Association between temperature variability and global meningitis incidence

Temperature change and male infertility prevalence: an ecological study

BACKGROUND

Although the effects of climate change on human health are widely recognized, its potential role in male infertility prevalence has not been thoroughly examined. This study seeks to explore the association between changes in ambient temperature and the prevalence of male infertility.

METHODS

This ecological study encompassed 174 countries and regions. We utilized data from 2000 to 2019 on the age-standardized prevalence rate (ASPR) of male infertility and ambient temperature to assess their potential association. The analysis accounted for several covariates, including the Sociodemographic Index (SDI), continent, smoking prevalence, alcohol consumption per capita (APC), nitrogen dioxide (NO₂), and ozone (O₃). Annual temperature values were derived by averaging monthly temperatures, and the deviance percentage of temperature (DPT) was computed based on the 20-year mean temperature. To examine spatial and nonlinear relationships between temperature and male infertility ASPR, we applied the geographic detector approach and Restricted Cubic Spline (RCS) curves. Furthermore, linear mixed-effects models were employed to quantify the association between DPT and male infertility ASPR, and adjusted models were subsequently used to forecast changes in ASPR under projected temperature scenarios for 2020-2030.

RESULTS

From 2000 to 2019, a spatial association was identified between temperature and the ASPR of male infertility. Additionally, a U-shaped correlation emerged, indicating the lowest ASPR at 15.7 °C. Higher DPT were linked to elevated male infertility ASPR, with an adjusted β estimate of 38.770 (95% CI: 8.392, 69.162). Projections suggest that ongoing temperature increases may continue to drive up male infertility ASPR.

CONCLUSION

Temperature change may be associated with an increased male infertility prevalence.

Spatiotemporal dynamics of the oropharyngeal microbiome in a cohort of Ivorian school children

The respiratory tract harbours microorganisms of the normal host microbiota which are also capable of causing invasive disease. Among these, Neisseria meningitidis a commensal bacterium of the oropharynx can cause meningitis, a disease with epidemic potential. The oral microbiome plays a crucial role in maintaining respiratory health. An imbalance in its composition is associated with increased risk of invasive disease. The main objective of this study was to evaluate changes in the spatio-temporal dynamics of the oropharyngeal microbiota considering meningococcal carriage in a cohort of 8-12-year-old school children within (Korhogo) and outside (Abidjan) of the meningitis belt of Côte d'Ivoire. A significant geographic difference in the oropharyngeal microbiome was identified between the two study sites in terms of bacterial abundance and diversity (p < 0.001), with greater diversity in children in Abidjan than in Korhogo. Meningococcal carriage was low in the cohort with eight Neisseria carriers identified in Korhogo (3.64%) including one Neisseria meningitidis (0.45%). No Neisseria were detected in Abidjan indicating geographical differences in carriage (p = 0.006). Negative correlations were also found between Neisseria abundance and humidity. Meningococcal carriage was very low during the study; however, Neisseria carriage differed between the two study areas, with a higher frequency in children in Korhogo. Analysis of the oropharyngeal microbiome showed significant differences between children followed in Abidjan and Korhogo with higher microbial diversity in Abidjan, which is generally associated with better health status. Significant correlations between Neisseria or other pathogens carriage and climatic variables (Temperature, Relative humidity, and Wind speed) were also demonstrated, indicating an important role of climate in the carriage of these bacteria; an important element to note in the current context of climate change.

Projected impact of climate change on human health in low- and middle-income countries: a systematic review

Low- and middle-income countries (LMICs) contribute relatively little to global carbon emissions but are recognised to be among the most vulnerable parts of the world to health-related consequences of climate change. To help inform resilient health systems and health policy strategies, we sought to systematically analyse published projections of the impact of rising global temperatures and other weather-related events on human health in LMICs. A systematic search involving multiple databases was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify studies with modelled projections of the future impact of climate change on human health. Qualitative studies, reviews and meta-analyses were excluded. The search yielded more than 2500 articles, of which 70 studies involving 37 countries met criteria for inclusion. China, Brazil and India were the most studied countries while the sub-Saharan African region was represented in only 9% of studies. Forty specific health outcomes were grouped into eight categories. Non-disease-specific temperature-related mortality was the most studied health outcome, followed by neglected tropical infections (predominantly dengue), malaria and cardiovascular diseases. Nearly all health outcomes studied were projected to increase in burden and/or experience a geographic shift in prevalence over the next century due to climate change. Progressively severe climate change scenarios were associated with worse health outcomes. Knowledge gaps identified in this analysis included insufficient studies of various high burden diseases, asymmetric distribution of studies across LMICs and limited use of some climate parameters as independent variables. Findings from this review could be the basis for future research to help inform climate mitigation and adaptation programmes aimed at safeguarding population health in LMICs.

Temperature-Driven Dengue Transmission in a Changing Climate: Patterns, Trends, and Future Projections

Dengue is a rapidly spreading mosquito-borne infectious disease that is sensitive to climate factors and poses a major public health concern worldwide. We analyzed dengue incidence trends and the relationship between annual mean minimum temperatures (AMMTs) and dengue incidence rates from 1990 to 2019 in 122 countries using the Global Burden of Disease and TerraClimate data sets. We also projected global dengue incidence rates under different carbon emission scenarios using temperature data from the Coupled Model Intercomparison Project Phase 6 (CMIP6) data set. Our results reveal a significant increase in global dengue cases from 1990 to 2019 and a positive correlation between temperature and dengue incidence. The association between AMMT and dengue incidence strengthened at temperatures exceeding 21°C. Central and eastern sub-Saharan Africa, as well as Oceania, were identified as the regions most sensitive to dengue; males and individuals aged 15-19 or 70-84 years were the most susceptible to dengue under rising temperatures. Our projections suggest that global dengue incidence will substantially increase by 2050 and 2100. By 2100, regions including Africa, the Arabian Peninsula, the southern United States, southern China, and island countries in the Pacific and Indian Oceans are projected to become year-round dengue-endemic under a high-emission climate scenario. Our findings underscore the importance of implementing effective measures to mitigate the impact of climate change on dengue transmission. Identifying high-risk areas and susceptible populations, along with understanding the projected expansion of dengue-endemic regions, will provide valuable guidance for targeted interventions to address this growing global health challenge in the face of changing climatic conditions.

Climate change and disorders of the nervous system

Anthropogenic climate change is affecting people's health, including those with neurological and psychiatric diseases. Currently, making inferences about the effect of climate change on neurological and psychiatric diseases is challenging because of an overall sparsity of data, differing study methods, paucity of detail regarding disease subtypes, little consideration of the effect of individual and population genetics, and widely differing geographical locations with the potential for regional influences. However, evidence suggests that the incidence, prevalence, and severity of many nervous system conditions (eg, stroke, neurological infections, and some mental health disorders) can be affected by climate change. The data show broad and complex adverse effects, especially of temperature extremes to which people are unaccustomed and wide diurnal temperature fluctuations. Protective measures might be possible through local forecasting. Few studies project the future effects of climate change on brain health, hindering policy developments. Robust studies on the threats from changing climate for people who have, or are at risk of developing, disorders of the nervous system are urgently needed.

Association between ambient temperature and chronic rhinosinusitis

BACKGROUND

Chronic exposure to particulate matter air pollution (PM2.5 ) is associated with chronic rhinosinusitis (CRS). Elevated ambient temperature may increase PM2.5 levels and thereby exacerbate sinonasal symptoms. This study investigates the association between high ambient temperature and the risk of CRS diagnosis.

METHODS

Patients with CRS were diagnosed at Johns Hopkins hospitals from May to October 2013-2022, and controls were matched patients without CRS meanwhile. A total of 4752 patients (2376 cases and 2376 controls) were identified with a mean (SD) age of 51.8 (16.8) years. The effect of maximum ambient temperature on symptoms was estimated with a distributed lag nonlinear model (DLNM). Extreme heat was defined as 35.0°C (95th percentile of the maximum temperature distribution). Conditional logistic regression models estimated the association between extreme heat and the risk of CRS diagnosis.

RESULTS

Exposure to extreme heat was associated with increased odds of exacerbation of CRS symptoms (odds ratio [OR] 1.11, 95% confidence interval [CI] 1.03-1.19). The cumulative effect of extreme heat during 0-21 lag days was significant (OR 2.37, 95% CI 1.60-3.50) compared with the minimum morbidity temperature (MMT) at 25.3°C. Associations were more pronounced among young and middle-aged patients and patients with abnormal weight.

CONCLUSIONS

We found that short-term exposure to high ambient temperature is associated with increased CRS diagnosis, suggesting a cascading effect of meteorological phenomena. These results highlight climate change's potentially deleterious health effects on upper airway diseases, which could have a significant public health impact.

The meningitis outbreak returns to Niger: Concern, efforts, challenges, and recommendations

Meningitis, a disease that commonly manifests in African meningitis belt, continues to be a public health problem as it is a fatal disease that leave survivors with long-term effects. Most cases of meningitis are due to bacterial and viral infection, although parasites, fungus, cancer, drugs, and immune disorders can rarely cause meningitis. Stiff neck, high temperature, light sensitivity, disorientation, headaches, and vomiting are the most typical symptoms of meningitis. Niger, being in African meningitis belt, has been affected by many meningitis outbreaks. Since 2015, a total of 20,789 cases and 1369 fatalities (CFR 6.6%) have been documented in Niger. In contrast to earlier seasons, the current outbreak of meningitis in Niger exhibits both an increase in the number of cases and a rise in the growth rate. A total of 559 cases of meningitis, including 18 fatalities (overall CFR 3.2%), were reported in the Zinder Region, southeast of Niger, from 1 November 2022 to 27 January 2023, compared to 231 cases reported from 1 November 2021 to 31 January 2022. In the current outbreak, the Neisseria meningitidis serogroup C (NmC) is responsible for the majority of laboratory confirmed cases (104/111; 93.7%). To organize the response to the outbreak, a global team of WHO and other partners, including MSF and UNICEF, has been sent to Niger. Even though there are many challenges in battle against meningitis in Niger, immunization, antibiotics administration and strong disease surveillance are recommended techniques to cope with the current meningitis outbreak in Niger.