Perch (Perca fluviatilis L.) parasites reflect ecosystem conditions: a comparison of a natural lake and two acidic reservoirs in Finland.

Parasite communities of perch were studied in a natural lake (Vetämäjärvi) and two reservoirs (the Kyrkösjärvi and Liikapuro reservoirs) located in Western Finland. All water bodies studied are small, shallow and humic. However, the reservoirs are more acidic than the lake (pH 5.9 and 5.3 vs. 6.4). Altogether, 18 parasite species were found, but the component communities were reduced in the harsh conditions of the reservoirs (12 and six species) as compared with the lake (17 species). In addition, the mean number of metazoan parasite specimens per fish was markedly lower in the reservoirs (64.3 and 14.3 specimens) than in the lake (116.1 specimens). Our prediction on the depauperation of parasite communities in reservoirs as compared with the lake was confirmed. Many ectoparasite groups were rare and most of the digenean parasites using molluscs as their intermediate host were absent from the reservoirs due to the inability of molluscs to tolerate the acidic water. The only digenean parasite found in the less acidic reservoir was Bunodera luciopercae. There were also species that preferred reservoirs as was expected. The protozoan ciliate Capriniana piscium benefiting acidic water and Acanthocephalus lucii, due to the abundance of its intermediate host, were most prevalent in the reservoir conditions.

Economic evaluation of rotavirus vaccinations in Finland: randomized, double-blind, placebo-controlled trial of tetravalent rhesus rotavirus vaccine.

The cost-benefit ratio of tetravalent rhesus rotavirus vaccine (RRV-TV) in Finland for prevention of rotavirus gastroenteritis was assessed in a randomized, double-blind, placebo-controlled trial. Costs related to vaccination, side effects, and gastroenteritis were identified. Children received RRV-TV (n = 1,191) or placebo (n = 1,207) at 2, 3, and 5 months of age with other infant vaccinations. Prospective follow-up averaged 1.0 years per child. An intention-to-treat analysis was performed from the perspective of society. Nine cases of severe rotavirus gastroenteritis occurred in the RRV-TV group, versus 100 in the placebo group (P < .0001); mean cost per vaccinated child was 4 Finnish marks (FIM) in the RRV-TV group, versus 203 FIM in the placebo group. Side effects with related costs occurred after 11% and 7% of doses in the RRV-TV group and placebo group, respectively (P < .001); mean cost per child was 89 FIM vs. 75 FIM. The break-even cost (i.e., net benefit, excluding cost of vaccine) of RRV-TV in prevention of severe rotavirus gastroenteritis was 109 FIM (U.S. $19.60) per child.

Symptoms associated with rhesus-human reassortant rotavirus vaccine in infants.

BACKGROUND: Severe rotavirus gastroenteritis is potentially preventable by oral rhesus-human reassortant tetravalent (RRV-TV) vaccine, which may soon be licensed in the US and Europe. The objective of this study was to evaluate symptoms associated with the high titer RRV-TV vaccine given concurrently with routine childhood immunizations. METHODS: In a randomized placebo-controlled double blind trial of RRV-TV vaccine titer 4 x 10(5) plaque-forming units vs. placebo, 2282 children received all 3 doses of study vaccine between ages 2 and 7 months. Symptoms were followed by parents who also took daily rectal temperatures. RESULTS: On Days 3 to 5 after the first dose of vaccine fever 38.0 degrees C or greater was detected in 387 of 1182 (33%) infants in the RRV-TV vaccine group vs. 27 of 1194 (2.3%) infants in the placebo group (P < 0.001) and fever 39.0 degrees C or greater was detected in 40 (3.4%) and 3 (0.2%) infants in the vaccine and placebo groups, respectively (P < 0.001). Irritability, decreased appetite and abdominal cramping on Days 3 to 5 postvaccination were also more common in the RRV-TV vaccine recipients than in the placebo recipients. One child in the RRV-TV group was hospitalized and 2 more infants seen in the clinic, vs. none in the placebo group, within the 5-day period after the first dose for a reason probably related to the RRV-TV vaccine. After the second and third doses of RRV-TV vaccine, there were only minor differences between the vaccine and placebo recipients in fever on Days 3 to 5 postvaccination. CONCLUSIONS: The first dose of RRV-TV vaccine is associated with a relatively high rate of febrile and other reactions, which may require a physician visit and, rarely, hospitalization.

Randomised placebo-controlled trial of rhesus-human reassortant rotavirus vaccine for prevention of severe rotavirus gastroenteritis.

BACKGROUND: Rotavirus is the most common cause of acute childhood gastroenteritis. Vaccination with live oral heterologous rotavirus vaccines may prevent rotavirus gastroenteritis. We assessed the efficacy of rhesus-human reassortant rotavirus tetravalent vaccine (RRV-TV) against severe rotavirus gastroenteritis in Finnish children in a randomised placebo-controlled double-blind trial. METHODS: Placebo or RRV-TV (titre 4x10(5) plaque-forming units) was given to infants at ages 2, 3, and 5 months. The children were followed up for one or two rotavirus epidemic seasons. The main outcome measure was protection against severe rotavirus gastroenteritis (score > or =11 on a 20-point severity scale). 2398 children were enrolled and received at least one dose of RRV-TV (n=1191) or placebo (n=1207). The primary efficacy analysis was based on children who received three doses of RRV-TV (n=1128) or placebo (n=1145). FINDINGS: 256 episodes of rotavirus gastroenteritis occurred at any time during the study; 65 were among 1191 RRV-TV recipients, and 191 among 1207 placebo recipients (vaccine efficacy 66% [95% CI 55-74]; intention-to-treat analysis). 226 episodes were included in the primary efficacy analysis of fully vaccinated children (54 among 1128 RRV-TV recipients, 172 among 1145 placebo recipients; vaccine efficacy 68% [57-76]). 100 episodes were severe, eight in RRV-TV recipients and 92 in placebo recipients (vaccine efficacy 91% [82-96]). INTERPRETATION: RRV-TV vaccine was highly effective against severe rotavirus gastroenteritis in young children. Incorporation of this vaccine into routine immunisation schedules of infants could reduce severe rotavirus gastroenteritis by 90% and severe gastroenteritis of all causes in young children by 60%.

Spectrum of 2,836 cases of invasive bacterial or fungal infections in children: results of prospective nationwide five-year surveillance in Finland. Finnish Pediatric Invasive Infection Study Group.

In a prospective nationwide laboratory-based surveillance study of all invasive bacterial and fungal infections among children < 16 years of age, 2,836 clinical cases were registered during the 5-year period 1985-1989. Of these cases, 136 were polymicrobial. During the study period, nationwide administration of Haemophilus influenzae type b conjugate vaccine reduced the incidence rates of invasive infection caused by this organism. The most common clinical diagnosis (48% of cases) was bacteremia without an identified focus of infection. The age-specific annual incidence rates of all invasive infections in children < or = 15 years of age, in children < or = 4 years of age, in children < or = 1 year of age, and in children < or = 28 days of age were 55.8, 141.4, 272.7, and 2,749.0 cases/100,000 person-years, respectively. Thirty percent of the children in the study had an underlying condition predisposing to infection. The case-fatality rate was 4.1% for all cases of invasive infection.

Risk factors for primary invasive pneumococcal disease among children in Finland.

OBJECTIVE: To study risk factors for invasive pneumococcal disease among children. DESIGN: A population-based, case-control study of 149 cases and 284 controls matched for age, sex, and place of residence. SETTING: Finland, November 1986 through November 1989. PATIENTS AND CONTROLS: Patients were identified from a prospective nationwide surveillance for invasive bacterial diseases among children (0 to 15 years of age) through a network of bacteriologic laboratories. Two matched controls were selected for 135 of the cases and one matched control for 14 of the cases from the respective cases' child health center or school. Questionnaires evaluating potential risk factors were mailed to families of cases and controls. RESULTS: An increased risk for invasive pneumococcal disease among children younger than 2 years was associated with day care center attendance (odds ratio [OR] = 36; 95% confidence interval [CI], 5.7 to 233), family day care (OR = 4.4; 95% CI, 1.7 to 12), and history of frequent otitis media (OR = 8.8; 95% CI, 2.5 31). For those at least 2 years of age, existence of siblings younger than school-age indicated increased risk for invasive pneumococcal disease (OR = 2.2; 95% CI, 1.1 to 4.4). CONCLUSIONS: Day care center attendance is a major risk factor for invasive pneumococcal disease for children younger than 2 years, with significantly higher risk than the risk associated with family day care.