How influenza vaccination and virus interference may impact combined influenza-coronavirus disease burden.

Demand for influenza vaccine rose as countries prepared for the second COVID-19 wave over the winter months of 2020-2021. High coverage of the influenza vaccine can significantly reduce morbidity and mortality of the burden of influenza. Natural influenza infection creates short-term non-specific immunity against respiratory viruses (virus interference). We model two viral diseases, both of the SEIR type, to investigate whether the influenza vaccine increases the combined disease burden of influenza and COVID-19 in a dual outbreak. We show that the combined disease burden's behavior depends on virus interference factors and the proportion of the population vaccinated against influenza. Our results indicate that influenza vaccination only lowers the overall disease burden when net virus interference is relatively low.

A Mathematical Modeling Study: Assessing Impact of Mismatch Between Influenza Vaccine Strains and Circulating Strains in Hajj.

The influenza virus causes severe respiratory illnesses and deaths worldwide every year. It spreads quickly in an overcrowded area like the annual Hajj pilgrimage in Saudi Arabia. Vaccination is the primary strategy for protection against influenza. Due to the occurrence of antigenic shift and drift of the influenza virus, a mismatch between vaccine strains and circulating strains of influenza may occur. The objective of this study is to assess the impact of mismatch between vaccine strains and circulating strains during Hajj, which brings together individuals from all over the globe. To this end, we develop deterministic mathematical models of influenza with different populations and strains from the northern and southern hemispheres. Our results show that the existence and duration of an influenza outbreak during Hajj depend on vaccine efficacy. In this concern, we discuss four scenarios: vaccine strains for both groups match/mismatch circulating strains, and vaccine strains match their target strains and mismatch the other strains. Further, there is a scenario where a novel pandemic strain arises. Our results show that as long as the influenza vaccines match their target strains, there will be no outbreak of strain H1N1 and only a small outbreak of strain H3N2. Mismatching for non-target strains causes about 10,000 new H3N2 cases, and mismatching for both strains causes about 2,000 more new H1N1 cases and 6,000 additional H3N2 cases during Hajj. Complete mismatch in a pandemic scenario may infect over 342,000 additional pilgrims (13.75%) and cause more cases in their home countries.

Global investigation for an "SIS" model for COVID-19 epidemic with asymptomatic infection.

In this paper, we analyse a dynamical system taking into account the asymptomatic infection and we consider optimal control strategies based on a regular network. We obtain basic mathematical results for the model without control. We compute the basic reproduction number (R) by using the method of the next generation matrix then we analyse the local stability and global stability of the equilibria (disease-free equilibrium (DFE) and endemic equilibrium (EE)). We prove that DFE is LAS (locally asymptotically stable) when R<1 and it is unstable when R>1. Further, the existence, the uniqueness and the stability of EE is carried out. We deduce that when R>1, EE exists and is unique and it is LAS. By using generalized Bendixson-Dulac theorem, we prove that DFE is GAS (globally asymptotically stable) if R<1 and that the unique endemic equilibrium is globally asymptotically stable when R>1. Later, by using Pontryagin's maximum principle, we propose several reasonable optimal control strategies to the control and the prevention of the disease. We mathematically formulate these strategies. The unique optimal solution was expressed using adjoint variables. A particular numerical scheme was applied to solve the control problem. Finally, several numerical simulations that validate the obtained results were presented.

How heterogeneity in density dependence affects disease spread: when lifestyle matters.

People's lifestyles play a major role in disease risk. Some employment sectors and transport modes involve fixed exposures regardless of community size, while in other settings exposure tracks with population density. MERS-CoV, a coronavirus discovered in Saudi Arabia in 2012 closely related to those causing SARS and COVID-19, appears to need extended contact time for transmission, making some segments of a community at greater risk than others. We model mathematically how heterogeneity in contact rate structure impacts disease spread, using as a case study a MERS outbreak in two Saudi Arabian communities. We divide the at-risk population into segments with exposure rates either independent of population density or density-dependent. Analysis shows disease spread is minimized for intermediate size populations with a limited proportion of individuals in the density-independent group. In the case study, the high proportion of density-independent exposure may explain the historical outbreak's extinction in the larger city.

Awareness of Carpal Tunnel Syndrome Among Adults in the Western Region of Saudi Arabia: A Cross-Sectional Study.

Introduction Carpal tunnel syndrome (CTS) is a peripheral neuropathy that happens when the median nerve is compressed by the transverse carpal ligament within the carpal tunnel. Public awareness is crucial for early detection and intervention; therefore, this study aims to assess the awareness of CTS among the adult population in the western region of Saudi Arabia. Methods The study design was a cross-sectional study where 1400 participants (although 1199 answers were included) from the western region were randomly asked to fill in an online questionnaire that was delivered to them via social media applications. Results The study sample was predominantly females (57.1%), and 88.7% were Saudi, mostly students and professionals (53% and 25.2% respectively); predominant chronic illness among study participants was diabetes mellitus (7%), and only 2% of the sample (27 participants) were diagnosed with CTS. Participants showed more level of awareness regarding the causes and features of CTS, 630 participants (52.5%) had a good awareness of the causes, and 652 (54.4%) had a good awareness of the features. Meanwhile, participants showed a poorer level of awareness regarding treatment, effects, and prevention; percentages of poor awareness were 56% (672) for treatment, 51.9% (622) for effects, and 52.8% (633) for prevention. Conclusion The study shows that the adult population in the western region of Saudi Arabia had insufficient awareness of CTS, especially regarding treatment, effects, and prevention. Therefore, more campaigns should be made to enhance population awareness of CTS, and the study also suggests a link between CTS and chronic diseases.

Stigmatization and discrimination against people living with HIV/AIDS: Knowledge, attitudes, and practices of healthcare workers in the primary healthcare centers in Madinah, Saudi Arabia, 2022.

BACKGROUND: There are very few studies in Saudi Arabia on stigmatization and discrimination against people living with HIV/AIDS (PLWHA), a critical step for the prevention and control of HIV. The aim of this study was to assess the level of stigmatization and discrimination against PLWHA by healthcare workers (HCWs) as well as their knowledge, attitude, and practices (KAP). MATERIALS AND METHODS: This cross-sectional study included 182 HCWs at primary healthcare centers in Medina, Saudi Arabia. The validated short version of the Healthcare Provider HIV/AIDS Stigma Scale and the AIDS Attitude Scale were used in this research. Student's t-test and analysis of variance (ANOVA) were used to assess the differences in the mean knowledge, attitudes, and practices KAP scores by various sociodemographic factors. Multiple linear regression analysis was used to determine factors associated with KAP scores. RESULTS: Most participants were males (58.2%) and aged more than 30 years (60.4%). The tendency to stigmatizing behavior was present in 24.2%-68.17% of the participants, and discriminatory practice was present in 11.5%-50% of the participants. In multiple linear regression analysis, factors that independently predicted the knowledge score were being a doctor compared to nurses (P < 0.001), receiving in-service training for PLWHA (P < 0.001), and male gender (P = 0.002). Attitude was predicted by being female (P = 0.008) and a doctor (P = 0.005). Practice was predicted by the knowledge score (P < 0.001) and being married (P = 0.035). CONCLUSION: This study found that stigmatization and discrimination were less prevalent in HCWs who had good HIV-related knowledge and had received in-service training for PLWHA. The results highlight the significance of continuing education and training opportunities for HCWs to provide effective and appropriate treatment to PLWHA.