Seasonal Pattern of Hand Foot and Mouth Disease in an Out-patient Clinic of a Tertiary Care Pediatric Hospital, Dhaka

Background : Hand, foot and mouth disease (HFMD) is a contagious disease of children, occurs primarily under five years of age, characterized by a history of brief febrile illness and a typical skin rash over hands and feet with or without sores in mouth, caused usually by Coxsackie virus[1]A16 viruses. It is mainly the disease of tropical and subtropical countries and bears a complex-relation with meteorological variables like temperature, rainfall and relative humidity, although no study has yet been done in Bangladesh to explain the complex relationship of the disease with these variables. Objective : This study sought to describe the occurrence of HFMD and its association with meteorological factors in Dhaka city. Methods : The present cross-sectional study collected data of 231 HFMD cases from the records of the daily register of Out-patient Department of Dhaka Shishu Hospital, Dhaka between January 2018 to December 2019. According to the study protocol a child was identified as having HFMD who had a history of brief febrile illness accompanied by a typical skin rash with or without mouth ulcers. Total numbers of cases treated monthly at OPD during the period were also recorded. Meteorological data were provided by Bangladesh Meteorological Department, which among others, included monthly average temperature, relative humidity and amount of rainfall. While the outcome variable was monthly number of HFMD cases, the predictive variables were average temperature, humidity and rainfall during the study period. Results : Majority (85.3%) children in the present study was < 5 years old. A male preponderance was observed in the series (60%) with male to female ratio being 3:2. A clustering of HFMD cases was observed to occur between June to October when monthly average temperature, total rainfall and humidity all were at their maximum compared to those found between November to April. The clustering of cases was more intense in the year 2019 than that in the year 2018. During the period average monthly temperature was 29.20C, average rainfall was 62.6% (238 mm) of the total annual precipitation and mean relative humidity was 79%. The proportion of HFMD cases out of total cases treated during the period was 2.2% in 2018 and was 4.1% in 2019, which in the dry season (November to April) was 0.4% and 0.5% in 2018 and 2019 respectively. Conclusions : The study concluded that majority of the HFMD cases occur under five years of age and boys are more likely to have the infection than the girls. A seasonality of HFMD occurrence is observed with a higher number of cases occurring in the monsoon season and fewer cases in the dry season.Clustering of HFMD cases occur between May to October when monthly average temperature, total rainfall and humidity all are at peak compared to those in November to April of the year. Northern International Medical College Journal Vol.11 (2) Jan 2020: 453-457

Seasonal Associations Between Foodborne Campylobacter Infections and Ambient Temperature in US, 2010–2019

Objectives In order to effectively mitigate the effects of climate change on human health, spatiotemporal relationships between Campylobacter infections and environmental drivers have to be systematically examined to determine whether common seasonal summer peaks observed in Campylobacter infections are well aligned with peaks in raising ambient temperatures. This study aims to evaluate the seasonal relationship between monthly ambient temperature and the monthly Campylobacter infections routinely collected by the CDC Foodborne Diseases Active Surveillance Network (FoodNet) in the United States in 2010–2019. Methods We created time series of monthly Campylobacter infection rates from the FoodNet Fast platform for ten participating states from January 2010 to December 2019 (120 months). We estimated average monthly temperatures for the ten states for the study period using the National Climate and Data Center's Global Summary of the Day database. To assess the seasonal synchronization and determine the lag effect, we used serial cross-correlation analysis. To examine the associations between Campylobacter rates with ambient temperature and adjust for seasonality and trend, we applied a harmonic negative binomial mixed-effects regression model. We also estimated peak timing and amplitude for infections and temperature using the δ-method. Results Serial synchronization between monthly Campylobacter infection rates and ambient temperature was observed in all FoodNet Surveillance states except for California. A one-month delay in peak infection after the peak in temperature was detected in Colorado, Connecticut, Maryland, Minnesota, New Mexico, New York, and Oregon. After adjusting for seasonality and trend across ten states, the relative risk of infection rates increased by 5% with the increase in monthly average temperature by 5.45°C equivalent to a shift from 75th to 95th percentile (95%CI: 1.02–1.09, p &lt; 0.002). Conclusions An increase in monthly average temperature is associated with an increased risk of Campylobacter infection after adjusting for common summer seasonal patterns. Knowledge of the relationship will potentially improve the reliability and accuracy of integrated early warning outbreak forecasts and could guide climate mitigation strategies. Funding Sources None.

ANALYTICAL MATHEMATICAL MODELS OF THE POPULATION OF ARTHROPODS IN THE NON-BLACK EARTH ZONE

The article provides an example of mathematical analytical modeling of the population size of blood-sucking arthropods on the example of mosquitoes and ixodid ticks that inhabit the Kaluga Region. The presented analytical mathematical models make it possible to clearly assess the influence of environmental factors on parasite populations. The following factors were taken into account: average temperature (monthly and yearly, t, oС); average precipitation (monthly and yearly, S, mm); mean atmospheric pressure (P, mm Hg) for mosquitoes, and monthly average temperature (t, o С), monthly mean relative humidity (Q, %), and mean atmospheric pressure (P, mm Hg) for ixodid ticks. The analysis of the obtained models shows that under weather conditions when monthly mean values of the considered factors are at a zero level, the estimated number of ixodid ticks and mosquitoes will be 1150 and 1529 individuals in the control area per year. The population of ixodid ticks is most significantly influenced by the mean atmospheric pressure; its influence is twice as strong as monthly mean humidity and 6.4 times stronger than the influence of monthly average temperature. The "+" sign indicates that the higher the atmospheric pressure is, the more active ticks are observed. Monthly average precipitation has the greatest effect on the mosquito population.

Climatic zoning for the building thermal design in China's rural areas

Building climatic zoning is a prerequisite for implementing building energy efficiency technology, which can help code makers and architects have an accurate understanding of the local climatic conditions. It takes the extreme monthly average temperature as the zoning index in the existing climatic zoning of rural areas in China. There will be unreasonable design phenomena of insufficient or excessive thermal insulation for a building envelope in rural areas. Aiming at the above problems, this paper modifies the current zoning. This research established the cooling and heating degree-day indexes HDD14 and CDD30 based on the thermal comfort characteristics of rural occupants and used the threshold method to subdivide rural areas into eight sub-zones. The results show that the problem of insufficient or excessive thermal insulation in rural areas can be effectively solved by replacing the extreme monthly average temperature index with the degree day index and the annual cumulative building load can be reduced by 6.4% on average without increasing the insulation cost. After more detailed zoning, the variance within the group is reduced and it accurately describes climate diversity, which is conducive to implementing climate-responsive energy-saving design in each subzone. Practical application: The major purpose of this paper is to solve the problem of unreasonable climate zone boundaries specified in the existing Design Standard for Energy Efficiency of Rural Residential Buildings. The existing zoning has led to conflicts between the actual heating demand and the building envelope thermal parameter limits specified in the standard. This work redefines the boundaries of the existing map using more up-to-date weather data to provide the right guidance for architectural designers.

Role of Climatic Conditions on the Incidence of Varicella in an Out-patient Clinic of a Tertiary Care Pediatric Hospital at Dhaka

Background & objective : Chicken pox or varicella is a disease of both tropical and temperate zones bearing a complex-relationship with climatic variables, like temperature, rainfall and relative humidity, wind velocity and so on. As no study has, by far, been conducted to relate its occurrence with these climatic variables in Bangladesh, this study was intended to explore the effect of weather conditions on the incidence of varicella in Dhaka city of Bangladesh. Methods: The present cross-sectional study obtained data of 172 varicella cases from the records of the daily register of Out-patient Department of Dhaka Shisu Hospital, Dhaka between January 2018 to December 2019. According to the study protocol a child was diagnosed as having varicella or chicken pox who had a history of short febrile illness accompanied by a pruritic vesicular eruption (on the face and trunk)) of the skin and mucous membranes which ultimate weeps out and crusts. Total number of cases treated monthly at Out-patient Department (OPD) during the period was also recorded. Climatic data were provided by Bangladesh Meteorological Department, which among others, included monthly average temperature, relative humidity (RH) and amount of rainfall or precipitation. While the outcome variable was monthly number of varicella cases, the predictive variables were average temperature, humidity and rainfall during the study period. Result: Over 70% of children were 1-10 years old with median age of the children being 5.5 years (range: < 1 month -14 years). Boys were a bit higher (54%) than the girls (46%). A seasonal pattern of chicken pox was seen with clustering of cases between mid-February to mid-April (spring season) with two peaks – one in February and another in April, when monthly average temperature, total rainfall and humidity all were at their optimum. The peak incidences of chicken pox cases during the spring both in 2018 and 2019 as correlated with climatic data of the same period, it is seen that the prevailing weather then was optimum-average temperature was 23°C, average precipitation was 20-25% of the total annual precipitation and relative humidity was around 65%. Conclusion: The study concluded that majority of the varicella cases occur under ten years of age and boys are a little more susceptible to have the infection than the girls. A seasonal pattern of chicken pox is clearly seen with clustering of cases between mid-February to mid-April (spring season) with two peaks when monthly average temperature, total rainfall and humidity all are optimally favorable for the multiplication of varicella zoster virus. Ibrahim Card Med J 2020; 10 (1&2): 11-17