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Epidemic Dynamics with Nonlinear Incidence Considering Vaccination Effectiveness Kamalia, Putri Zahra; Aldila, Dipo
Jambura Journal of Biomathematics (JJBM) Volume 6, Issue 3: September 2025
Publisher : Department of Mathematics, Universitas Negeri Gorontalo

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37905/jjbm.v6i3.33815

Abstract

This paper presents a mathematical model that examines the effect of nonlinear incidence on disease transmission dynamics.  Furthermore, we also accommodate newborn and adult vaccination strategy as the prevention strategy to prevent rapid spread of the disease due to nonlinear incidence rate. Assuming a constant population  size,  the  system is  reduced  to  a  two-dimensions and  nondimensionalized using  the  average infectious period as the time scale.   Analytical results reveal the existence of both disease-free and endemic equilibria, with the possibility of backward bifurcation when the nonlinear incidence parameter exceeds a critical threshold.   This implies that disease persistence may still occur even when the basic reproduction number is less than one.  Numerical simulations using MATCONT conducted to visualize the occurrence of both forward and backward bifurcations phenomena.    Using COVID-19 parameter values,  a  global sensitivity analysis via Partial Rank Correlation Coefficient - Latin Hypercube Sampling method indicates that newborn vaccination has a stronger impact on reducing the basic reproduction number. These findings provide important insights for designing effective vaccination strategies and understanding the complex dynamics arising from nonlinear transmission and imperfect immunization.
Forward and Backward Bifurcation Analysis From an Imperfect Vaccine Efficacy Model With Saturated Treatment and Saturated Infection Fatahillah, Hakan Ahmad; Aldila, Dipo
Jambura Journal of Biomathematics (JJBM) Volume 5, Issue 2: December 2024
Publisher : Department of Mathematics, Universitas Negeri Gorontalo

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37905/jjbm.v5i2.28810

Abstract

This paper aims to study the saturation effect on the infection and recovery process within a Susceptible-Vaccination-Infected model featuring an imperfect vaccine efficacy. First, we nondimensionalized the model under the assumption of a constant population, resulting in the reduction of the model from three to two-dimensional differential equations. The analysis indicates the presence of a disease-free equilibrium (DFE) and potentially multiple endemic equilibria (EE) within the model. The calculation of the basic reproduction number further explains the model's solution conditions. In particular, we discovered that a backward bifurcation is possible under specific saturation effect values. Dulac's criterion confirmed the absence of a closed orbit in the solution region, suggesting the global stability of the endemic equilibrium when the basic reproduction number exceeds one. To supplement the analytical study, a numerical simulation was conducted to generate a bifurcation diagram, autonomous simulation, and global sensitivity analysis. The global sensitivity analysis revealed that changing the vaccination rate or recovery rate could significantly impact the basic reproduction number. Moreover, the bifurcation diagram depicting the relationship between the transmission rate and vaccination rate demonstrated that increasing the vaccination rate while maintaining the transmission rate can reduce the proportion of infected individuals within the population.
Erratum: Assessing the Impact of Medical Treatment and Fumigation on the Superinfection of Malaria: A Study of Sensitivity Analysis Handari, Bevina D.; Aldila, Dipo; Tamalia, Evllyn; Khoshnaw, Sarbaz H.A.; Shahzad, Muhammad
Communication in Biomathematical Sciences Vol. 8 No. 2 (2025)
Publisher : The Indonesian Bio-Mathematical Society

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/cbms.2025.8.2.8

Abstract

This erratum has been issued to correct an error in the Acknowledgement section of our previously published article (COMMUN. BIOMATH. SCI., VOL. 6, NO. 1, PP. 51-73, 2023). The research grant number was incorrectly stated due to a typographical mistake during manuscript preparation. The correct research grant number should read as indicated in this erratum. The authors apologize for this oversight and confirm that the correction does not affect the scientific content, results, or conclusions of the original article.
Knowledge, Attitudes, and Practices Among Hepatitis B Patients in Jakarta, Indonesia: A Cross-Sectional Study Arkok, Hashem S.; Wahyono, Tri Yunis Miko; Prihartono, Nurhayati Adnan; Aldila, Dipo
Kesmas Vol. 21, No. 2
Publisher : UI Scholars Hub

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Hepatitis B remains a major public health problem in Indonesia. This study assessed the knowledge, attitudes, and practices (KAP) of hepatitis B patients in Jakarta to identify gaps in prevention and control and to explore relationships among KAP components. A cross-sectional study was conducted among 128 patients at a government hospital in South Jakarta, using a structured questionnaire that collected demographic information and assessed knowledge, attitudes, and practices regarding hepatitis B transmission and prevention. Despite moderate knowledge levels, major gaps remained. Only a small proportion (10.9%) correctly identified common symptoms, transmission routes (10.2%), and possible complications (18.8%). Misconceptions about transmission and vaccine safety were common, although attitudes toward early diagnosis and treatment were generally positive. Practices also fell within a moderate range; notably, 46.1% of respondents still shared personal items that could facilitate transmission. Higher education, vaccination, income, and awareness participation were associated with better knowledge, attitudes, and practices. There were positive correlations among knowledge, attitude, and practice scores, indicating that better knowledge may lead to improved behaviors. In conclusion, the study reveals persistent misconceptions and behaviors that continue to place hepatitis B patients at risk, despite generally positive attitudes toward care.