The reliability of tweets as a supplementary method of seasonal influenza surveillance.

BACKGROUND: Existing influenza surveillance in the United States is focused on the collection of data from sentinel physicians and hospitals; however, the compilation and distribution of reports are usually delayed by up to 2 weeks. With the popularity of social media growing, the Internet is a source for syndromic surveillance due to the availability of large amounts of data. In this study, tweets, or posts of 140 characters or less, from the website Twitter were collected and analyzed for their potential as surveillance for seasonal influenza. OBJECTIVE: There were three aims: (1) to improve the correlation of tweets to sentinel-provided influenza-like illness (ILI) rates by city through filtering and a machine-learning classifier, (2) to observe correlations of tweets for emergency department ILI rates by city, and (3) to explore correlations for tweets to laboratory-confirmed influenza cases in San Diego. METHODS: Tweets containing the keyword "flu" were collected within a 17-mile radius from 11 US cities selected for population and availability of ILI data. At the end of the collection period, 159,802 tweets were used for correlation analyses with sentinel-provided ILI and emergency department ILI rates as reported by the corresponding city or county health department. Two separate methods were used to observe correlations between tweets and ILI rates: filtering the tweets by type (non-retweets, retweets, tweets with a URL, tweets without a URL), and the use of a machine-learning classifier that determined whether a tweet was "valid", or from a user who was likely ill with the flu. RESULTS: Correlations varied by city but general trends were observed. Non-retweets and tweets without a URL had higher and more significant (P<.05) correlations than retweets and tweets with a URL. Correlations of tweets to emergency department ILI rates were higher than the correlations observed for sentinel-provided ILI for most of the cities. The machine-learning classifier yielded the highest correlations for many of the cities when using the sentinel-provided or emergency department ILI as well as the number of laboratory-confirmed influenza cases in San Diego. High correlation values (r=.93) with significance at P<.001 were observed for laboratory-confirmed influenza cases for most categories and tweets determined to be valid by the classifier. CONCLUSIONS: Compared to tweet analyses in the previous influenza season, this study demonstrated increased accuracy in using Twitter as a supplementary surveillance tool for influenza as better filtering and classification methods yielded higher correlations for the 2013-2014 influenza season than those found for tweets in the previous influenza season, where emergency department ILI rates were better correlated to tweets than sentinel-provided ILI rates. Further investigations in the field would require expansion with regard to the location that the tweets are collected from, as well as the availability of more ILI data.

The complex relationship of realspace events and messages in cyberspace: case study of influenza and pertussis using tweets.

BACKGROUND: Surveillance plays a vital role in disease detection, but traditional methods of collecting patient data, reporting to health officials, and compiling reports are costly and time consuming. In recent years, syndromic surveillance tools have expanded and researchers are able to exploit the vast amount of data available in real time on the Internet at minimal cost. Many data sources for infoveillance exist, but this study focuses on status updates (tweets) from the Twitter microblogging website. OBJECTIVE: The aim of this study was to explore the interaction between cyberspace message activity, measured by keyword-specific tweets, and real world occurrences of influenza and pertussis. Tweets were aggregated by week and compared to weekly influenza-like illness (ILI) and weekly pertussis incidence. The potential effect of tweet type was analyzed by categorizing tweets into 4 categories: nonretweets, retweets, tweets with a URL Web address, and tweets without a URL Web address. METHODS: Tweets were collected within a 17-mile radius of 11 US cities chosen on the basis of population size and the availability of disease data. Influenza analysis involved all 11 cities. Pertussis analysis was based on the 2 cities nearest to the Washington State pertussis outbreak (Seattle, WA and Portland, OR). Tweet collection resulted in 161,821 flu, 6174 influenza, 160 pertussis, and 1167 whooping cough tweets. The correlation coefficients between tweets or subgroups of tweets and disease occurrence were calculated and trends were presented graphically. RESULTS: Correlations between weekly aggregated tweets and disease occurrence varied greatly, but were relatively strong in some areas. In general, correlation coefficients were stronger in the flu analysis compared to the pertussis analysis. Within each analysis, flu tweets were more strongly correlated with ILI rates than influenza tweets, and whooping cough tweets correlated more strongly with pertussis incidence than pertussis tweets. Nonretweets correlated more with disease occurrence than retweets, and tweets without a URL Web address correlated better with actual incidence than those with a URL Web address primarily for the flu tweets. CONCLUSIONS: This study demonstrates that not only does keyword choice play an important role in how well tweets correlate with disease occurrence, but that the subgroup of tweets used for analysis is also important. This exploratory work shows potential in the use of tweets for infoveillance, but continued efforts are needed to further refine research methods in this field.

[Effects of opiate receptor blockade with naloxone on prolactin (PRL) secretion in patients with diabetes type I (IDDM) with chronic renal failure treated with hemodialysis (HD)]. / Wplyw blokady receptorów opioidowych naloksonem na wydzielanie prolaktyny (PRL) u chorych na cukrzyce typu I (IDDM) z przewlekla niewydolnoscia nerek leczonych hemodializami (HD).

The aim of the study was to answer the questions: 1) does the prolactin secretion in the TRH test (0.4 mg i.v.) differ in haemodialyzed patients with diabetes nephropathy in the end stage renal failure in comparison to haemodialyzed chronic renal failure patients with non-diabetic nephropathy and healthy subjects; 2) does the opiate receptors blockade with naloxone (2 mg i.v.) modify the prolactin secretion during the TRH test in those patients. 39 subjects were studied. The patients were divided into three groups: group I: 12 haemodialyzed patients with IDDM and diabetic nephropathy in the end stage renal failure, group II: 15 haemodialyzed chronic renal patients with non-diabetic nephropathy and the control group: 12 healthy persons. The basic prolactin secretion and area over basic value (AOBV) of the prolactin were estimated. Prolactin concentration was measured by LIA. 1) The basic prolactin secretion was significantly higher in the patients with chronic renal failure. 2) The basic prolactin secretion in IDDM patients with diabetic nephropathy in the end stage renal failure treated with haemodialysis was significantly lower than in haemodialyzed patients with chronic renal failure of non-diabetic etiology. 3) TRH and TRH with naloxone caused significant increase of prolactin secretion in all investigated groups, but the increase is significantly lower in chronic renal failure patients than in healthy subjects. 4) Naloxone decreases significantly the prolactin secretion during TRH test only in haemodialyzed patients with chronic renal failure of non-diabetic etiology.

[Analysis of risk factors and prevalence of spinal osteoporosis in a population sample of Warsaw residents over 50 years of age]. / Analiza czynników ryzyka i czestosc wystepowania osteoporozy kregoslupa w próbce populacyjnej mieszkanców Warszawy powyzej 50. roku zycia.

Vertebral fractures are the one typically seen in osteoporosis. An incidence of vertebral body fractures and risk factors for osteoporosis were analysed in the retrospective population based epidemiological study. Population sample included 607 Warsaw inhabitants aged between 50 and 80 years (301 women and 306 men divided into age groups of 5 years, including approx. 50 subjects each). Vertebral body fractures were diagnosed on thoraco-lumbar spine X-rays made in the lateral projection. Risk factors for osteoporosis were analysed with the aid of an questionnaire. Bone mineral density was measured with dual energy X-ray absorptiometry and single photon absorptiometry in about 1/3 of the examined women. The prevalence of vertebral osteoporosis was high in both women (20.5%) and in men (27.8%). Low dietary calcium intake (below 800 mg daily) and low serum vitamin D levels (250HD less than 11 micrograms/ml) were characteristic for about 90% of the examined population. In osteoporotic subjects the following risk factors were significantly more frequent: age (p < 0.01), tobacco smoking (p < 0.001), low physical activity (p < 0.05), long-term immobilization (p < 0.01). Densitometry showed significantly lower bone mineral density in both women with vertebral fractures (p < 0.01) and low serum vitamin D levels (p < 0.05). Osteoporotic vertebral fractures were diagnosed more frequently in women with early menopause (p < 0.001). In the examined population there is a ligh prevalence of vertebral osteoporosis (predominating in mean) and risk factors.

[Bone density in axial and peripheral skeleton and mineral density of the entire body as an age dependent factor in a population sample of healthy women]. / Gestosc masy kostnej w szkielecie osiowym i obwodowym oraz gestosc mineralna calego ciala w zaleznosci od wieku w próbce populacyjnej zdrowych kobiet.

Bone mineral density has been measured with dual energy X-ray absorptiometry (DEXA) in both axial and peripheral skeleton of 208 randomly selected healthy women aged between 20 and 80 years. Examined women have been stratified into the age groups of every 10 years. Bone mineral density has been measured in lumbar spine L2-L4 (AP), L2-L3 (Lat.) and proximal femur together with total body mineral density in every examined woman. The obtained results are considered reference values for the Polish population.

[Epidemiology of proximal femur fracture and results of therapy in patients treated at the Orthopedic-Trauma Ward of the Railway Hospital in Warsaw in the years 1986-1990]. / Epidemiologia zlaman czesci blizszej kosci udowej oraz ocena kosztów leczenia (material Oddzialu Ortopedyczno-Urazowego Szpitala Kolejowego w Warszawie w latach 1986-1990).

A retrospective analysis included 441 hospitalized patients with fractures of the proximal femoral bone, treated at the orthopedic-traumatology ward in 1986-1990. Such patients constituted 9.12% of all patients treated during those years. There were 313 women aged between 26 and 99 years (mean 77.4 years) and 128 men aged between 30 and 95 years (mean 68.3 years). Fractures were more frequent in women than in men (rate 2.4:1). Four hundred four patients (91.6%) were treated surgically. Mortality rate in this group was about 10% whereas in patients treated conservatively--approximately 66%. Locomotive functions were restored in the majority of patients under 80 years of age. Mean hospitalization time was 22 days. Mean cost per patient in zlotys treated surgically was 4.97 million in 1990, and 8.3 million in 1992.