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[The 2003/2004 influenza season in the Netherlands with a limited epidemic of the virus variant A/Fujian, and the vaccine composition for the 2004/2005 season].

In contrast to the three previous influenza seasons, the influenza epidemic of the 2003/2004 season started early in week 49 of 2003. The epidemic was predominantly caused by influenza-A viruses of the H3N2 subtype. All isolated influenza-A viruses were antigenically related to influenza virus A/Fujian/411/02, which was already detected in the influenza season 2002/2003 and that deviated from the vaccine-reference strain A/Moscow/10/99 to a certain extent. The magnitude of the epidemic was limited despite the fact that it was caused by influenza-A H3N2-virus-drift variants. Immunity caused by natural infection with influenza viruses during previous seasons or vaccination has possibly provided sufficient cross protection against these new H3N2-drift variant. No influenza-A viruses of the H1N1 or H1N2 subtypes were detected in the influenza season 2003/2004. Only a small number of influenza-B viruses were isolated, which all belonged to the B/Yamagata/16/88 lineage, which was temporarily replaced by the B/Victoria2/87 lineage in the previous influenza season. On the basis of epidemiological and serological data the World Health Organization has recommended the following vaccine composition for the 2004/2005 influenza season: A/Fujian/411/02 (H3N2), A/New Caledonia/20/99 (H1N1) and B/Shanghai/361/02.

Global Health↗

[Effect of organic material incorporation in rice season on N2O emissions from following winter wheat growing season].

In a field experiment, five fertilizer treatments including chemical fertilizer (CF), rapeseed cake + chemical fertilizer (RC + CF), wheat straw + chemical fertilizer (WS + CF), cow manure + chemical fertilizer (CM + CF), and pig manure + chemical fertilizer (PM + CF), were dedicated to examine the effect of organic materials incorporation in the rice season on N2O emissions from the following winter wheat season and to assess the climatic impacts from CH4 and N2O emissions in a rice-wheat rotation. Organic material was incorporated at the same rate (225 g x m(-2)) for organic treatments at the depth of 10 cm in the soil as the basal fertilizer just before rice transplanting. An identical synthetic nitrogen fertilizer was adopted for all treatments. Results show that the seasonal amount of N20 emissions from the following wheat season differed with organic material applied in rice season. No pronounced difference in N20 emissions was found between the CF and RC + CF treatments. In contrast with the CF treatment, however, N2O emission was decreased by 15% for the WS + CF treatment, but increased by 29% and 16% for the CM + CF and PM + CF treatments, respectively. Over the entire annual rotation cycle, N2O amount was increased by 17% for the CM + CF treatment, 7% for the PM + CF treatment, and 6% for the RC + CF treatment, but decreased by 16% for the WS + CF treatment in comparison with the CF treatment. Based on total emissions of CH4 in rice season and N2O over the entire rotation cycle, the estimation of combined Global Warming Potentials (GWPs) for CH4 and N20 shows that over a 20 years horizon or a 500 years horizon, the value of annual total GWPs was ranked in the order of RC + CF > WS + CF > CM + CF > PM + CF > CF or RC + CF > CM + CF > PM + CF > WS + CF > CF. The highest, middle and the lowest value of the GWPs per unit crop grain yield occurred for the crop residue, farmyard manure and pure synthetic fertilizer treatments, respectively. Compared to the chemical fertilizer treatment, accordingly, organic material combined with chemical fertilizer application in rice season increased climatic impacts from CH4 and N20 emissions in a rice-winter wheat rotation system.

Agriculture↗

Long days and thyroxine program american tree sparrows for seasonality: evidence for temporal flexibility of the breeding season of euthyroid females.

To explore the role of the thyroid in the control of seasonality, photosensitive female American tree sparrows (Spizella arborea) were thyroidectomized (THX), moved to long days, and given daily injections of thyroxine (T4) for 3 weeks; THX and thyroid-intact (THI) controls received daily injections of alkaline vehicle. Birds were retained on long days 4 additional weeks and then moved to constant light and given T4 in drinking water for 5 weeks in order to test for photorefractoriness. Endpoints were ovarian mass, molt score, and hypothalamic cGnRH-I (chicken gonadotropin-releasing hormone I) content; data were collected as independent measures at intervals of 1 to 5 weeks. THX females given T4 replacement therapy (THXT4 females) exhibited all components of seasonality (i.e., photoperiodic ovarian growth, photorefractoriness, and postnuptial molt), as did THI females. THX females not given replacement T4 were aseasonal: They showed only minor thyroid-independent photoperiodic ovarian growth; they remained photosensitive, despite chronic photostimulation; and they did not initiate postnuptial molt. Collectively, these observations support, and extend to female tree sparrows, our model of seasonality in male tree sparrows, wherein control circuits are programmed for gonadal growth, photorefractoriness, and postnuptial molt by interactive effects of long days and thyroid hormone during the first 3 weeks of photostimulation. The unexpected finding that constant light and/or exogenous T4 extended the simulated breeding seasons of some THI females prompted us to investigate the nature and expression of photorefractoriness. Our approach was to evaluate the same endpoints as before in chronically photostimulated THI females either retained on long days, with or without T4 in drinking water, or moved to constant light, with or without T4. The results showed that exposure to constant light (not T4) near the end of a simulated breeding season can-though usually it does not-temporarily extend the breeding season and prevent the onset of postnuptial molt. It remains unclear whether these perturbations caused by constant light reflect a transitional relative photorefractoriness or merely a delay in the onset of absolute photorefractoriness. In either case, the thyroid- and daylength-dependent programs controlling seasonality in female American tree sparrows have a heretofore undemonstrated potential for limited temporal flexibility.

Animals↗

[Viral respiratory infections in small children in the season in the season 1996-1997].

Using the immunofluorescence method, the etiology of virus respiratory infection was assayed in children aged 0-2 years, hospitalized because of respiratory diseases in the epidemic season 1996-1997. Data obtained were compared with those from the preceding season (1995-1996), as well as, from the 10 preceding seasons (1985-1995). In the season under study, participation of respiratory viruses was a little higher in the infections to be hospitalized. As compared with the preceding season, and the preceding 10 seasons, infections with parainfluenza type 1 and 3 viruses were higher in statistically significant way. Compared with the preceding seasons, more viral respiratory infections were found in November 96, as well as, in January and February 97. The number of viral respiratory infections was increased among children aged 10-12 months.

Adult↗

Seasonal mood disorders. Patterns of seasonal recurrence in mania and depression.

DSM-III-R criteria, applied retrospectively in a research-oriented psychiatric clinic, identified patients (N = 146) with a mood disorder and a seasonal pattern of recurrence (seasonal mood disorder). The seasonal mood disorder syndrome was not rare (10% of all mood disorders); diagnostic distribution was as follows: recurrent depression, 51%, and bipolar disorder, 49%, with 30% of the latter having mania (bipolar disorder type I) and 19% having hypomania (bipolar disorder type II). Most patients were women (71%); onset age averaged 29 years, with a mean of eight cycles in 12 years of illness; mean episode duration was 5.0 months. Mood disorder was found in a high proportion (68%) of the families. All but one patient followed one of two seasonal patterns in equal frequency: type A, fall-winter depression with or without spring-summer mania or hypomania; and type B, spring-summer depression with or without fall-winter mania or hypomania. Both types showed consistent times of onset and remission. These results emphasize that DSM-III-R seasonal mood disorder includes severe cases of recurrent depression and bipolar disorder and support a distinction between two seasonal subtypes.

Adult↗

The role of genetic factors in the etiology of seasonality and seasonal affective disorder: an evolutionary approach.

The degree to which seasonal changes affect mood, energy, sleep, appetite, food preference, or the wish to socialize with other people has been called seasonality. Seasonal affective disorder (SAD), a condition where depressions in fall and winter alternate with non-depressed periods in spring and summer, is the most marked form of seasonality. Several lines of evidence suggest that genetic factors play an important role in the etiology of seasonality and SAD. Millions of years of evolution and adaptation have optimized human biochemical and physiological systems for function and survival under equatorial environmental conditions. Modern humans began their migration out of Africa only about 150 000 years ago. Little change in our 'equatorial' systems might have been expected over this relatively short evolutionary time-span. The author suggests that a genetic susceptibility to seasonal changes in mood and behavior is a genetic predisposition to an insufficient adaptation to temperate and high latitudes.

Biological Evolution↗

Eosinophil markers in seasonal allergic rhinitis. Intranasal fluticasone propionate inhibits local and systemic increases during the pollen season.

BACKGROUND: The purpose was to study activation markers of the eosinophil granulocytes in seasonal allergic rhinitis, and the impact of topical steroid therapy thereupon. METHODS: Sixty-three rhinitis patients with monoallergy to grass were examined before and at peak pollen season. Blood eosinophil count, eosinophil cationic protein (ECP), and eosinophil peroxidase (EPO) in serum and nasal lavage fluid were measured. During the season, patients were randomized to treatment with intranasal fluticasone propionate 0.1 mg o.d. (n=26), 0.2 mg o.d. (n=25), or placebo (n=12). Six healthy persons served as controls. RESULTS: During the season, all parameters, except nasal lavage ECP, increased in the placebo group (P<0.001-P<0.05). Significant differences were seen between the steroid groups and the placebo group for all parameters (P<0.001-P<0.05). Higher eosinophil count (P<0.05), serum EPO (P<0.02), and nasal lavage EPO (P<0.05) were found in patients before season than in controls. The following winter, 44 patients returned for repeated measurement. Lower levels of nasal lavage EPO were observed for patients than levels at the beginning of the season (P<0.0001). CONCLUSIONS: Intranasal fluticasone propionate reduced inflammation of the nasal mucosa, demonstrated locally by nasal lavage ECP and EPO, and systemically by blood eosinophils, serum ECP, and serum EPO. EPO seemed more sensitive than ECP as indicator of allergic inflammation. EPO demonstrated some perennial eosinophil activity in hay fever patients, increasing locally during spring.

Acute-Phase Proteins↗

Seasonal mood symptoms in bulimia nervosa and seasonal affective disorder.

Mood and appetite disturbances are commonly found in bulimia nervosa and seasonal affective disorder (SAD). To investigate seasonality of mood symptoms, we administered the Seasonal Pattern Assessment Questionnaire (SPAQ) to 38 consecutive bulimic patients, 38 age- and sex-matched SAD patients, and 25 age- and sex-matched normal controls. The SPAQ is a reliable, retrospective, self-rated questionnaire that assesses seasonal changes in mood, sleep, weight, and social activity. The SAD patients had significantly higher Global Seasonality Scores (GSS) than the bulimic patients, who had higher scores than the control group (F = 78.6, df = 2.98, P less than .0001). Forty-two percent of bulimics met case-finding SPAQ criteria for SAD, compared with none of the control group (chi 2 = 14.1, df = 1, P less than .0005). These data suggest that a significant number of unselected bulimic patients have seasonal mood symptoms as severe as that seen in SAD. We propose that a common neurobiologic abnormality, such as serotonergic dysfunction, may underlie the common symptoms found in bulimia and SAD.

Adult↗

The four seasons: food intake frequency in seasonal affective disorder in the course of a year.

Patients with seasonal affective disorder (SAD) report atypical symptoms of increased appetite, particularly "carbohydrate craving," increased body weight, and sleepiness, during their winter depression. To document feeding behavior in detail, a Food/Drink Frequency Questionnaire (FDFQ) was given to female control subjects and SAD patients at each of the four seasons. SAD patients consumed carbohydrate-rich foods (starch and not sweets) more often than controls (annual mean) and also showed a seasonal rhythm with maximum values in winter and minimum values in summer. In contrast, protein-rich food intake was identical in both groups and did not show seasonal variation. Fiber-rich food intake was also increased in SAD patients. SAD patients ate more meals per day, both at breakfast and in the second half of the day. Again, SAD patients showed seasonal changes of meal number with a minimum in summer. Body weight and body mass index did not undergo significant seasonal changes in the group as a whole, nor did SAD patients differ from controls. These atypical symptoms in SAD can be interpreted as a "medial hypothalamus syndrome" involving alpha 2-noradrenergic and serotonergic mechanisms.

Adult↗

Unstable malaria in Sudan: the influence of the dry season. Malaria in areas of unstable and seasonal transmission. Lessons from Daraweesh.

Most studies of the natural history of Plasmodium falciparum infection have been performed in areas of stable malaria transmission and the acquisition of immunity to malaria in individuals who live in such areas is well documented. For the past 10 years, we have monitored host-parasite relationships in an area characterized by unstable and seasonal malaria of low transmission intensity. The work was performed in the village Daraweesh located in north-eastern Sudan 16 km from Gedaref town. The climate of the region is characterized by well-defined wet and dry periods with a short rainy season followed by a long dry season. In some years the rains fail and there is little precipitation even during the wet season. Malaria cases are rare in the dry season and during droughts. In years with rains, falciparum malaria sweeps through Daraweesh during the wet season and 20-40% of the entire population suffer at least 1 attack of malaria. All age-groups are affected, but the risk of getting a clinical attack is about twice as high in the age-group from 5 to 20 years as in adults aged above 30 years. Serological data and evidence obtained by polymerase chain reaction indicate that only about half of new blood-stage infections cause clinical disease. Together these findings suggest that many new infections are controlled immunologically and that individuals aged over 30 years are more successful in controlling infections than are teenagers. Parasite strains collected in Daraweesh are genotypically diverse and it is likely that the outcome of new P. falciparum infections depends on the preparedness of the host immune system to mount an attack against polymorphic or variable antigens expressed by the infecting parasite.

Adolescent↗

A cohort study of Plasmodium falciparum diversity during the dry season in Ndiop, a Senegalese village with seasonal, mesoendemic malaria.

Prolonged carriage of Plasmodium falciparum in humans during the dry season is critical for parasite survival, as the infected subjects constitute a major reservoir in the absence of transmission. Yet, very little is known about the host/parasite interactions contributing to parasite persistence. In order to study the characteristics of P. falciparum infections during the dry season, we have genotyped parasites collected from untreated, asymptomatic individuals during 3 cross-sectional surveys conducted during the dry season in Ndiop, a Senegalese village with seasonal, mesoendemic malaria. Monthly entomological surveillance did not detect any transmission during that period. Parasite prevalence decreased markedly in the children aged < 7 years after 7 months of undetected transmission, but was stable in older children and adults throughout the dry season. In all chronically infected individuals, infection complexity remained stable, but there were substantial fluctuations of individual genotype(s), reflecting complex dynamics of multiple-clone infections during chronic asymptomatic parasite carriage. This fluctuation resulted in changes in the msp1 and msp2 allelic distribution within the cohort after 7 months of undetected transmission, contrasting with the stability observed during the preceding rainy season in that village.

Adolescent↗

Are duodenal ulcer seasonal fluctuations paralleled by seasonal changes in 24-hour gastric acidity and Helicobacter pylori infection?

The occurrence of duodenal ulcer is characterized by seasonal variation, for poorly understood reasons. No previous study has assessed whether 24-h intragastric acidity and Helicobacter pylori infection have similar seasonal fluctuations in patients with this disorder. For this reason, we evaluated retrospectively the circadian gastric pH in 319 new patients (226 men and 93 women, mean age 45.2 years) with endoscopically proven duodenal ulcer, who agreed to undergo this examination during the years 1987-1992 in our center. The month-by-month occurrence of the disease over the global 6-year period was assessed, and the mean pH values were calculated for each patient during three time intervals of interest: 24 h, daytime (08:00-19:59 h), and nighttime (20:00-07:59 h). The mean pH values of these three time periods were then calculated month by month throughout the annual cycle. H. pylori infection was sought by histology in 171 patients examined in the period from 1990 to 1992. The percentage of H. pylori-positive duodenal ulcer patients was then calculated for each season. The calendar fluctuation of duodenal ulcer occurrence showed an evident increase (p < 0.001) in fall (October-December) and in winter (January-March) compared with spring (April-June) and summer (July-September). Both 24-h and nighttime gastric acidity showed no significant variation by month, whereas daytime gastric pH varied significantly (p < 0.05) with two evident decreases, meaning higher acidity, in April and August. H. pylori infection was detected in 152 of 171 patients (89%), and the percentage of H. pylori-positive duodenal ulcers did not differ from season to season. We conclude that there was no parallel circannual fluctuation of duodenal ulcer, gastric acidity, and H. pylori infection in the restricted sample of patients we studied. This reduces the apparent relevance of acid in inducing ulcer seasonal fluctuation. Also, the responsibility of H. pylori in this phenomenon can be excluded until a reliable diagnostic method capable of distinguishing recent from old infection is found.

Adult↗

Cortisol in light treatment of seasonal and non-seasonal depression: relationship between melatonin and cortisol.

The effect of bright light on cortisol and the relationship between melatonin and cortisol were studied in 63 depressed patients (42 patients with a seasonal pattern and 21 patients with a non-seasonal pattern). The patients were matched for age, time of treatment and severity of depression. Before and after light treatment the severity of the depression was rated with the Comprehensive Psychopathological Rating Scale (23 items) and the Hamilton Depression Rating scale (18 items), and serum cortisol and melatonin were drawn at nine time-points between 20.00 and 08.00 hours. Two hours of light treatment (350 cd m-2) was given daily for 10 days either in the morning (06.00-08.00 hours) or in the evening (18.00-20.00 hours). As reported earlier, patients with a seasonal pattern improved significantly more than patients with a non-seasonal pattern of depression, and no significant differences were found between the treatment efficacy of morning compared to evening light. A cosinor analysis showed that the cortisol batyphase was significantly advanced by morning light, but was not delayed by evening light. A delay in batyphase cortisol showed a weak significant correlation with a decrease in the absolute and relative sum of scores. The batyphase of cortisol occurred approximately 3 h earlier than the acrophase of melatonin. Of the changes in the melatonin acrophase 43% were reflected in a change of cortisol batyphase, indicating a hierarchical relationship with melatonin as the co-ordinating hormone transducing part of the information of the external light to the phase position of cortisol. No significant differences between patients with a seasonal or a non-seasonal pattern were seen in mesor, amplitude or batyphase of cortisol before treatment, and no significant changes in mesor or amplitude were seen as a result of light treatment.

Adult↗

Daily, weekly, seasonal, within- and between-individual variation in nutrient intake according to four season consecutive 7 day weighed diet records in Japanese female dietitians.

OBJECTIVE: To study daily, weekly, seasonal, within- and between-individual variance in intake of selected nutrients and minimal days necessary for assessing true intake with a specified degree of error based on four season consecutive 7 day weighed diet records (WDRs). SUBJECTS AND METHODS: We evaluated consumption of energy and 30 nutrients based on four season consecutive 7 day WDRs from 80 Japanese female dietitians in 1996-1997. We examined daily, weekly, seasonal, within- and between-individual variation in nutrient intake, relative contributions of their variances to total variance, and minimal days required to estimate a person's nutrient intake within 10% and 20% of their true mean with 95% confidence intervals. RESULTS: The relative contributions of variation for all nutrients by person were larger than those by day, week and season. Within-individual variances were greater than the between-individual variances. The ratios of within- vs. between-individual variances thus ranged from 1.3-26.9. Minimal days necessary for estimating nutrient consumption per person within 10% (20%) of the true mean with 95% confidence intervals ranged from 10-35 (3-9) days for energy and major nutrients and 15-640 (4-160) days for micro-nutrients. CONCLUSIONS: The relative contributions of variability by person were largest for all nutrients, followed by those due to sequence of days, season and day of week. Within-individual variation was greater than between-individual variation. Minimal days necessary for ascertaining major nutrients were in general fewer than micro-nutrients.

Adult↗

[Connection between the season of year, season of birth, and trimester of the individual year in patients with ischemic heart disease at risk for myocardial infarction and its complications].

AIM: To clarify whether the periods of the individual year (from one birthday to another), season of the year, season of birth of patients with ischemic heart disease (IHD) are involved in development of myocardial infarction and its complications. MATERIAL AND METHODS: Case histories of 349 men hospitalized for acute myocardial infarction (MI) have been analysed. The analysis concerned the rate of MI onset in various seasons of the year, trimesters of the individual year (IY) and seasons of the patient's birth. RESULTS: Incidence of MI was higher in winter and summer. MI complications develop more frequently in spring. Trimester I and IV (months i-III and IX-XII since birthday) appeared more favourable for development of MI and its complications. Most favourable for IM was trimester III of IY, for MI complications--trimester II of IY. IM occurred more frequently in IHD patients born in autumn, complications in those born in summer. CONCLUSION: Development of MI and its complications is determined by a number of chronobiological factors: season of the year, season of the patient's birth and period of the individual year. This information is valuable in planning preventive measures.

Humans↗

Seasonal variation in the frequency of Helicobacter pylori infection: a possible cause of the seasonal occurrence of peptic ulcer disease.

OBJECTIVES: The seasonal variation of duodenal ulcer disease and its complications have been repeatedly demonstrated in Israel by several independent studies. The aim of this study was to determine possible seasonal variations in the occurrence of H. pylori infection among dyspeptic patients in Israel. METHODS: All 14C-urea breath tests performed in dyspeptic patients at the gastroenterology department in the Tel Aviv Medical Center from January 1991 to December 1992 were reviewed. The monthly variation in the proportion of patients with H. pylori infection was determined, and compared with that of an unrelated 14C-cholyl-glycine breath test. RESULTS: Altogether, 702 patients were examined, and 371 (52.8%) of them were found to be infected with H. pylori. During summer months (July-September), a significant decrease in the percentage of patients infected with H. pylori was found, compared with winter months (December-January, 42.3% vs. 60.9%, p < 0.007). No seasonal variation was found in the results of 14C-cholyl-glycine test. The fluctuations in H. pylori infection were highly correlated with the seasonal occurrence of peptic ulcer disease in Israel. CONCLUSIONS: The frequency of H. pylori infection in dyspeptic patients in Israel is significantly increased during the winter months and decreased in the summer. This seasonal variation is identical to that found in duodenal ulcer disease. Thus, the seasonal variation of peptic ulcer disease could be explained by H. pylori infection, as seen in other communicable infectious diseases.

Breath Tests↗