Epidemiological investigations into multiple sclerosis in Southern Hesse I.

An epidemiological field-survey on multiple sclerosis (MS) was carried out in the southern part of the state of Hesse (West Germany). Out of 472 patients primarily ascertained, 75% could finally be accepted as definite or probable MS cases. Cross-checking of the 3 sources for case-finding (practitioners and specialists, neurological hospital, MS society) revealed that case-finding in all and especially that of definite and probable MS cases was rather complete. The overall prevalence rate was 58.3, the annual incidence 2.15 and the mortality rate 2.0 per 100,000. Male patients showed a faster course than females. The prevalence in immigrants who mostly originated from Mediterranean countries, was significantly lower (14.3 per 100,000) than the prevalence in the German population (63.1 per 100,000).     

Prevalence of multiple sclerosis in Valladolid, northern Spain

The aim of this study was to ascertain the prevalence of multiple sclerosis (MS) in a northern Spanish region and to compare it with that from the most recent epidemiological studies in the country. MS prevalence was studied for a period of 2 years using multiple sources of information in the province of Valladolid, with a sample comprising a total population of 92,632. Patients were classified according to the Poser criteria. The crude prevalence of definite and probable MS was 58.3 per 100,000 (95% confidence interval: 43.7–75.7). The same methods have been used in ascertaining similar prevalence rates in Vélez-Málaga, Osona, and Gijón and a slightly lower rate in Teruel. Our survey confirms Spain as a high-risk area for MS, with prevalence rates over 50 per 100,000. Received: 4 March 1998 Received in revised form: 13 May 1998 Accepted: 10 June 1998     

Frequency of multiple sclerosis in Valle d'Aosta, 1971-1985

According to studies done before 1980, the multiple sclerosis (MS) prevalence rate in Italy ranged from 7.2 to 27.1 cases per 100,000 inhabitants. More recent work has consistently put the MS prevalence rate to over 30 cases per 100,000 inhabitants. If these recent data are confirmed in the future, Italy can no longer be regarded as a country at low risk for MS, but must be included among the medium-high risk countries of continental Europe. We report the results of a prevalence and incidence survey conducted in Valle d'Aosta, a region whose special features make it an excellent epidemiological model. The mean annual incidence was 2.1 and on December 31, 1985, the prevalence was 39 cases per 100,000 inhabitants. These results confirm that the incidence and prevalence rate of MS in Valle d'Aosta is close to that of areas at high-risk for MS.     

Incidence and distribution of multiple sclerosis in Halle District

An epidemiological study of multiple sclerosis (MS) in the district of Halle, Halle-Neustadt and the area near the river Saale was carried out. We found 178 patients with a definite diagnosis in a total population of 396,529, corresponding to a prevalence of 44.9/100,000. The annual incidence rate was 2/100,000. When probable but not definitely diagnosed cases are included in the count, the estimated prevalence rises to 53.7/100,000 population.     

Estimated prevalence of multiple sclerosis in Italy in 2015

Italy is a high risk area for multiple sclerosis (MS) as confirmed by the numerous prevalence and incidence studies conducted in several regions/districts of the country. Nevertheless, there are no recent published epidemiological data, nor studies about the total prevalence of MS in Italy. Our aim was to update as of 2015 the prevalence rates of MS in different geographical areas using already published epidemiological studies, and to estimate the overall prevalence of the disease in Italy. We made a search in MEDLINE database of all published studies on epidemiology of MS in Italy. Then, we applied, to the already published prevalence data, the last published incidence and mortality rates to recalculate, as of 2015, the prevalence of MS. So, we calculated the mean prevalence rate from our extrapolations, and we applied it to the population in 2015 to estimate the number of MS patients in Italy. Our prevalence extrapolations ranged from 122 to 232 cases/100,000 in the mainland and Sicily, with an average of 176/100,000, and from 280 to 317 cases/100,000 in Sardinia with an average of 299/100,000. Applying these media to the Italian population in 2015, we obtained an estimate of more than 109,000 MS patients in Italy. Our estimates were higher than the latest published rates but consistent with the annual increase of prevalence due to incidence that exceeds mortality, with the increase of survival and, maybe, with the probable increase of incidence.     

A further study on the prevalence of multiple sclerosis in Sicily: Caltanissetta city

The prevalence of probable multiple sclerosis (MS) in Caltanissetta city, Sicily, is at least 51 per 100,000. If possible multiple sclerosis patients are included, it is 54 per 100,000. This value is similar to that found in other cities in Sicily: Enna, Monreale and Agrigento. The high prevalence of multiple sclerosis in Caltanissetta confirms the previous data on Sicily and emphasises the importance of small population studies in the epidemiology of MS.     

Multiple sclerosis in southern Europe A PREVALENCE STUDY IN THE SOCIOSANITARY DISTRICT OF COPPARO, NORTHERN ITALY

The prevalence of multiple sclerosis (MS) in the Italian studies presently available is reported to be between 3.3 and 19.5 per 100,000. All these studies, however, have been undertaken in populations exceeding 300,000 and probably offer underestimates of MS frequency. Current sanitary organization in Italy is inadequate for epidemiological search and many patients with MS may be overlooked when large populations are studied. So, accurate estimates of MS frequency are possible only as a result of intensive surveys in small population groups. Prevalence figures of 53 and 32 per 100,000 have been recently reported by Dean et al. who studied the frequency of MS in small population groups in Sicily. The present study reports the results of a similar survey in the district of Copparo (population 45,153) in northern Italy. The prevalence of probable MS found in Copparo was 31 per 100,000. This result confirms the findings of Dean et al. in southern Italy and supports Dean's opinion that the true frequency of MS in Italy as a whole is higher than that indicated by the Italian studies.     

A reappraisal of the epidemiology of multiple sclerosis in Olmsted County, Minnesota

A review of multiple sclerosis (MS) case reports, using the unified record system at the Mayo Clinic for the Olmsted County population, revealed age- and sex-adjusted prevalence rates per 100,000 persons of 160 for Olmsted County and 173 for Rochester, Minnesota, on January 1, 1985. The annual age- and sex-adjusted incidence rate per 100,000 person-years from 1975 to 1984 for Olmsted County was 6.2 and for Rochester, 6.3. This incidence rate is significantly higher than what had been reported previously in Rochester (3.6/100,000) or in other communities. The estimated 25-year survival of the MS population was 76.2% +/- 4.5% compared with 87.7% for the general US white population of a similar age and sex. Survival for men was less than for women. There was no increase in survival for patients diagnosed with MS in more recent decades. No significant increase was found in cancer or autoimmune disease rates in the MS patients.     

The epidemiology of multiple sclerosis in Finland: increase of prevalence and stability of foci in high-risk areas

ABSTRACT- Reliable data on the epidemiology of multiple sclerosis (MS) in Finland are available from 1964 and 1972. They show that the whole country is a high-risk area of MS with clustering in the western part. A reassessment of the prevalence data was carried out in the southern province of Uusimaa and in the western province of Vaasa, the prevalence day being January 1, 1979. The age-adjusted prevalence was 52.9 per 100,000 in Uusimaa and 92.9 per 100,000 in Vaasa, figures that were three times higher than those recorded for the same areas in 1964. The communities with the highest prevalence rates in the province of Vaasa were the same as those in the survey of 1972; some rates exceeded 200 per 100,000. The increase in the prevalence rates may be due to a better registration of MS cases, but it may also represent a true increase, a possibility that only can be answered by further incidence studies.     

Multiple sclerosis in the Cambridge health district of east Anglia.

A survey of multiple sclerosis (MS) in the Cambridge Health District has identified 374 cases in a population of 288,410, giving a prevalence of 130 per 100,000. A total of 322 cases (86%) had either clinically definite or probable multiple sclerosis on 1 July 1990 (112 per 100,000) and 52 cases (14%) had suspected multiple sclerosis (18 per 100,000.) The incidence during 1989-91 was 5.94 per 100,000 per year. The prevalence figure is higher than in recent surveys from other southern parts of the United Kingdom, but correction for the age and sex characteristics of the at risk population eliminates these differences. The overall prevalence of multiple sclerosis is probably between 108 and 120 per 100,000 in the southern United Kingdom.     

Multiple sclerosis in Nord-Trøndelag County, Norway: a prevalence and incidence study

Objective – To calculate the prevalence and incidence of multiple sclerosis (MS) in Nord‐Trøndelag County, Norway. Material and methods – The study comprised everyone diagnosed with MS according to the Poser criteria. On 1 January 2000 a total of 208 were identified: 130 women (62.5%) and 78 men (37.5%). We calculated the crude and age‐adjusted annual incidence rates from 1974 to 1999. Results – The prevalence on 1 January 2000 was 163.6 of 100,000, 204.8 of 100,000 for women and 122.6 of 100,000 for men. The age‐adjusted annual incidence increased from 3.9 to 5.6 per 100,000 from 1974 to 1999; women from 4.6 to 6.3 and men from 2.2 to 4.4. After 1984, the incidence among women increased most, peaking at 10.2 per 100,000 in 1984–88. Conclusions – MS incidence is increasing in Nord‐Trøndelag County. The prevalence is among the highest ever in Norway.     

Prevalence of multiple sclerosis in Gypsies and Bulgarians.

There are occasional reports about the low prevalence of multiple sclerosis among Gypsies. To verify these reports of low prevalence of multiple sclerosis among Gypsies compared to the white population in Bulgaria, an epidemiological study was conducted in two small regions of Bulgaria. All patients with clinically or laboratory-supported, definite multiple sclerosis according to Poser's criteria were personally interviewed and examined. The study was begun on January 1, 1997 and March 31, 1998 was selected as prevalence day. For the white population, the prevalence ratio of multiple sclerosis per 100,000 population was 44.9 in the first region and 44.4 in the second. The prevalence of multiple sclerosis in Gypsies was found to be 19.1/100,000 in the first region and 18.4 in the second. It is concluded that multiple sclerosis is less common in Gypsies than in whites living in the same areas.     

Multiple sclerosis in the Republic of San Marino,Italian peninsula: an incidence and prevalence study from a high-risk area

Epidemiological studies on multiple sclerosis (MS) carried out in Southern Europe in the last years have shown a significant increase in the disease frequency. Previous surveys conducted in the Republic of San Marino, Northern Italian peninsula, identified that the population is at high risk for MS, with a prevalence of 51.6 per 100,000 population in 1982 and of 166.7 in 2005 and with a mean annual incidence of 7.9 per 100,000 for the period 1990–2005. The present work is a community-based intensive prevalence and incidence survey, by a complete enumeration approach, to update the prevalence and incidence of MS in the Republic of San Marino. The mean annual incidence for the period 2005–14 was 7.7 (95% CI 4.9–11.4) per 100,000, 3.3 (95% CI 1.1–7.6) for men and 11.9 (95% CI 7.2–18.6) for women. On 31 December 2014, 67 patients (19 men and 48 women), suffering from definite or probable MS and living in the Republic of San Marino, yielded a crude prevalence of 204.3 (95% CI 158.4–259.5) per 100,000, 117.8 (95% CI 70.9–183.7) for men and 288.2 (95% CI 212.4–383.3) for women. Our study has confirmed San Marino is an area at high risk for MS, in line with epidemiological data from continental Italy. The marked increase in MS prevalence over time in this population can be ascribable to increased survival and improved ascertainment, in the presence of a substantially stable, yet high, incidence rate.     

Multiple sclerosis in southern Europe: Monreale City, Italy. A twenty-year follow-up incidence and prevalence study

BACKGROUND: Several follow-up studies showed increasing prevalence and incidence rates for multiple sclerosis (MS). OBJECTIVE: To ascertain, throughout a follow-up study, the incidence and prevalence of MS in the city of Monreale, Sicily, southern Italy. METHODS: We calculated crude and age- and sex-specific prevalence rates on December 31, 2000, and determined incidence rates for the period January 1, 1992 to December 31, 2000. RESULTS: The prevalence of MS was 71.2 per 100,000 population (48,5/100,000 in men; 93,0/100,000 in women). The incidence rate of MS for the period 1992-2000 was 4.0/100,000 per year. CONCLUSION: This study showed a nonsignificant increase in MS incidence rates in Monreale city for 1992-2000 compared to 1981-1991. Prevalence rates were similar to those of the previous follow-up study. Intervals between onset of symptoms and diagnosis seemed shorter than in prior studies. There is no evidence that the high prevalence and incidence rates have changed in this interval but numbers are too small for firm statements. These findings indicate that in Monreale city MS prevalence is stable and confirm Sicily as a high-risk area for MS.     

A possible spatial and temporal cluster of multiple sclerosis in the town of Linguaglossa,Sicily

We carried out an epidemiological survey to determine prevalence and incidence of multiple sclerosis in the little town of Linguaglossa in the Province of Catania. We calculated prevalence rate as point prevalence at 1 January 2001 and incidence during 1991–2000.We studied the frequency of multiple sclerosis in the community of Linguaglossa in a population of 5,422 inhabitants in the 2001 census. The primary sources for the case ascertainment were the general practitioners of Linguaglossa, the local Italian Multiple Sclerosis Association and the neurological departments, Multiple Sclerosis Centers and private neurologists of the province of Catania. We considered as prevalent and incident cases all patients who satisfied the Poser’s diagnostic criteria. We detected 11 patients with multiple sclerosis who had had the onset of disease on prevalent day (P.D.). The onset–adjusted prevalence rate was 203/100,000 (95% CI 107–352).Prevalence was higher in women (247/100,000) than in men (154/100,000). From 1991 to 2000, 10 subjects with MS had clinical onset of disease. The mean annual incidence risk was 18.2/100,000 (C. I. 95 % 5.9–42.5).Conversely in the same population prevalence on 1 January 1991 was 37/100,000 while the onset adjusted annual incidence risk during the previous decade (1981–1991) was 3.6/100,000. Prevalence and incidence rates of MS during the last decade in the little town of Linguaglossa are higher than those found in the same area during the previous ten years and also than those reported in other Sicilian and Italian surveys suggesting a possible cluster of MS.     

Prevalence of multiple sclerosis door-to-door survey in Maltepe, Istanbul, Turkey

BACKGROUND: The prevalence of multiple sclerosis (MS) in Istanbul, Turkey, is unknown. We investigated the prevalence of MS in the district of Maltepe, Istanbul, Turkey. METHODS: This was a cross-sectional field research study using door-to-door sampling. Maltepe is a district of Istanbul beside the sea of Marmara (population 359,298 from 2000 census). The two-phase study screened 32,531 subjects using the Poser criteria for clinical diagnosis. The chi(2) test was used for analyses of frequency distributions. RESULTS: 33 of 32,531 people were diagnosed with MS. Their average age was 41 +/- 12.0 years (43 +/- 12.7 years for females and 37 +/- 9.6 years for males). The prevalence of MS in Maltepe was 101.4/100,000 within the total population (118.7/100,000 in the female and 76.0/100,000 in the male populations). CONCLUSIONS: The prevalence rates of MS in the Turkish population living in a district of Istanbul are considerably higher than we thought. And the prevalence rate is much higher than neighboring countries. They are similar to those recently recorded in Sicily and Germany. These figures suggest that the prevalence rate of MS is not totally dependent upon geographical variation. However, the research of our results needs to be confirmed with further investigations in order to determine the prevalence of MS in Turkey with confidence.     

Multiple sclerosis is prevalent in the Zoroastrians (Parsis) of India

Using Schumacher's classification, we determined the prevalence rate of clinically definite multiple sclerosis (MS) in the distinct but tiny Zoroastrian (largely Parsi) community in the adjacent cities of Bombay (latitude, 18.55 degrees) and Poona (Pune). On prevalence day, 16 clinically definite cases of MS were counted, 14 in Bombay and 2 in Poona, from a total Zoroastrian population of 50,053 and 3,399, respectively. The crude prevalence ratio was 26 per 100,000 for Bombay and 58 per 100,000 for Poona. The age-adjusted prevalence ratio for Bombay was 24 per 100,000, with 95% confidence limits of 13.1 to 40.3. These are much higher than the low rates believed to be prevalent in India, and are comparable with those found in parts of Europe and the United States.     

Bayesian mapping of multiple sclerosis prevalence in the province of Pavia, northern Italy

The geographical analysis of a disease risk is particularly difficult when the disease is non-frequent and the area units are small. The practical use of the Bayesian modelling, instead of the classical frequentist one, is applied to study the geographical variation of multiple sclerosis (MS) across the province of Pavia, Northern Italy. 464 MS-affected individuals resident in the province of Pavia were identified on December 31st 2000. The overall prevalence was 94 per 100,000 inhabitants. This estimate indicates an increasing MS prevalence in the province, in accordance with the vast majority of the Italian areas where prevalence studies have been repeated. We mapped the geographical variation of MS prevalence across the 190 communes of the province both with a classical approach and a Bayesian approach. The frequentist approach produced an extremely dishomogeneous map, while the Bayesian map was much smoother and more interpretable. Our study underlines the usefulness of Bayesian methods to obtain reliable maps of disease prevalence and to identify possible clusters of disease where to carry out further epidemiological investigations.     

Prevalence and mortality of patients with multiple sclerosis in France in 2012: a study based on French health insurance data

Data on the prevalence of multiple sclerosis (MS) in France are scarce. National and regional updated estimates are needed to better plan health policies. In this nationwide study, we provided estimates of the prevalence of MS in France in 2012 and mortality rate in 2013. MS cases were identified in the French national health insurance database (SNIIRAM-PMSI) using reimbursement data for disease-modifying treatment, long-term disease status for MS, disability pension for MS, and hospitalisation for MS (MS ICD-10 code: G35). We identified 99,123 MS cases, corresponding to an overall crude prevalence rate of 151.2 per 100,000 inhabitants [95% confidence interval (CI) 150.3–152.2]: 210.0 per 100,000 in women (95% CI 208.4–211.5) and 88.7 per 100,000 in men (95% CI 87.6–89.7). The overall prevalence rate was 155.6 per 100,000 inhabitants (95% CI 154.7–156.6) after standardization on the 2013-European population. We observed a prevalence gradient with a higher prevalence (190–200 per 100,000) in North-Eastern France and a lower prevalence in Southern and Western France (126–140). The crude mortality rate in 2013 was 13.7 per 1,000 MS cases (11.4 in women and 20.3 in men). The standardized mortality ratio was 2.56 (95% CI 2.41–2.72). Our results revise upwards the estimation of MS prevalence in France and confirm the excess mortality of MS patients compared to the general population.