A quantitative risk assessment to evaluate the efficacy of mitigation strategies to reduce highly pathogenic avian influenza virus, subtype H5N1 (HPAI H5N1) in the Menoufia governorate, Egypt.

BACKGROUND: The poultry industry in Egypt has been suffering from endemic highly pathogenic avian influenza (HPAI) virus, subtype H5N1 since 2006. However, the emergence of H9N2, H5N8, and H5N2 in 2011, 2016, and 2019 respectively, has aggravated the situation. Our objective was to evaluate how effective are the mitigation strategies by a Quantitative Risk Assessment (QRA) model which used daily outbreak data of HPAI-H5N1 subtype in Egypt, stratified by different successive epidemic waves from 2006 to 2016. RESULTS: By applying the epidemiologic problem-oriented approach methodology, a conceptual scenario tree was drawn based on the knowledgebase. Monte Carlo simulations of QRA parameters based on outbreak data were performed using @Risk software based on a scenario-driven decision tree. In poultry farms, the expected probability of HPAI H5N1 prevalence is 48% due to failure of mitigation strategies in 90% of the time during Monte Carlo simulations. Failure of efficacy of these mitigations will raise prevalence to 70% with missed vaccination, while failure in detection by surveillance activities will raise it to 99%. In backyard poultry farms, the likelihood of still having a high HPAI-H5N1 prevalence in different poultry types due to failure of passive and active surveillance varies between domestic, mixed and reservoir. In mixed poultry, the probability of HPAI-H5N1 not detected by surveillance was the highest with a mean and a SD of 16.8 × 10-3 and 3.26 × 10-01 respectively. The sensitivity analysis ranking for the likelihood of HPAI-H5N1 in poultry farms due to missed vaccination, failure to be detected by passive and active surveillance was examined. Among poultry farms, increasing vaccination by 1 SD will decrease the prevalence by 14%, while active and passive surveillance decreases prevalence by 12, and 6%, respectively. In backyard, the active surveillance had high impact in decreasing the prevalence by 16% in domestic chicken. Whereas the passive surveillance had less impact in decreasing prevalence by 14% in mixed poultry and 3% in domestic chicken. CONCLUSION: It could be concluded that the applied strategies were not effective in controlling the spread of the HPAI-H5N1 virus. Public health officials should take into consideration the evaluation of their control strategies in their response.

Racial differences in 5-year relative survival rates of cervical cancer by stage at diagnosis, between African American (black) and white women, living in the state of Alabama, USA.

BACKGROUND: Our objective was to assess racial differences in the 5-year relative survival rates (RSRs) of Cervical Cancer (CerCancer) by stage at diagnosis, between Black and White women, living in Alabama, USA. METHODS: Data for 3484 Blacks and 21,059 Whites diagnosed with CerCancer were extracted from the 2004 to 2013 Surveillance, Epidemiology, and End Results (SEER) database. We incorporated age groups, CerCancer stages, county, and year of diagnosis to compare the RSR between Blacks and Whites, using SEER*Stat software. RESULTS: In urban, Black Belt (BB) and other rural counties, Whites diagnosed with localized stage of CerCancer always had better chances of survival because their RSRs were always more than 77%, compared to Blacks. Only exception was in Blacks living in other rural counties, who had a significantly higher RSR of 83.8% (95% Cl, 74.2-90.1). Which was the same as in Whites (83.8% (95% CI 74.5-89.9) living in BBC. Although, in other rural counties, Whites had a slightly lower RSR of 83.7% (95% CI 79.9-86.8%), their RSR was better compared to Blacks and Whites living in BB and other rural counties who had slightly higher RSRs of 83.8%. This was due to statistical precision, which depended on their larger sample size and a lower variability therefore, more reliability resulting in a tighter confidence interval with a smaller margin of error. In all the three county groups, Whites 15-44 years old diagnosed with localized stage of CerCancer had a higher RSR of 93.6% (95% CI 91.4-95.2%) for those living in urban and BB counties, and 94.6% (95% CI 93.6-95.4) for those living in other rural counties. The only exception was in Blacks 65-74 years old living in other rural counties who had the highest RSR of 96.9% (95% Cl, 82.9-99.5). However, Whites were considered to have a better RSR. This was also due to the statistical precision as mentioned above. CONCLUSION: There were significant racial differences in the RSRs of CerCancer. Overall, Black women experienced the worst RSRs compared to their White counterparts.

A quantitative risk assessment of multiple factors influencing HIV/AIDS transmission through unprotected sex among HIV-seropositive men.

The objective of this study is to conduct a quantitative risk assessment of multiple factors influencing HIV/AIDS transmission through unprotected sexual practices among HIV-seropositive men. A knowledgebase was developed by reviewing different published sources. The data were collected from different sources including Centers for Disease Control and Prevention, selected journals, and reports. The risk pathway scenario tree was developed based on a comprehensive review of published literature. The variables are organized into nine major parameter categories. Monte Carlo simulations for the quantitative risk assessment of HIV/AIDS transmission was executed with the software @Risk 4.0 (Palisade Corporation). Results show that the value for the likelihood of unprotected sex due to having less knowledge about HIV/AIDS and negative attitude toward condom use and safer sex ranged from 1.24 × 10(-5) to 8.47 × 10(-4) with the mean and standard deviation of 1.83 × 10(-4) and 8.63 × 10(-5), respectively. The likelihood of unprotected sex due to having greater anger-hostility, anxiety, less satisfied with aspects of life, and greater depressive symptoms ranged from 2.76 × 10(-9) to 5.34 × 10(-7) with the mean and standard deviation of 5.23 × 10(-8) and 3.58 × 10(-8), respectively. The findings suggest that HIV/AIDS research and intervention programs must be focused on behavior, and the broader setting within which individual risky behaviors occur.

Knowledge and Awareness about Cervical Cancer and Human Papillomavirus among Women Living in Macon County, Alabama.

In Alabama, despite the high screening rates for cervical cancer in Blacks, they still have higher mortality rates compared to Whites. Our objective was to increase knowledge and awareness of cervical cancer with the intention to encourage more women to have Pap tests, Human Papillomavirus (HPV) tests and HPV vaccinations after a short-term educational-based intervention. Pre and post questionnaires were administered to collect data before and after a primary educational intervention in Macon County was taught by a team of experts in the subject area. Descriptive statistics were done using SAS software to generate frequency and chi-square tests. Out of the 100 participants: 9% had cervical cancer; 86% were Blacks; about 65% were over the age of 35 and earned less than $50,000/year; 62% lived in the Tuskegee community; 34% were students, staff or faculty of Tuskegee University; about 25% were either married or living with their partner; leaving about 75% of the women as single, divorced or widowed; and more than 80% were students between their first year of college and graduate school with only 40% working for pay. The short-term educational intervention increased participants' knowledge of: who knew what cervical cancer was; ever heard of HPV; and ever had an HPV-test by margins of 9%, 23% and 4% respectively. Participants who had ever heard of Pap test had the same knowledge of 97% before and after the intervention. There was a significant knowledge level increased: in understanding that cervical cancer was caused by 38% HPV infection; 39% of all HPV infections lead to cervical cancer; and cervical cancer has decreased in recent years by 50%. Significant differences were observed only among participants who had ever heard of Pap test before and after the educational intervention with p-values of 0.004 and 0.03 respectively, compared to participants who knew what cervical cancer was and who had ever heard of HPV test. Although some participants lacked knowledge in certain areas, this study showed an apparent increase in their knowledge and awareness following the educational intervention.

Psychosocial responses associated with perceived risk of cancer in an African-American community.

This epidemiologic health survey study examined the association between health risk perceptions and psychosocial factors in 145 African Americans in East Montgomery, Alabama. The survey gathered information on demographics, population dynamics, health risk perceptions, and coping behaviors. Psychosocial variables measured were worries, concern, stress, and trauma associated with perceived risk of cancer. Results indicated that women were more concerned about the environmental health risks in their community than men. Compared to men, women were highly concerned about the economic effect of perceived environmental health risk. The findings indicate that an individual's health status and educational level were significant predictors of psychosocial responses.

A comparative study of substance use before and after establishing HIV infection status among people living with HIV/AIDS.

OBJECTIVE: To determine if significant differences exist in substance use among people living with HIV/AIDS (PLWHA) before and after establishing their HIV infection status. METHOD: The study participants are HIV positive clients of a community based HIV/AIDS outreach facility located in Montgomery, Alabama. The questionnaire includes demographics, substance use and risky sexual behaviors pertaining to HIV transmission. Each participant completed an anonymous questionnaire. A total of 341 questionnaires were distributed and 326 were fully completed and returned, representing a response rate of 96%. RESULTS: Findings revealed a statistically significant difference in alcohol consumption before sex among PLWHA before and after establishing their HIV infection status (p = .001). No significant differences were observed among participants who reported as having used drugs intravenously (p = .89), and among those sharing the same syringe/needle with another person (p = .87) before and after establishing their HIV infection status. CONCLUSION: There is continued substance use and alcohol consumption before sex among PLWHA after establishing their HIV status despite clear evidence of such risky behaviors that could lead to an increase in exposure to HIV.

A Comparative Study of Health Disparities in Cervical Cancer Mortality Rates Through Time Between Black and Caucasian Women in Alabama and the US.

Background: The main purpose of this study was to assess changes in cervical cancer mortality rates through time between Black and Caucasian women residing in Alabama and the US. Methods: Alabama cervical cancer mortality rates (MR), percentage differences, percentage changes and annual percentage changes for trends were compared with the US baseline and target rates. The US Baseline data and target objectives of utilization of cervical cancer screening and MR were obtained from Healthy People 2020. The cervical cancer behavioral risk factors and utilization of screening tests data were obtained from CDC's Behavioral Risk Factor Surveillance System (BRFSS). The cervical cancer MR data were obtained from the Surveillance, Epidemiology, and End Results (SEER). The analysis was done using SEER*Stat and Linear Trendlines analysis. Results: Although Blacks in Alabama had higher cervical cancer MR through times, a decreasing trend was noted for both races. However, in Alabama, there is no significant change in Blacks aged 65 years and older in cervical cancer MR, despite a high screening rate compared to Whites. In contrast, between 2002 and 2012, Whites in Alabama and the US made a significant progress toward the Healthy People 2020 goal. Conclusions: In Alabama, there exists cervical cancer MR disparity in Blacks despite the higher rates of screening for cervical cancer as would otherwise be expected. The state has not yet achieved the Healthy People 2020 goal. Public health officials should monitor progress toward reduction and/or elimination of these disparities by focusing in a follow up of screening.

Applying the epidemiologic problem oriented approach (EPOA) methodology in developing a knowledge base for the modeling of HIV/AIDS.

INTRODUCTION: In the epidemiologic modeling of diseases, the epidemiologic problem oriented approach (EPOA) methodology facilitates the development of systematic and structured knowledge bases, which are crucial for development of models. A detailed understanding of the epidemiology of a given disease provides the essential framework for model development and enables the laying out of the comprehensive and fundamental structures for the models. OBJECTIVE: To develop such a knowledge base for developing HIV/AIDS models. METHODS: The EPOA methodology was utilized to develop the knowledge base for HIV/AIDS; it is composed of six pillars within two triads: the Problem Identification/Characterization and the Problem Management/Solution/Mitigation Triads, interlinked by the diagnostic procedure. RESULTS: Using information from various sources, the triads are decomposed into their respective pillar variables and parameters. The agent pillar identifies the causative agent (HIV) and its characteristics. The host pillar identifies and characterizes the host (human). The environment pillar characterizes the physical, biological and socioeconomic environments for both the host and agent. The therapeutics/treatment pillar considers the treatment options for HIV/AIDS. The prevention/control pillar considers prevention and control measures. The health maintenance/health promotion pillar considers measures for the health maintenance of the population. CONCLUSION: Models for HIV/AIDS can be conceptual, in vivo or in vitro, systems analysis, mathematical, or computational just to name a few. The knowledge base developed using the EPOA methodology provides a well-organized structured source of information, which is used in the variable and parameter estimations as well as analysis (biological, mathematical, statistical and computer simulations), which are crucial in epidemiologic modeling of HIV/AIDS. EPOA methodology has become an important tool in the development of models that can enlighten decision making in public health.

Assessing HIV/AIDS intervention strategies using an integrative macro-micro level computational epidemiologic modeling approach.

INTRODUCTION: Epidemiologic research involves the study of a complex set of host, environmental and causative agent factors as they interact to impact health and diseases in any population. The most advanced of these efforts have focused on micro (cellular) or macro (human) population level studies but lacked the integrative framework as presented in this article. Modeling the cumulative impact of HIV/AIDS at the cellular, molecular, and individual behaviors at the population-level can be complex. The main objective of our research is to develop a macro-micro level computational epidemiologic model that integrates the dynamic interplay of HIV/AIDS at the cellular and molecular level (micro-epidemiologic modeling), and the dynamic interplay of multifactorial determinants: biomedical, behavioral, and socioeconomic factors at the human population level (macro-epidemiologic modeling). METHODS: The computational epidemiologic model was constructed using systems dynamics modeling methodology. The dynamics of the relationships was described by means of ordinary/partial differential equations. All state equations in the model were approximated using the Runge-Kutta 4th order numerical approximation method. RESULTS: Computational tools and mathematical approaches that integrate models from micro to macro levels in a seamless fashion have been developed to study the population-level effects of various intervention strategies on HIV/AIDS. The critical variables that facilitate transmission of HIV and intracellular interactions and molecular kinetics were examined to assess different interventions strategies. Such multilevel models are essential if we are to develop quantitative, predictive models of complex biological systems such as HIV/AIDS.

The Impact of Race and Geographical Location on the Treatment Options of Cervical Cancer in Black and White Women Living in the State of Alabama.

This study assesses the association between age, race, geographical-location, stage, and treatments of Cervical Cancer (CerCancer) in Black and White women, living in Alabama. Data from 2004-2013 was provided by the Alabama Cancer Registry. To perform Chi-square and logistic regression tests, SAS-software was used for analysis. In urban counties, Blacks 40-49 years old diagnosed with localized stage of CerCancer were the most likely to receive surgery (74.14%; P < .0001), followed by Whites 17-39 years old diagnosed with regional stage, were the most likely to receive radiation and surgery-radiation sequence (66.32 and 66.67%; P < .0001) respectively. Also, Whites 50 years and older diagnosed with regional stage were the most likely to receive chemotherapy (65.87%; P < .0001). In rural counties, Blacks 40-49 years old diagnosed with regional stage were the most likely to receive radiation (70.37%) and chemotherapy (83.33%) with P = .005 and .003 respectively, followed by Whites 17-39 years old diagnosed with localized stage were the most likely to receive surgery (76.81%; P < .0001). Adjusting for age, stage and county, Blacks had 1.12 (95% CI = .88-1.42) times the odds of receiving more radiation treatment. Blacks had .76 times adjusted odds (95% CI .59-.99) of receiving less surgery compared to Whites. Treatment disparities exist between Blacks and Whites in Alabama.

Disparities in Cervical Cancer Treatment Options between African American (Black) and White Women in Alabama.

There are disparities in cervical cancer treatment options between African American (Black) and White women in Alabama. The objective of this study was to identify and assess factors contributing to the prevailing inequalities in cervical cancer treatment options between Blacks and Whites, who are living in urban, rural Black Belt (BB), and other rural counties of Alabama. The data of our study population, which was comprised of 2,124 cases of cervical cancer in women 17 years and older, were extracted from the 2004 to 2013 dataset of the Alabama Department of Public Health (ADPH) Cancer Registry. For the analysis of frequency distributions, chi-square, and logistic regression tests SAS software was used. Racial disparities in cervical cancer treatment options for Blacks living within the same counties as Whites still exist. The study analysis showed that younger Blacks living in urban counties with advanced stages of cervical cancer were more likely to receive radiation treatment options but were less likely to undergo surgical treatment options (p-value <.0001). Younger Blacks living in the rural BB and other rural counties were mainly treated with radiation options for the early stages of cervical cancer (p-value 0.001), while older ones received surgery options (p-value <.0001), and combined therapy of surgery and radiation options (p-value 0.05). When adjusted for age, stage of cancer, and county of residence, Blacks had 2.76 (95% CI 0.90-8.86) times the odds ratio of receiving immunotherapy options compared to Whites. Blacks had 0.74 (95% CI 0.58-0.95) times adjusted odds ratio of undergoing less surgery option compared to Whites. Our study findings suggest that cervical cancer treatment options and control interventions targeted towards disadvantaged women, particularly Blacks living in the rural BB and other rural counties have the potential to reduce and/or eradicate this preventable disease.

The correlation between alcohol consumption and risky sexual behaviors among people living with HIV/AIDS.

The objectives of this study were to determine if significant correlation exists between drinking any alcoholic beverage and risky sex among 326 AIDS patients. Participants completed anonymous surveys. The result of the regression and Pearson Correlation analyses revealed a significant positive correlation between drinking alcohol before sex and frequency of condom use (p < .0001). The number of sex partners respondents reported was also correlated with the frequency of alcohol use (p = .003). The result shows that the quantity of alcohol consumption was correlated with two indicators of risky sex: having multiple sexual partners (p < .0001) and having sexual intercourse without a condom (p < .001). Interventions are that integrate HIV risk reduction with alcohol risk reduction is very useful to minimize the risk of new HIV infections and/or manage existing infections.

Quantitative risk assessment of entry of contagious bovine pleuropneumonia through live cattle imported from northwestern Ethiopia.

Contagious bovine pleuropneumonia (CBPP) is a highly contagious bacterial disease of cattle caused by Mycoplasma mycoides subspecies mycoides small colony (SC) bovine biotype (MmmSC). It has been eradicated from many countries; however, the disease persists in many parts of Africa and Asia. CBPP is one of the major trade-restricting diseases of cattle in Ethiopia. In this quantitative risk assessment the OIE concept of zoning was adopted to assess the entry of CBPP into an importing country when up to 280,000 live cattle are exported every year from the northwestern proposed disease free zone (DFZ) of Ethiopia. To estimate the level of risk, a six-tiered risk pathway (scenario tree) was developed, evidences collected and equations generated. The probability of occurrence of the hazard at each node was modelled as a probability distribution using Monte Carlo simulation (@RISK software) at 10,000 iterations to account for uncertainty and variability. The uncertainty and variability of data points surrounding the risk estimate were further quantified by sensitivity analysis. In this study a single animal destined for export from the northwestern DFZ of Ethiopia has a CBPP infection probability of 4.76×10(-6) (95% CI=7.25×10(-8) 1.92×10(-5)). The probability that at least one infected animal enters an importing country in one year is 0.53 (90% CI=0.042-0.97). The expected number of CBPP infected animals exported any given year is 1.28 (95% CI=0.021-5.42). According to the risk estimate, an average of 2.73×10(6) animals (90% CI=10,674-5.9×10(6)) must be exported to get the first infected case. By this account it would, on average, take 10.15 years (90% CI=0.24-23.18) for the first infected animal to be included in the consignment. Sensitivity analysis revealed that prevalence and vaccination had the highest impact on the uncertainty and variability of the overall risk.

Public health considerations in human consumption of wild game.

The role of a few microorganisms, like Brucella and Mycobacterium and certain parasites of food animals, in causing human disease has been recognized for a hundred years. By the 1990s, other microorganisms derived from food animals were recognized as contributing to human illness. Handling and/or consumption of wild game may result in human exposure to novel microorganisms; these unrecognized or unknown agents or diseases in wild species may cross into humans and cause "new" diseases with which we are not familiar.

The Role of Computational Epidemiology and Risk Analysis in the Fight Against HIV/AIDS.

Substantial progress in the understanding of HIV and CD4 cell dynamics using computational models undergirded by sound epidemiologic and mathematical principles has been achieved. The early stages of the applications of these models were based on relatively simple mathematical models that considered the body as a one-compartment system. In spite of these models attractiveness due to the experimental and/or mathematical standpoints, the underlying simplification neglected a lot of important factors affecting the population dynamics both on macro (human) and micro (cellular) population levels. This simplification also affected the kinetics linked to the immunology, infection and chemotherapy dynamics throughout the host. Epidemiologic research involves the study of a complex set of host, environmental and causative agent factors as they interact to impact health and diseases in any given population whether biotic or abiotic. This leads in generating large data sets which require the use of powerful computational methods for studying these large and complex models by means of computational epidemiologic methods. Another dimension of a great challenging problem to public health decision makers is that of emerging diseases, as they have to face and deal with a lot of uncertainty at the early stages of disease outbreaks. However, at this juncture, epidemiologic problem-solving and decision-making often proceeds in the face of uncertainties and limited information. One methodology to address these types of shortcomings is the application of risk analysis. Risk analysis is a process for decision making under uncertainty that consists of three fundamental tasks: risk management, risk assessment, and risk communication. Excitingly, the prospective role that computational models and risk analysis may possibly play in the advancement of the theoretical understanding of disease processes and the identification of specific intervention strategies holds the potential to impact and save human lives.

Psychosocial factors as predictors of HIV/AIDS risky behaviors among people living with HIV/AIDS.

Infection with the human immunodeficiency virus (HIV) that causes acquired immunodeficiency syndrome (AIDS) is still rising globally. In order to develop effective HIV/AIDS risky behavior reduction intervention strategies and to further decrease the spread of HIV/AIDS, it is important to assess the prevalence of psychosocial problems and HIV/AIDS risky behaviors in people living with HIV/AIDS (PLWHA). The objective of this study is to assess the relationship between psychosocial variables and HIV/AIDS risky behaviors among PLWHA. A total of 341 questionnaires were distributed and 326 were fully completed and returned, 96% response rate. The relationships between the identified psychosocial and HIV/AIDS risky behaviors among PLWHA were analyzed using The Moment Structures software version 17.0 (SPSS Inc.) The results indicate that psychosocial health problems were significant predictors of HIV/AIDS risky behaviors in PLWA. Further cross-disciplinary research that addresses the manner in which psychosocial problems and HIV/AIDS risky behaviors interact with each other among PLWHA is needed.

The association between religious affiliation and frequency of attendance at religious services on HIV risky behaviors among people living with HIV/AIDS.

The purpose of this study was to examine if religious affiliation and frequency of attendance at religious services were associated with HIV risky behaviors among people living with HIV/AIDS (PLWHA). The participants are HIV positive clients of a community based HIV/AIDS outreach facility (CBHAOF) located in Montgomery, Alabama, USA. The participants completed the questionnaire during their medical visits to the clinic at their own convenience and that of the facility's staff. A total of 341 questionnaires were distributed to PLWHA and 326 (96%) were fully completed and returned. There were more male than female participants (56 versus 42%). The majority of the respondents (67%) were between 30 and 49 years of age. Nearly two thirds of the participants (64%) were African Americans whilst 36% were other races combined (White = 29%, Hispanic = 3% and other races = 4%). A chi-square test was used to examine the association between selected variables. Findings show substantial variations of selected HIV risky behaviors according to religious affiliation and frequency of attendance at religious services (p < 0.05). The study findings suggest the importance of religious affiliation and frequency of attendance at religious services in reducing HIV risky behaviors among PLWHA. The findings have implications for HIV/AIDS prevention and we recommend that it is important to incorporate Faith-based organizations in the global fight against HIV/AIDS.

The Association between Interrelationships and Linkages of Knowledge about HIV/AIDS and its Related Risky Behaviors in People Living with HIV/AIDS.

The relationship between knowledge about HIV/AIDS and its associated risky behaviors is complex and has not been sufficiently explored. It is especially important to look at some of the aspects of this relationship among people living with HIV/AIDS (PLWHA) in order to develop effective intervention strategies to reduce HIV/AIDS risky behaviors. The objective of this study was to investigate the association between knowledge about HIV/AIDS and its risky behaviors among PLWHA. METHODS: Risk taking behavior among the participants was measured as the number of all risky behaviors before and after the knowledge of their HIV/AIDS positive status. Knowledge was measured by the extent to which participants answered the HIV/AIDS related questions. The relationships between the identified HIV/AIDS risky behaviors and the knowledge among PLWHA were analyzed using Structural Equation Modelling. RESULTS: 341 questionnaires were administered and 326 (96%) were completed and returned from PLWHA clients of HIV/AIDS outreach facility in Alabama. Analysis revealed that, knowledge of HIV/AIDS, and knowledge of a properly used condom in preventing the infection through sexual activity were positively related with knowledge of where to get tested for HIV/AIDS. Using drugs before sex was significantly related with having sex with prostitutes (total effects' standardized regression coefficient (TESRC)=0.29, p<0.001). Sharing the same syringe or needle with another person or other people to inject oneself was strongly related with number of sexual partners within one year (TESRC=0.25, p<0.001), and sex with injecting drug users (TESRC=0.45, p<0.001). CONCLUSION: A deeper understanding of HIV/AIDS and some of its transmission pathways appears to be very effective in practicing the taking of preventive measures such as using condoms or getting tested for HIV. Increasing access to HIV/AIDS education could therefore be very useful in providing further gains in HIV/AIDS awareness among PLWHA.

Epidemiology of influenza A 2009 H1N1 virus pandemic in the U.S.

A novel influenza, Influenza A 2009 H1N1 virus outbreak, emerged in mid-April 2009, and by December 2009, spread across the world. This epidemiologic analysis uses the epidemiologic problem oriented approach to gather information for, and develop a quantitative risk assessment model that evaluates the likelihood of an influenza outbreak in the U.S., utilizing weekly incidence rates (WIR) and case fatality rates (CFR) stratified by age and the 10 U.S. regions. In addition ArcGIS was used to show variability regarding morbidity rate and WIR. Using data from the Centers for Disease Control and Prevention (CDC) Emerging Infections Program and applying Monte Carlo simulations with @Risk software, the analysis revealed morbidity to be highest in region 8 (1.27×10-2) and lowest in region 2 (0.13×10-2). Heat map results revealed WIR were higher in younger children, for all regions. Case fatality rates were 10 times greater in younger people than in older people and children. Using these different temporal-spatial epidemiologic methods can help decision-makers identify high-risk population clusters and help in prevention and control of pandemics.

Computational Modelling of Intracellular Viral Kinetics and CD4+ Cellular Population Dynamics of HIV/AIDS.

Computational microepidemiologic modelling can facilitate the understanding of complex biomedical systems. It provides novel methods for quantitatively studying population health dynamics from the micro level of genomes and molecules to the higher macro levels such as HIV/AIDS in humans. Untangling the dynamics between the human immunodeficiency virus-1 (HIV-1) and CD4(+) lymphocyte populations and intracellular molecular kinetics of interactions in an integrative systems dynamics approach can help to understand the effective points of interventions in the HIV life cycle. With that in mind, we have developed a stochastic systems dynamics model that includes intracellular molecular level interactions. A sequence of events, molecular interactions and cytochemical kinetics are triggered when the HIV infects a CD4(+) lymphocyte. The full sequence of molecular level dynamics includes: attachment and fusion; reverse transcription; integration; transcription; translation; and budding or release of new virus. The newly released virus circulates back and infects a new CD4(+) lymphocyte and the cycle continues repeatedly. Mathematical models that account for these processes were developed. The model developed provides insights into how an intracellular/molecular level model can be incorporated within a macro-epidemiologic integrative systems dynamics model for examining a variety of computational experimentations. Such experimentations can help in evaluating scientific questions related to effective strategies in HIV drug therapy interventions.