Nature and prevalence of risk factors associated to type B and C acute viral hepatitis cases in Bucharest, 1998-2000.

The main objective of the study was to calculate and report the prevalence of probable risk factors involved in the transmission of pathogenic agents among type B and C acute viral hepatitis cases confirmed in Bucharest (1998-2000). The standardized values of the risks detected in the 45-180 days preceding the onset of illness suggest that in both types of acute viral hepatitis considered in our study transmission associated to the individuals' behaviour (19.0%-hepatitis B and 20.1%-hepatitis C) seems more frequent than "iatrogenic" transmission; in case of hepatitis B, sexual contacts with more than one partner coming first (15.7%), whilst in case of hepatitis C the use of i.v. drugs (heroine) was most frequently incriminated (12.4%). The study reviews the present knowledge of the risk factors involved in the transmission of the disease and approaches prevention strategies.

Measles epidemic in Romania, 1996-1998: assessment of vaccine effectiveness by case-control and cohort studies.

A measles epidemic occurred in Romania with 32,915 cases and 21 deaths reported between November 1996 and June 1998, despite high vaccination coverage since the early 1980s. Most cases were unvaccinated children aged <2 years and vaccinated school-aged children. A case-control study among preschool children and a cohort study among primary-school children were conducted to estimate effectiveness of Romanian-produced measles vaccine, and to evaluate age at vaccination and waning immunity as risk factors for vaccine failure. Both studies indicated that measles vaccine was highly effective. One dose reduced the risk for measles by 89% (95% confidence interval (CI) 85, 91); two doses reduced the risk by 96% (95% CI 92, 98). Children vaccinated at <1 year of age were not at increased risk for measles compared with children vaccinated at > or =1 year. Waning immunity was not identified as a risk factor since vaccine effectiveness was similar for children vaccinated 6-8, 9-11, and 12-14 years in the past. Because specific groups were not at risk for vaccine failure, an immunization campaign that targets all school-aged children who lack two doses may be an effective strategy for preventing outbreaks. A mass campaign followed by increased first-dose coverage should provide the population immunity required to interrupt indigenous measles virus transmission in Romania.

PIP: Two studies examined the effectiveness of measles vaccines in Romania during the measles epidemic between 1996 and 1998. A case control study among preschool children and a cohort study among primary school children were conducted to estimate Romanian-produced vaccine effectiveness and to identify risk factors for measles among these age groups. Both studies found that measles vaccine was highly effective. Single-dose vaccine effectiveness was 89% and double-dose vaccine effectiveness was 96%. Univariate analysis of the case-control study indicated that being unvaccinated and being born of itinerant parents were significant risk factors for measles among preschool children. Children vaccinated at less than 1 year of age were not at increased risk for measles compared with children who receive the vaccine at 1 year or older. Because specific groups were not at risk for vaccine failure, an immunization campaign targeting all school-aged children who lacks two doses of measles vaccine may be an effective measure to prevent outbreaks in Romania.

Risk factors for West Nile virus infection and meningoencephalitis, Romania, 1996.

In 1996, an epidemic of 393 cases of laboratory-confirmed West Nile meningoencephalitis occurred in southeast Romania, with widespread subclinical human infection. Two case-control studies were performed to identify risk factors for acquiring infection and for developing clinical meningoencephalitis after infection. Mosquitoes in the home were associated with infection (reported by 37 [97%] of 38 asymptomatically seropositive persons compared with 36 [72%] of 50 seronegative controls, P<.01) and, among apartment dwellers, flooded basements were a risk factor (reported by 15 [63%] of 24 seropositive persons vs. 11 [30%] of 37 seronegative controls, P=.01). Meningoencephalitis was not associated with hypertension or other underlying medical conditions but was associated with spending more time outdoors (meningoencephalitis patients and asymptomatically seropositive persons spent 8.0 and 3.5 h [medians] outdoors daily, respectively, P<.01). Disease prevention efforts should focus on eliminating peridomestic mosquito breeding sites and reducing peridomestic mosquito exposure.

Sequential and combined use of inactivated and oral poliovirus vaccines: Dolj District, Romania, 1992-1994.

To determine the feasibility of a vaccination strategy that would reduce the risk of vaccine-associated paralysis while retaining a barrier against the spread of wild poliovirus, a 2-year project was undertaken using enhanced-potency inactivated poliovirus vaccine (IPV) administered at 2 and 3 months of age followed by doses of both IPV and oral poliovirus vaccine (OPV) administered at 4 and 9 months of age. Vaccination coverage by 12 months of age with three or more doses of IPV and two doses of OPV among 16,566 infants eligible for vaccination was > 95% and > 80%, respectively. Among 51 children from whom blood samples were obtained 45 days after their third dose of IPV and first dose of OPV, 100% had serum neutralizing antibodies (reciprocal titer > or = 10) to all three poliovirus types. No cases of paralytic poliomyelitis due to either wild or vaccine-related strains were reported. The project demonstrated the feasibility, safety, and high immunogenicity of sequential use of IPV followed by OPV in Romania.

Intramuscular injections within 30 days of immunization with oral poliovirus vaccine--a risk factor for vaccine-associated paralytic poliomyelitis.

BACKGROUND: In Romania the rate of vaccine-associated paralytic poliomyelitis is for unexplained reasons 5 to 17 times higher than in other countries. Long ago it was noted that intramuscular injections administered during the incubation period of wild-type poliovirus infection increased the risk of paralytic disease (a phenomenon known as "provocation" poliomyelitis). We conducted a case-control study to explore the association between intramuscular injections and vaccine-associated poliomyelitis in Romania. METHODS: The patients were 31 young children in whom vaccine-associated paralytic poliomyelitis developed from 1988 through 1992. Eighteen were vaccine recipients, and 13 had acquired the disease by contact with vaccine recipients. Each of these children was matched with up to five controls according to health center, age, and in the case of vaccine recipients, history of receipt of the live attenuated oral poliovirus vaccine. Data were abstracted from medical records that documented the injections administered in the 30 days before the onset of paralysis. RESULTS: Of the 31 children with vaccine-associated disease, 27 (87 percent) had received one or more intramuscular injections within 30 days before the onset of paralysis, as compared with 77 of the 151 controls (51 percent) (matched odds ratio, 31.2; 95 percent confidence interval, 4.0 to 244.2). Nearly all the intramuscular injections were of antibiotics, and the association was strongest for the patients who received 10 or more injections (matched odds ratio for > or = 10 injections as compared with no injections, 182.1; 95 percent confidence interval, 15.2 to 2186.4). The risk of paralytic disease was strongly associated with injections given after the oral polio virus vaccine, but not with injections given before or at the same time as the vaccine (matched odds ratio, 56.7; 95 percent confidence interval, 8.9 to infinity). The attributable risk in the population for intramuscular injections given in the 30 days before the onset of paralysis was 86 percent (95 percent confidence interval, 66 to 95 percent); that is, we estimate that 86 percent of the cases of vaccine-associated paralytic poliomyelitis in this population might have been prevented by the elimination of intramuscular injections within 30 days after exposure to oral poliovirus vaccine. CONCLUSIONS: Provocation paralysis, previously described only for wild-type poliovirus infection, may rarely occur in a child who receives multiple intramuscular injections shortly after exposure to oral poliovirus vaccine, either as a vaccine recipient or through contact with a recent recipient. This phenomenon may explain the high rate of vaccine-associated paralytic poliomyelitis in Romania, where the use of intramuscular injections of antibiotics in infants with febrile illness is common.

Paralytic poliomyelitis in Romania, 1984-1992. Evidence for a high risk of vaccine-associated disease and reintroduction of wild-virus infection.

Although poliomyelitis due to wild-virus infection has virtually disappeared from Romania, with no cases having been documented between 1984 and 1989, vaccine-associated paralytic poliomyelitis has been reported at very high rates for over two decades. In November 1990, to decrease the risk of vaccine-associated paralytic poliomyelitis, oral poliovirus vaccine produced in Romania was replaced by imported oral vaccine made by a Western European manufacturer. To better quantify the risk of vaccine-associated paralytic poliomyelitis and the impact of the change in vaccine manufacturer, the authors reviewed clinical, epidemiologic, and laboratory data on poliomyelitis cases that occurred in Romania from 1984 to 1992. Poliovirus isolates were characterized at the US Centers for Disease Control and Prevention. During the period 1984-1992, 132 confirmed cases of paralytic poliomyelitis were reported in Romania, of which 13 were classified as wild-virus-associated, 93 as vaccine-associated, and 26 as "of unknown origin." Wild type 1 poliovirus was isolated during 1990-1992 from nine of 13 (69%) cases in an outbreak that occurred primarily among undervaccinated gypsy children. Vaccine-associated cases were epidemiologically and virologically distinct from wild-virus cases. Of the 93 vaccine-associated cases, 45 children were recipients and 48 were contacts. The overall risk of vaccine-associated paralytic poliomyelitis in Romania (1 case per 183,000 doses of oral poliovirus vaccine distributed) was 14-fold higher than the risk in the United States. The risks of recipient vaccine-associated paralytic poliomyelitis related to the first dose of oral vaccine were similar for Romanian and imported vaccine (1 case per 95,000 doses and 1 case per 65,000 doses, respectively), as were the total risks of vaccine-associated paralytic poliomyelitis. These findings definitively demonstrate a substantially elevated risk of vaccine-associated paralytic poliomyelitis in Romania which was not affected by a change in oral poliovirus vaccine manufacturer.

[An analysis of the medical contraindications for poliomyelitis vaccination in a district of the city of Bucharest]. / Analiza contraindicatiei medicale la vaccinarea antipoliomielitica într-un sector din municipiul Bucuresti.

The authors report on the results of the analysis of frequency, motives and possible consequences associated to the medical contraindication of inoculations with TPDV (thermal polio-destroyed virus) during the antipoliomyelitis vaccination in the spring of 1989 in District 3 of Bucharest. The failure share in the first antipoliomylitis vaccination was of 2.2% in the 2,500 children selected: 46 (83.6%) were CIM in one of the inoculations and 9 (16.4%) in both inoculations with TPDV of the vaccination. Infectious acute affections were the most numerous motives (89.1-57.1%) of the medical contraindications of inoculation with TPDV; in 59.6-31.2% of these causes the hospitalization of the cases was necessary. The false contraindications were at the basis of 10.9-42.9% of the medical decisions that contraindicated inoculation with TPDV. Of the children with contraindications at inoculation with TPDV, 41.8% met the risk criteria after the first stage and 12.7% after the second stage of the vaccination.

[An estimate of the index of collective measles immunity among the pupils in 8-year elementary education in 1988-1989 in sector III of the city of Bucharest]. / Estimarea indicelui de imunitate colectiva antirujeoloasa la elevii din învatamîntul elementar de 8 ani din anul 1988-1989 din sectorul III al municipiului Bucuresti.

The authors have verified morbidity antecedents in the medical files of 18.5% of the cohort of 47,354 students registered in classes I-VIII in the year 1988-1989 in the III-rd Sector of Bucharest. On the basis of simple hypotheses concerning the post-infectious anti-rubeola immunity, and the post-vaccinal immunity respectively an index was estimated of the anti-rubeola collective immunity of 89.1% a value associated to the risk of transmission of the rubeola infection in this cohort. These observations have permitted the authors to suggest anti-rubeola vaccination of students without documented evidence of anti-rubeola immunity on the one hand, immediately in all the classes (I--VIII) of the present scholar year, and, on the other hand, to vaccinate all the students in the first class, yearly, as an additional measure in the present control anti-epidemic strategy of rubeola.

[A plan for poliomyelitis vaccination]. / Unele consideratii privind schema de vaccinare antipoliomielitica.

A study of the vaccinal antecedents on a representative group of children between 12 and 45 months in the district 3 of Bucharest showed that there exists a certain and direct correlation between the number of simultaneous DTP/VPOT administrations programmed in the immunization scheme and the vaccinal coverage with I DTP revaccination at the minimum age recommended. Administration of VPOT at the ages of 3, 5 and 11 months, simultaneously with the corresponding doses of DTP is the most efficient immunization scheme with these vaccines, in order to proceed to steady rate of antipoliomyelitis vaccination.

[Vaccinal coverage at 1 year of age of the generation of children born in February 1987 in District 3 of the city of Bucharest]. / Acoperirea vaccinala la vîrsta de 1 an la generatia de copii din februarie 1987 din sectorul 3 al Municipiului Bucuresti.

The authors checked the vaccine coverage and the situations in which the compulsory vaccines were not administered up to the age of one year in the children born in February 1987 in District III of Bucharest. The results show a vaccine coverage of more than 90% in BCG vaccination (99.4%), antipoliomyelitic with one dose (94.2%) and with two doses of oral polyvaccine (92.2%) respectively, and the first DTP vaccination (95.9%). The values were under 90% in antimeasles vaccination (87.2%) and the second vaccination with 1 DTP (25.5%). The main causes leading to vaccine coverage could have been prevented. Discussion of these results shows that better vaccination values might be obtained by improving the present control on the immunoprophylaxis activity of the paediatric medical units, by intensifying both their control actions and aims.