Effectiveness of thirteen-valent pneumococcal conjugate vaccine to prevent serotype 3 invasive pneumococcal disease in Quebec in children, Canada.

In the province of Quebec, Canada, a 2 + 1 dose pneumococcal conjugate vaccine (PCV) program for children was implemented in 2004. PCV7 was replaced by PCV10 in 2009, by PCV13 in 2011 and by PCV10 in 2018, without catch-up in all instances. The objective was to estimate PCV13 effectiveness to prevent serotype 3 invasive pneumococcal disease in children aged less than 5 years, using 2010-2018 mandatory notification and laboratory surveillance data, an indirect cohort design and multivariate logistic regression models. A total of 29 cases of serotype 3 and 290 non-vaccine serotype cases as controls were analysed. Overall vaccine effectiveness (≥1 dose) was estimated at 59% [-39% to 88%]. During the first year after the last dose effectivness was 88% [47% to 97%] whereas no protection was observed thereafter. There was no trend towards increased effectiveness with the number of doses. PCV13 protection against serotype 3 IPD seems to be short-lived.

The changing landscape of travel health services in Canada.

Canadians are increasingly travelling to areas that would necessitate a pre-travel consultation. Changes in professional regulations in Canada allow greater autonomy of nurses and pharmacists, resulting in shifts in provision of travel health services. We surveyed 824 Canadian travel clinics, 270 (33%) of whom responded. Private clinics were most common, and more likely to offer extended hours and drop-in appointments. In one province, pharmacies dominated. Half the services were relatively new and a similar proportion saw fewer than 10 patients weekly; 1/3 had a single provider. The increased spectrum of services may increase convenience for travellers but the large proportion seeing low numbers of clients will challenge providers to maintain competence.

Travel-related shigellosis in Quebec, Canada: an analysis of risk factors.

BACKGROUND: Travel-related shigellosis is not well documented in Canada although it is frequently acquired abroad and can cause severe disease. OBJECTIVES: To describe the epidemiology of travel-related cases of shigellosis for Quebec (Canada) and to identify high-risk groups of travelers. METHOD AND DATA SOURCES: We performed a random sampling of 335 shigellosis cases (from a total of 760 cases) reported in the provincial database of reportable diseases from January 1, 2004, to December 31, 2007. Each case was analyzed according to information available in the epidemiology questionnaire. Total number of trips by region from Statistics Canada was used as denominator to estimate the risk according to region of travel. RESULTS: Annually, between 43 and 54% of the shigellosis cases were reported in travelers, 45% of whom were aged between 20 and 44 years. Children under 11 years accounted for nearly 16% of cases, but represent only 4% of travelers. Most cases in travelers were serogroups Shigella sonnei (50%) or Shigella flexneri (45%). Almost 31% of cases were reported between January and March. The majority (64%) were acquired in Central America, Mexico, or the Caribbean. However, the Indian subcontinent, Africa, and South America had the highest ratio of number of cases per number of trips. Tourists represented 76% of the cases; 62% of them had traveled for <2 weeks. At least 15% of cases among travelers were hospitalized. CONCLUSIONS: In Quebec, travel-related cases of shigellosis represent a large burden of total cases. Short-term travelers are at risk, as well as young children. The majority of cases occur in the winter months, corresponding to the peak of travel to "sunshine destinations." Continuous efforts should be made to encourage all travelers to seek pre-travel care, and to inform primary care practitioners of health risks faced by their patients abroad, even for those going to resorts.

Cases of malaria, hepatitis A, and typhoid fever among VFRs, Quebec (Canada).

BACKGROUND: Visiting friends and relatives (VFRs), especially young VFRs, are increasingly recognized in the industrialized world as a high-risk group of travelers. METHODS: We performed a descriptive, cross-sectional design study of cases of malaria, hepatitis A, and typhoid reported to the Quebec registry of notifiable diseases between January 2004 and December 2007, occurring in VFRs and non-VFRs travelers. RESULTS: VFRs account for 52.9% of malaria cases, 56.9% of hepatitis A cases, and 94.4% of typhoid cases reported in Quebec travelers. Almost all (91.6%) of the malaria cases among VFRs were acquired in Africa, particularly in sub-Saharan Africa. An important proportion of malaria cases among VFRs (86.4%) were due to Plasmodium falciparum. The vast majority (76.6%) of typhoid fever cases among VFRs were reported by travelers who had visited the Indian subcontinent. Among VFRs, 40% of total cases were under 20 y of age, compared to less than 6% among non-VFRs. Those under 20 years of age also accounted for 16.9% of malaria cases, 50% of typhoid cases, and 65.2% of hepatitis A cases among VFRs. CONCLUSION: Our study clearly shows that VFR children should be a primary target group for pre-travel preventive measures.

Hepatitis A, typhoid and malaria among travelers--surveillance data from Québec (Canada).

Analysis of epidemiological data on health problems related to international travel helps put into perspective preventive interventions for travelers. To document the epidemiological context of travel health interventions in Québec, we reviewed surveillance data for three infectious diseases. The analysis included data collected in the notifiable diseases surveillance system for hepatitis A, typhoid, and malaria cases reported from 2000 to 2002. Additional data were obtained from the provincial hepatitis risk factor database as well as from regional public health departments. More than 40% of cases of hepatitis A for which risk factor information is available are associated with international travel; 20% of these cases were contracted in Mexico and 22% in the West Indies. The risk of acquiring hepatitis A seems to be higher among travelers under 35 years of age; also, given the number of Quebecers traveling to all regions of the world, this risk is proportionally higher in Africa. Data gathered for typhoid indicate that the risk to travelers from Québec is proportionately higher for Quebecers traveling to the Indian subcontinent and whose purpose is to visit family and friends, and for those who stay abroad for 4 weeks or longer. The risk of malaria is greater in Africa (where contracted cases are mostly caused by Plasmodium falciparum). Over half of malaria cases involve individuals traveling abroad for business (including volunteerism), and almost 75% contracted the disease during a stay of a month or more. Nearly half of the cases had not taken chemoprophylaxis. Available data have limitations for infectious disease surveillance among Québec travelers: imprecise number of cases (underdiagnosis and underreporting), imprecise denominators (number of travelers), and lack of data on the characteristics of trips taken. However, despite its limitations, this profile of infectious diseases among travelers from Québec provides interesting data for preventive intervention.

Travel clinics in Québec (Canada).

To continuously improve its assistance to Québec travel health providers, the Québec Advisory Committee on Travel Health conducted an exploratory and descriptive survey of dedicated travel clinics in Québec (Canada). During autumn 2003, a cross-sectional descriptive survey was carried out among the 97 travel health clinics listed in Québec. Data were collected using a self-administered questionnaire sent by mail. The response rate was 94%. More than three quarters of travel clinics in Québec are located in community health centers; the others are in private clinics and in hospitals. Although 80% of the clinics are located outside the most densely inhabited regions of Québec, they carry out less than 30% of the total number of pretravel consultations. Almost 60% of the clinics have fewer than 500 consultations a year. Overall, more than 114,000 travel health consultations are performed annually in Québec travel health clinics. Preventive services to travelers, including the most commonly used vaccines for travelers, are available in all regions of Québec, except in the northernmost region. Smaller clinics offer fewer services to travelers in terms of antimalarial prescriptions, less common vaccines, and post-travel consultations. The main sources of information for travel health practitioners are guidelines provided by public health authorities. Data obtained provide an up-to-date portrait of the services available in travel clinics in Québec that should assist public health authorities adapt their interventions to the needs and realities of these clinics.