Impacts of heat exposure in utero on long-term health and social outcomes: a systematic review

BACKGROUND

Climate change, particularly global warming, is amongst the greatest threats to human health. While short-term effects of heat exposure in pregnancy, such as preterm birth, are well documented, long-term effects have received less attention. This review aims to systematically assess evidence on the long-term impacts on the foetus of heat exposure in utero.

METHODS

A search was conducted in August 2019 and updated in April 2023 in MEDLINE(PubMed). We included studies on the relationship of environmental heat exposure during pregnancy and any long-term outcomes. Risk of bias was assessed using tools developed by the Joanna-Briggs Institute, and the evidence was appraised using the GRADE approach. Synthesis without Meta-Analysis (SWiM) guidelines were used.

RESULTS

Eighteen thousand six hundred twenty one records were screened, with 29 studies included across six outcome groups. Studies were mostly conducted in high-income countries (n = 16/25), in cooler climates. All studies were observational, with 17 cohort, 5 case-control and 8 cross-sectional studies. The timeline of the data is from 1913 to 2019, and individuals ranged in age from neonates to adults, and the elderly. Increasing heat exposure during pregnancy was associated with decreased earnings and lower educational attainment (n = 4/6), as well as worsened cardiovascular (n = 3/6), respiratory (n = 3/3), psychiatric (n = 7/12) and anthropometric (n = 2/2) outcomes, possibly culminating in increased overall mortality (n = 2/3). The effect on female infants was greater than on males in 8 of 9 studies differentiating by sex. The quality of evidence was low in respiratory and longevity outcome groups to very low in all others.

CONCLUSIONS

Increasing heat exposure was associated with a multitude of detrimental outcomes across diverse body systems. The biological pathways involved are yet to be elucidated, but could include epigenetic and developmental perturbations, through interactions with the placenta and inflammation. This highlights the need for further research into the long-term effects of heat exposure, biological pathways, and possible adaptation strategies in studies, particularly in neglected regions. Heat exposure in-utero has the potential to compound existing health and social inequalities. Poor study design of the included studies constrains the conclusions of this review, with heterogenous exposure measures and outcomes rendering comparisons across contexts/studies difficult.

TRIAL REGISTRATION

PROSPERO CRD 42019140136.

A WHO-led global strategy to control greenhouse gas emissions: a call for action

BACKGROUND

Climate change, driven by anthropogenic greenhouse gas emissions, is among the greatest threats to human health. The World Health Organisation (WHO), has led global efforts to respond to emerging public health threats including the control of hazardous substances such as tobacco, alcohol, lead and asbestos, with remarkable health gains. BODY: Despite WHO's clear messaging on the enormous and growing health risks of climate change, greenhouse gases are not yet classified as hazardous substances, requiring control through a global strategy or framework. Additionally, WHO has not classified disease attributable to climate change as a result of the promulgation of these hazards as a Public Health Emergency of International Concern (PHEIC), despite the serious and preventable health risks it poses globally. Several historical precedents set the stage for WHO to declare excess greenhouse gases as health hazards, including the control of ozone-depleting substances and breast-milk substitutes where the public benefit of control exceeded the potential benefit of their promulgation. In addition, WHO's undertaking within the International Health Regulations to protect global health, providing imperative to declare climate change a PHEIC, with Tedros Adhanom Ghebreyesus, director-general of WHO, declaring: "The climate crisis is a health crisis, fuelling outbreaks, contributing to higher rates of noncommunicable diseases, and threatening to overwhelm our health workforce and health infrastructure". Importantly, the health sector, perhaps more than other sectors, has successfully overcome formidable, vested interests in combatting these threats to health.

CONCLUSION

It is thus imperative that WHO make full use of their credibility and influence to establish a global framework for the control of greenhouse gases through the declaration of excess greenhouse gas emissions as a hazardous substance, and declaring climate change a PHEIC. Who else is better placed to drive the considerable societal transformation needed to secure a liveable future?

Herpes simplex virus infection of the central nervous system in human immunodeficiency virus-type 1-infected patients

We report clinical, radiological and virological data from nine consecutive HIV-infected patients with herpes simplex virus (HSV) infection of the central nervous system (CNS). Three patients presented with confusion, two with fever and headache, two with anxiety and depression, one with slow mentation and memory loss and one with expressive dysphasia. Five patients had previous AIDS-defining diagnoses: four of these five patients had previous cutaneous HSV infection. HSV DNA was detected by the polymerase chain reaction (PCR) on cerebrospinal fluid (CSF) in seven patients. HSV infection was diagnosed by brain biopsy (after negative PCR on CSF) in one patient and at autopsy in one patient (after negative CSF PCR and brain biopsy). Seven patients received specific anti-viral therapy; two died of unrelated causes and the other five recovered. Two patients were not treated, in one the diagnosis was made at autopsy and the other recovered spontaneously. HIV-infected patients with CNS HSV infection have a varied presentation. Diagnosis by PCR on CSF identified the majority of cases. With specific treatment the outcome was good.

Perspectives on One Health: a survey of national Delegates to the World Organisation for Animal Health, 2012

In 2012, the World Organisation for Animal Health (OIE) surveyed all 178 national Delegates to better understand the perceptions and priorities of Veterinary Services with respect to One Health efforts and to guide future work in that area. For the purposes of this survey, the concept or practice of One Health was defined as 'the intersectoral collaborative approach to preventing, detecting, and controlling diseases among animals and humans, including the collaboration among the institutions and systems that support their prevention, detection and control'. A total of 120 OlE Delegates, representing countries from all five OIE regions, responded to the survey. Delegates identified zoonoses, rabies and influenza as high-priority disease areas and disease reporting and food safety as high-priority programme areas for One Health approaches. Veterinary Services participated in joint programmes, involving these priority disease and programme areas, with national intersectoral partners. Delegates reported barriers to implementing One Health approaches, including a lack of resources, the complexity of collaboration, inadequate capacity within their Veterinary Services, and a lack of adequate legislation, policy, guidance and political will for One Health activities. Delegates supported OIE efforts to enhance One Health activities, and requested that the OIE and partners provide technical information and advice and conduct training and capacity-building seminars for One Health. Veterinary Services cannot effectively apply One Health approaches at the national level without effective partnerships across sectors. The OlE can serve as a model for countries by continuing its commitment to these intersectoral partnerships at the international level.

Mumps epididymo-orchitis with prolonged detection of virus in semen and the development of anti-sperm antibodies

Epididymo-orchitis is the most common complication of mumps in post-pubertal men. A case of MMR vaccine failure, in whom mumps and mumps-associated unilateral epididymo-orchitis developed, is presented in this article. Mumps virus was isolated from the semen 14 days after onset and mumps RNA was detected in semen for up to 40 days using RT-PCR. Epididymo-orchitis was associated with transient but significant reduction in sperm count and severe abnormalities in sperm morphology. It also led to the appearance of anti-sperm antibodies, which may have potential long-term adverse effects on the patient's fertility. Sequencing of the SH gene of the virus showed this to be a new mumps genotype distinct from the virus circulating currently in the UK.

The public health response to a case of Lassa fever in London in 2000

OBJECTIVES

Evaluation of the Department of Health 1996 guidance, the Memorandum on the Management and Control of Viral Haemorrhagic Fevers.

METHODS

Description of the public health management in 2000 of the fifth UK patient confirmed to have Lassa fever.

RESULTS

Delayed risk categorisation of the patient occurred for a variety of reasons. DH Guidance was followed once infection control advice was sought. Active surveillance of 125 contacts was extremely resource intense, involving over 3000 communications. Self-monitoring by healthcare workers should be considered in future. Advice on use of ribavirin prophylaxis is not included in the Memorandum, nor advice or templates for information sheets for contacts. Information sheets are now available from the Health Protection Agency in the event of future cases. International aspects not adequately addressed include the need for reliable risk assessment to be carried out before patients are medically evacuated from the country of origin, and the steps required to repatriate UK nationals. Effective and efficient communication is required between national and international organisations involved in such incidents.

CONCLUSIONS

If guidelines are unclear or impracticable they will not be followed. It is important that lessons are learned and documented and that national guidance be regularly reviewed.

Prophylaxis with a nevirapine-containing triple regimen after exposure to HIV-1

Evidence suggests that nevirapine, a non-nucleoside reverse-transcriptase inhibitor, might be very effective in the prevention of HIV-1 integration and the reduction of risk of HIV-1 acquisition after exposure. We used a triple combination regimen, including nevirapine, for prophylaxis after occupational or sexual exposure to HIV-1 infection. Of 57 individuals who started therapy, only 41 returned for follow-up. Five had a grade three or four drug-induced hepatitis, two of whom also had a rash. This high rate of major adverse events raises concerns over the safety of such a regimen for its use in this population.

Varicella zoster virus-associated neurological disease in HIV-infected patients

Varicella zoster virus (VZV) is an uncommon but well recognized cause of neurological disease in HIV-infected patients. Analysis of cerebrospinal fluid (CSF) using the polymerase chain reaction (PCR) in HIV-infected patients presenting with neurological disease has increasingly allowed diagnosis of VZV-associated pathology. We report clinical, radiological and virological data from 15 consecutive patients with VZV-associated neurological disease. Clinical presentation was varied, including meningo-encephalitis in 9 and isolated cranial nerve palsies in 6. VZV deoxyribonucleic acid (DNA) was detected by PCR in CSF of 11/15; pleocytosis was present in only 6/15, raised protein in 11/15. Magnetic resonance imaging (MRI) appearances were focal signal abnormalities in 8, meningeal enhancement in 2 and normal in 2. With specific anti-VZV therapy 10 patients recovered fully. The predictive value of PCR on CSF for diagnosis of VZV-associated neurological disease should take into account the patient's clinical presentation, concurrent infections and response to anti-VZV therapy.

Comparative quantification of IL-1beta, IL-10, IL-10r, TNFalpha and IL-7 mRNA levels in UV-irradiated human skin in vivo

OBJECTIVE AND DESIGN

Ultraviolet (UV) exposure induces local immunosuppression and inflammation in human skin. Cytokines are, in part, responsible for these responses. To investigate the effects of UV-induced gene expression at the molecular level we established a sensitive in vivo/ex vivo method for a comparative quantification of cytokines and receptors involved in the local skin immune reactions.

MATERIAL AND METHODS

Specific mRNA levels of human UV-irradiated skin were determined by real time quantification (TaqMan RT-PCR). Highly efficient PCR-reaction conditions were obtained by designing very short PCR-templates (72-87 bp). The most sensitive PCR-conditions were obtained by optimisation of primer and Mn(OAc)2-concentrations, which led to significant PCR signals (C(T)-value) of less than 36 cycles. A strong correlation between PCR efficiency of the internal control (GAPDH) compared to targets (IL-1beta, IL-10, IL-10r, TNFalpha, IL-7) allowed the use of deltadelta C(T)-method to quantify comparable mRNA levels.

RESULTS

Interleukin-1beta (IL-1beta), Interleukin-10 (IL-10), and tumour necrosis factor alpha (TNFalpha) mRNA levels were increased in a time- and dose-dependent manner. Interleukin-1beta induction reached a maximum (approx. 44-fold) 6 h after a UV-dose equivalent to 3 times the minimal erythemal doses just perceptible (MEDjp). Maximal TNFalpha mRNA expression (approx. 14-fold) was also detected 6 h after UV exposure. Interleukin-10 mRNA induction reached a maximum of approximately 14-fold 24 h after UV-irradiation of 3 MEDjp. Time- and dose-dependent changes in Interleukin-7 and Interleukin-10 receptor mRNA levels did not occur after UV-irradiation.

CONCLUSIONS

Time-distinct gene induction of IL-1beta, TNFalpha and IL-1beta is involved in UV-induced immune reactions, but no considerable changes were found for IL-10r or IL-7.

Glomerulonephritis after human parvovirus infection in homozygous sickle-cell disease

Glomerulonephritis with proteinuria of sufficient degree to manifest the nephrotic syndrome followed aplastic crises induced by human parvovirus (B19) in seven patients with homozygous sickle-cell disease, within 7 days in five patients and 6-7 weeks in two. Segmental proliferative glomerulonephritis was found in all four patients who underwent acute renal biopsies and focal segmental glomerulosclerosis was found in the fifth patient who had a biopsy 4 months later. One patient recovered completely, one died in chronic renal failure after 3 months, and the others had impaired creatinine clearance, four with continuing proteinuria.