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Dive into the research topics where Richard F. Armenta is active.

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Featured researches published by Richard F. Armenta.


PLOS Computational Biology | 2013

Multiple estimates of transmissibility for the 2009 influenza pandemic based on influenza-like-illness data from small US military populations.

Pete Riley; Michal Ben-Nun; Richard F. Armenta; Jon A. Linker; Angela A. Eick; Jose L. Sanchez; Dylan B. George; David P. Bacon; Steven Riley

Rapidly characterizing the amplitude and variability in transmissibility of novel human influenza strains as they emerge is a key public health priority. However, comparison of early estimates of the basic reproduction number during the 2009 pandemic were challenging because of inconsistent data sources and methods. Here, we define and analyze influenza-like-illness (ILI) case data from 2009–2010 for the 50 largest spatially distinct US military installations (military population defined by zip code, MPZ). We used publicly available data from non-military sources to show that patterns of ILI incidence in many of these MPZs closely followed the pattern of their enclosing civilian population. After characterizing the broad patterns of incidence (e.g. single-peak, double-peak), we defined a parsimonious SIR-like model with two possible values for intrinsic transmissibility across three epochs. We fitted the parameters of this model to data from all 50 MPZs, finding them to be reasonably well clustered with a median (mean) value of 1.39 (1.57) and standard deviation of 0.41. An increasing temporal trend in transmissibility (, p-value: 0.013) during the period of our study was robust to the removal of high transmissibility outliers and to the removal of the smaller 20 MPZs. Our results demonstrate the utility of rapidly available – and consistent – data from multiple populations.


Drug and Alcohol Dependence | 2015

Association between non-fatal opioid overdose and encounters with healthcare and criminal justice systems: Identifying opportunities for intervention

Karla D. Wagner; Lin Liu; Peter J. Davidson; Jazmine Cuevas-Mota; Richard F. Armenta; Richard S. Garfein

BACKGROUND Accidental overdose, driven largely by opioids, is a leading cause of death among people who inject drugs (PWIDs). We conducted secondary analysis of data from a cohort of PWIDs to identify venues where high-risk PWID could be targeted by overdose education/naloxone distribution (OEND) programs. METHODS 573 PWIDs completed a quantitative survey between June, 2012 and January, 2014, which was analyzed using multivariable logistic regression. The dependent variable was a dichotomous indicator of experiencing a heroin/opioid-related overdose in the past six months. Independent variables included: demographics, drug use behavior, and encounters with two venues - the health care and criminal justice systems - that could serve as potential venues for OEND programs. RESULTS Almost half (41.5%) reported ever experiencing a heroin/opioid overdose, and 45 (7.9%) reported experiencing at least one heroin/opioid overdose in the past six months. In the final multivariable model, receiving care in a hospital in the past six months (Adjusted Odds Ratio [AdjOR] 4.08, 95% Confidence Interval [C.I.] 2.07, 8.04, p<0.001) and being arrested for drug possession in the past six months (AdjOR 5.17, 95% C.I. 2.37, 11.24, p<0.001) were associated with experiencing an opioid overdose in the past six months. CONCLUSIONS Identifying venues outside of those that traditionally target services to PWIDs (i.e., syringe exchange programs) will be critical to implementing OEND interventions at a scale sufficient to address the growing epidemic of heroin/opioid related deaths. Clinical settings, such as hospitals, and drug-related encounters with law enforcement officers are promising venues for the expansion of OEND programs.


American Journal of Public Health | 2015

Awareness of HCV Infection Among Persons Who Inject Drugs in San Diego, California

Melissa G. Collier; Sandeep K. Bhaurla; Jazmine Cuevas-Mota; Richard F. Armenta; Eyasu H. Teshale; Richard S. Garfein

We asked persons who inject drugs questions about HCV, including past testing and diagnosis followed by HCV testing. Of 540 participants, 145 (27%) were anti-HCV positive, but of those who were positive, only 46 (32%) knew about their infection. Asking about previous HCV testing results yielded better results than did asking about prior HCV diagnosis. Factors associated with knowing about HCV infection included older age, HIV testing, and drug treatment. Comprehensive approaches to educating and screening this population for HCV need implementation.


Substance Abuse | 2016

Factors Associated With Patterns of Mobile Technology Use Among Persons Who Inject Drugs

Kelly Collins; Richard F. Armenta; Jazmine Cuevas-Mota; Lin Liu; Steffanie A. Strathdee; Richard S. Garfein

ABSTRACT Background: New and innovative methods of delivering interventions are needed to further reduce risky behaviors and increase overall health among persons who inject drugs (PWID). Mobile health (mHealth) interventions have potential for reaching PWID; however, little is known about mobile technology use (MTU) in this population. In this study, the authors identify patterns of MTU and identified factors associated with MTU among a cohort of PWID. Methods: Data were collected through a longitudinal cohort study examining drug use, risk behaviors, and health status among PWID in San Diego, California. Latent class analysis (LCA) was used to define patterns of MTU (i.e., making voice calls, text messaging, and mobile Internet access). Multinomial logistic regression was then used to identify demographic characteristics, risk behaviors, and health indicators associated with mobile technology use class. Results: In LCA, a 4-class solution fit the data best. Class 1 was defined by low MTU (22%, n = 100); class 2, by PWID who accessed the Internet using a mobile device but did not use voice or text messaging (20%, n = 95); class 3, by primarily voice, text, and connected Internet use (17%, n = 91); and class 4, by high MTU (41%, n = 175). Compared with low MTU, high MTU class members were more likely to be younger, have higher socioeconomic status, sell drugs, and inject methamphetamine daily. Conclusion: The majority of PWID in San Diego use mobile technology for voice, text, and/or Internet access, indicating that rapid uptake of mHealth interventions may be possible in this population. However, low ownership and use of mobile technology among older and/or homeless individuals will need to be considered when implementing mHealth interventions among PWID.


Substance Use & Misuse | 2017

Potential Risks of Ecological Momentary Assessment Among Persons Who Inject Drugs

Alexis M. Roth; John Rossi; Jesse L. Goldshear; Quan Truong; Richard F. Armenta; Stephen E. Lankenau; Richard S. Garfein; Janie Simmons

ABSTRACT Background: Ecological momentary assessment (EMA)—which often involves brief surveys delivered via mobile technology—has transformed our understanding of the individual and contextual micro-processes associated with legal and illicit drug use. However, little empirical research has focused on participants perspective on the probability and magnitude of potential risks in EMA studies. Objectives: To garner participant perspectives on potential risks common to EMA studies of illicit drug use. Methods: We interviewed 38 persons who inject drugs living in San Diego (CA) and Philadelphia (PA), United States. They completed simulations of an EMA tool and then underwent a semi-structured interview that systematically explored domains of risk considered within the proposed revisions to the Federal Policy for the Protection of Human Subjects or the “Common Rule.” Interviews were transcribed verbatim and coded systematically to explore psychological, physical, social, legal, and informational risks from participation. Results: Participants perceived most risks to be minimal. Some indicated that repetitive questioning about mood or drug use could cause psychological (i.e., anxiety) or behavioral risks (i.e., drug use relapse). Ironically, the questions that were viewed as risky were considered motivational to engage in healthy behaviors. The most cited risks were legal and social risks stemming from participant concerns about data collection and security. Importance: Improving our understanding of these issues is an essential first step to protect human participants in future EMA research. We provide a brief set of recommendations that can aid in the design and ethics review of the future EMA protocol with substance using populations.


International Journal of Drug Policy | 2015

Effect of legal status of pharmacy syringe sales on syringe purchases by persons who inject drugs in San Francisco and San Diego, CA

Saira S. Siddiqui; Richard F. Armenta; Jennifer L. Evans; Michelle Yu; Jazmine Cuevas-Mota; Kimberly Page; Peter J. Davidson; Richard S. Garfein

BACKGROUND Sharing blood-contaminated syringes is the main risk factor for acquiring and transmitting blood-borne infections among persons who inject drugs (PWID). To reduce this risk, in 2005, California enacted legislation allowing local health jurisdictions to legalize non-prescription syringe sales after approving a disease prevention demonstration project (DPDP). With San Francisco approving a DPDP immediately and San Diego never approving one, we compared PWID across cities for their use of pharmacies PWID to obtain syringes. METHODS PWID age 18-30 years old were recruited into separate studies in San Francisco (n=243) and San Diego (n=338) between 2008 and 2011. We used multivariable logistic regression to compare the proportions of PWID who obtained syringes from pharmacies by city while controlling for sociodemographics, injection practices and other risk behaviors. RESULTS Overall, most PWID were White (71%), male (63%), and between the ages of 18-25 years (55%). Compared to San Francisco, a smaller proportion of PWID in San Diego had bought syringes from pharmacies in the prior three months (16.9% vs. 49.8%; p<0.001), which remained statistically significant after adjusting for sociodemographic and behavioral factors (adjusted odds ratio=4.45, 95% confidence interval: 2.98, 6.65). CONCLUSIONS Use of pharmacies to obtain syringes was greater where it was legal to do so. Public health policy can influence HIV and hepatitis C associated risk among PWID; however, implementation of these policies is crucial for the benefits to be realized.


Obesity | 2015

Association of breastfeeding with postmenopausal visceral adiposity among three racial/ethnic groups

Richard F. Armenta; Donna Kritz-Silverstein; Deborah L. Wingard; Gail A. Laughlin; Wilma Wooten; Elizabeth Barrett-Connor; Maria Rosario G. Araneta

We examined the association between breastfeeding and postmenopausal visceral adiposity.


Journal of Traumatic Stress | 2015

Prescription Stimulants and PTSD Among U.S. Military Service Members.

Nancy F. Crum-Cianflone; Melissa A. Frasco; Richard F. Armenta; Christopher J. Phillips; Jaime L. Horton; Margaret A. K. Ryan; Dale W. Russell; Cynthia A. LeardMann

Posttraumatic stress disorder (PTSD) is a prevalent condition among military service members and civilians who have experienced traumatic events. Stimulant use has been postulated to increase the risk of incident PTSD; however, research in this area is lacking. In this study, the association between receipt of prescription stimulants and PTSD was examined in a secondary analysis among active duty U.S. military members (n = 25,971), participating in the Millennium Cohort Study, who completed a baseline (2001-2003) and two follow-up surveys (between 2004-2008). Prescription stimulant data were obtained from the military Pharmacy Data Transaction Service. PTSD was assessed using the PTSD Checklist-Civilian Version and incident PTSD was defined as meeting the criteria at follow-up among those who did not have a history of PTSD at baseline. Overall, 1,215 (4.7%) persons developed new-onset PTSD during follow-up. Receipt of prescription stimulants were significantly associated with incident PTSD, hazard ratio = 5.09, 95% confidence interval [3.05, 8.50], after adjusting for sociodemographic factors, military characteristics, attention-deficit/hyperactivity disorder, baseline mental and physical health status, deployment experiences, and physical/sexual trauma. Findings suggested that prescription stimulants are associated with incident PTSD among military personnel; these data may inform the underlying pathogenesis of and preventive strategies for PTSD.


Global Public Health | 2018

Deportation of non-citizen military veterans: A critical analysis of implications for the right to health

Danielle Horyniak; Ietza Bojorquez; Richard F. Armenta; Peter J. Davidson

ABSTRACT Military personnel are commonly exposed to health-harming conditions during their service, resulting in higher rates of physical and mental health conditions compared with the general population. In an era of mass deportations, it is notable that non-citizen military veterans are not exempt from deportation. We utilised a human rights framework to conduct a critical analysis of potential health consequences of deportation for U.S. military veterans, identifying three ways in which veterans’ rights to health may be constrained through deportation. First, honourably discharged deported veterans may be denied access to free or subsidised Veterans Affairs health services to which they would likely otherwise be entitled. Second, availability of and access to healthcare may be limited for reasons including barriers to enrolling in public insurance schemes, challenges navigating unfamiliar health systems and stigma and discrimination towards deported migrants. Finally, quality of available care may be sub-optimal due to limited expertise in service-related health issues and lack of evidence-based treatment for some health conditions (e.g. substance abuse/dependence). Binational multi-sectoral efforts are necessary to ensure that the rights to health of deported military veterans are adequately protected.


Substance Use & Misuse | 2017

Cold Preparation of Heroin in a Black Tar Market

Alexis M. Roth; Richard F. Armenta; Karla D. Wagner; Steffanie A. Strathdee; Jesse L. Goldshear; Jazmine Cuevas-Mota; Richard S. Garfein

ABSTRACT Background: Black tar heroin is typically prepared for injection with heat which decreases the risk of HIV transmission by inactivating the virus. We received reports that persons who inject drugs (PWID) in Tijuana, Baja California, Mexico, a black tar heroin market, were using only water to dissolve heroin. Objectives: Because Tijuana abuts San Diego County, CA, United States, we undertook the present analyses to determine the prevalence of this practice among PWID in San Diego, California. Methods: PWID completed quarterly behavioral assessments and serological testing for blood-borne viruses. Bivariate and multivariable logistic regression models were constructed to assess for individual, social, and structural correlates of preparing heroin without heat within the preceding 6 months. Results: Nearly half of black tar heroin users (149/305) reported they had prepared heroin without heat within 6 months. In multivariable analysis, cold preparation was independently associated with younger age (10 year decrease; AOR = 1.25; 95% CI 1.03, 1.53), more drug injecting acquaintances (per 5 acquaintance increase; AOR = 1.05; 95% CI 1.01, 1.09) and prefilled syringe use (injecting drugs from syringes that are already filled with drugs before purchase; AOR = 1.86; 95% CI 1.14, 3.02). Conclusions/Importance: To our knowledge, this is the first paper to report that PWID living in a black tar heroin market are preparing heroin without heat. Additional research is needed to determine whether this is an endemic practice or PWID are engaging in new forms of drug preparation in response to changes in the environment.

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Cynthia A. LeardMann

Henry M. Jackson Foundation for the Advancement of Military Medicine

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