Cryptosporidiosis in Kuwaiti children: seasonality and endemicity

Objective    To detect the incidence of cryptosporidial infection in children presenting with gastrointestinal symptoms at the local hospital in Kuwait.
Methods   Over a period of 3 years, September 1995 to August 1997, a single fecal sample from 3549 children was analyzed by modified saframin–methylene blue (SM-B) staining and a direct immunofluorescence test for the presence of Cryptosporidium oocysts.
Results   Cryptosporidium oocysts were detected in 51 (10%) children with diarrhea. Prevalence was highest (73%) in children > 2 years of age compared with children < 2 years of age. The maximum number of cases, 38 of 51 (75%), was seen during the months January to April, indicating a marked seasonal variation. Polyparasitism was common in children with diarrhea; however, 43 of the 51 (84%) children with cryptosporidiosis had cryptosporidium infection only. Blastocystis hominis and Endolimax nana were the most common parasites detected (38% and 15%, respectively). Forty-seven of the 51 (90%) children with cryptosporidiosis were Kuwaiti and gave no history of travel abroad, suggesting that the infection was acquired indigenously. Sociodemographic information on children with cryptosporidiosis suggests three possible modes of transmission of infection: drinking contaminated water stored in overhead water tanks, person to person, or contact with infected animals.
Conclusion   In this study, we observed water-borne transmission of cryptosporidium infection in chidren with diarrhea. The infection is seasonal and endemic.     

The seasonal relationships between household dietary diversity and child growth in a rural Timor‐Leste community

Both child growth and dietary diversity are poor in rural Timor‐Leste. The rainy season is associated with food scarcity, yet the association between seasonal scarcity, food diversity, and child growth is underdocumented. This study assesses the relationship between household dietary diversity and children''s standardized growth across the 2018 food‐scarce (April–May; post‐rainy period) and post‐harvest (October) seasons in the agricultural community of Natarbora, on the south‐coastal plains of Timor‐Leste. We conducted household interviews and collected anthropometric data across 98 and 93 households in the post‐rainy and post‐harvest periods, respectively. Consumed household foods were obtained via 24‐h diet recalls and were subsequently categorized into a nine‐food‐group dietary diversity score (DDS; number of different food groups consumed). The DDS was related to children''s standardized short‐term growth (z‐weight, z‐body mass index [BMI] and percent change in weight over the harvest season) via linear mixed models. Across seasons, DDS increased from 3.9 (standard deviation [SD] = 1.0) to 4.3 (SD = 1.4; p < 0.05). In the post‐rainy season, children in high DDS households had higher z‐weight than those in low DDS households and higher z‐BMI than children in medium and low DDS households. In the post‐harvest period, household DDS did not predict children''s z‐weight but predicted z‐BMI. Consumption of protein‐rich foods, particularly animal‐source foods and legumes, in low‐ and medium‐DDS households may be associated with improved child growth. While consuming more animal‐source foods in the post‐rainy season would be ideal, promoting the consumption of locally grown legumes, such as beans and pulses, may facilitate better nutritional outcomes for more children in rural Timor‐Leste.     

Maternal diets matter for children's dietary quality: Seasonal dietary diversity and animal‐source foods consumption in rural Timor‐Leste

Improving the dietary quality of women and children is essential to reduce all forms of malnutrition. In this study, we assessed seasonal child and maternal dietary diversity and consumption of animal‐source foods (ASF), using 1,236 observations from combined data collected among 167 mother–child dyads in rural Timor‐Leste. We used generalized linear and logistic mixed‐effects models to examine the dietary differentials of mothers and children in two agricultural livelihood zones and across the seasons, as well as to identify household and agroecological characteristics associated with children's dietary quality in relation to their mothers'. We found dietary quality to be marginally better in coastal than in mid‐altitude zones. However, women's diets were strikingly poor, and their intake of ASF was lower than among children. Mothers exhibited preferential allocation patterns of specific ASF, dairy products and eggs, to children. The intake of ASF was predicted by seasonality. Flesh foods and red meat were much more likely to be consumed during the dry season, when cultural ceremonies are often performed. We found a positive and strongly significant association between children's dietary indicators—dietary diversity score, minimum dietary diversity and ASF consumption, and those of their mothers'. Maternal dietary quality and educational attainment, more so than agroecological characteristics, were explanatory factors of children's diet. Our study highlights that addressing the dietary quality of children in Timor‐Leste would benefit from improving women's diets through better access to nutritious foods and to secondary education.     

Seasonal risk of low pathogenic avian influenza virus introductions into free‐range layer farms in the Netherlands

Poultry can become infected with avian influenza viruses (AIV) via (in) direct contact with infected wild birds. Free‐range chicken farms in the Netherlands were shown to have a higher risk for introduction of low pathogenic avian influenza (LPAI) virus than indoor chicken farms. Therefore, during outbreaks of highly pathogenic avian influenza (HPAI), free‐range layers are confined indoors as a risk mitigation measure. In this study, we characterized the seasonal patterns of AIV introductions into free‐range layer farms, to determine the high‐risk period. Data from the LPAI serological surveillance programme for the period 2013–2016 were used to first estimate the time of virus introduction into affected farms and then assess seasonal patterns in the risk of introduction. Time of introduction was estimated by fitting a mathematical model to seroprevalence data collected longitudinally from infected farms. For the period 2015–2016, longitudinal follow‐up included monthly collections of eggs for serological testing from a cohort of 261 farms. Information on the time of introduction was then used to estimate the monthly incidence and seasonality by fitting harmonic and Poisson regression models. A significant yearly seasonal risk of introduction that lasted around 4 months (November to February) was identified with the highest risk observed in January. The risk for introduction of LPAI viruses in this period was on average four times significantly higher than the period of low risk around the summer months. Although the data for HPAI infections were limited in the period 2014–2018, a similar risk period for introduction of HPAI viruses was observed. The results of this study can be used to optimize risk‐based surveillance and inform decisions on timing and duration of indoor confinement when HPAI viruses are known to circulate in the wild bird population.     

Persistent MHV (mouse hepatitis virus) infection reduces the incidence of diabetes mellitus in non-obese diabetic mice

Summary The frequency of diabetes mellitus was compared in non-obese diabetic mice before and after inadvertent exposure of the colony to mouse hepatitis virus infection. Prior to exposure, diabetes prevalence and cumulative diabetes incidence in 7-month-old mice was 65% and 25% in females and males, respectively. Diabetes incidence/quarter revealed a seasonal pattern with peaks in winter. After mouse hepatitis exposure, the diabetes incidence in the colony decreased and testing for mouse hepatitis antibody in blood samples revealed a persistent infection. In the offspring of mice delivered by caesarian section, the diabetic incidence increased sharply from a nadir of 36% to 95% and from 9% to 65% in females and males, respectively. In individual mice, diabetes resistance was strongly correlated to high titres of mouse hepatitis virus antibody. The results of this inadvertent viral infection demonstrate that a diabetes-susceptible genotype is strongly modulated by environmental factors. Investigators studying this diabetes model should strive for specific pathogen-free colony status and a high incidence of diabetes before attempting to investigate therapeutic modalities.     

Seasonal variation of mood and behaviour in a healthy middle-aged population in Japan

A population survey of seasonality in six representative cities in Japan was conducted using the Japanese version of the Seasonal Pattern Assessment Questionnaire (SPAQ). The questionnaires were given to 951 parents (male: female ratio 1 : 1 age range 34-59 years) of high-school students. Significant regional differences in seasonal variations of mood, length of sleep, and weight were observed; the proportion of individuals reporting high seasonality in the two northern cities was significantly higher than that in the other areas. These results provide evidence for a northern predominance in the prevalence of seasonal affective disorder in Japan.     

Caregivers' nutritional knowledge and attitudes mediate seasonal shifts in children's diets

Smallholder farmers dependent on rain‐fed agriculture experience seasonal variations in food and nutrient availability occasioned by seasonality of production patterns. This results in periods of nutrient abundance in the plenty seasons followed closely by periods of nutrient inadequacies and malnutrition. This pattern contributes to a cycle of deteriorating health and nutrition status and deprives children of their ability to realize full developmental potential. This study investigates the role of caregiver's nutritional knowledge and attitudes in mediating effects of seasonality on children's diets. Repeated cross‐sectional surveys were conducted on 151 randomly selected households in the plenty and lean seasons to collect dietary data using two non‐consecutive quantitative 24‐hr recalls and caregiver's nutritional knowledge and attitudes assessed using interviewer administered questionnaire. Sixty‐five percent of the caregivers had attained a primary level education or less. There was a positive modest correlation between caregivers' nutritional knowledge and their attitudes (r = 0.3, P < 0.000, α = 0.01). Children's mean adequacy ratio was significantly higher in the plenty season than in the lean season (0.84 vs. 0.80, P < 0.000). A two‐block hierarchical regression to predict the seasonal changes in dietary quality of children using caregiver's nutritional knowledge and attitude scores while controlling for the effect of sociodemographics and mean adequacy ratio at first season (plenty) found that caregiver's nutritional knowledge (ß = ?0.007, SE = 0.003, P = 0.027, 95% CI [?0.013, ?0.001] ?² = 0.034) but not attitudes had significant contribution to the prediction. Maternal nutritional knowledge mediates seasonal variation in child nutrient intakes.     

Dynamics of the Occurrence of Influenza in Relation to Seasonal Variation in Chennai,Tamil Nadu: A 7 -Year Cumulative Study

Background: Influenza viruses have emerged as virulent pathogens causing considerable burden across the world. A thorough understanding of the pattern in occurrence of influenza globally is the need of hour. The present study deals with analysis of the dynamics of Influenza virus, especially the influence of seasonal change on viral circulation and causation of epidemics/pandemics in the context of subtropical region. Methods: During the 7 year (2009–2015) study, 36670 specimens were subjected to influenza analysis. Nasopharyngeal swabs collected from suspected patients from Chennai, Tamil Nadu, were tested and typed by real-time polymerase chain reaction assay. Results: During 2009 pandemic, among influenza A positives 95.16% were Apdm09, indicating that there was a predominant circulation of Apdm09. During postpandemic period, there were waves in the occurrence of Apdm09 which indicates fall in immunity with buildup in the susceptible population. Conclusion: In Chennai, Tamil Nadu, influenza positivity started with the onset of monsoon and peaks during the postmonsoon months throughout the study period. The assessment of meteorological factors compounding influenza activity can help in raising alerts to the public health officials of impending disaster which suggests that Influenza vaccination can be initiated before monsoon months in South India.     

Influenza and Other Respiratory Viruses: Seasonality of coronaviruses and other respiratory viruses in Canada: Implications for COVID-19

BackgroundLike endemic coronaviruses, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is believed to have emerged in humans from a zoonotic source and may ultimately develop a seasonal pattern. A seasonal pattern, particularly if combined with other seasonal outbreaks of respiratory virus infections, may have significant impacts on the healthcare system. We evaluated the seasonal pattern of existing endemic coronaviruses and several other common respiratory viruses to determine the potential impacts of added burden of respiratory disease should SARS-CoV-2 establish seasonality.MethodsNational surveillance data for laboratory confirmations of endemic coronaviruses, influenza A and B viruses, rhinovirus/enterovirus, human metapneumovirus, respiratory syncytial virus and parainfluenza virus for the past 10 years were obtained from the Government of Canada Open Data and FluWatch. Epidemic curves were generated from total case numbers and percent of samples testing positive for each respiratory virus by epidemiological week.ResultsIn Canada, endemic coronaviruses and other common respiratory viruses cause annual seasonal outbreaks in the winter months. Should SARS-CoV-2 develop a seasonal pattern similar to endemic coronaviruses and respiratory viruses, co-circulation would be expected to peak between January and March. Peak endemic coronavirus activity occurs during the nadir of rhinovirus/enterovirus and parainfluenza activity.ConclusionHealthcare settings, assisted-living and long-term care homes, schools and essential services employers should anticipate and have contingencies for seasonal outbreaks of SARS-CoV-2 and co-circulating respiratory viruses during peak seasons. Given the likelihood of co-circulation, diagnostic multiplex testing targeting co-circulating pathogens may be more efficient than single target assays for symptomatic individuals if a seasonal pattern to coronavirus disease 2019 (COVID-19) is established.