Evaluating the Completeness of HIV Surveillance Using Capture–Recapture Models,Alameda County,California

HIV prevalence in Alameda County (including Oakland) is among the highest in California, yet the case registry may under-appreciate the full burden of disease. Using lists from health care facilities serving socioeconomically diverse populations and the HIV surveillance list, we applied capture–recapture methods to evaluate the completeness of the surveillance system by estimating the number of diagnosed people living with HIV and seeking care in Alameda County in 2013. Of the 5376 unique individuals reported from the lists, 397 were missing from the surveillance list. Models projected the total population size to be 5720 (95% CI 5587–6190), estimating the surveillance system as 87% complete. Subgroup analyses identified groups facing a disproportionate burden of HIV as more likely to be detected by the surveillance list. The Alameda County HIV surveillance system reports a high proportion of persons diagnosed with HIV within the jurisdiction. Capture–recapture analysis can help track progress towards maximizing engagement in HIV care.     

Exploring the Impact of Underage Sex Work Among Female Sex Workers in Two Mexico–US Border Cities

Although sex work and younger age increase HIV vulnerability, empirical data regarding the impacts of underage sex work are lacking. We explored associations between features of the risk environment, sex work, and drug use history, and underage sex work entry among 624 female sex workers (FSWs) in Tijuana and Ciudad Juarez, Mexico. Forty-one percent (n = 253) of women began sex work as minors, among whom HIV and any STI/HIV prevalence were 5.2 and 60.7%. Factors independently associated with increased odds of underage sex work were inhalants as the first drug used, forced first injection, number of drug treatment attempts, and recent receptive syringe sharing. Number of recent condom negotiation attempts with steady partners and depression as a reason for first injecting were negatively associated with underage entry. These results underscore the importance of efforts to prevent underage sex work and the wider factors contributing to HIV risk among vulnerable youth and underage FSWs.     

The Spectrum of α-Thalassemia Mutations in the Lak Population of Iran

α-Thalassemia (α-thal) is one of the most common genetic disorders worldwide. The aim of this study was to investigate for the first time the α-thal mutation spectrum in the Lak population living in Lorestan Province, Iran. One hundred and seventy-six α-thal carriers participated in the study. Multiplex gap-polymerase chain reaction (gap-PCR), amplification refractory mutation system (ARMS)-PCR and direct sequencing were used for the detection of different mutations on the α-globin (HBA1 and HBA2) genes. A total of 11 different mutations was identified. The –α^3.7 (rightward; NG_000006.1: g.34164_37967del3804) deletion was observed most frequently (56.35%), followed by α^?5?ntα (HBA2: c.95+2_95+6delTGAGG), α^polyA2α (HBA2: c.*92A>G) and – –^{MED I} (NG_000006.1: g.24664_41064del16401), with frequencies of 15.47, 9.39, and 6.08%, respectively. These four mutations accounted for more than 87.0% of the total mutated alleles. Moreover, 19 different genotypes were identified. The types and distribution pattern of the mutations identified in this study, in comparison with other studies conducted in Iran, was most similar to the Kurdish population of Kermanshah Province, Iran. Due to the lack of information on α-thal in Lorestan Province, it was not possible to compare the mutation spectrum in the Lur and Lak populations. In conclusion, our results may help in setting up a strategy for an α-thal screening program and genetic counseling in the Lak people.     

Buerger’s disease: a 10-year experience in Tehran,Iran

The clinical spectrum of Buerger’s disease (TAO; thromboangiitis obliterans) seems to be changing. Considering the lack of any formal studies on the epidemiology of this disease in Iran, we evaluated the data of 198 confirmed cases of TAO during the period 1996–2006. Diagnosis was based on Papa’s scoring system. All patients were male and aged at the time of diagnosis 40.5 ± 10.1 years. All patients were smokers for a duration of 22.2 ± 11.6 years. There was a strong seasonal variation for admission with winter admissions being significantly the most common (P < 0.001). Patients, 181 (91.4%), had only lower limb involvement, 4 (2.0%) had solely upper limb disease, and 13 (6.6%) suffered from both. Sympathectomy, amputation, and bypass graft surgery were performed in 97 (49.0%; lumbar: 92, thoracic: 5), 71 (35.9%), and 28 (14.1%) patients, respectively. The present report is the second one to show seasonal variation in TAO.     

Female hypogonadism: evaluation of the hypothalamic–pituitary–ovarian axis

Female hypogonadism refers to deficient or abnormal function of the hypothalamic–pituitary–ovarian axis that clinically presents with menstrual cycle disturbances. Female hypogonadism can be due to a congenital or acquired cause, and the defect can be at the level of the hypothalamus, pituitary or ovary. A careful history, physical exam and selected laboratory testing can often determine the locus of the defect and whether it results from a structural or hormonal problem. Laboratory testing generally relies on basal hormone levels; however, timing of blood sampling in relation to menses is important to interpretation of the data.     

Molecular Study of Deletional and Nondeletional Mutations on the α-Globin Locus in the Azeri Population of Northwestern Iran

The aim of this study was to determine the molecular spectrum and frequency of deletional and nondeletional α-thalassemia (α-thal) mutations and the genotype–phenotype correlation in common mutations in the Azeri population of Northwestern Iran. A total of 1256 potential carriers with microcytic and hypochromic anemia and normal Hb A₂ levels (<3.5%) and without iron deficiency anemia plus three fetuses were identified. Multiplex gap-polymerase chain reaction (gap-PCR) and sequencing for α-thal mutations were carried out. In 606 individuals, the α-globin gene was normal, but in 650 persons (51.6%) and three fetuses, 10 different mutations were detected. The most frequent deletional genotypes were as follows: αα/–α^3.7 (61.7%), –α^3.7/–α^3.7 (11.9%), αα/–α^4.2 (4.6%), αα/– –^MED (4.3%) and αα/–(α)^20.5 (3.8%). The most frequent nondeletional genotypes were αα/α^{IVS-I (–5?nt)}α (HBA2: c.95+2_95+6delTGAGG) and αα/α^{Poly A2}α [polyadenylation signal (polyA2) (AATAAA>AATGAA); HBA2: c.*96G>A] with frequencies of 1.08% and 0.92%, respectively. Meanwhile, 7.71% of individuals with a proven β-thalassemia (β-thal) mutation were found to also carry an α-thal mutation. Persons having two functional α-globin genes showed lower mean corpuscular volume (MCV) and mean corpuscular hemoglobin (Hb) (MCH) values compared to those with one mutated α-globin gene, provided that they had normal β-globin genes. Overall, the incidence of α-thal was 2.7% in the Azeri population in Northwestern Iran. Our results showed that the variability of α-thal mutations are high in the Azeri population and that α-thal mutations are highly heterogeneous in both deletional and nondeletional genotype aspects.     

Prevalence and Correlates of Female Condom Use and Interest Among Injection Drug-Using Female Sex Workers in Two Mexico–US Border Cities

Little is known about female condom use among female sex workers who inject drugs (FSW-IDUs) in Northern Mexico, where HIV/STI prevalence is high. We examined the prevalence and correlates of female condom use and interest in female condom use among FSW-IDUs aged?>18?years in Tijuana and Ciudad Juárez, Mexico enrolled in a behavioral intervention designed to reduce high-risk sexual and injection behaviors. Of 621 FSW-IDUs, 8?% reported ever using female condoms, and 67.2?% expressed interest in trying female condoms. Factors independently associated with female condom use were having had a client become angry at the suggestion of using condoms and having engaged in unprotected vaginal sex with non-regular clients. Factors independently associated with interest in using female condoms were lifetime physical abuse and lifetime sexual abuse. Increasing the availability of female condoms and providing education on their use in the context of drug use and violence is recommended.     

Evaluation of the National Prevention Program in Iran, 2007–2009: the Accomplishments and Challenges with Reflections on the Path Ahead

β-Thalassemia major (β-TM) is an inherited disease and efforts have been made in several countries to reduce the number of affected births. In the present study, we aimed to evaluate the Iranian thalassemia prevention program, considered to be an important program in the region. The time period of the present study ranges from 2007–2009, during which new thalassemic births and the relevant causes were evaluated throughout the country. A cross-sectional analytical study was conducted at the Iranian Blood Transfusion Organization (IBTO), Tehran, Iran. A questionnaire was forwarded to all blood centers of the IBTO so as to obtain information about the new cases of thalassemia and the causes of these thalassemic births. Provincial thalassemia societies also received the questionnaires so that screening and prenatal diagnosis (PND) errors would be recorded. The results showed that 755 new thalassemia cases were born during 2007–2009 with the average fall in affected thalassemia births of 80.82%. The main cause of the new births was attributed to unregistered “timeless religious marriages” based on the conventions of the Sunni community which accounted for 43.17% of all new cases mainly having occurred in Sistan & Baluchestan Province. Not using PND was evaluated to be another main cause. Although the prevention program has led to a great reduction in thalassemic births, new measures are required, including research on how to make the program compatible with social and economic conventions and norms of Sistan & Baluchestan Province. The province of Kohgiluyeh Boyer Ahmad also needs to be revisited in terms of the program efficacy.     

Migration and Mobility: Correlates of Recent HIV Testing Among Substance Using Female Sex Workers at the Mexico–Guatemala Border

AIDS and Behavior - The goal of this paper is to determine the association between traveling to engage in sex work in another country and recent access to HIV testing among substance-using female...     

Trends in the prevalence of diabetes and impaired fasting glucose in association with obesity in Iran: 2005–2011

Aims

To estimate the prevalence and trends of diabetes mellitus (DM) and impaired fasting glucose (IFG), 2005–2011, and to determine the contribution of obesity to DM prevalence.

Patients and methods

Data from Surveillance of Risk Factors of Non-communicable Diseases (SuRFNCD) conducted in 2005, 2007, and 2011 were gathered. DM was defined as presence of self-reported previous diagnosis or a fasting plasma glucose (FPG) ≥ 7 mmol/L. IFG was diagnosed with FPG levels between 5.6 and 6.9 mmol/L. Prevalence rates for 2011 and trends for 2005–2011 were determined by extrapolating survey results to Iran's adult population. Population attributable fraction (PAF) of obesity was also calculated.

Results

In 2011, IFG and total DM prevalence rates were 14.60% (95%CI: 12.41–16.78) and 11.37% (95%CI: 9.86–12.89) among 25–70 years, respectively. DM was more common in older age (p < 0.0001), in women (p = 0.0216), and in urban-dwellers (p = 0.0001).In 2005–2011, trend analysis revealed a 35.1% increase in DM prevalence (OR: 1.04, 95%CI: 1.01–1.07, p = 0.011); albeit, IFG prevalence remained relatively unchanged (OR: 0.98, 95%CI: 0.95–1.00, p = 0.167). In this period, DM awareness improved; undiagnosed DM prevalence decreased from 45.7% to 24.7% (p < 0.001). PAF analysis demonstrated that 33.78%, 10.25%, and 30.56% of the prevalent DM can be attributed to overweight (BMI ≥ 25 kg/m²), general obesity (BMI ≥ 30 kg/m²), and central obesity (waist circumference ≥ 90 cm), respectively. Additionally, the DM increase rate in 2005–2011, was 20 times higher in morbidly obese compared with lean individuals.

Conclusion

More than four million Iranian adults have DM which has increased by 35% over the past seven years, owing in large part, to expanding obesity epidemic.     

Direct observation of prefreezing at the interface melt–solid in polymer crystallization

Crystallization is almost always initiated at an interface to a solid. This observation is classically explained by the assumption of a reduced barrier for crystal nucleation at the interface. However, an interface can also induce crystallization by prefreezing (i.e., the formation of a crystalline layer that is already stable above the bulk melting temperature). We present an atomic force microscopy (AFM)-based in situ observation of a prefreezing process at the interface of a polymeric model system and a crystalline solid. Explicitly, we show an interfacial ordered layer that forms well above the bulk melting temperature with thickness that increases on approaching melt–solid coexistence. Below the melting temperature, the ordered layer initiates crystal growth into the bulk, leading to an oriented, homogeneous semicrystalline structure.The fundamental process of crystallization from the liquid or gaseous state is of importance in many areas of condensed matter physics and materials science. In practice, crystallization is, in most cases, initiated at an interface to a solid. Crystal growth on solid substrates from the gaseous state has been studied in depth, and detailed understanding of different growth modes as well as interfacial thermodynamics has been achieved (1–3). Much less experimental data are available for crystallization occurring at the interface from the solid to the melt. Generally, crystallization can be initiated at the solid–melt interface by two processes: heterogeneous nucleation or formation of a crystalline wetting layer (so-called prefreezing) (4–6). In terms of thermodynamics, these processes are very different. Whereas nucleation takes place under nonequilibrium conditions at finite supercooling below the melting temperature T_m of the bulk material, the formation of a wetting layer is an equilibrium phenomenon taking place above T_m (4). It is often assumed that heterogeneous nucleation is the more relevant process (7), but in simulations, nucleation as well as prefreezing have been shown to occur (4, 8). Prefreezing is expected for strongly attractive surfaces or epitaxial systems for which the lattices of the substrate and the crystallizing materials match well (9–12). In the case of polymers, prefreezing can also manifest itself in the conformational degrees of freedom, leading to an interfacial layer with nematic order, which was recently shown in simulations (13). Because of the difficult accessibility of the buried interface between a melt and a solid, direct observation of crystallization of molecular systems at the interface is lacking, and there is only limited, indirect evidence that, in some cases, prefreezing at the solid interface exists (e.g., for the growth of aluminum crystals on TiB₂ particles) (14, 15). Recently, it has been suggested that prefreezing also plays a role during epitaxial crystallization in some polymeric systems (16). It is well-known, however, that one or sometimes several ordered layers of organic molecules can form on suitable substrates at temperatures above the bulk melting point, which was observed for, for example, alkanes or similar molecules on graphite by scanning tunneling microscopy (17), atomic force microscopy (AFM) (18–20), or scattering methods (21, 22; review in ref. 23). A related but more special phenomenon is surface freezing of liquids (22). In some liquids, an ordered monolayer forms at the free surface in a finite temperature range above the bulk melting temperature [e.g., alkanes (24), alkylated side chain polymers (25), and AuSi alloys (26)]. It is an open question, however, which exact role all of these structures play for the initiation of crystal growth (27) and in most cases, the temperature range around melt–solid coexistence, where crystallization starts has not been studied in detail. Only for colloidal model systems has crystallization by prefreezing been directly observed (28) and studied in simulations (8, 10, 11).We here present direct AFM observations of an ordered wetting layer at the interface to a solid close to coexistence of the solid and the liquid phases of a polymeric model system. We show evidence for a temperature-dependent thickness of the wetting layer and its disappearance at a prewetting transition at finite superheating above T_m. Our observations are in line with a divergence of the layer thickness at the bulk melting temperature as expected for complete wetting. Below T_m, crystal growth into the film is initiated by the interfacial layer.     

Distribution,Size, and Origin of Juvenile Chinook Salmon in Shallow-Water Habitats of the Lower Columbia River and Estuary, 2002–2007

Abstract

We monitored fish assemblages monthly at estuarine and tidal freshwater sites in the lower Columbia River and estuary from January 2002 through September 2007 in order to identify specific salmon stocks and migration stages that may benefit from habitat restoration initiatives. We report landscape-scale and seasonal variation in abundance, size, hatchery production (based on adipose fin clips), and genetic stock of origin of juvenile Chinook salmon Oncorhynchus tshawytscha. From fish implanted with coded wire tags (CWTs), we also determined the sites of release and inferred migration patterns. Chinook salmon were found in diverse life history stages and forms, including fry migrants, fingerlings, and (fewer) yearlings. Abundance increased in February and decreased in August, but salmon were present in all months each year. Spatial gradients in abundance and size were strong, with fewer but larger fish in brackish than in tidal freshwater zones. Overall, 30% of the Chinook salmon measured were fry (≤60 mm) that were likely naturally produced fish. These occurred at higher mean monthly proportions in tidal freshwater than in estuarine zones. In contrast, most larger fish were probably raised in hatcheries. Genetic stock assessment revealed that the majority of the Chinook salmon analyzed were from fall-run stock groups originating in the lower Columbia River, with 15% originating from other stock groups. Of these minority contributors, about 6% were identified as upper Columbia River summer–fall-run Chinook salmon while seven other stock groups accounted for the remainder, including 3% from transplants originating in southern Oregon's Rogue River. Recaptures of tagged fish revealed maximum migration times of 143 d for subyearlings and 52 d for yearlings, and both CWT and genetic data indicated that fall Chinook salmon from coastal rivers occasionally entered the estuary. These data demonstrated a widespread temporal and spatial distribution of subyearling Chinook salmon in shallow-water habitats of the lower Columbia River and estuary.

Received June 28, 2011; accepted February 28, 2012     

Cost–Utility Analysis of A Female Condom Promotion Program in Washington, DC

A retrospective economic evaluation of a female condom distribution and education program in Washington, DC. was conducted. Standard methods of cost, threshold and cost-utility analysis were utilized as recommended by the U.S. Panel on cost-effectiveness in health and medicine. The overall cost of the program that distributed 200,000 female condoms and provided educational services was $414,186 (at a total gross cost per condom used during sex of $3.19, including educational services). The number of HIV infections that would have to be averted in order for the program to be cost-saving was 1.13 in the societal perspective and 1.50 in the public sector payor perspective. The cost-effectiveness threshold of HIV infections to be averted was 0.46. Overall, mathematical modeling analyses estimated that the intervention averted approximately 23 HIV infections (even with the uncertainty inherent in this estimate, this value appears to well exceed the necessary thresholds), and the intervention resulted in a substantial net cost savings.