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The 1918-19 influenza epidemic killed more than fifty million people worldwide. The SARS epidemic of 2002-3, by comparison, killed fewer than a thousand. The success in containing the spread of SARS was due largely to the rapid global response of public health authorities, which was aided by insights resulting from mathematical models. Models enabled authorities to better understand how the disease spread and to assess the relative effectiveness of different control strategies. In this book, Lisa Sattenspiel and Alun Lloyd provide a comprehensive introduction to mathematical models in epidemiology and show how they can be used to predict and control the geographic spread of major infectious diseases. Key concepts in infectious disease modeling are explained, readers are guided from simple mathematical models to more complex ones, and the strengths and weaknesses of these models are explored. The book highlights the breadth of techniques available to modelers today, such as population-based and individual-based models, and covers specific applications as well. Sattenspiel and Lloyd examine the powerful mathematical models that health authorities have developed to understand the spatial distribution and geographic spread of influenza, measles, foot-and-mouth disease, and SARS. Analytic methods geographers use to study human infectious diseases and the dynamics of epidemics are also discussed. A must-read for students, researchers, and practitioners, no other book provides such an accessible introduction to this exciting and fast-evolving field.

Why have governments responded to the HIV/AIDS pandemic in such different ways? During the past quarter century, international agencies and donors have disseminated vast resources and a set of best practice recommendations to policymakers around the globe. Yet the governments of developing countries in sub-Saharan Africa, Asia, Latin America, and the Caribbean continue to implement widely varying policies. Boundaries of Contagion is the first systematic, comparative analysis of the politics of HIV/AIDS. The book explores the political challenges of responding to a stigmatized condition, and identifies ethnic boundaries--the formal and informal institutions that divide societies--as a central influence on politics and policymaking. Evan Lieberman examines the ways in which risk and social competition get mapped onto well-institutionalized patterns of ethnic politics. Where strong ethnic boundaries fragment societies into groups, the politics of AIDS are more likely to involve blame and shame-avoidance tactics against segments of the population. In turn, government leaders of such countries respond far less aggressively to the epidemic. Lieberman's case studies of Brazil, South Africa, and India--three developing countries that face significant AIDS epidemics--are complemented by statistical analyses of the policy responses of Indian states and over seventy developing countries. The studies conclude that varied patterns of ethnic competition shape how governments respond to this devastating problem. The author considers the implications for governments and donors, and the increasing tendency to identify social problems in ethnic terms.

We propose a mathematical spatiotemporal epidemic SICA model with a control strategy. The spatial behavior is modeled by adding a diffusion term with the Laplace operator, which is justified and interpreted both mathematically and physically. By applying semigroup theory on the ordinary differential equations, we prove existence and uniqueness of the global positive spatiotemporal solution for our proposed system and some of its important characteristics. Some illustrative numerical simulations are carried out that motivate us to consider optimal control theory. A suitable optimal control problem is then posed and investigated. Using an effective method based on some properties within the weak topology, we prove existence of an optimal control and develop an appropriate set of necessary optimality conditions to find the optimal control pair that minimizes the density of infected individuals and the cost of the treatment program.

Objectives: Data on HIV/AIDS cases in Italy are collected using a standardised form. Regional epidemiology may vary. We described the epidemiological and clinical characteristics of newly diagnosed persons with HIV in the ‘Cotugno’ hospital in Naples during 2011–2018 and compared them with national data to identify similarities and differences. Methods: Data source for the Campania region is the data collection forms sent to the national surveillance system. The data source for the national data is from the periodic annual bulletins on HIV/AIDS published by the National Institute of Health. Results: In all, 1149 persons with HIV were diagnosed in ‘Cotugno’ (69.7% of those diagnosed in Campania). Persons with HIV in Campania showed many similarities with the Italian population: men were in the majority in both groups (about 75%), foreign origin was about 30%, heterosexuals were the most represented risk group, followed by men who have sex with men and injecting drug use in both samples. Some notable differences are also present. Among the risk factors for HIV acquisition, injecting drug use is significantly more common in Campania. Among the reasons for testing, significant differences are evident for almost all reasons, with screening activities (testing for concurrent diseases, for diagnosis of sexually transmitted diseases, screening in hospital during maternity care and screening in drug-addition services or prisons) being more common at the national level. The Campania population has a more severe disease pattern, with a significantly higher proportion of patients diagnosed with less than 200 CD4 cells/µL and AIDS. For each variable, we compared trends in the Campania region and in Italy using Spearman’s correlation coefficient. Almost all trends show a weak correlation. Conclusion: In conclusion, the prevalence of injecting drug use is still consistent, and requires specific campaigns. The reasons for testing are different: screening activities work less in Campania than in Italy. This untimely approach contributes to a more severe clinical picture in Campania.

Background In Southeast Asia, though fishermen are known to be a key population at high risk of HIV, little is known about their co-infection rates with Hepatitis C virus (HCV), or how illness and risk behaviors vary by occupation or type of fishermen. In Myanmar, this lack of knowledge is particularly acute, despite the fact that much of the country’s border is coastline. Methods We conducted a retrospective analysis to assess clinical, demographic, and risk characteristics of HIV-infected, ≥15-year-old males under HIV care from 2004 to 2014. Subgroups of fishermen were categorized according to the location of fishing activities, boat ownership, and length of time at sea. Generalized linear models assessed odds of high risk behaviors, including MSM (men who have sex with men), transactional sex, injection drug use (IDU), and HCV co-infection among international, local subsistence, and national migrant fishermen. Results Of 2798 adult males who enrolled in HIV care between 2004 and 2014, 41.9% ( n  = 1172) were fishermen. Among these, migrants had the highest odds of engaging in risk behaviors such as sex work (Myanmar national migrants: OR 3.26 95% CI: 2.20 to 4.83), and injecting drugs (international migrants: OR 2.93, 95% CI: 1.22 to 3.87) when compared to the general male HIV clinic population. 15.9% of all fishermen reported past or current IDU (23.0% of international migrants). 22.8% of all fishermen were also co-infected with HCV, and though predictably injectors had the highest odds (OR 20.1, 95% CI: 13.7 to 29.5), even after controlling for other risk factors, fishermen retained higher odds (OR 2.37 95% CI: 1.70 to 3.32). Conclusions HIV positive fishermen in Myanmar had higher odds of HCV co-infection. They also disproportionally injected drugs and engaged in transactional sex more than other patients. This is especially pronounced among international migrant fishermen. HIV-infected fishermen should be counseled on high risk activities, screened for HCV, and targeted by harm reduction programs.

To understand associations between location of sex and sexual risk, it is most helpful to compare sexual encounters within persons. We systematically reviewed within-subjects comparisons of sexual encounters reported by men who have sex with men (MSM) with respect to location of sex. Within-subjects comparisons of sexual risk and location of sex were eligible if they collected data post-1996 from samples of MSM. We independently screened results and full-text records in duplicate. Of 6,336 deduplicated records, we assessed 138 full-text studies and included six, most of which compared unprotected anal intercourse against other anal intercourse. This small, but high quality, body of evidence suggests that associations between attendance at sex-on-premises venues and person-level sexual risk may be due to overall propensity towards unprotected sex. However, there may be some location factors that promote or are associated with serononconcordant unprotected anal intercourse. Health promoters may wish to focus on person-level characteristics.

Objectives. To explore US geographic areas with limited access to HIV preexposure prophylaxis (PrEP) providers, PrEP deserts. Methods. We sourced publicly listed PrEP providers from a national database of PrEP providers from 2017 and obtained county-level urbanicity classification and population estimates of men who have sex with men (MSM) from public data. We calculated travel time from census tract to the nearest provider. We classified a census tract as a PrEP desert if 1-way driving time was greater than 30 or 60 minutes. Results. One in 8 PrEP-eligible MSM (108 758/844 574; 13%) lived in 30-minute-drive deserts, and a sizable minority lived in 60-minute-drive deserts (38 804/844 574; 5%). Location in the South and lower urbanicity were strongly associated with increased odds of PrEP desert status. Conclusions. A substantial number of persons at high risk for HIV transmission live in locations with no nearby PrEP provider. Rural and Southern areas are disproportionately affected. Public Health Implications. For maximum implementation effectiveness of PrEP, geography should not determine access. Programs to train clinicians, expand venues for PrEP care, and provide telemedicine services are needed.

In this work we propose the definition of the ratio of hidden infection of HIV/AIDS epidemics, as the division of the unknown infected population by the known one. The merit of the definition lies in allowing for an indirect estimation of the whole of the infected population. A dynamical model for the ratio is derived from a previous HIV/AIDS model, which was proposed for the Cuban case, where active search for infected individuals is carried out through a contact tracing program. The stability analysis proves that the model for the ratio possesses a single positive equilibrium, which turns out to be globally asymptotically stable. The sensitivity analysis provides an insight into the relative performance of various methods for detection of infected individuals. An exponential regression has been performed to fit the known infected population, owing to actual epidemiological data of HIV/AIDS epidemics in Cuba. The goodness of the obtained fit provides additional support to the proposed model.

Women with human immunodeficiency virus (HIV) infection have higher rates of concurrent human papillomavirus (HPV) infection and cervical dysplasia than do HIV-uninfected women. They are also more commonly infected with multiple HPV types simultaneously. To determine the prevalence of different HPV genotypes in a group of HIV-infected women and to correlate these findings with cervical cytological results, we studied a group of 229 women attending a university-based HIV clinic during a 7-year period. When cervicovaginal lavage specimens, the reverse line-blot assay, and DNA sequencing were used, the most commonly detected HPV types (in decreasing order of frequency) were 56, 53, 16, 58, 52, MM7, MM8, and 33. These results contrast sharply with similar studies of HIV-uninfected women, in whom HPV-16 and -18 generally predominate. In our study, the HPV types most commonly associated with low-grade squamous intraepithelial lesions (SILs) were 56 and 53. Types most commonly associated with high-grade SILs were 52 and 58. High-risk HPV types other than 16 and 18 are often found in HIV-infected women and are frequently associated with abnormal cervical cytological results in this setting. These observations have implications for the design of future HPV vaccines