Mobile health interventions for improving maternal and child health outcomes in South Africa:a systematic review

Background:Maternal and child health(MCH)remains a significant public health concern globally despite previous efforts made to improve MCH services.Initiatives such as antenatal care,postnatal care services exclusive breastfeeding,child vaccination and supplements have been rolled out to improve MCH outcomes.However,inadequate maternal healthcare,socioeconomic factors,obstetric haemorrhaging,complications of hypertension during pregnancy,lack of maternal information,poor universal health coverage and uptake of MCH services exacerbate maternal mortality and child mortality rates,especially in resource-constrained areas in many sub-Saharan African countries including South Africa.Objective:This study aimed to review mobile health(mHealth)interventions deployed to improve maternal and child health outcomes.Methods:The study adopted the Preferred Reporting Items for Systematic Reviews and Meta-Analyses model to search and retrieve relevant literature from reputable,prominent electronic databases(Google Scholar,Scopus,PubMed,Embase,CINAHL,Web of Science,etc.).A total of 26 papers were selected and analyzed.Results:The findings revealed several mHealth interventions such as MomConnect,Mobile Alliance for Maternal Action,NurseConnect,ChildConnect,CommCare,Road to Health Application and Philani Mobile Video Intervention for Exclusive Breastfeeding have been utilized by healthcare workers and women to improve access to MCH services.However,inadequate digital infrastructure,digital divide,resistance to change,inadequate funding,language barriers,short message service and data costs,lack of digital skills and support,compatibility,scalability and interoperability issues,legislative and policy compliance,lack of mHealth awareness,data security and privacy concerns hinder uptake and utilisation of mHealth interventions.There is a need to scale up and sustain mHealth interventions and update existing regulatory framework,policies and strategies.Conclusion:mHealth interventions offer unprecedented opportunities to improve access to maternal information and substantially improve maternal and child health services.Stakeholder engagement and the development of sustainable funding strategies are important for successfully implementing and scaling mHealth projects while addressing existing and emerging key issues.

Exploring the moderating role of financial development in environmental Kuznets curve for South Africa:fresh evidence from the novel dynamic ARDL simulations approach

The extant literature has produced mixed evidence on the relationship between finan-cial development and ecological sustainability.This work addresses this conundrum by investigating financial development’s direct and indirect consequences on ecologi-cal quality utilizing the environmental Kuznets curve(EKC)methodological approach.Our empirical analysis is based on the novel dynamic autoregressive distributed lag simulations approach for South Africa between 1960 and 2020.The results,which used five distinct financial development measures,demonstrate that financial develop-ment boosts ecological integrity and environmental sustainability over the long and short terms.In the instance of South Africa,we additionally confirm the validity of the EKC theory.More importantly,the outcomes of the indirect channels demonstrate that financial development increases energy usage’s role in causing pollution while attenuating the detrimental impacts of economic growth,trade openness,and foreign direct investment on ecological quality.Moreover,the presence of an inadequate financial system is a requirement for the basis of the pollution haven hypothesis(PHH),which we examine using trade openness and foreign direct investment variables.PHH for both of these variables disappears when financial development crosses specified thresholds.Finally,industrial value addition destroys ecological quality while tech-nological innovation enhances it.This research provides some crucial policy recom-mendations and fresh perspectives for South Africa as it develops national initiatives to support ecological sustainability and reach its net zero emissions goal.

Revisiting the nexus between fiscal decentralization and CO_(2)emissions in South Africa:fresh policy insights

The argument over fiscal decentralization and carbon dioxide emission(CO_(2))reduction has received much attention.However,evidence to back this claim is limited.Economic theory predicts that fiscal decentralization affects environmental quality,but the specifics of this relationship are still up for debate.Some scholars noted that fiscal decentralization might lead to a race to the top,whereas others contended that it would result in a race to the bottom.In light of the current debates in environmental and development economics,this study aims to provide insight into how this relationship may function in South Africa from 1960 to 2020.In contrast to the existing research,the present study uses a novel dynamic autoregressive distributed lag simulation approach to assess the positive and negative changes in fiscal decentralization,scale effect,technique effect,technological innovation,foreign direct investment,energy consumption,industrial growth,and trade openness on CO_(2)emissions.The following are the main findings:(i)Fiscal decentralization had a CO_(2)emission reduction impact in the short and long run,highlighting the presence of the race to the top approach.(ii)Economic growth(as represented by the scale effect)eroded ecological integrity.However,its square(as expressed by technique effect)aided in strengthening ecological protection,validating the environmental Kuznets curve hypothesis.(iii)CO_(2)emissions were driven by energy utilization,trade openness,industrial value-added,and foreign direct investment,whereas technological innovation boosted ecological integrity.Findings suggest that further fiscal decentralization should be undertaken through further devolution of power to local entities,particularly regarding environmental policy issues,to maintain South Africa’s ecological sustainability.South Africa should also establish policies to improve environmental sustainability by strengthening a lower layer of government and clarifying responsibilities at the national and local levels to fulfill the energy-saving functions of fiscal expenditures.

Molecular evidence and phylogenetic delineation of spotted fever group Rickettsia species in Amblyomma ticks from cattle in Gauteng and Limpopo Provinces,South Africa

Objective:To determine the prevalence of tick-borne pathogens with a particular focus on Rickettsia spp.in ticks collected from cattle in Gauteng and Limpopo Provinces,South Africa.Methods:A total of 200 ticks were collected from cattle within the Madala livestock,Pretoria,Gauteng Province and in Mankweng Township,Polokwane,Limpopo Province in 2019.The ticks were morphologically identified and processed individually for a total genomic DNA extraction.Specific primers targetting ompA,ompB,and the 17KDa genes were used for a molecular screening and delineation of Rickettsia from the extracted genetic materials using polymerase chain reaction(PCR)technique.PCR amplicons of positive samples were sequenced bidirectionally using the Sanger sequencing method.Sequences generated were processed and analysed using appropriate bioinformatics software.Results:The ticks were morphologically identified as Amblyomma spp.PCR profiling of the genomic DNA samples revealed the presence of the Rickettsia pathogen in 42(21%)of the ticks collected from both Provinces.Out of the genes profiled,14(7%)were positive for 17KDa,42(21%)for ompA and 32(16%)were positive for ompB genes respectively.The nucleotide blast of the sequenced genomes showed high similarity,as high as 100% with other reference Rickettsia(R.)africae in the GenBank.The phylogenetic analysis of the sequences further validated them as R.africae with their characteristic clustering pattern with related reference sequences.Conclusions:There is an abundance of R.africae in Amblyomma ticks collected from cattle in the study areas.This has serious public health implications as individuals who accidentally get infested with the ticks could acquire R.africae.Hence,adequate precautions in terms of sensitization of farmers about the risk and mass mobilization drive to control the vectors in the areas are highly recommended to safeguard public health.

Mental health implications of suicide rates in South Africa

Mental health challenges are a severe issue that could lead to suicide if not properly addressed.South Africa has a significant burden of mental health issues,which contributes to the soaring rate of suicide.Adequate mental health-care provision could reduce the high suicide rate in South Africa.Since the apartheid regime,the country has made a series of efforts to improve mental health.This study aimed to review and examine available literature on mental health and suicide issues in South Africa and demonstrate the policy implications.This study adopted a narrative review approach.Electronic databases(PubMed,Scilit,Google Scholar and Semantic Scholar)were used to identify published articles in the English language with crucial search terms that included mental health,South African mental health policy,South Africa,suicide and policy.Literature suggests that at the provincial level,there are no adequate mental health policies,and the implementation of the country’s mental health policy is faced with many challenges,such as a shortage of professionals and finances.The review also showed that task sharing and counselling have been pilot-tested and shown to be effective methods for the prevention of mental illness and promotion of positive mental health.This study concludes that the mental health treatment gap still exists in South Africa,and this needs to be tackled using effective,multi-level counselling interventions and policy initiatives.Adequate mental health-care provision and effective implementation of mental health policy could reduce the high rate of suicide in South Africa.

Ethical Trading： The Implications of the Human Rights Watch Report on South African Fruit Exports

This paper presents an ex-ante assessment of the potential implications of the 2011 Human Rights Watch Report on the South African fruit industry. The report explicitly mentions the lack of compliance with ethical codes within the fruit industry, the prevalence of exploitative conditions for farm workers and diverse human rights abuses in farms. The report recommends import ban on culprits as well as engaging third party auditing to ensure compliance. The high vulnerability of the smallholder farmers justified the special interest in the implications on their reputation and hence their ability to access profitable export markets. Although large-scale commercial farmers are potentially at risk of reputational damage due to the Human Rights Watch Report, they are better able to cope owing to their stronger capital base. The opinions of knowledgeable industry insiders were therefore elicited through qualitative research that used a five-point Likert scale to assess perceptions about market access. On the basis of the results, it is probable that the report will lead to improved working conditions for farm workers, improved concern for consumers＇ health, and enforcement of legislation by the govemment. The negative implications involve increased competition, possibility of retailers＇ rationalising their supply base and increased evaluation that ends at the farm gate. There is also high probability of increased marginalisation of the already disadvantaged smallholder suppliers, and possible increase in costs of auditing and accreditation for the entire fruit industry. Thus, active collaboration among all stakeholders to ensure the competitiveness of the fruit industry is inevitable.

Socio-economic factors influencing mopane worm(Imbrasia belina) harvesting in Limpopo Province, South Africa

In South Africa, non-timber forest products, especially mopane worms （Imbrasia belina） have become an important source of food and cash income for rural people living in or near the mopane woodlands. However, the continued harvesting has implications for long term management of the mopane woodlands in the northern parts of South Africa. In order to keep a balance between mopane worm harvesting and biodiversity, an understand- ing of socio-economic factors influencing the harvest at household level is vital to reducing depletion and overex- ploitation of the mopane woodland resources. This study evaluated the socio-economic factors influencing mopane worm harvesting decisions in rural households in Limpopo Province, South Africa using a binary logistic regression model based on a household survey of 120 respondents. Age, gender, education, income from mopane worm sales, social capital （group affiliation）, household size, lack of institution/law to regulate use, distance to the nearest har- vesting site, and regional locations were statistically significant factors influencing household mopane worm harvest decisions. Implications for policy are discussed.

Geochemical Evaluation of the Permian Ecca Shale in Eastern Cape Province, South Africa:Implications for Shale Gas Potential

Shale gas has been the exploration focus for future energy supply in South Africa in recent time. Specifically, the Permian black shales of the Prince Albert, Whitehill, Collingham, Ripon and Fort Brown Formations are considered to be most prospective rocks for shale gas exploration. In this study,outcrop and core samples from the Ecca Group were analyzed to assess their total organic carbon(TOC), organic matter type, thermal maturity and hydrocarbon generation potential. These rocks have TOC ranging from 0.11 to 7.35 wt%. The genetic potential values vary from 0.09 to 0.53 mg HC/g,suggesting poor hydrocarbon generative potential. Most of the samples have Hydrogen Index(HI) values of less than 50 mg HC/g TOC, thus suggesting Type-Ⅳ kerogen. Tmax values range from 318℃ to601℃, perhaps indicating immature to over-maturity of the samples. The vitrinite reflectance values range from 2.22% to 3.93%, indicating over-maturity of samples. Binary plots of HI against Oxygen Index(OI), and HI versus Tmax show that the shales are of Type II and mixed Type Ⅱ-Ⅲ kerogen.Based on the geochemical data, the potential source rocks are inferred as immature to over-matured and having present-day potential to produce gas.

Virtual healthcare services and digital health technologies deployed during coronavirus disease 2019(COVID-19)pandemic in South Africa:a systematic review

Aims:To identify virtual healthcare services and digital health technologies deployed in South Africa during coronavirus disease 2019(COVID-19)and the challenges associated with their use.Metiiods:To determine the status of digital health utilization during COVID-19 in South Africa,the preferred reporting items for systematic reviews and meta-analyses model was used to perform a systematic and in-depth critical analysis of previously published studies in well-known and trusted online electronic databases using specific search keywords words that are relevant to this study.We selected published peer-reviewed articles available from the onset of COVID-19 to July 2021.Results:Total of 24 articles were included into this study.This study revealed that South Africa adopted digital technologies such as SMS-based solutions,mobile health applications,telemedicine and telehealth,WhatsApp-based systems,artificial intelligence and chatbots and robotics to provide healthcare services during COVID-19 pandemic.These innovative technologies have been used for various purposes including screening infectious and non-infectious diseases,disease surveillance and monitoring,medication and treatment compliance,creating awareness and communication.The study also revealed that teleconsultation and e-prescription,telelaboratory and telepharmacy,teleeducation and teletraining,teledermatology,teleradiology,telecardiology,teleophthalmology,teleneurology,telerehabilitation,teleoncology and telepsychiatry are among virtual healthcare services delivered through digital health technologies during COVID-19 in South Africa.However,these smart digital health technologies face several impediments such as infrastructural and technological barriers,organization and financial barriers,policy and regulatory barriers as well as cultural barriers.Conclusion:Although COVID-19 has invigorated the use of digital health technologies,there are still some shortcomings.The outbreak of pandemics like COVID-19 in the future is not inevitable.Therefore,we recommend increasing community networks in rural areas to bridge the digital divide and the modification of mHealth policy to advocate for the effective use of innovative technologies in healthcare and the development of sustainable strategies for resources mobilization through private-public partnerships as well as joining available international initiatives advocating for smart digital health.

Trajectories of deagrarianization in South Africa−Past,current and emerging trends:A bibliometric analysis and systematic review

Inquiries into rural households’engagement with smallholder agriculture remain ambiguous and complex.For this reason,research on cultivation patterns has been informed by numerous articles published in recent decades.However,studies detailing the development and progress of deagrarianization remain understudied.In attempts to bridge this knowledge gap,the study aims to provide empirical insights into the trajectories of deagrarianization in South Africa.Studies published between 1996 and 2021 were retrieved from Clarivate Web of Science for analysis.A combination of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)and bibliometric analysis was adopted to provide a comprehensive review of deagrarianization dynamics.The findings emphasize that the field of deagrarianization is gaining momentum as publications gradually emerge to indicate that although cultivation is dominant among rural households,there is a reduction in field cultivation and an increase in home-gardening in former homelands of South Africa.Furthermore,common keywords in deagrarianization literature,from a global,African and South African perspective include poverty and livelihoods.Considering that majority of deagrarianization studies analyze patterns,drivers and consequences of the phenomenon,future research needs to consider novel methodologies such as participatory GIS and new avenues that incorporate,but are not limited to,other livelihood issues such as social identities and food security.It is advised that strategies for enhancing rural development and agricultural policies focus on broader solutions that do not only sustain home-gardens but also revitalize both active and abandoned fields.

Conservation of Quiver Trees in Namibia and South Africa under a Changing Climate

Aloe dichotoma (Quiver tree) occurs in the arid regions of Namaqualand and Bushman land in South Africa, and in arid regions of southern Namibia. The Quiver trees are not only threatened by agricultural expansion, overgrazing, and mining;but also by climate changes and droughts. Previous studies show that Quiver trees are very sensitive to environmental changes, and do not respond well to extreme hot and dry conditions. This study investigates the current status of the Quiver tree within its existing environment, and also assesses the projected future changes of the Quiver tree habitat under different climatic scenarios. It provided evidence regarding the importance of the study to understanding the climate change impacts on the Quiver tree and its geographical response to climate changes.

Influences of Seed Source, Pre-chilling, Light and Temperature on the Germination of South African Pelargonium sidoides

Pelargonium sidoides DC is used in herbal medicine for the treatment of various infections. The roots are being indiscriminately harvested for local and export trade and the collection rate is becoming unsustainable. Seed germination dynamics of this species was studied with the aim to reveal factors that influence its survival in the wild in order to adopt the appropriate germination conditions for use in ex-situ propagation and conservation program. Germination was affected by age of seeds, temperature and pre-chilling conditions. Temperature higher than 25 oC reduced germination by 60%. When seeds of P. sidoides were subjected to pre-chilling treatment for seven days, there was a significant drop in final germination by 29% compared to the other treatments. Although, final germination was not affected by different light treatments, continuous light significantly promoted germination velocity Seeds harvested from the plants grown in the green house performed better in germination than those collected from the field. The ecological implications of these observations on the propagation and conservation ofP. sidoides are discussed.

The Key Factor of Acid Mine Drainage (AMD) in the History of the Contribution of Mining Industry to the Prosperity of the United States and South Africa: A Review

Mining industry has significantly contributed to the prosperity of the nation with economic growth, whereas mining operation has caused Acid Mine Drainage (AMD) with the abandonment of mines. As some researchers suggest, the history of AMD is, generally, affected by the change in not only mining industry but also in social and economic conditions. Thus, historical analysis is an effective way to find the key factors of AMD. In this study, in order to find the key factors of AMD, we examine the history of the United States (U.S.) and South Africa, where their economy had been developed owing to the large-scale mining, based on the findings in the previous studies. The results indicated that the abandoned mines due to the economic depression triggered AMD in the U.S. and South Africa. While the U.S. had progressively adopted anti-AMD methods in terms of prevention, prediction, and remediation (PPR) as a comprehensive approach, especially since the 1970s onwards because of the rise of environmental consciousness as well as strict regulations, South Africa is at the early stage of implementing the regulations following PPR. The public attention should be directed to environmental conservation in addition to the implementation of the regulations in South Africa. The improvement in socio-economic conditions is, additionally, necessary for the rise of environmental consciousness in South Africa in the light of the three pillars of sustainable development: social, economic, and environmental elements.

The development and evaluation of a nurse anaesthesia model for practice in South Africa

Objective This article aimed to present a developed model for nurse anaesthesia practice in South Africa and then to evaluate the model by national and international anaesthetist experts.Methods For the model development,a theory-generative research design was used as guided by Chinn&Kramer.The study included four steps to develop and evaluate the model:step one,concept analysis;step two,placing the concepts into relationships;step three,description and critical reflection of the model;step four,evaluation of the model.For evaluation of the model,data were collected using individual,in-depth interviews.Four South African medical specialist anaesthesiologists and four international nurse anaesthetists were interviewed.Transcribed interviews were analyzed using Tesch’s eight steps of thematic data analysis.Results The model was described in four phases:relationship phase,working phase,termination phase,and independent phase.The model shows a development process of a student nurse anaesthetist by a nurse anaesthetist facilitator to the mastery of the scope of practice of a nurse anaesthetist.Two themes(six categories)emerged through thematic analysis:the model and guidelines for implementation were found to be appropriate(model and guidelines for implementation are important because of the need for nurse anaesthetist,the model is applicable because it is described as comprehensive,the relationship phase was found to be important and the interdependence between disciplines is imperative,the affirmation that mastery has to be attained by nurse anaesthetists due to the complexity of services rendered),anticipated limitations to the South African nurse anaesthetist(the need to identify complex patients and limitations on the setting and refer to higher level of care,limitations due to red tape).Conclusions This model provides fertile soil to inform and outline the education(curriculum)and practice(scope of practice)and research for nurse anaesthesia practice in South Africa.

Understanding South African mothers’challenges to adhere to exclusive breastfeeding at the workplace:A qualitative study

Objective:This study aimed to gain an in-depth understanding of the experience of South African working mothers in the adherence to exclusive breastfeeding when returning from maternity leave.Methods:The data of the study was collected using face-to-face semi-structured interviews.Eight breastfeeding mothers were purposefully selected from two primary health care clinics in Rustenburg,North West Province,South Africa.The data were coded,categorized,and clustered into themes using Giorgi’s phenomenological analysis.Ethical considerations and measures of trustworthiness were adhered to throughout the study.Results:The findings revealed three themes:a desire for working mothers to continue the adherence to exclusive breastfeeding,workplace support for breastfeeding mothers in the adherence to exclusive breastfeeding,and an unsuitable workplace environment for the adherence to exclusive breastfeeding.Six sub-themes were identified:the need to return to the workplace soon after baby’s birth,psychological responses in the adherence to exclusive breastfeeding,lack of support from employers and coworkers in the adherence to exclusive breastfeeding,lack of or partial implementation of breastfeeding policies in the workplace,the workplace not being supportive for mothers’having to express and the workplace not being supportive for mothers’having to store breastmilk.Conclusion:Based on the findings,South African government should revisit employment policies to support working mothers who need to continue with exclusive breastfeeding after returning from maternity leave.

Geochronological,Geochemical and Paleomagnetic Clues for Existence of a~2.1Ga Dyke Generation in the Mashishing Area,South Africa

Dyke swarms are widespread throughout the Kaapvaal Craton(KC)in South Africa and have been documented in some detail.Up to date,only the^2.9 Ga SE-trending and the^2.7 to^2.66 Ga radiating dyke arrays are

Analysis on the Impact of Amphibian Export in South Africa on Global Chytrid Distribution: Taking China as an Example

Chytridiomycosis, caused by chytrid fungus, is a dominant infectious disease in anura after metamorphosis. Previous evidence suggests that Africa is the birthplace of chytridiomycasis. At present, with the increasingly rapid development of international trade in amphibians, the rapid spread and widespread outbreak of chytridiomycosis poses a huge threat to amphibian populations in the world. In this study, according to the entry-exit inspection and quarantine standards of the people~ Republic of China, the impact of amphibian importation from South Africa on ecological security in China was analyzed based on release assessment, contact exposure assessment and consequence assessment, to investigate the risk of chytrid fungus through the importation of amphibians from South Africa to China and the possibility of the colonization and dissemination of chytrid fungus after the introduction. The result of risk assessment of chytrid fungus through the importation of amphibians from South Africa to China and the result of possibility assessment of the colonization and dissemination of chytrid fungus after the introduction were both identified as ＂ moderate＂, which indicated that the importation of amphibians from South Africa to China exhibited a certain risk, and the introduction of chytrid fungus in China would cause certain risk of colonization and dissemination.

The Social Determinants of Health and the Role of the Health Care System: A Case Study of the Significance of Good Governance in Public Hospitals in South Africa

Increasingly international and national policies are being directed at actions for the social determinants of health and for an integrated approach to health care provision, not only in terms of institutional cooperation but also stakeholder involvement. A key component of both these policies is the development of good governance principles in all health care agencies and organizations. A neglected dimension in these debates has been the role of the public hospital which remains a vital and expensive dimension of service provision. In a case study of a public hospital in South Africa, this paper charts the readiness of its management principles and activities to provide quality health care linked to population health and to contribute to the non-medical determinant of health. Using Taylor’s principles of good governance, we conclude that there is a mixture of good and not so good governance activity. The paper concludes by examining the external constraints on the public hospital and by providing suggestions for future activities.

Postnatal PMTCT: Women’s Perception Barriers at a Johannesburg Health Centre, South Africa

Background: Maximising women’s participation and ensuring optimal outcomes will require that the women’s perception barriers to postnatal prevention of Mother-to-Child Transmission (PMTCT) programme of HIV be addressed. However, little is known about women’s perception barriers to postnatal PMTCT programme of HIV and how these barriers affect the women’s health seeking behavior and uptake. Objective: This study sought to explore the women’s perception barriers to postnatal PMTCT programme at a Johannesburg Community Health Centre during April-May, 2016. Methods: A qualitative study on 30 women (aged 20 - 39 years) was conducted at a Johannesburg community health (CHC), South Africa, during May-June 2016, after obtaining their consent. The data was analysed thematically to understand women’s perception barriers to postnatal PMTCT programme. Results: The study found that inadequate counselling was perceived to be the single key health service barrier to PMTCT programme. At the individual level, adherence to ART was considered the leading women’s barriers to the postnatal PMTCT. Exclusive breastfeeding was, however, perceived as important women’s barriers to the postnatal PMTCT. Inadequate emotional support from families and community was a noteworthy women’s perception barrier to the programme. Conclusion: The study makes two recommendations: firstly, the staff, programme managers and health policy makers need to be aware of the women’s perception barriers to the postnatal PMTCT programme. Secondly, the programme should be strengthened by addressing perception barriers to the programme to enhance women participation to ensure optimal outcomes for women and their infants.

Risk Factors for Prevalence of Enterotoxigenic Escherichia coli (ETEC) in Diarrheic and Non-diarrheic Neonatal and Weaner Pigs, South Africa

Enterotoxigenic Escherichio coli （ETEC） causes neonatal and post-weaning diarrhea in pigs. In order to determine the risk factors, rectal/fecal swabs and visceral organs obtained from pig farms in two regions of South Africa were analyzed microbiologically against risk variables. Seventy-two percent of young pigs were found to be positive for ETEC toxin genes; estB （38.9%）, estB/STAP （25%）, and estB/LT （13.9%） were dominant. Risk factors for ETEC-diarrhea in pigs include： leaving sick piglets in a pen with healthy piglets [odds ratio （OR） = 33.52; P 〈 0.0001]; water spillage in pen （OR = 42.87; P 〈 0.0001）; hypothermic piglets （OR = 7.29; P 〈 0.0001）; runt piglets in pen with healthy littermates （OR = 3.65; P 〈 0.0001）; and prolonged use of antibiotics （OR = 3.05; P = 0.05）.