Aug 2026· American Journal of Bioscience and Bioinformatics· Vol 5, pp. 8-17· 0 citations
TL;DR
The findings suggest that climatic conditions influence transmission through their effects on environmental suitability, rodent ecology, and opportunities for human exposure through their effects on environmental suitability, rodent ecology, and opportunities for human exposure during the dry season.
Abstract
Lassa fever remains a major public health challenge in Nigeria, where recurrent outbreaks continue to impose substantial health and socioeconomic burdens. Although climatic variability has been implicated in disease transmission, the relative contributions of key environmental factors to outbreak occurrence remain insufficiently quantified. This study examined the influence of temperature, rainfall, humidity, and seasonality on Lassa fever epidemiology in Nigeria using national surveillance and meteorological data collected between 2020 and 2025. A total of 1,404 observations comprising confirmed cases and associated climatic variables were analysed using descriptive statistics, Pearson correlation analysis, and Negative Binomial Regression to account for overdispersion in disease counts. The findings revealed a pronounced seasonal pattern, with 77.1% of confirmed cases occurring during the dry season and peak transmission observed between January and March. Temperature was positively associated with disease incidence, whereas rainfall exhibited a significant inverse relationship. Negative Binomial Regression identified temperature (IRR = 1.024, p < .001), rainfall (IRR = 0.987, p < .001), humidity (IRR = 1.007, p = .001), and seasonality (IRR = 2.131, p < .001) as significant predictors of Lassa fever occurrence. After adjusting for climatic factors, disease incidence during the dry season was approximately 113% higher than during the wet season. These patterns suggest that climatic conditions influence transmission through their effects on environmental suitability, rodent ecology, and opportunities for human exposure. This study provides updated national-level evidence on the climatic determinants of Lassa fever transmission in Nigeria and demonstrates the dominant role of seasonality in shaping outbreak dynamics. By simultaneously quantifying the independent effects of multiple environmental drivers using a modelling framework appropriate for overdispersed disease count data, the study advances understanding of climate-sensitive Lassa fever epidemiology and provides an evidence base for climate-informed surveillance, early warning systems, and outbreak preparedness strategies.
Lassa fever (LF) is a viral disease that is widespread throughout West Africa, with significant global health consequences. Nigeria bears the highest burden (1309 confirmed cases in 2024) of LF among all endemic countries. Within Nigeria, Ebonyi State bears a high burden of cases. Clinical observations suggest that there may be an increase in the geographic spread and case fatality rate of LF across the State. Ebonyi State case-based data on confirmed cases from 2019 to 2023 collated on the Nigeria Centre for Disease Control and Prevention (NCDC) Surveillance, Outbreak Response Management and Analysis System (SORMAS) platform were analyzed. Descriptive statistics, spatial distribution and time series analysis were performed. Multivariate logistic regression analysis was used to identify predictors of LF mortality and factors associated with PCR positivity. A total of 1,624 suspected cases were reported, 1,343 and 273 were laboratory negative and positive respectively, while 8 probable cases were reported. The yearly number of cases remained stable throughout the study period. Out of the 273 confirmed, 107 died from LF, resulting in a case fatality rate (CFR) of 39.2%. CFR increased non-significantly over time, ranging from 28.6% to 55.8%. Variations in geographic distribution were observed; in 2019 ten local government areas (LGAs) were affected compared to twelve in 2020. A higher incidence was observed between January and March annually. Age above 44 years, bleeding and seizures were significant predictors of mortality. Lower incidence of cases was consistently reported in the Southern LGAs. PCR positivity was associated with individuals who reside in Ebonyi LGA and who have had contact with confirmed cases. The increase in CFR and identification of high-burden areas will help shape policies, allocate resources and provide actionable intervention strategies to combat LF in the State.
E. C. Nwojiji, N. Nwambeke, P.-W. Shih et al.· medRxiv· 0 citations
Leptospirosis remains a significant public health concern in the Philippines, particularly in urban tropical settings where environmental and climatic conditions favor disease transmission. This study examined temporal trends and factors associated with human leptospirosis in Davao City, Philippines, using surveillance data from 2015 to 2025. A retrospective observational study was conducted using 1104 surveillance records obtained from the Davao City Health Office–City Epidemiological Surveillance Unit. Annual incidence and mortality rates were calculated per 100,000 population; temporal trends were assessed using Mann–Kendall tests; and associations with demographic, seasonal, geographic, and environmental factors were evaluated using Poisson and negative binomial regression models, as appropriate, based on model diagnostics and comparative fit. Increasing incidence trends were observed across several strata, whereas increasing mortality trends were identified in selected demographic and environmental categories. In the incidence analysis, a higher disease burden was associated with age ≥ 15 years (aIRR = 14.75, 95% CI: 10.77–20.21), male sex (aIRR = 4.78, 95% CI: 3.74–6.11), high population density (aIRR = 4.19, 95% CI: 2.75–6.38), and the wet season (aIRR = 1.30, 95% CI: 1.04–1.61). Mortality was also strongly associated with age ≥ 15 years (aIRR = 36.75, 95% CI: 13.61–99.22) and male (aIRR = 8.50, 95% CI: 4.73–15.27). These findings provide a long-term surveillance-based assessment of leptospirosis in Davao City and identify demographic and environmental patterns relevant to targeted surveillance, seasonal preparedness, and locally adapted prevention strategies for leptospirosis.
Rachelle Laine Durang, Rvin John T. Servillon, Aprilyn F. Francisco-Breva et al.· Acta Microbiologica Hellenic...· 0 citations
This study examines the impact of climatic variables temperature, rainfall, and humidity on malaria transmission in Bauchi State, Nigeria, from 2015 to 2025. Time series and regression analyses were employed to assess the influence of climate factors on malaria incidence. Secondary data on malaria cases were obtained from the Bauchi State Ministry of Health, while climatic data were sourced from the Nigerian Meteorological Agency (NiMet). The Autoregressive Integrated Moving Average (ARIMA) (2,0,1) model revealed strong seasonal patterns in malaria transmission, with cases peaking during the rainy season and declining during the dry months. Regression results indicated that rainfall and humidity had significant positive effects on malaria incidence, whereas temperature exhibited a significant negative relationship. The model demonstrated a high explanatory power (R² = .969), suggesting that climatic factors account for approximately 96.9% of the variation in malaria cases. Forecasting outcomes predict that malaria incidence will stabilize around 1,000 cases per period, implying sustained transmission unless preventive measures are intensified. The study concludes that climate variability significantly influences malaria dynamics in Bauchi State and recommends integrating climate monitoring into public health planning, enhancing seasonal interventions, and strengthening community awareness to mitigate the impacts of climate change on malaria transmission.
YUSUF BALA, MAS’UD SHUAIBU, ABDUL HARUNA BALA· International Journal of Nat...· 0 citations
Dengue fever has emerged as a major public health concern in Pakistan, particularly in Balochistan, where climatic variability and limited surveillance infrastructure have contributed to increasing disease burden. This study aimed to investigate the relationship between climatic factors and dengue transmission across multiple districts of Balochistan using a retrospective district-level epidemiological approach. Dengue surveillance data were collected from Public Health Laboratories, District Health Offices (DHOs), dengue surveillance units, and People’s Primary Healthcare Initiative (PPHI) centers, while climatic variables including temperature, rainfall, and humidity were obtained from national and global meteorological sources. The integrated datasets were analyzed using RStudio to assess seasonal trends, spatial distribution, and climate–dengue associations through descriptive statistics, correlation analysis, and negative binomial regression modeling. A total of 26,482 confirmed dengue cases were identified from 125,780 diagnostic tests conducted during 2024. The highest disease burden was observed in Turbat, Panjgur, Jhal Magsi, and Khuzdar districts. Dengue incidence showed a strong seasonal pattern, with cases increasing sharply during the summer and post-monsoon months and peaking in September. Regression analysis demonstrated that increasing temperature was significantly associated with higher dengue incidence, while rainfall exhibited delayed effects through enhanced vector breeding conditions. The combined influence of high temperature and high rainfall produced the greatest transmission intensity. The findings indicate that dengue transmission in Balochistan is highly climate-sensitive and increasingly shifting toward an endemic transmission pattern. Strengthening climate-informed surveillance systems, improving early warning mechanisms, enhancing vector control strategies, and promoting community awareness are essential for reducing the growing dengue burden in the region.
Iqra batool, Abdul Rehman, Ali Nawaz et al.· International Journal of Agr...· 0 citations
Malaria transmission is strongly influenced by climatic conditions that regulate Anopheles mosquito survival and parasite development. However, existing studies in Bangladesh are largely short-term or region-specific, limiting understanding of long-term climate–malaria dynamics. This study addresses this gap by examining national-level, long-term associations between malaria incidence and climatic factors. A retrospective ecological time-series study was conducted using monthly malaria surveillance data from Bangladesh between January 2008 and December 2023. Climatic variables—rainfall, temperature, relative humidity, and sunshine duration—were obtained from the Bangladesh Meteorological Department for the same period ensuring full temporal alignment with malaria data. Descriptive analyses were used to assess long-term trends and seasonality. Pearson correlation was used to assess linear relationships between variables, while Spearman correlation was applied to capture potential monotonic but non-linear associations and reduce sensitivity to outliers. Multiple linear regression models incorporating one-month lagged variables were developed to identify independent climatic predictors of transmission. A total of 192 monthly observations were analyzed. Malaria incidence showed a marked long-term decline, yet a consistent seasonal pattern persisted, with transmission peaking during the monsoon months (July–September). Mean relative humidity demonstrated the strongest positive correlation with malaria incidence (p < 0.001), followed by lagged rainfall (p < 0.01). In multivariate analysis, mean humidity, lagged rainfall, and lagged sunshine duration remained significant predictors, while temperature was not independently associated. The regression model accurately captured seasonal timing but underestimated peak magnitude during outbreak years. Despite declining incidence, malaria in Bangladesh retains a stable, climate-driven seasonal signature. Climatic variables are effective in predicting transmission timing but insufficient to explain outbreak intensity. Integrating climate indicators into surveillance systems may strengthen preparedness and support malaria elimination efforts in residual transmission settings.
Sania Akter, Zesan Ahmed, Ragib Abid et al.· Tropical Medicine and Health· 0 citations
Ebonyi State in southeastern Nigeria has experienced a notably high number of deaths from Lassa fever (LF). Despite this, there is a dearth of studies on the epidemiological and management outcomes of LF outbreaks over the years. The study aims to describe and analyze the epidemiological and management factors of LF for a period of six years (2018–2023) in Ebonyi State with a view to informing targeted interventions, control, and prevention of LF in the state. Secondary data of the LF outbreak from January 2018 to December 2023 were obtained from the Ebonyi State Ministry of Health. The primary outcome was survival from LF, assessed by identifying predictors through logistic regression and estimating survival probability using survival analysis. Associations between demographic and clinical variables were evaluated using odds ratios, chi-square, and Fisher’s exact tests. Geospatial mapping with ArcGIS explored the spatial distribution of LF cases. A total of 1,910 suspected cases were reported, with 368 confirmed. The case fatality rate (CFR)among confirmed cases was 33.97%, increasing yearly. Nearly half (49.7%) were from Abakaliki Local Government Area (LGA), showing a clustered spatial pattern. The median age was 32 years (IQR: 22–42), with 52.7% male. Dehydration (OR: 0.45), nausea/vomiting (OR: 0.57), neurologic disorders (OR: 0.33), bleeding (OR: 0.48), sepsis (OR: 0.39), and respiratory disorders (OR: 0.44) significantly reduced survival odds. Median time from symptom onset to hospital presentation was 10 days (IQR: 7–18), and from presentation to diagnosis was 12 days (IQR: 4–23). The CFR of LF in Ebonyi State is high, with Abakaliki LGA as the hotspot. Delays in hospital presentation and diagnosis exist. Regular community sensitization and improved training of medical personnel are needed to promote early symptom reporting and enhance timely LF management.
P. Iziomo, E. Awosanya, O. Taiwo et al.· PLOS Global Public Health· 0 citations