Network analysis of England's single parent household COVID-19 control policy impact: a proof-of-concept study.

Lockdowns have been a core infection control measure in many countries during the coronavirus disease 2019 (COVID-19) pandemic. In England's first lockdown, children of single parent households (SPHs) were permitted to move between parental homes. By the second lockdown, SPH support bubbles between households were also permitted, enabling larger within-household networks. We investigated the combined impact of these approaches on household transmission dynamics, to inform policymaking for control and support mechanisms in a respiratory pandemic context. This network modelling study applied percolation theory to a base model of SPHs constructed using population survey estimates of SPH family size. To explore putative impact, varying estimates were applied regarding extent of bubbling and proportion of different-parentage within SPHs (DSPHs) (in which children do not share both the same parents). Results indicate that the formation of giant components (in which COVID-19 household transmission accelerates) are more contingent on DSPHs than on formation of bubbles between SPHs, and that bubbling with another SPH will accelerate giant component formation where one or both are DSPHs. Public health guidance should include supportive measures that mitigate the increased transmission risk afforded by support bubbling among DSPHs. Future network, mathematical and epidemiological studies should examine both independent and combined impact of policies.

[Immunotherapy of Colorectal and Anal Carcinoma]. / Imunoterapie nádoru dolní cásti trávicí trubice.

BACKGROUND: The lower part of the digestive tract includes the large intestine, rectum and anus. Treatment algorithms of cancers in these localities have significant differences in both early and advanced stages. The vast majority of metastatic cases are incurable. A few years ago, it was generally accepted that gastrointestinal tumors are poorly immunogenic and modern immunotherapy would not work in gastrointestinal cancers. The breakthrough has become the recognition of the mismatch repair system (MMR) that affects the microsatellite instability (MSI) and its role in the development of colorectal carcinoma (CRC). Metastatic colorectal carcinoma (mCRC) with defect MMR (dMMR) and MSI-H, resp. is immunogenic and can be a target of modern imunotherapy directed on the PD1/PD-L1 axis. Such a treatment can improve prognosis and life quality od patients with mCRC MSI-H. Immunotherapy effectiveness was shown also in a subgroup of patients with a BRAF mutation where the effectiveness of existing systemic treatment is low. The proven predictive factor is dMMR/MSI-H. PD-1 expression does not have this significance. Results of clinical studies with nivolumab and pembrolizumab result in the inclusion of these drugs in mCRC treatment algorithms. Phase II study shows nivolumab effectiveness also in pretreated metastatic anal cancer. PURPOSE: An overview of basic information on the possibilities of immunotherapy in CRC and anal cancers.Key words: cancer immunotherapy - checkpoint inhibitors - colorectal cancer - anal cancer - nivolumab - pembrolizumab Supported by MH CZ - DRO (MMCI, 00209805) I declare that, in connection with the abovementioned contribution, which I am an author, I have a conflict of interest with the following companies: BMS, Roche, Merck, Amgem and Bayer. The author declares he has no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 7. 9. 2017Accepted: 5. 11. 2017.

Compact pairwise models for epidemics with multiple infectious stages on degree heterogeneous and clustered networks.

This paper presents a compact pairwise model describing the spread of multi-stage epidemics on networks. The multi-stage model corresponds to a gamma-distributed infectious period which interpolates between the classical Markovian models with exponentially distributed infectious period and epidemics with a constant infectious period. We show how the compact approach leads to a system of equations whose size is independent of the range of node degrees, thus significantly reducing the complexity of the model. Network clustering is incorporated into the model to provide a more accurate representation of realistic contact networks, and the accuracy of proposed closures is analysed for different levels of clustering and number of infection stages. Our results support recent findings that standard closure techniques are likely to perform better when the infectious period is constant.

Influence of risk-taking health behaviours of adolescents on cervical cancer prevention: a Hungarian survey.

An anonymous questionnaire survey was conducted among the Hungarian adolescents to establish their use of tobacco, alcohol and drugs in relation to sexual behaviours, knowledge of human papillomavirus (HPV) and cervical cancer, and beliefs and attitudes towards screening and vaccination. Results indicated that adolescent risk-taking health behaviours correlate with risky sexual behaviours. As risk-taking behaviours do not correlate with a better awareness of the risk associated with HPV infection, it is of crucial importance that HPV/cervical cancer preventing educational programmes shall be sensitive to this 'vulnerable' population and draw the attention of these adolescents to their increased risk of sexually transmitted diseases and undesired pregnancies. Well-designed behavioural change interventions may be effective when in addition to providing adolescents (both men and women) with clear information about the implications of an HPV infection, they also aim to improve safer sex behaviours: consistent condom usage, limiting the number of sex partners, as well as encouraging regular participation in gynaecological screenings and uptake of the HPV vaccine. As this study population demonstrated positive attitudes towards the primary and secondary prevention of cervical cancer, the free HPV vaccination for the 12-13-year-old girls in Autumn 2014 will hopefully increase the currently low uptake of the vaccine in Hungary.

Dynamics of Multi-stage Infections on Networks.

This paper investigates the dynamics of infectious diseases with a non-exponentially distributed infectious period. This is achieved by considering a multi-stage infection model on networks. Using pairwise approximation with a standard closure, a number of important characteristics of disease dynamics are derived analytically, including the final size of an epidemic and a threshold for epidemic outbreaks, and it is shown how these quantities depend on disease characteristics, as well as the number of disease stages. Stochastic simulations of dynamics on networks are performed and compared to output of pairwise models for several realistic examples of infectious diseases to illustrate the role played by the number of stages in the disease dynamics. These results show that a higher number of disease stages results in faster epidemic outbreaks with a higher peak prevalence and a larger final size of the epidemic. The agreement between the pairwise and simulation models is excellent in the cases we consider.

Exact Equations for SIR Epidemics on Tree Graphs.

We consider Markovian susceptible-infectious-removed (SIR) dynamics on time-invariant weighted contact networks where the infection and removal processes are Poisson and where network links may be directed or undirected. We prove that a particular pair-based moment closure representation generates the expected infectious time series for networks with no cycles in the underlying graph. Moreover, this "deterministic" representation of the expected behaviour of a complex heterogeneous and finite Markovian system is straightforward to evaluate numerically.

Human papillomavirus infections among Hungarian female sex workers.

The purpose of this study was to assess the human papillomavirus (HPV) prevalence in cervical, oropharyngeal and anal samples of the high-risk population of Hungarian female sex workers (FSWs). HPV testing of swab specimens from FSWs (n = 34) using polymerase chain reaction (PCR) methodology was performed. Results were compared with control group (n = 52) matched for age. Questionnaires were used to obtain data regarding participants' sexual behaviour. Data were analysed using SPSS. HPV DNA was detected in at least one location in a great majority of FSWs (82.4%), compared with 46.2% of the general female population (P < 0.05). Both the cervical and the anal samples of sex workers showed higher infection rates than those of controls (64.7% vs. 34.6% and 50.0% vs. 15.4%, respectively, P < 0.05). High-risk HPV prevalence was also significantly higher in sex workers (55.9% vs. 25.0%, P < 0.05). A significantly higher proportion of FSWs had a history of genital warts (26.5% vs. 3.8%, P < 0.05). The results suggest that condom use may not result in adequate protection from HPV infection. The high infection rates among FSWs should be viewed as a priority group for HPV and cervical cancer prevention programmes since they are sources of HPV infection for the general population.

Barriers and supportive factors in engaging cancer patients in physical activity programmes - a literature review.

BACKGROUND: Regardless of cancer type or stage of treatment, physical activity (PA) has been shown to reduce the risk of cancer recurrence and death. It is associated with a range of positive effects on patients' physical and psychological well-being, particularly in the areas of aerobic fitness, fatigue, mental health and perceived overall quality of life. However, in current oncology practice, the combination of its indication with treatment is still relatively rare. At the same time, cancer patients' participation in regular physical activity is usually very low. However, as PA is an effective method to support cancer treatment and plays an important role in prevention, it is necessary to find effective strategies to involve patients more widely in physical activities. To this end, physical activity programmes organised directly by facilities providing comprehensive cancer care appear to be very suitable. PURPOSE: This literature review maps the main barriers and facilitators to cancer patients' participation in physical activity programmes. In particular, economic factors related to health policy, reflected in the availability of this type of supportive care for patients, the level of health literacy, the organization of PA programs, health care providers - both physicians and health care workers, social support and intrapsychic influences on the part of patients play a major role. Since the implementation of physical activity programmes into the existing cancer care system is a rather challenging process, the paper also deals with the possibilities of using the Health Belief Model. In the given context, this model allows the prediction and identification of barriers and supportive factors to patients' involvement in PA programs in order to maximize their effectiveness and adapt them to the needs of patients and, at the same time, to the capabilities of a specific medical facility.

Prevalence of sexually transmitted infections in women of the Czech Republic Armed Forces: a cross-sectional pilot study.

INTRODUCTION: Sexually transmitted infections (STIs) are an everlasting health issue globally. The military environment is recognised as a high-risk setting. Human papillomavirus (HPV), Chlamydia trachomatis and Neisseria gonorrhoeae are the most frequent STIs worldwide. This prospective cross-sectional pilot study focuses on the prevalence of selected STIs in the female population of the Czech Republic's Armed Forces. METHODS: C. trachomatis, N. gonorrhoeae and HPV detection and genotyping were performed between August 2020 and December 2022 in 141 women. Participants were divided into three groups according to their military status-recruits (n=72), active soldiers (n=25) and control civilian group (n=44). Cervical smear tests were performed, and data on STI risk factors were obtained through a questionnaire. RESULTS: A significant difference in the HPV prevalence between recruits (64.5 %) and both active soldiers (46.4 %) and civilians (47.3 %) was found when adjusted for age (p=0.007 and p=0.01, respectively). Lower age of coitarche (median 16; p=0.005) and smaller agglomeration origin (p=0.013) were reported for military recruits. No difference was proven in other researched risk factors. Associations between HPV detection and the higher number of sexual partners (p=0.013), early coitarche (p=0.016) and single marital status (p=0.002) across the groups were observed. Not a single case of N. gonorrhoeae was detected in any of the 141 participants. The prevalence of C. trachomatis did not differ significantly between the three evaluated groups-recruits, control civilian group, and active soldiers (5.6%, 2.3%, 0%, respectively; p=0.567). CONCLUSIONS: This pilot study showed a significantly higher HPV prevalence in female military recruits compared with both active military and civilian women. Recruits reported earlier coitarche which is a strong STI risk factor. Further study is needed to expand on the findings of this pilot study and generate data to support adjustment of STI preventive measures within the Czech Republic Armed Forces.

Clinical impact of PAI 1 4G/5G gene polymorphism in colorectal carcinoma patients.

Plasminogen activator ihnibitor (PAI 1) belongs to the plasminogen activator system, which is part of the metastatic cascade and significantly contributes to invasive growth and angiogenesis of malignant tumors. Its plasma level is normally low but 4G/4G homozygotes have higher concentrations of PAI 1. This genotype may be associated with worse prognosis and proximal location of colorectal cancer than 5G/5G homozygotes. In our prospective evaluation we examined plasma level PAI 1 (using photometric microplate method ELISA) pre-surgery and, subsequently, 6-8 weeks later, from 80 patients. For the PAI 1 rs1799889 -675 4G/5G polymorphism test the PCR amplification was used.Analysis of collected data was confirmed that significantly higher plasma levels of PAI 1 were found in patients before starting therapy, which decreased (p=0.004) after initiation of treatment. Patients with higher plasma level PAI 1 before (p=0.013) and after therapy (p=0.004) had significantly shorter survival. We found no relationship between polymorphisms of PAI 1 (-675 4G/5G) in relation to stage, survival or tumor location. PAI 1 is useful as a negative marker of prognosis and could be advantageous when planning adjuvant treatment of patients with colorectal carcinoma. Although opinions on the importance of polymorphisms of PAI 1 in relation to the prognosis are not uniform, it does seem that their role in the prognosis of patients with colorectal cancer is not essential.