study was undertaken to determine the seroprevalence of CMV IgG antibodies and the rate of seroconversion in a cohort of pregnant women in the province of Québec, Canada. We used serum samples and questionnaire data collected as part of the 3D Pregnancy and Birth Cohort Study (2010-2013) conducted in Québec, Canada. CMV IgG antibodies were determined in serum samples collected at the first and third trimesters. Associations between independent variables and seroprevalence were assessed using logistic regression, and associations with seroconversions, by Poisson regression. Of 1938 pregnant women tested, 40·4% were seropositive for CMV at baseline. Previous CMV infection was associated with: working as a daycare educator, lower education, lower income, having had children, first language other than French or English, and being born outside Canada or the United States. Of the 1122 initially seronegative women, 24 (2·1%) seroconverted between their first and third trimesters. The seroconversion rate was 1·4 [95% confidence interval (CI) 0·9-2·1]/10 000 person-days at risk or 3·9 (95% CI 2·5-5·9)/100 pregnancies (assuming a 280-day gestation). The high proportion of pregnant women susceptible to CMV infection (nearly 60%) and the subsequent rate of seroconversion are of concern.

Detection of pathogenic protozoa in the diagnostic laboratory: result reproducibility, specimen pooling, and competency assessment.

Stool microscopy as performed in clinical parasitology laboratories is a complex procedure with subjective interpretation. Quality assurance (QA) programs often emphasize proficiency testing as an assessment tool. We describe a result reproducibility assessment tool, which can form part of a broader QA program, and which is based on the blinded resubmission of selected clinical samples, using concordance between the reports of the initial and resubmitted specimen as an indicator. Specimens preserved in sodium acetate-acetic acid-formalin can be stored for several months for use in such a program. The presence of multiple protozoa in one specimen does not affect concordance. Some dilution of specimens occurs in this process, and this may explain poor concordance when specimens with low protozoal concentrations are resubmitted. Evaluation of this tool in a large parasitology laboratory revealed concordance rates for pathogenic protozoa (Entamoeba histolytica/Entamoeba dispar, Giardia lamblia, and Dientamoeba fragilis) of about 80%, which may be considered for use as a benchmark value. We also used this tool to demonstrate that when pairs of specimens from one patient are pooled to create a single specimen, concordance between the results of the individual and pooled specimens is high.

Governance, organization, accountability and sustainability of a region-wide school-based deworming program in Loreto, Peru.

Chau Cuica was the name given by the regional government of Loreto in Peru for its school-based deworming program which was initiated in 2012 with a donation of mebendazole from an international non-governmental organization. Embedded in the program from the start was a sentinel surveillance component which consisted of 16 sentinel schools representing Loreto's seven provinces. Coverage rates varied between 35% and 61% over the first two years of the program (and seven deworming cycles). Initial prevalences of soil-transmitted helminth infections were high, with 82.4% of schoolchildren having at least one infection and prevalences of both Ascaris lumbricoides and Trichuris trichiura infections both exceeding 60%. After two years, these prevalences had dropped to 56% for any STH infection, 38% for A. lumbricoides and 34% for T. trichiura. Importantly, the proportions of children with moderate and heavy infections also dropped. Both the regional Ministry of Health and the Ministry of Education were jointly charged to implement this deworming program. The program's costs were estimated to be approximately 22 cents (USD) per child per deworming cycle. The responsibility for the surveillance component was initially undertaken by research partners from a local NGO and a Canadian university, which transferred gradually over the course of the deworming program to being entirely the responsibility of the Ministry of Health. This regional deworming program may serve as a model for other jurisdictions that are planning a school-based deworming program with an integrated surveillance component to monitor impact.

Imported malaria. Clinical presentation and examination of symptomatic travelers.

BACKGROUND: The diagnosis of malaria in nonendemic countries presents a continuing challenge. Increasing physician awareness of the variability in its clinical presentation will improve clinical management and health outcomes. METHODS: Charts of patients in whom malaria was diagnosed at two hospital-based tropical disease centers between September 1, 1980, and December 31, 1991, were reviewed. RESULTS: Of a total of 482 cases, 182 were caused by Plasmodium falciparum and 246 by Plasmodium vivax. Fifty-two patients with P falciparum malaria were hospitalized; 13 were classified as having severe falciparum malaria. Nineteen patients with P vivax malaria required hospitalization. The only death was caused by P vivax. Chemoprophylaxis was used by, or prescribed for, 46% of patients; however, of these, only half were compliant in taking their medication. Eighty-seven percent of patients with falciparum malaria presented within 6 weeks of return from travel to an endemic area. One third of patients with P vivax malaria presented more than 6 months after travel. The average time between onset of symptoms and physician contact was 6.7 days. Diagnosis was often delayed in those who sought care outside the referral center. Almost all patients had a history of fever, but only half were febrile at presentation. Presenting symptoms and signs were non-specific. Fifty percent of patients were thrombocytopenic. Other laboratory abnormalities were mild. CONCLUSIONS: Since the presentation of malaria is vague and nonspecific, the diagnosis should be considered in any appropriately symptomatic patient with a history of travel to a malaria-endemic area, and appropriate testing should be done. Up-to-date information on chemoprophylaxis should be provided to all travelers to malaria-endemic regions.

Randomized controlled trial of artesunate plus tetracycline versus standard treatment (quinine plus tetracycline) for uncomplicated Plasmodium falciparum malaria in Brazil.

A triple-blind, randomized, clinical trial was undertaken in a Brazilian Amazon region to compare the effectiveness of oral artesunate (seven days, total dose = 0.75 g) plus tetracycline (seven days, total dose = 10.5 g) (AT) and oral quinine (three days, total dose = 6 g) plus tetracycline (seven days, total dose = 10.5 g) (QT) against uncomplicated Plasmodium falciparum malaria. Effectiveness was assessed by cure rates (World Health Organization [WHO]) and parasite clearance at day 2. Patients were randomized, 88 to each group. The groups had similar baseline clinical characteristics. The incidence of side effects was much higher in the QT group (82%) than in the AT group (50%) (P < 0.001). Cure rates were similar: 80% in the AT group and 77% in the QT group (P = 0.68). Parasitemia (by day 2) cleared faster in the AT group than in the QT group (98.5% versus 47.6%, respectively; P < 0.001). These results indicate that the combination of artesunate plus tetracycline is effective in the treatment of uncomplicated falciparum malaria and may provide a useful alternative to other treatment regimens.

Diagnosis of malaria in the febrile traveler.

To determine if clinical presentation can be used for predicting malaria infection in febrile patients with recent travel to a malaria-endemic area, 157 patients with malaria, a history of fever, and recent travel to a malaria-endemic area were compared with 157 matched controls in case-control study. Fever pattern, symptom duration, temperature, splenomegaly, and platelet count were correlated with malaria infection. These criteria, however, either singly or in combination, had low sensitivity for accurately identifying patients with malaria. Because no criterion could accurately predict the presence of malaria, it is concluded that microscopic examinations of blood for malaria parasites should be done in all symptomatic patients with a history of travel to a malaria-endemic area.

Compliance with antimalarial chemoprophylaxis and the subsequent development of malaria: a matched case-control study.

To determine if there is a difference in compliance with antimalarial chemoprophylaxis between febrile travelers with and without malaria, 157 patients with malaria, a history of fever, and recent travel to a malaria-endemic area were compared with 157 matched controls. Antimalarial prophylaxis had been taken by 48% of all patients. Chemoprophylaxis use was correlated with region and purpose of travel. Cases were less likely to have taken prophylaxis (53%) than controls (76%) (odds ratio = 0.35, confidence interval = 0.27, 0.73), even after controlling for region of travel, purpose of travel, and previous exposure to malaria. Chemoprophylaxis was effective in reducing malaria risk. Travel agents and health practitioners should provide all travelers to malaria-endemic areas with adequate information about chemoprophylaxis and its importance.

The population biology and control of Ascaris lumbricoides in a rural community in Iran.

Adults of Ascaris lumbricoides were recovered from 252 persons in the village of Jazin near Esfahan, Iran after treatment with pyrantel pamoate. This horizontal study provides information on age-specific prevalence rates, intensities of infection, frequency distributions, sex ratios and eggs per gram of stool at different parasite intensities. Recruitment of A. lumbricoides was then monitored at 7, 30, 60, 90 and 365 days after treatment in 110 persons. A separate sample population was examined at monthly intervals and, in addition, the stool of each member of a nine-person family was examined for 10 consecutive days. These data are analysed and used to describe the dynamics of transmissions and recruitment of A. lumbricoides in Jazin. The population dynamics of ascariasis are discussed in the context of R the basic reproductive rate of the parasite. The relationships of R with frequency distributions, prevalencies and worm burdens are discussed. Because of the considerable potential of A. lumbricoides to re-infect man in endemic areas, it is shown that it will be difficult to eradicate ascariasis by the use of chemotherapy, even when drugs with a high efficacy are used repeatedly.

Monitoring and evaluation of large scale helminth control programmes.

An essential component of any helminth control programme is its monitoring and evaluation. These activities provide opportunities to adjust programme implementation, to resolve issues that are problematic, to reinforce personnel satisfaction, to ensure programme quality, and to document the impact of the programme on health and other outcomes. A set of core indicators is proposed to be able to compare the impact of control programmes in different jurisdictions or countries. By ensuring regular programme performance appraisal through monitoring and evaluation activities, future programme implementation can be sustained and cost-effectiveness can be optimized.

Inferences for likelihood ratios in the absence of a "gold standard".

Likelihood ratios are extensively used to evaluate the performances of diagnostic tests and to update prior odds of disease to posttest odds. Since few tests are truly 100% accurate, including many used as "gold standards," it is important to be able to estimate likelihood ratios in cases where no such standard is available. In this paper, methods to calculate point and interval estimates for likelihood ratios are described. The results numerically coincide with those reviewed by Centor when a "gold standard" is assumed available, but typically provide wider interval estimates when such a standard is not available, reflecting the increased uncertainty inherent in such situations. Unlike previous techniques, the methods do not require normal approximations or logarithmic transformations, and hence provide accurate estimates even when parameter distributions are highly skewed. The methods are illustrated using the results of two different diagnostic tests for the presence of an intestinal parasitic infection.

Tattoos as risk factors for transfusion-transmitted diseases.

BACKGROUND: Several infectious diseases have been found to be associated with tattooing, including some transfusion-transmitted diseases (TTDs). Information on tattooing has been included in screening interviews of prospective blood donors and may be a reason for deferral. METHODS: Review of articles identified through Medline (and other computerized data bases) using medical subject heading (MeSH) terms and textwords for "tattooing," "transfusion", "hepatitis", "human immunodeficiency virus", "acquired immunodeficiency syndrome", "syphilis", "Chagas disease", "infection", "risk factors", and their combinations. RESULTS: There is strong evidence for the transmission of hepatitis B virus (HBV) infection, hepatitis C virus (HCV) infection, and syphilis by tattooing. Tattooing may also transmit the human immunodeficiency virus (HIV), although convincing evidence is still lacking. There is little or no evidence that other TTDs can be transmitted by tattooing. Epidemiologic studies to date have shown a large variation in odds ratio estimates of the association between tattooing and HBV, HCV, and HIV infections. CONCLUSION: Further studies are required to clarify the risk of tattoos in transmitting infectious diseases through blood transfusions. A reassessment of tattoos as a screening criterion among blood donors is justified.

Increasing referral of at-risk travelers to travel health clinics: evaluation of a health promotion intervention targeted to travel agents.

BACKGROUND: Increases in travel-related illness require new partnerships to ensure travelers are prepared for health risks abroad. The travel agent is one such partner and efforts to encourage travel agents to refer at-risk travelers to travel health clinics may help in reducing travel-attributable morbidity. METHODS: A health promotion intervention encouraging travel agents to refer at-risk travelers to travel health clinics was evaluated. Information on the knowledge, attitudes, and behaviors of travel agents before and after the intervention was compared using two self-administered questionnaires. The Wilcoxon signed rank test was used to compare the mean difference in overall scores to evaluate the overall impact of the intervention and also subscores for each of the behavioral construct groupings (attitudes, barriers, intent, and subjective norms). Multiple regression techniques were used to evaluate which travel agent characteristics were independently associated with a stronger effect of the intervention. RESULTS: A small improvement in travel agents overall attitudes and beliefs (p =.03) was found, in particular their intention to refer (p =.01). Sixty-five percent of travel agents self-reported an increase in referral behavior; owners or managers of the agency were significantly more likely to do so than other travel agents (OR = 7.25; 95% CI: 1.64 32.06). Older travel agents, those that worked longer hours and those with some past referral experience, had significantly higher post-intervention scores. CONCLUSIONS: Travel agents can be willing partners in referral, and agencies should be encouraged to develop specific referral policies. Future research may be directed toward investigating the role of health education in certification curricula, the effectiveness of different types of health promotion interventions, including Internet-facilitated interventions, and the direct impact that such interventions would have on travelers attending travel health clinics.

Intestinal parasites in refugee claimants: a case study for selective screening?

The medical profiles of 1,967 refugee claimants to Montreal, Quebec, Canada from January 1987 to July 1987 were reviewed to evaluate the importance of imported intestinal parasite infection in this group and to re-examine the screening policy governing these infections. An overall infection rate of 29.3% was obtained for pathogenic parasites, where helminths were four times more frequently found than the protozoa Entamoeba histolytica and Giardia lamblia. Age, sex, years of schooling, country of origin and level of eosinophilia were found to be associated with infection, with country of origin being the strongest predictor of infection. These results document the parasite infection in a select group of immigrants which would not have been identified and treated if a special program of screening were not in operation. We suggest that the present immigration policy of no screening for intestinal parasite infection be at least modified to include a recommendation that new arrivals, who are considered to be at high risk for parasite infection, be informed that an examination for parasites would be beneficial to their personal health.

The hepatitis B immunization strategy in Nova Scotia: is it effective?

Since 1987, both hepatitis B disease and hepatitis B vaccine utilization have increased dramatically in Nova Scotia. We present a review of hepatitis B vaccine utilization relative to the occurrence of disease in Nova Scotia. In the two regions with the highest incidence rates, cases have been increasingly associated with lifestyle-related risk factors. Vaccine utilization was primarily for occupational risks. The current provincial hepatitis B immunization strategy is to recommend immunization to targeted high-risk groups. This strategy was judged to be ineffective. The cost of the vaccine is the most important deterrent for adopting an expanded or universal immunization strategy. The pooling of hepatitis B vaccine orders across Canada is suggested as a means to effect significant reductions in the cost of vaccine. Provincial programs would then be able to expand coverage to include populations at immediate risk and youngsters prior to the start of high-risk activity.

Contact-tracing among injection drug users in a rural area.

An epidemic of hepatitis B occurring in 1988 and 1989 in Cape Breton brought to light the existence of a group of "buddies" who engaged in injection drug use. Interviewing was conducted by Public Health in 82% of the 186 IDU contacts named. In comparison with published reports of contact-tracing efforts for viral hepatitis among IDUs, the Cape Breton experience seems successful. This article describes the approach used by Public Health. Aspects of the management of the epidemic and the interview technique which may have contributed to the comparative success of contact-tracing include collaboration with family physicians and laboratories; collaboration among public health investigators; and a nonjudgemental interview technique with 6 "golden rules".

Evaluation of the effectiveness of immunization delivery methods.

Scientific evidence documenting the effectiveness of immunization delivery methods was summarized using the generic approach developed by the Community Health Practice Guidelines Working Group. The delivery methods examined were those for the adult and childhood vaccines of influenza, pneumococcal infection, hepatitis B, measles-mumps-rubella and diphtheria-pertussis-tetanus-polio. Based on a critical appraisal of 54 eligible comparative studies, the effects of different interventions were obtained and pooled effects were calculated for delivery methods oriented to the client, the provider and the system. The results indicate those interventions found to be most effective for each vaccine. This review of the scientific evidence of the effectiveness of immunization delivery methods provides a base for policy development and assists in the planning of resource allocation.

Practice survey of immunization in Canada.

A survey was undertaken in September 1991 to document current immunization practice across Canada. Information was obtained during interviews with provincial epidemiologists and key persons involved in immunization programs and recorded on standard data collection forms. Variations in practice are described in five areas: public/private health administration; legislation; monitoring system/coverage rates/surveillance; vaccine management and costs. As changes are being considered to immunization programs, a critical examination of issues such as standardization (in coding, in assessment of waste, in assessment of coverage), surveillance systems and the use of serosurveys would be beneficial.

Immunization delivery methods: practice recommendations.

Immunization has unequivocally contributed to large-scale reductions in mortality and morbidity due to infectious diseases. In general, consensus on the scheduling of immunizations has been achieved at the national or international level by immunization advisory committees. However, immunization delivery methods are varied and numerous. Although specific methods have been proposed, compared and evaluated, the available evidence has not been comprehensively summarized for informed public health action. This paper integrates evidence based on scientific documentation, a Canada-wide practice survey and expert opinion to formulate practice recommendations for immunization delivery methods and to identify areas for further research.

An approach to the development of practice guidelines for community health interventions.

The Community Health Practice Guidelines (CHPG) project was initiated to develop a systematic approach to the critical evaluation of evidence on the effectiveness and efficiency of community health interventions and to the formulation of evidence-based practice recommendations. Three community health interventions--immunization delivery methods, partner notification for sexually transmitted diseases and the combination of restaurant inspection and education of food handlers--were used as prototypes to develop a standardized approach. The CHPG process consists of three components: a review of scientific evidence, a practice survey and formulation of practice guidelines. Imperatives for further development of the CHPG and define research priorities process include creating a coalition of public health organizations to sponsor the process and refining the consensus process so that the practice guidelines accurately reflect both the scientific basis of public health practice and the values of those affected.

Prevention of perinatal hepatitis B virus transmission in an obstetric/infant population.

STUDY DESIGN: This retrospective study reviewed the screening practice and seroprevalence of hepatitis B surface antigen (HBsAg) among all mothers with live births at a teaching hospital in Montreal between November 1, 1990 and April 30, 1991. RESULTS: Most women (94%) were screened prenatally and 5.2% postnatally. Screening status could not be determined for 0.8% of women. One-quarter of all postnatal screening results were available only at 48 h or more postdelivery. No infants born to women with postnatal screening or to women with unknown screening status were immunized expectantly. The maternal seroprevalence was 1.08% (95% confidence interval from 0.6, 1.4). All 22 infants born to HBsAg-positive mothers had received hepatitis B immune globulin within 12 h of birth and the first dose of hepatitis B vaccine within 24 h. Follow-up of infants revealed that only 50% had received the second and third doses according to the recommended protocol, with 83% completing the immunization series. CONCLUSION: These results indicate that a program of prenatal HBsAg screening and neonatal prophylaxis against hepatitis B can be successfully instituted in a high volume obstetric hospital, and that better monitoring of infants is required to ensure completion of vaccination.