Tuberculosis with relapse: A model

ABSTRACT

In a model of tuberculosis with relapse, the basic reproduction number R₀ includes new and relapse infections. Lyapunov functions help to prove that the global dynamic is completely determined by R₀. Replicated Latin hypercube sampling shows that early diagnosis and treatment are more efficient when relapse cases are considered.     

Human migrations and mosquito-borne diseases in Africa

ABSTRACT

The efficacy of border screening as a prophylactic measure against mosquito-borne diseases in Africa depends on the value of the lower bound of the basic reproduction number. If this lower bound is greater than one, then border screening may be ineffective. In this case, the best prophylaxis is to isolate and treat patients in their region of residence.     

Sex-Structured Dynamic of Multi-Group Herpes Simplex Virus 2

A 3(n + l)-dimensional ordinary differential equation for HSV-2 includes l groups of men and n groups of women with different risks of infection. Global Lyapunov functions based on graph theory and on LaSalle invariance principle show that the model dynamics are completely determined by the basic reproduction number ?₀. The disease-free equilibrium is globally asymptotically stable when ?₀ ≤ 1; a unique endemic equilibrium is globally asymptotically stable in the interior of the feasible region when ?₀ > 1.     

A simple in-host model for Mycobacterium tuberculosis that captures all infection outcomes

ABSTRACT

Tuberculosis infection can result in clearance, latent infection, or active disease, with slow or fast progression. A four-dimensional model of in-host tuberculosis infection includes macrophages, T lymphocytes, tuberculosis bacteria, and their interactions. Changes in the infection rate, cell-mediated immunity rate, macrophage loss rate, and bacteria killing rate most affect disease outcomes. Simulations show that a periodic solution can occur. When the infected macrophage killing rate is constant, a backward bifurcation exists and the system is globally stable.     

Multiple mobilities in Mexico’s fertility industry

ABSTRACT

How can we conceptualize travel in search of fertility treatment? While current research on transnational reproduction mostly conceptualizes mobility as horizontal movement from A to B, this article shows how horizontal mobilities converge, contradict, and are interdependent with other forms of mobility; namely vertical mobilities in terms of social upward and downward mobility, representational mobilities in form of imaginative geographies, and the actual embodied experiences of mobility. Based on ethnographic research on the reproductive tourism industry in Mexico, the article explores the multiplicity of mobilities that constitute transnational reproduction. The article evaluates how the concept of multiple mobilities contributes to the study of medical tourism from a critical mobilities’ perspective.     

Transmission Probabilities and Reproduction Numbers for Sexually Transmitted Infections with Variable Infectivity: Application to the Spread of HIV Between Low- and High-Activity Populations

Probabilities of transmission and numbers of secondary cases are given for an infection which is transmitted sexually by individuals engaged in multiple partnerships with specified durations and timings. The results applied to the human immunodeficiency virus (HIV) hinge on a function which captures the dependence of the per coital act probability of transmission on the time since disease onset and on the duration of infection at death. Reproduction numbers are derived in a heterogeneous population consisting of low- and high-activity men and women. An expression for the basic reproduction number R ₀ of this system sheds light on the role of concurrency, on the timing of the partnerships, and on bridging effects. A high-activity group can cause a significant epidemic outbreak no matter how small the bridging effect, as long as it is not 0. Only if the bridging effect is eliminated altogether can the growth factor in the low-activity group be reduced independently of what happens in the high-activity group. The role of the relationship between client and sex worker and the role of bridging populations in sub-Saharan Africa are assessed.     

The effect of variability in the fertility schedule on numbers of kin

The kinship formulas developed by Goodman, Keyfitz, and Pullum (1974) are extended to encompass populations in which fertility varies among women. An expression is derived to determine the amount by which the number of sisters in a heterogeneous population exceeds that in a population with homogeneous fertility. This expression, which is a function of the variance in the gross reproduction rate of the population, can readily be applied to numbers of other kin, such as aunts and cousins. Several trial calculations indicate that calculations of average numbers of sisters based on an assumption of uniform fertility could result in an underestimate of about 13 percent.     

Predictors of postpartum depression service use: A theory-informed,integrative systematic review

ProblemPostpartum depression affects many women globally, yet rates of treatment use are low. A comprehensive view of factors associated with treatment use, from women’s and providers’ perspectives, based on a theoretical model is lacking.BackgroundSeveral studies examined various factors associated with postpartum depression service use; however, each study focused on a small number of factors.AimThis study describes a systematic literature review based on the Behavioral Model of Health Service Use. The purpose of this article is to review and synthesize the available literature regarding factors associated with women’s mental health service use for postpartum depression from women’s and healthcare providers’ perspectives, and provide a comprehensive integrative view of the subject.MethodsThree electronic databases were searched, and 35 studies published up to 2018 in English language journals met inclusion criteria for review. Factors associated with postpartum depression service use were classified according to the Behavioral Model of Health Service Use’s constructs.FindingsService use for postpartum depression is a function of a woman’s predisposition to use mental health services; individual, familial, and communal factors which enable or pose barriers to use of mental health services; and the woman’s perceived or evaluated need for treatment. In addition, societal determinants impact the woman’s decision to seek help directly or through impacting the health and mental health care service system’s resources and organization.ConclusionThis review illustrates key factors for researchers and practitioners to consider when treating postpartum women and developing interventions to enhance postpartum depression treatment use.     

Reproductive mobilities

ABSTRACT

This special issue brings reproduction into a critical mobilities framework. We extend scholarship in cross-border reproductive care and medical mobilities into new theoretical and empirical directions. Reproductive mobilities articulates the mutual constitution of reproduction and mobilities. Human (and nonhuman) movement not only shapes reproduction but produces reproductive imaginaries, desires, futures, trajectories, as well as the subjectivities and ‘becoming-ness’ of diverse reproductive subjects. Through the lens of reproduction, we examine how contemporary mobilities—and immobilities—intersect with gendered, racialized, sexually expressive, nation-inscribed, fertile, infertile, young, aging, pregnant, surrogate, and/or otherwise non/reproductive bodies and persons. Can human reproduction be analyzed without noticing all things mobile and immobile that converge to construct reproductive (and non-reproductive) desires and practices? Can mobility and immobility be considered without thought to how worlds and worlding comes about? Mobility facilitates reproduction, and new possibilities for reproduction; reproduction is mobile at scales from the molecular to the transnational. This effort to bring the fields of reproduction and mobilities into dialogue does not introduce a new sub-field but rather creates the opening for a trajectory of empirical work and theoretical ideas that invigorates mobilities with newfound attention on the matter and becoming-ness of reproduction.     

On some probability distributions for forward birth interval

Parents’ decisions to have children are modeled by a simple stopping rule that describes the probability of having another child as a function of the number of boys and girls already born to the parents. Because the stopping rule depends on the sex of the offspring, the rule may introduce a correlation between sex of offspring and the number of siblings the offspring has. When this is coupled with a correlation between number of siblings and well‐being, a correlation between sex and well‐being may emerge despite equal treatment of the two sexes within each family. The author provides sufficient conditions on a stopping rule for it to be sexist in the sense that the average well‐being of one sex is higher than that of the other sex.     

North American surrogate reproductive mobilities incited by cross-border reproductive care

ABSTRACT

The transnational mobility of intended parents traveling abroad for reproductive technologies has been heavily accounted for and theorized. On the other hand, scholars have emphasized the immobility of surrogates in places like India, Nepal and Cambodia. In order to extend an examination of how reproductive travel informs mobility, this paper will turn a critical eye toward North American surrogates’ reproductive mobilities that are incited by their participation in cross-border reproductive care. Surrogates in the United States are strikingly different from the images presented of surrogates in India. In fact, when the North American surrogates cycle for international intended parents, in some aspects they become less and more mobile. This paper will focus on multiple types of reproductive mobilities that are involved in the global fertility industry when international intended parents travel to North America for assisted reproduction.     

The self-prescribed use of aromatherapy oils by pregnant women

BackgroundWhile some studies have reported effectiveness of aromatherapy oils use during labour there is no reported evidence of efficacy or risks of aromatherapy oils use for pregnancy-related symptoms or conditions. A number of aromatherapy oils are unsafe for use by pregnant women yet there is currently no research examining the prevalence and characteristics of women who use aromatherapy oils during pregnancy.AimTo conduct an empirical study of the prevalence and characteristics of women who use aromatherapy oils during pregnancy.MethodsThe research was conducted as part of the Australian Longitudinal Study on Women's Health (ALSWH), focusing on the nationally representative sample of Australian women aged 31–36 years. Data were collected via a cross-sectional questionnaire (n = 8200) conducted in 2009.ResultsSelf-prescribed aromatherapy oils were used by 15.2% of pregnant women. Pregnant women were 1.57 (95% CI: 1.01, 2.43) times more likely to self-prescribe use of aromatherapy oils if they have allergies or hayfever, and 2.26 (95% CI: 1.34, 3.79) times more likely to self-prescribe use of aromatherapy oils if they have a urinary tract infection (UTI).ConclusionOur study highlights a considerable use of aromatherapy oils by pregnant women. There is a clear need for greater communication between practitioners and patients regarding the use of aromatherapy oils during pregnancy, as well a need for health care practitioners to be mindful that pregnant women in their care may be using aromatherapy oils, some of which may be unsafe.     

The reproduction of reproduction: theorizing reproductive (im)mobilities

ABSTRACT

Through a reading of the articles gathered in this special issue, this commentary seeks to assess how critical research on reproductive processes, spatialities, temporalities, and assemblages can push mobilities theory towards rethinking the politics of (im)mobilities, which can also give us a new lens on the reproduction of reproduction. It begins with questions of scale, and the power relations involved in the heterogeneous mobile embodiments and bodily entanglements of reproduction, including mobilities involved in fertility, assisted conception, surrogacy, abortion, egg freezing, or traveling to give birth. It then draws on process theories and relational ontologies within mobilities theory to think about multiple kinds of becoming as crucial to temporal processes of reproduction, involving both molar and molecular politics. Lastly, it elucidates the kinopolitics of reproduction and broadens the field of critical mobility studies to better take into account the material assemblages and affective entanglements of reproductive politics.     

Culture-based versus risk-based screening for the prevention of group B streptococcal disease in newborns: A review of national guidelines

BackgroundMaternal colonisation with group B streptococcus (GBS) is recognised as the most frequent cause of severe early onset infection in newborns. National and international guidelines outline two approaches to the prevention of early onset disease in the neonate: risk based management and antenatal culture-based screening. We undertook an analysis of existing national and international guidelines in relation to GBS in pregnancy using a standardised and validated instrument to highlight the different recommended approaches to care.MethodsEnglish language guidelines on the screening and management of GBS colonisation in pregnant women and the prevention of early-onset group B streptococcal disease in newborns were sought.ResultsFour guidelines met the inclusion criteria, one from the United States of America (USA), the United Kingdom (UK), Canada and New Zealand. All four were appraised as at a high standard in terms of development using the AGREE II tool. Both approaches were recommended in the guidelines with different regions of the world advocating different approaches often based on the same evidence. Guidelines from the USA recommend an antenatal culture-based approach while the UK guidelines recommend risk-based management.ConclusionBased on an AGREE II analysis, the standard of the guidelines was high despite having disparate recommendations. Both approaches to the prevention of early onset GBS infection in neonates are recommended with the split being geographically-based.     

Multiseason transmission for Rift Valley fever in North America

ABSTRACT

Rift Valley fever is a vector-borne disease, primarly found in West Africa, that is transmitted to humans and domestic livestock. Its similarities to the West Nile virus suggest that establishment in the developed world may be possible. Rift Valley fever has the potential to invade North America, where seasons play a role in disease persistence. The values for the basic reproductive number show that, in order to eradicate the disease, the survival time of mosquitoes must decrease below 8.67 days. Mechanisms such as aggressive spraying that decreases the mosquito population can contain an outbreak. Otherwise, Rift Valley fever is likely to establish itself as a recurring seasonal outbreak. Rift Valley fever poses a potential threat to North America that would require aggressive interventions in order to prevent a recurring seasonal outbreak.     

Childbearing women’s experiences of the maternity care system in Australia during the first wave of the COVID-19 pandemic

BackgroundSubstantial changes occurred in Australian healthcare provision during the COVID-19 pandemic to reduce the risk of infection transmission. Little is known about the impact of these changes on childbearing women.AimTo explore and describe childbearing women’s experiences of receiving maternity care during the COVID-19 pandemic in Australia.MethodsA qualitative exploratory design using semi-structured interviews was used. Women were recruited through social media and self-nominated to participate in an interview. Maximum variation sampling was used. Twenty-seven interviews were conducted with women from across Australia. Data was analysed thematically.FindingsThree primary themes and nine sub-themes emerged: ‘navigating a changing health system’ (coping with constant change, altered access to care, dealing with physical distancing restrictions, and missing care), ‘desiring choice and control’ (experiencing poor communication, making hard decisions, and considering alternate models of care), and ‘experiencing infection prevention measures’ (minimising the risk of exposure and changing care plans to minimise infection risk).DiscussionThe substantial changes in care delivery for pregnant and postpartum women during the pandemic appear to have reduced woman-centred care. In most cases, care was perceived as impersonal and incomplete, resulting in a very different experience than expected; consequences included missing care. The presence of a known care provider improved women’s sense of communication, choice, and control.ConclusionThis study provides unique insight into the experiences of childbearing women across Australia. The importance of respectful woman-centred care cannot be forgotten during a pandemic. The findings may inform future service planning during pandemics and disaster situations.     

The solution of time‐dependent population models

We analyze the dynamics of age‐structured population renewal when vital rates make a transition in a finite time interval from arbitrary initial values to any specified final values. The general solution to the renewal equation in such cases is obtained. This solution describes the birth sequence explicitly, and also leads to a general formula for population momentum. We show that the duration of the transition determines the complexity of the solution for the birth sequence. For transitions that are completed in a time smaller than the maximum age of reproduction, we show that the classical Lotka solution found in every textbook also applies, with a small modification, to the time‐dependent case. Our results substantially extend previous work that has often focused on instantaneous transitions or on slow and infinitely persistent change in vital rates.     

Providing maternity care for disadvantaged women in Aotearoa New Zealand: The impact on midwives

BackgroundHealth inequities and socio-economic disadvantage are causes for concern in Aotearoa New Zealand. Becoming pregnant can increase a woman’s vulnerability to poverty, with the potential for an increase in multiple stressful life events. Providing midwifery care to women living in socio-economic deprivation has been found to add additional strains for midwives. Exploring the perspectives of the midwives providing care to women living with socio-economic deprivation can illuminate the complexities of maternity care.AimTo explore the impact on midwives when providing care for socio-economically disadvantaged women in Aotearoa New Zealand.MethodInductive thematic analysis was used to analyse an open-ended question from a survey that asked midwives to share a story around maternal disadvantage and midwifery care.FindingsA total of 214 stories were received from midwives who responded to the survey. Providing care to disadvantaged women had an impact on midwives by incurring increased personal costs (time, financial and emotional), requiring them to navigate threats and uncertainty and to feel the need to remedy structural inequities for women and their wider families. These three themes were moderated by the relationships midwives held with women and affected the way midwives worked across the different maternity settings.ConclusionMidwives carry a greater load when providing care to socio-economically deprived women. Enabling midwives to continue to provide the necessary support for women living in socio-economic deprivation is imperative and requires additional resources and funding.