Surveillance of aseptic central nervous system infections in Poland: is it meeting its objectives?

In Poland, a surveillance system capturing generic information on both diagnosed and undiagnosed aseptic central nervous system infections (ACI) has been in operation since 1966. This study evaluates to what extent the ACI surveillance is able to meet its objectives to monitor ACI trends and to detect signals of public health importance such as enteroviral outbreaks, tick-borne encephalitis (TBE) endemic foci, poliovirus appearance or emergence of new neurotropic viruses. Between 2004 and 2008, aetiology was established for 17% of ACI cases. Of the 1,994 reported ACI cases, 232 (11.6%) were diagnosed with TBE virus, 46 (2.3%) with enterovirus, 35 (1.8%) with herpesvirus, and 32 (1.6%) had other viral causes such as Epstein Barr virus or adenovirus. The system's performance varied between the provinces, with the frequency of suspected ACI cases referred for viral aetiology investigation in 2008 ranging from 1.98 to 285.4 samples per million inhabitants. The sensitivity of physicians' reporting, estimated as the proportion of hospitalised ACI cases reported to the surveillance system, was 48% nationally, with vast regional differences (range 30­91%). To conclude, the ACI surveillance system in Poland does currently not meet its objectives, due to limited availability of aetiological diagnosis and microbiological confirmation and to regional differences in reporting sensitivity.

[Hepatitis C in Poland 1999]. / Wirusowe zapalenie watroby typu C w 1999 roku.

In 1999, a total of 1,988 (5.1 per 100,000) acute and chronic hepatitis C cases were noted. HCV and HBV coinfections accounted for 7.6% reported cases. Incidence in urban areas (6.9 per 100,000) was 200% those in rural areas (2.3 per 100,000). Incidence among men (6.0 per 100,000) was 40% those among women (4.3 per 100,000). The most predominant groups were age 40-44 (235 cases, 11.8%) and 65-74 (229 cases, 11.5%). Presented data should be taken cautiously because of development of diagnosis and reporting.

[Infectious diseases in Poland in 1999]. / Choroby zakazne w Polsce w 1999 roku.

Improvement of epidemiological situation of infectious diseases was continued in Poland in 1999. The end of epidemics of measles, pertussis, mumps, scarlatine, chickenpox, and rubella was observed. In comparison with the number of cases of infectious diseases registered in 1998, decrease in the number of notified cases of salmonellosis, dysentery, meningitis, encephalitis, and hepatitis type B and A as well as increase in the number of influenza cases and trichinosis was noticed. In 1999, compared with 1998, among all notified deaths percentage of deaths attributed to infectious diseases (0.80%) and infectious diseases death rate (7.71 per 100,000) were slightly higher as an effect of the influenza deaths increase.

[Studies of effectiveness of vaccination against pertussis during 1997-1998 outbreak in Poland]. / Skutecznosc szczepien przeciw krztuscowi w okresie epidemii 1997-1998 w Polsce.

During the last decade shift in incidence of pertussis toward the older age groups was observed. Also marked increase in incidence of pertussis in the second half of 1997 and first half of 1998 has occurred in our highly vaccinated population. In lieu of those facts question arises on effectiveness of national vaccination program in respect to immunological adequacy of vaccine used as well as to the vaccinations calendar. Estimations of the values of vaccine efficiency coefficient were calculated for age groups of 2-5, 6-9 and 10-13 years for six month periods in 1997-1998. Sustained good effectiveness of vaccinations was observed in a group 2-5 years of age. In older groups marked decrease of effectiveness was observed during 1997/1998 outbreak of whooping cough. The effectiveness of vaccinations among children of 10-13 years dropped at the outbreak to insignificant levels. Such results indicate good vaccine protection at the age of 2-5 which reflects immunological adequacy of vaccine used in Poland. But this protective effect declines in later years indicating need for additional dose of vaccine for children after five years of age.

[Scarlet fever in Poland in 1999]. / Plonica w 1999 roku.

Following the last compensatory epidemic of scarlet fever in 1995 the number of cases decreased, although the decrease rate was low. In 1999 the incidence rate for the entire country was 25.1 per 100,000 (range from 11.5 to 38.6 in different voivodeships). Incidence in urban areas was 92% higher than in rural areas. Two percent of cases were hospitalized. No scarlet fever deaths were noted. Children and adolescents under 14 years of age accounted for 96% cases. As in previous years, the highest incidence rates were noted among children aged 5 (247.4 per 100,000), 6 (277.3 per 100,000), and 7 years (242.3 per 100,000). In the last decade incidence peak has shifted from 4-6 to 6-7 year old age group. It was probably due to demographic and socioeconomic changes taking place in Poland.

[Rubella in Poland in 1999]. / Rózyczka w 1999 roku.

In Poland in 1999 rubella was characterized by an epidemiological stability. A total of 30 958 rubella cases (including one case of Congenital Rubella Syndrome) were registered. The incidence rate was 80.1 per 100,000 and was 28% lower than in 1998. Of all reported cases, children aged 14 and less accounted for 94.6% cases. The highest incidence rate was among children aged 7 years (752.8 per 100,000). Comparing with the eighties, the last decade was characterized by a decline of the mean incidence rate in the population under 30 years of age, which was probably the consequence of mandatory vaccinations of 13 year old schoolgirls. Also, a decline of incidence rate among 2-5-year old children was observed, which was probably due to recommended vaccinations with MMR-II vaccine. The incidence rate among children aged 6-9 years was higher in 1999, as compared with previous years. Of all rubella cases, 0.5% were hospitalized. No deaths from rubella were reported.

[Infectious diseases in Poland in 1998]. / Choroby zakazne w Polsce w 1998 roku.

Epidemiological situation of majority of infectious diseases in Poland was in 1998 consecutively improved. Decrease of incidence of infectious hepatitis type A and B was noted as well as of tuberculosis and sexually transmitted diseases. Percentage of deaths caused by infectious diseases decreased to 0.6%. Sustaining of such positive trends will require first of all continuation of preventive immunizations at present level, improvement of laboratory diagnoses, but also an improvement of identification of diseased and infected peoples and also notification of cases.

[Scarlet fever in 1998]. / Plonica w 1998 roku.

Following last compensatory epidemic of scarlet fever in 1995 number of cases decreases more slowly then after earlier epidemics. In 1998 incidence for the whole country was 41.9 per 100,000 with a range of 9.2 to 72.5 for individual voivodeships. Relations between incidence and age, gender and habitation (rural vs. urban areas) did not change. In 1998 the highest incidence was noted among children 6 years old (462.4) and 7 years old (440.5). Incidence among men was slightly higher (44.5) then women (39.4). Incidence in urban areas (52.8) more than twofold surpassed incidence in rural areas (24.2). 1% of cases were hospitalized. There were not any fatalities noted.

[Rubella in 1998]. / Rózyczka w 1998 roku.

In 1998 in Poland the incidence rate of rubella has been reduced three times in comparison with 1997 outbreak. 43,239 rubella cases (111.8/100,000) were registered, including 4 CRS cases (1.0/100,000 live births). 148 persons (0.34% of all cases) were hospitalised. 94.1% of cases were children under age of 14. The highest incidence rate was noted in the group of age 5-9 (790.1/100,000). The following rate of vaccinated schoolgirls was reported in 1998: 97.3% in-group of 13-year old, 97.3%--14 y.o. and 98.9%--15 y.o.

[Hepatitis C in 1998]. / Wirusowe zapalenie watroby typu C w 1998 roku.

In 1998, 1,710 cases of viral hepatitis type C were reported (incidence 4.4 per 100,000). There were 149 (8.7%) mixed infections: HCV + BBV. Both acute cases and newly diagnosed chronic cases were registered. Highest incidence was found in people 55-59 years old (7.49) and 60-64 years old (7.05). Cumulative incidence was higher in men (5.2), than in women (3.7). In particular in age groups of 15-34 incidence in men was even 2-3 times higher that in women. Incidence in cities (5.9) was 3 times higher then in rural areas (2.0). Among reported cases at least 113 (6.6%) employees of health system were found. Data presented above should be taken cautiously because separate registration of hepatitis C was introduced in Poland as late as in 1997.

[Demographic condition of Poland in years 1950-1998 and prognosis of its development up to the year 2050]. / Sytuacja demograficzna Polski w latach 1950-1998 i prognoza jej rozwoju do 2050 roku.

Proper evaluation of epidemiology data for a country requires knowledge of its demographic background. The most relevant data related to demographic structure and migration in 1950-1998 were chosen as a reference for epidemiological analysis. The review includes demographic prognoses developed in authors program of employees of Glówny Urzad Statystyczny (National Office for Statistics) in Poland.

[Infectious diseases in Poland in 1997]. / Choroby zakazne w Polsce w 1997 roku.

Decreasing of number of cases as well as incidence rate of hepatitis type B and type A, and increasing of pertussis, leptospirosis, encephalitis and some other diseases was noted in Poland in 1997. The biggest percentage of deaths was caused by tuberculosis--43.1%, sepsis--over 21.9% and hepatitis--10.6%. Introduction of ICD-10 as well as strikes of health workers in Poland in 1997 caused undernotification especially of deaths.

[Scarlet fever in 1997]. / Plonica w 1997 roku.

In 1997, two years after the last epidemic peak of scarlet fever, the speed of decrease of the number of registered cases has been slower than after earlier epidemics. However, the seasonal distribution of cases does not forecast an increase of incidence of scarlet fever in the near future. The age, sex, urban/rural distribution of scarlet fever remain stable. The highest incidence rates are noted in 7-8-year old children. Scarlet fever cases are hospitalized in 1%.

[Rubella in 1997]. / Rózyczka w 1997 roku.

A cyclical epidemic of rubella has been noted in Poland in 1997. The relatively high incidence rate persistent in the last interepidemic period and local outbreaks in some areas in 1995-1996 caused smaller range of 1997 epidemic. The incidence was much lower than in 1986 and 1992 when the biggest registered rubella outbreaks were noted. The last epidemic outbreak of rubella didn't change significantly the existing relation between the incidence, age, gender and place of residence (rural, urban). The percentage of hospitalized cases was similar to past (0.2%).