Search

OBJECTIVE: To describe a dynamic compartmental simulation model for Botswana and India, developed to identify the best strategies for preventing spread of HIV/AIDS. METHODS: The following interventions were considered: a behavioural intervention focused on female sex workers; a conventional programme for the treatment of sexually transmitted infections; a programme for the prevention of mother-to-child transmission; an antiretroviral treatment programme for the entire population, based on a single regimen; and an antiretroviral treatment programme for sex workers only, also based on a single regimen. FINDINGS: The interventions directed at sex workers as well as those dealing with sexually transmitted infections showed promise for long-term prevention of human immunodeficiency virus (HIV) infection, although their relative ranking was uncertain. In India, a sex worker intervention would drive the epidemic to extinction. In Botswana none of the interventions alone would achieve this, although the prevalence of HIV would be reduced by almost 50%. Mother-to-child transmission programmes could reduce HIV transmission to infants, but would have no impact on the epidemic itself. In the long run, interventions targeting sexual transmission would be even more effective in reducing the number of HIV-infected children than mother-to-child transmission programmes. Antiretroviral therapy would prevent transmission in the short term, but eventually its effects would wane because of the development of drug resistance. CONCLUSION: Depending on the country and how the antiretroviral therapy was targeted, 25-100% of HIV cases would be drug- resistant after 30 years of use.

Objectives. We explored whether excesses in influenza severity can be detected by combining respiratory syndromic hospital and mortality data with data on influenza-like illness (ILI) cases obtained from general practitioners. Methods. To identify excesses in the severity of influenza infections in the population of the Netherlands between 1999 and 2005, we looked for increases in influenza-associated hospitalizations and mortality that were disproportionate to the number of ILI cases reported by general practitioners. We used generalized estimating equation regression models to associate syndromic hospital and mortality data with ILI surveillance data obtained from general practitioners. Virus isolation and antigenic characterization data were used to interpret the results. Results. Disproportionate increases in hospitalizations and mortality (relative to ILI cases reported by general practitioners) were identified in 2003/04 during the A/Fujian/411/02(H3N2) drift variant epidemic. Conclusions. Combined surveillance of respiratory hospitalizations and mortality and ILI data obtained from general practitioners can capture increases in severe influenza-associated illness that are disproportionate to influenza incidence rates. Therefore, this novel approach should complement traditional seasonal and pandemic influenza surveillance in efforts to detect increases in influenza case fatality rates and percentages of patients hospitalized. (Am J Public Health. 2010;100:2248-2254. doi: 10.2105/AJPH.2009.168245)

Syndromic surveillance is increasingly used to signal unusual illness events. To validate data-source selection, we retrospectively investigated the extent to which 6 respiratory syndromes (based on different medical registries) reflected [...]

High blood pressure is a risk factor for cardiovascular disease regardless of what nationality or ethnic group people belong to. Researchers studied the relationship between blood pressure and death from cardiovascular disease in six different geographical regions: the US, Northern Europe, Mediterranean southern Europe, inland southern Europe, Serbia, and Japan. Although the absolute death rates from cardiovascular disease were lowest in Japan and highest in the US and Northern Europe, in every region, people with high blood pressure had higher mortality rates from cardiovascular disease than people with normal blood pressure.

In mathematical models for predicting the spread of sexually transmitted diseases (STDs), the rate of acquisition of new sex partners and concurrency, the number of simultaneous sexual partnerships, are important parameters. Yet, information on these parameters is rarely obtained in routine sexual behavior surveys; instead, questions about the total number of sex partners during specific periods are often asked. We present two methods that estimate the rate of partnership acquisition and concurrency from reported numbers of sex partners in two overlapping periods. The first method assumes homogeneous behavior, while the second method also takes account of heterogeneity in sexual behavior. Both methods assume random (Poisson) partnership acquisition and the possibility of overlap in relationships. For both methods it might be relevant to distinguish individuals who are in a stable relationship from those who are not., The advent of the HIV/AIDS epidemic has greatly stimulated the study of sexual behavior. Empirical behavior studies such as surveys (e.g., ACSF investigators, 1992; Catania, Coates & Turner, 1992; Cleland [...]

To the Editor: Mycobacterium tuberculosis infection is a necessary, but not sufficient, cause of tuberculosis (TB). Infection with HIV is the strongest known risk factor for disease progression to TB. [...]

ANTIRETROVIRAL (ARV) THERAPY IS USED FOR both treatment and prevention of HIV infection. It decreases patients' viral loads, dramatically improves their health, and delays death (1). ARVs also successfully reduce [...]

The association of variants of genes encoding interleukin (IL)-4 and the IL-4 receptor a chain (IL-4Rα) with respiratory syncytial virus (RSV) bronchiolitis was examined in hospitalized infants. Polymorphisms in IL-4 (C-590T) and IL-4Rα (ISOV and Q551R) were genotyped by restriction fragment-length polymorphism analysis. Control subjects included parents of the hospitalized children (for the transmission/disequilibrium test), and a random population sample (for the case-control study). Results were also analyzed in a combination of these 2 tests, using Fisher's method. The IL-4 590T allele was found more frequently among children hospitalized with RSV than expected in the case-control (odds ratio [OR], 1.43; P = .04) and combination (OR, 1.41; P = .02) tests. Among children who were >6 months old when they were hospitalized, compared with the control group or with the <6 months old who were hospitalized for RSV infection, higher frequencies of both the IL-4 590T allele and the IL-4Rα R551 allele were found. These results indicate that gain-of-function variants of T helper type 2 cytokine genes may play a role in increasing the severity of RSV disease, which appears more pronounced after the first half-year of life. [ABSTRACT FROM AUTHOR]

Examines whether HLA polymorphism influences HIV-1 susceptibility using a cohort of highly HIV-1-exposed female sex workers based in Nairobi, Kenya. Differences in HIV-1 susceptibility; Association of decreased HIV-1 infection risk with the possession of a cluster of closely related HLA alleles; Immunological aspect of HIV-1 infection resistance.

Analyzes the change in the restriction fragment length polymorphism (RFLP) patterns of Mycobacterium tuberculosis based on the serial isolates from 544 patients. Details of how the RFLP patterns showed from the initial isolates; Changes in RFLP patterns more common for persons with extrapulmonary disease.

When pathogenic microorganisms enter the human body via ingestion with food or drinking water, they encounter a system of barriers mounted by the host. In order to reach parts of the intestinal tract that are suitable for growth and attachment, each of the barriers must be overcome successfully. The present view on infection states that at least one of the ingested pathogens must survive to start colonization. This is the basis for dose response models, used for quantitative risk assessment. In this paper, the usefulness of the Beta Poisson model for multiple barrier is corroborated. Infection is associated with the presence of elevated numbers of reproducing pathogens in the intestinal tract. This does not necessarily imply illness symptoms: when intestinal microorganisms engage in damaging activities, this may lead to illness symptoms. At the same time, these activities probably elicit defensive measures from the host, promoting the removal of pathogens and terminating infection. The duration of the period of colonization reflects the balance between the colonization potential of pathogens and the strength of host defenses. Starting from the assumption that during infection the host has a certain hazard of becoming ill, a simple dose response relation for acute gastroenteritis is developed. With the use of literature data from volunteer experiments, we show that examples can be found for three possible alternatives: an increase in the probability of illness with increasing dose, a decrease with higher doses, and a probability of illness (given infection) independent of the ingested dose. These alternatives may reflect different modes of interaction between pathogens and host. [ABSTRACT FROM AUTHOR]