Differences In Contact Rates Research Articles

Child protection inequalities for Pasifika children in Aotearoa New Zealand: diverse realities

ABSTRACT Child protection inequalities are population group differences in contact rates, experiences and outcomes of child protection systems. This article reports rates of Pasifika children’s contact with the statutory child protection system at three outcomes: substantiation, having a family group conference, (FGC) or entering care (placement), and describes intersections between these outcomes and socio-economic deprivation. Including all children resident in Aotearoa New Zealand in 2019–2020 aged 0–17 years, this study compared rates between sole Pasifika, Pasifika plus other ethnicities (Pasifika+), and Non-Māori, Non-Pasifika (NMNP) children. Substantiation was twice as likely for Pasifika, even after controlling for sociodemographic factors, and Pasifika children were 25% more likely to enter care than NMNP children. As socio-economic deprivation increased, rates of substantiation increased for all groups, but most sharply for Pasifika+ children. Sole Pasifika children had the highest rate of substantiation and FGCs in the least deprived quintile of socio-economic deprivation, but the lowest FGC and placement rates in areas of highest deprivation. Pasifika+ children had double the rate of sole Pasifika children for placement in high-deprivation areas, but this was equal to the NMNP rate. Findings are analysed via theories of inequalities. Aggregated ethnic categories obscure considerable variation in within-group experiences.

The influence of gender on COVID-19 infections and mortality in Germany: Insights from age- and gender-specific modeling of contact rates, infections, and deaths in the early phase of the pandemic.

Recent research points towards age- and gender-specific transmission of COVID-19 infections and their outcomes. The effect of gender, however, has been overlooked in past modelling approaches of COVID-19 infections. The aim of our study is to explore how gender-specific contact behavior affects gender-specific COVID-19 infections and deaths. We consider a compartment model to establish short-term forecasts of the COVID-19 epidemic over a time period of 75 days. Compartments are subdivided into different age groups and genders, and estimated contact patterns, based on previous studies, are incorporated to account for age- and gender-specific social behaviour. The model is fitted to real data and used for assessing the effect of hypothetical contact scenarios all starting at a daily level of 10 new infections per million population. On day 75 after the end of the lockdown, infection rates are highest among the young and working-age, but they also have increased among the old. Sex ratios reveal higher infection risks among women than men at working ages; the opposite holds true at old age. Death rates in all age groups are twice as high for men as for women. Small changes in contact rates at working and young ages have a considerable effect on infections and mortality at old age, with elderly men being always at higher risk of infection and mortality. Our results underline the high importance of the non-pharmaceutical mitigation measures (NPMM) in low-infection phases of the pandemic to prevent that an increase in contact rates leads to higher mortality among the elderly, even if easing measures take place among the young. At young and middle ages, women’s contribution to increasing infections is higher due to their higher number of contacts. Gender differences in contact rates may be one pathway that contributes to the spread of the disease and results in gender-specific infection rates and their mortality outcome. To further explore possible pathways, more data on contact behavior and COVID-19 transmission is needed, which includes gender- and socio-demographic information.

A cross-sectional study measuring contact patterns using diaries in an urban and a rural community in South Africa, 2018

BackgroundDescribing contact patterns is crucial to understanding infectious disease transmission dynamics and guiding targeted transmission mitigation interventions. Data on contact patterns in Africa, especially South Africa, are limited. We measured and compared contact patterns in a rural and urban community, South Africa. We assessed participant and contact characteristics associated with differences in contact rates.MethodsWe conducted a cross-sectional study nested in a prospective household cohort study. We interviewed participants to collect information on persons in contact with for one day. We described self-reported contact rates as median number people contacted per day, assessed differences in contact rates based on participant characteristics using quantile regression, and used a Poisson model to assess differences in contact rates based on contact characteristics within age groups. We also calculated cumulative person hours in contact within age groups at different locations.ResultsWe conducted 535 interviews (269 rural, 266 urban), with 17,252 contacts reported. The overall contact rate was 14 (interquartile range (IQR) 9–33) contacts per day. Those ≤18 years had higher contact rates at the rural site (coefficient 17, 95% confidence interval (95%CI) 10–23) compared to the urban site, for those aged 14–18 years (13, 95%CI 3–23) compared to < 7 years. No differences were observed for adults. There was a strong age-based mixing, with age groups interacting more with similar age groups, but also interaction of participants of all ages with adults. Children aged 14–18 years had the highest cumulative person hours in contact (116.3 rural and 76.4 urban).ConclusionsAge played an important role in the number and duration of contact events, with children at the rural site having almost double the contact rate compared to the urban site. These contact rates can be utilized in mathematical models to assess transmission dynamics of infectious diseases in similar communities.

Investigating Reef Contact Rates of Snorkel Visitors at Koh Sak, Pattaya on Guided and Non-guided Coral Reef Tours

Recreational snorkelling is a popular activity at Koh Sak, Pattaya Bay and although most snorkel visitors to the island arrive by speedboat on guided tours, many visitors arrive on tours that do not provide a guide. Because there is widespread agreement that reef-based tourism negatively impacts coral reefs it is important to understand the potential role guides play in reducing visitor impacts. In this study 421 snorkelers (35 % of whom came on non-guided tours) were observed on the reef for a period of 10 minutes. The following information was recorded so that a per person reef-contact rate could be calculated: the snorkelers’ distance from their guide (if they had one), the number of people in their snorkelling group, and the number of contacts with the reef. There was no difference in contact rate between males (0.09 contacts min-1) andfemales (0.11 contacts min-1) nor was there any difference based on the group size (2-7 people). However, contact rates for snorkelers on tours with no guide (0.09 contacts min-1) and snorkelers far from their guide (0.08 contacts min-1) were significantly lower than visitors who snorkelled near their guide (0.18 contacts min-1; p &lt; 0.001). The contact rate of guides (0.36 contacts min-1) was significantly greater than the snorkelers they were looking after (0.17 contacts min-1) in part due to the lack of knowledge and experience of snorkelers and guides alike. To reduce negative impacts to the coral reefs of Koh Sak guides need to change their destructive behaviour and improve their knowledge of reef biology and ecology.

Dynamics and control of infections on social networks of population types

Random mixing in host populations has been a convenient simplifying assumption in the study of epidemics, but neglects important differences in contact rates within and between population groups. For HIV/AIDS, the assumption of random mixing is inappropriate for epidemics that are concentrated in groups of people at high risk, including female sex workers (FSW) and their male clients (MCF), injecting drug users (IDU) and men who have sex with men (MSM). To find out who transmits infection to whom and how that affects the spread and containment of infection remains a major empirical challenge in the epidemiology of HIV/AIDS. Here we develop a technique, based on the routine sampling of infection in linked population groups (a social network of population types), which shows how an HIV/AIDS epidemic in Can Tho Province of Vietnam began in FSW, was propagated mainly by IDU, and ultimately generated most cases among the female partners of MCF (FPM). Calculation of the case reproduction numbers within and between groups, and for the whole network, provides insights into control that cannot be deduced simply from observations on the prevalence of infection. Specifically, the per capita rate of HIV transmission was highest from FSW to MCF, and most HIV infections occurred in FPM, but the number of infections in the whole network is best reduced by interrupting transmission to and from IDU. This analysis can be used to guide HIV/AIDS interventions using needle and syringe exchange, condom distribution and antiretroviral therapy. The method requires only routine data and could be applied to infections in other populations.

Ethnic concentration and language fluency of immigrants: Evidence from the guest-worker placement in Germany

This paper analyses the impact of regional ethnic concentration on the language proficiency and language use of immigrants. It solves the endogeneity of immigrants’ location choices by exploiting a peculiar episode of the German immigration history: the exogenous placement of guest-workers after WWII, one of the largest guest-worker programs on record. The econometric approach accounts for several sources of measurement error and provides a falsification exercise that hypothetically relocates the most language proficient immigrants into ethnic enclaves to test the extent of cross-regional sorting necessary to render the results purely spurious. The results show a robust negative effect of ethnic concentration on immigrants’ language ability which is driven by differences in contact rates with natives and not by differences in the willingness to integrate. The paper discusses these findings against the background of a language production function and in the light of feasible policy options to foster the language acquisition of immigrants.

Explaining Cross-Country Differences in Survey Contact Rates: Application of Decomposition Methods

SummarySurvey contact rates differ across countries. However, to date the reasons for these cross-country differences have not been identified. Differences can be due to differences in survey characteristics, differences in population characteristics and differences in processes, i.e. in the association between the first and second reasons and contact propensity. The paper investigates correlates of contact by decomposing cross-country differences in predicted mean contact propensities into these three components. The findings explain which fieldwork strategies and population characteristics are related to cross-country differences in contact rates. The analyses distinguish factors explaining within-country contact propensity from factors explaining cross-country differences. We demonstrate the suitability of decomposition methods for analysing group differences in survey outcomes.

A comparison of pectoral fin contact between two different wild dolphin populations

Contact behaviour involving the pectoral fin has been documented in a number of dolphin species, and various explanations about its function have been offered. Pectoral fin contact can take a variety of forms, and involves a number of body parts and movements, likely differing depending upon social or ecological context. For this study, we compare the pectoral fin contact behaviour of two species of wild dolphins: Indo-Pacific bottlenose dolphins (Tursiops aduncus) from around Mikura Island, Japan, and Atlantic spotted dolphins (Stenella frontalis) from The Bahamas. The two study populations exhibit surprising similarity in the ways in which pectoral fin contacts are used, despite differences in species and environmental conditions at the two sites. Differences in contact rates for calves between the two sites suggest that calf-focused aggression from adult dolphins is more prevalent at Mikura than in The Bahamas. Our results suggest that pectoral fin contact behaviour seems to be driven primarily by social pressures, and may be similar in function to allogrooming described in primates.

Socioeconomic differences in general practice consultation rates in patients aged 65 and over: prospective cohort study

Objective: To examine socioeconomic differences in general practice consultation rates among patients aged 65 years and over.Design: Secondary analysis of data from the fourth national survey of morbidity in general...

Population dynamic interference among childhood diseases.

Epidemiologists usually study the interaction between a host population and one parasitic infection. However, different parasite species effectively compete, in an ecological sense, for the same finite group of susceptible hosts, so there may be an indirect effect on the population dynamics of one disease due to epidemics of another. In human populations, recovery from any serious infection is normally preceded by a period of convalescence, during which infected individuals stay at home and are effectively shielded from exposure to other infectious diseases. We present a model for the dynamics of two infectious diseases, incorporating a temporary removal of susceptibles. We use this model to explore population-level consequences of a temporary insusceptibility in childhood diseases, the dynamics of which are partly driven by differences in contact rates in and out of school terms. Significant population dynamic interference is predicted and cannot be dismissed in the limited case-study data available for measles and whooping cough in England before the vaccination era.

Adolescent smoking and drinking: are they "epidemics"?

During adolescence, cumulative prevalences of ever using alcohol and ever smoking a cigarette increase systematically and dramatically. We applied a statistical theory of the transmission of epidemic infectious disease to model life-time prevalences of smoking and drinking. Alcohol use prevalences fit closely to a logistic curve used to model an epidemic process that assumed adolescents have random contacts with one another each year. An "adequate contact" will convert a nondrinker to drinking status if he/she is contacted; drinkers average .48 adequate contacts per year. Smoking prevalences were fit assuming both that the entire population was "at risk" and that some individuals were "immune": the mean contact parameter was .28 for smoking if no immune class was assumed and .77 if an immune class was assumed. Extensions of these epidemic process models could include individual differences in contact rates and transitions among several smoking or drinking statuses (e.g., non-user, experimenter, regular user and recovered user).

Recurrent outbreaks of measles, chickenpox and mumps. II. Systematic differences in contact rates and stochastic effects.

Recurrent outbreaks of measles, chickenpox and mumps. II. Systematic differences in contact rates and stochastic effects.