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ABSTRACTSex workers have been demonstrated to have increased vulnerabilities to HIV and a high population prevalence of the disease. Despite their increased risk, sex workers have been underrepresented in molecular epidemiology studies assessing HIV in Mesoamerica. This study aims to describe the sociodemographic characteristics and phylogenetic profile of HIV-1 within a cohort of HIV-positive female sex workers (FSW) situated at the Guatemala-Mexico border. HIV viral sequences were collected from a cohort of FSW ≥18 years of age from San Marcos, Guatemala (n = 6) and compared to viral sequences collected as part of the Mesoamerican Drug Resistance Monitoring Programme to assess HIV viral diversity in Mexico and Guatemala (n = 3956). All of the FSW sampled were determined to have genetically unrelated HIV infections, suggesting multiple introductions of the virus and/or the potential existence of populations not captured by current surveillance efforts. Many reported numerous vulnerabilities that may have heightened their risk of acquiring and transmitting HIV through sex work activities. Our phylogenetic analysis indicated that national surveillance programmes may not fully capture the viral diversity among FSW and their clients within this region. Additional research is needed to fully capture HIV diversity and transmission in Mesoamerica, especially in the Guatemala-Mexico border region.

Economic vulnerability is often reported to underlie involvement in sex work among female sex workers (FSW), but may also create urgency in women's work, limiting women's negotiating power with clients and in turn, increasing their vulnerability for violence and HIV. This study assessed economic vulnerability in relation to violence and sexual risk behaviors for HIV among a sample of FSW in Tijuana, Mexico. FSW at least 18 years of age were recruited through venue-based sampling for a survey (n = 228) and in-depth interviews (n = 50) to investigate HIV risk factors in this region. Using crude and adjusted logistic regression models, we assessed lack of financial support from others as well as reports of financial hardship separately in relation to experiencing sexual violence (e.g. by clients, police, relationship partners, in the past 6 months), physical violence (past 6 months), STI diagnosis, and inconsistent condom use (past 30 days). Qualitative interviews (n = 50), conducted with a subsample of the survey participants, were also examined for related themes. FSW who reported no financial support were more likely to report sexual violence (OR = 2.1; 95% CI:1.1-4.2). FSW who reported financial hardship were more likely to experience sexual violence (OR = 1.9; 95% CI:1.1-3.6) and physical violence (OR = 1.9; 95% CI:1.1-3.6), as well as to report past 30-day inconsistent condom use (OR = 2.4; 95%CI: 1.3-4.6) and to test positive for an STI (OR = 1.9; 95% CI:1.1-3.4). Qualitative data substantiated these findings. Findings suggest that interventions to improve economic well-being may be useful to prevent the intersecting concerns of violence and HIV among FSW.

Migration from Central America to the United States has become a strategy to escape economic poverty, exclusionary state policies and violence for people of Mayan descent. Under the principles Community Based Participatory Research, we explored the health concerns of Indigenous Mayans in rural migrant-sending communities of Guatemala using their own visual images and narratives through a Social Constructivist lens. Half of households in the study region have at least one member emigrated to the United States, making many "transnational families." Focus groups and photographs and narratives from 20 Photovoice participants, aged 16-65, revealed significant health challenges related to conditions of poverty. Drivers of immigration to the United States included lack of access to healthcare, lack of economic opportunity, and an inability to pay for children's education. Health implications of living in communities "left-behind" to immigration centered around changes in societal structure and values. Mental health challenges, sadness and loss were experienced by both children and adults left behind. An increase in substance use as a coping mechanism is described as increasingly common, and parental absence leaves aging grandparents raising children with less guidance and supervision. Lack of economic opportunity and parental supervision has left young adults vulnerable to the influence of cartel gangs that are well-established in this region. Findings from this study provide insight into challenges driving immigration, and the health impacts faced by rural, Indigenous communities left behind to international immigration. Results may inform research and interventions addressing disparities and strategies to cope with economic and health challenges.

Tobacco use disproportionately affects low-income communities. Prevalence among patients in Federally Qualified Health Centers (FQHCs) is higher (29.3%) than the general population (20%). Little is known about the rates of referrals to cessation services and cessation pharmacotherapy practices in FQHCs. This study will examine referral and prescribing patterns based on patient characteristics at a large FQHC in Southern California. We conducted a retrospective analysis of EHR data from 2019. Patients who were ≥ 18 years old and had "tobacco use" as an active problem were included in analyses. We characterized the proportion of 1) those who were referred to California Smokers' Helpline (CSH), 2) referred to smoking cessation counseling (SCC) at the FQHC clinic, or 3) received pharmacotherapy. Associations of demographic characteristics and comorbidities with referral types and uptake of services were evaluated using mixed-effects multinomial and logistic regressions. Of the 20,119 tobacco users identified, 87% had some cessation intervention: 66% were advised to quit and given information to contact CSH, while 21% were referred to SCC. Patients were least likely to get referred to cessation services if they had more medical, psychiatric, or substance use comorbidities, were in the lowest income group, were uninsured or were Hispanic. Although EHR systems have enhanced the ease of screening, most patients do not receive more than brief advice to quit during a PCP visit. Most (70%) low-income smokers see their PCPs at least once a year, making FQHCs excellent settings to promote smoking cessation initiatives in low-income populations.

Tijuana, Mexico, has a concentrated HIV epidemic among overlapping key populations (KPs) including people who inject drugs (PWID), female sex workers (FSW), their male clients, and men who have sex with men (MSM). We developed a dynamic HIV transmission model among these KPs to determine the extent to which their unmet prevention and treatment needs is driving HIV transmission. Over 2020-2029 we estimated the proportion of new infections acquired in each KP, and the proportion due to their unprotected risk behaviours. We estimate that 43.7% and 55.3% of new infections are among MSM and PWID, respectively, with FSW and their clients making-up

OBJECTIVES:: In Tijuana, Mexico, sex work is regulated by the municipal health department and includes regular testing for HIV and other sexually transmitted infections (STIs) for registered female sex workers (FSWs). However, Pap testing is missing from current sexual health assessments. We aimed to answer the following research questions: 1.) What is the prevalence of cervical abnormalities among a sample of FSWs in Tijuana, Mexico? 2.) What are the correlates of cervical abnormalities among a sample of FSWs in Tijuana, Mexico? STUDY DESIGN:: From 2013-2014, a cohort of 300 FSWs in Tijuana, Mexico were recruited using modified time-location sampling. Participants were given Pap, HIV, and STI tests. RESULTS:: The prevalence of an abnormal Pap was 11.7% (35/300). FSWs ever registered with municipal health services were less likely to have an abnormal Pap result (4.8% vs 14.4%, p=0.03), were more likely to report a previous Pap test (88.1% vs 70.4%, p=.001), and were more likely to report a sexual health checkup in the last year (60.7% vs 37.0%, p

Introduction and aimsSmoking methamphetamine is associated with increased risk of HIV among female sex workers (FSW). The structural context of substance use is an important shaper of individual behaviour; however, structural determinants of methamphetamine use among FSWs are largely unknown. We identified individual, structural and neighbourhood factors associated with smoking methamphetamine among FSWs in the border city of Tijuana, Baja California, Mexico.Design and methodsA prospective cohort of 301 FSWs sampled from indoor and outdoor sex work venues throughout Tijuana participated in quantitative surveys on behaviours and mapping of home and work neighbourhoods across three visits. Multinomial logistic regression using generalised estimating equations identified individual, structural and neighbourhood variables associated with smoking methamphetamine.ResultsMethamphetamine use, particularly smoking, was highly prevalent among FSWs. Over half (61%) of FSWs had ever used methamphetamine in their lifetime and at baseline, 38% currently smoked methamphetamine. Smoking methamphetamine daily was associated with living in the red light district [adjusted odds ratio (AOR) = 2.72, 95% confidence interval (CI) = 1.23-6.02] and with perceived homelessness, but only among women in a good financial situation (AOR = 4.08, 95% CI = 1.58-10.50). Smoking methamphetamine less than daily was associated with older age (AOR = 1.06, 95% CI = 1.02-1.10).Discussion and conclusionsOur findings point to the important dynamic between the residential environment and more severe methamphetamine use. FSWs may prioritise the purchase of methamphetamine over stable housing if they have the financial means. Given the high prevalence of smoking methamphetamine among FSWs in Tijuana, drug treatment options, especially for women living in the red light district, are needed.

The current wave of interest in human trafficking and the commercial sexual exploitation of children has exposed a lack of knowledge about the vulnerabilities leading to underage entry into sex work. This knowledge is necessary for the development of effective prevention programs to identify girls who are most at-risk, especially in Latin America, a region that is believed to be a large source of persons moved across international borders for the purposes of sexual and labor exploitation. The objective of this study was to explore and increase understanding of the vulnerability factors and pathways leading to underage entry into sex work experienced by women currently engaging in sex work in two cities on the northern border of Mexico. From August 2013 to October 2014, 20 female sex workers (FSWs) with a history of entry into sex work prior to age 18 were recruited for in-depth interviews from a larger time-location sample of female sex workers (FSWs) participating in a quantitative survey in Tijuana and Ciudad Juarez. The median age of entry into sex work was 14 (range 10-17); 12/21 participants reported being forced into sex work and, of these, 7 were transported to another city where they began engaging in sex work. Family dysfunction (e.g., domestic violence between parents, parent drug use, neglect, etc.), sexual and physical abuse, and teen pregnancy were among the key themes that emerged as vulnerabilities to underage entry into sex work. Women's narratives clearly illustrated that the vulnerabilities and pathways leading to underage entry are manifold, complex, and often intersect with each other. Our findings begin to lay the groundwork for understanding the potential vulnerabilities and pathways leading to underage entry into sex, and may have relevance to Latin America in general. This study also provides a foundation for further research to explore what may mitigate these vulnerabilities as well as creating evidence-based interventions to prevent commercial sexual exploitation of minors in the region.

BackgroundGlobally, female sex workers (FSWs) have been identified as a high-risk group for human immunodeficiency virus (HIV) and sexually transmitted infections (STIs). However, as women of reproductive age, FSWs also have children. Few studies have investigated if financial responsibilities associated with motherhood increase women's vulnerability to HIV and STIs among FSWs.MethodsFrom March 2013 to March 2014, 603 FSWs aged ≥18 years were recruited from Tijuana and Ciudad Juarez (Mexico) to participate in a study assessing HIV/STI risk environments.ResultsFindings from logistic regression models indicate that FSWs who reported motherhood were more likely to report (in the past 30 days): a higher client volume (>30 clients) (adjusted odds ratio [AOR], 1.91; 95% confidence interval [CI], 1.27-2.87) and always using alcohol right before or during sex with clients in the past 30 days (AOR, 1.77; 95% CI, 1.19-2.61). In contrast, they were more likely to report consistent condom use for vaginal or anal sex with clients (AOR, 1.68; 95% CI, 1.10-2.55), less likely to report using drugs right before or during sex with clients (AOR, 0.38; 95% CI, 0.26-0.56) and less likely to have tested positive for STIs at baseline (AOR, 0.63; 95% CI, 0.43-0.91).ConclusionsThese results provide a glimpse of the complex relationship between motherhood and women who are sex workers. Understanding the convergence of motherhood and sex work and how this can influence a woman's decision when engaging in sex work and affect her health is essential to designing effective programs addressing reduce risk for HIV and STIs among FSWs in this region and elsewhere.

BackgroundAs geospatial data have become increasingly integral to health and human rights research, their collection using formal address designations or paper maps has been complicated by numerous factors, including poor cartographic literacy, nomenclature imprecision, and human error. As part of a longitudinal study of people who inject drugs in Tijuana, Mexico, respondents were prompted to georeference specific experiences.ResultsAt baseline, only about one third of the 737 participants were native to Tijuana, underscoring prevalence of migration/deportation experience. Areas frequented typically represented locations with no street address (e.g. informal encampments). Through web-based cartographic technology and participatory mapping, this study was able to overcome the use of vernacular names and difficulties mapping liminal spaces in generating georeferenced data points that were subsequently analyzed in other research.ConclusionIntegrating low-threshold virtual navigation as part of data collection can enhance investigations of mobile populations, informal settlements, and other locations in research into structural production of health at low- or no cost. However, further research into user experience is warranted.

Human migration has been identified as a potential factor for increased Chagas disease risk and has transformed the disease from a Latin American problem to a global one. We conducted a systematic review of the scientific literature between 2004-2014 in order to: summarize recent seroprevalence estimates of Chagas disease among Latin American migrants, in both endemic and non-endemic settings; compare seroprevalence estimates in migrants to countrywide prevalence estimates; and identify risk factors for Chagas disease among migrants. A total of 320 studies were screened and 23 studies were included. We found evidence that the prevalence of Chagas disease is higher than expected in some migrant groups and that reliance on blood donor screening prevalence estimates underestimates the burden of disease. Overall there is a dearth of high quality epidemiologic studies on the prevalence of Chagas disease in migrants, especially among intra-regional migrants within Latin America. Given that this zoonotic disease cannot likely be eradicated, improved surveillance and reporting is vital to continuing control efforts. More accurate health surveillance of both Latin American migrants and the Chagas disease burden will help countries appropriately scale up their response to this chronic disease. Overall, improved estimates of Chagas disease among migrants would likely serve to highlight the real need for better screening, diagnostics, and treatment of individuals living with the disease.

Female sex workers (FSWs) are disproportionately affected by both HIV and gender-based violence, such as that perpetrated by clients (CPV). We used a structural determinants framework to assess correlates of physical or sexual CPV in the past 6 months among FSWs in the Mexico/U.S. border cities of Ciudad Juárez and Tijuana. Bivariate and multivariate logistic regression analysis identified individual, client, interpersonal, work environment and macrostructural factors associated with recent CPV. Among 496 FSWs, 5 % experienced recent CPV. Witnessing violence towards other FSWs in one's neighborhood (aOR 5.6, 95 % CI 1.8-17.2), having a majority of foreign (aOR 3.5, 95 % CI 1.4-8.4) or substance using (aOR 4.0, 95 % CI 1.5-10.4) clients, and being a street worker (aOR 3.0, 95 % CI 1.1-7.7) were independently associated with recent CPV. Our findings underscore the vulnerability of FSWs and the need to design policies and interventions addressing macro-level influences on CPV rather than exclusively targeting individual behaviors.

Large scale antibody responses in Plasmodium vivax malaria remains unexplored in the endemic setting. Protein microarray analysis of asexual-stage P. vivax was used to identify antigens recognized in sera from residents of hypoendemic Peruvian Amazon. Over 24 months, of 106 participants, 91 had two symptomatic P. vivax malaria episodes, 11 had three episodes, 3 had four episodes, and 1 had five episodes. Plasmodium vivax relapse was distinguished from reinfection by a merozoite surface protein-3α restriction fragment length polymorphism polymerase chain reaction (MSP3α PCR-RFLP) assay. Notably, P. vivax reinfection subjects did not have higher reactivity to the entire set of recognized P. vivax blood-stage antigens than relapse subjects, regardless of the number of malaria episodes. The most highly recognized P. vivax proteins were MSP 4, 7, 8, and 10 (PVX_003775, PVX_082650, PVX_097625, and PVX_114145); sexual-stage antigen s16 (PVX_000930); early transcribed membrane protein (PVX_090230); tryptophan-rich antigen (Pv-fam-a) (PVX_092995); apical merozoite antigen 1 (PVX_092275); and proteins of unknown function (PVX_081830, PVX_117680, PVX_118705, PVX_121935, PVX_097730, PVX_110935, PVX_115450, and PVX_082475). Genes encoding reactive proteins exhibited a significant enrichment of non-synonymous nucleotide variation, an observation suggesting immune selection. These data identify candidates for seroepidemiological tools to support malaria elimination efforts in P. vivax-endemic regions.

BackgroundHIV sequence data can be used to reconstruct local transmission networks. Along international borders, like the San Diego-Tijuana region, understanding the dynamics of HIV transmission across reported risks, racial/ethnic groups, and geography can help direct effective prevention efforts on both sides of the border.MethodsWe gathered sociodemographic, geographic, clinical, and viral sequence data from HIV infected individuals participating in ten studies in the San Diego-Tijuana border region. Phylogenetic and network analysis was performed to infer putative relationships between HIV sequences. Correlates of identified clusters were evaluated and spatiotemporal relationships were explored using Bayesian phylogeographic analysis.FindingsAfter quality filtering, 843 HIV sequences with associated demographic data and 263 background sequences from the region were analyzed, and 138 clusters were inferred (2-23 individuals). Overall, the rate of clustering did not differ by ethnicity, residence, or sex, but bisexuals were less likely to cluster than heterosexuals or men who have sex with men (p = 0.043), and individuals identifying as white (p ≤ 0.01) were more likely to cluster than other races. Clustering individuals were also 3.5 years younger than non-clustering individuals (p < 0.001). Although the sampled San Diego and Tijuana epidemics were phylogenetically compartmentalized, five clusters contained individuals residing on both sides of the border.InterpretationThis study sampled ~ 7% of HIV infected individuals in the border region, and although the sampled networks on each side of the border were largely separate, there was evidence of persistent bidirectional cross-border transmissions that linked risk groups, thus highlighting the importance of the border region as a "melting pot" of risk groups.FundingNIH, VA, and Pendleton Foundation.

BackgroundAlthough most people who inject drugs (PWID) in Tijuana, Mexico, primarily inject heroin, injection and non-injection use of methamphetamine and cocaine is common. We examined patterns of polydrug use among heroin injectors to inform prevention and treatment of drug use and its health and social consequences.MethodsParticipants were PWID residing in Tijuana, aged ≥18 years who reported heroin injection in the past six months and were recruited through respondent-driven sampling (n = 1,025). Latent class analysis was conducted to assign individuals to classes on a probabilistic basis, using four indicators of past six-month polydrug and polyroute use: cocaine injecting, cocaine smoking or snorting, methamphetamine injecting, and methamphetamine smoking or snorting. Latent class membership was regressed onto covariates in a multinomial logistic regression.ResultsLatent class analyses testing 1, 2, 3, and 4 classes were fit, with the 3-class solution fitting best. Class 1 was defined by predominantly heroin use (50.2%, n = 515); class 2 by methamphetamine and heroin use (43.7%, n = 448), and class 3 by methamphetamine, cocaine, and heroin use (6.0%, n = 62). Bivariate and multivariate analyses indicated a group of methamphetamine and cocaine users that exhibited higher-risk sexual practices and lower heroin injecting frequency, and a group of methamphetamine users who were younger and more likely to be female.ConclusionsDiscrete subtypes of heroin PWID were identified based on methamphetamine and cocaine use patterns. These findings have identified subtypes of heroin injectors who require more tailored interventions to reduce the health and social harms of injecting drug use.

Respondent-driven sampling's (RDS) widespread use and reliance on untested assumptions suggests a need for new exploratory/diagnostic tests. We assessed geographic recruitment bias and outcome-correlated recruitment among 1,048 RDS-recruited people who inject drugs (Tijuana, Mexico). Surveys gathered demographics, drug/sex behaviors, activity locations, and recruiter-recruit pairs. Simulations assessed geographic and network clustering of active syphilis (RPR titers ≥1:8). Gender-specific predicted probabilities were estimated using logistic regression with GEE and robust standard errors. Active syphilis prevalence was 7 % (crude: men = 5.7 % and women = 16.6 %; RDS-adjusted: men = 6.7 % and women = 7.6 %). Syphilis clustered in the Zona Norte, a neighborhood known for drug and sex markets. Network simulations revealed geographic recruitment bias and non-random recruitment by syphilis status. Gender-specific prevalence estimates accounting for clustering were highest among those living/working/injecting/buying drugs in the Zona Norte and directly/indirectly connected to syphilis cases (men: 15.9 %, women: 25.6 %) and lowest among those with neither exposure (men: 3.0 %, women: 6.1 %). Future RDS analyses should assess/account for network and spatial dependencies.

In global health, critical challenges have arisen from infectious diseases, including the emergence and reemergence of old and new infectious diseases. Emergence and reemergence are accelerated by rapid human development, including numerous changes in demographics, populations, and the environment. This has also led to zoonoses in the changing human-animal ecosystem, which are impacted by a growing globalized society where pathogens do not recognize geopolitical borders. Within this context, neglected tropical infectious diseases have historically lacked adequate attention in international public health efforts, leading to insufficient prevention and treatment options. This subset of 17 infectious tropical diseases disproportionately impacts the world's poorest, represents a significant and underappreciated global disease burden, and is a major barrier to development efforts to alleviate poverty and improve human health. Neglected tropical diseases that are also categorized as emerging or reemerging infectious diseases are an even more serious threat and have not been adequately examined or discussed in terms of their unique risk characteristics. This review sets out to identify emerging and reemerging neglected tropical diseases and explore the policy and innovation environment that could hamper or enable control efforts. Through this examination, we hope to raise awareness and guide potential approaches to addressing this global health concern.

BackgroundSubstance use and HIV are growing problems in the Mexico-U.S. border city of Tijuana, a sex tourism destination situated on a northbound drug trafficking route. In a previous longitudinal study of injection drug users (IDUs), we found that >90% of incident HIV cases occurred within an 'HIV incidence hotspot,' consisting of 2.5-blocks. This study examines behavioral, social, and environmental correlates associated with injecting in this HIV hotspot.MethodsFrom 4/06 to 6/07, IDUs aged ≥18 years were recruited using respondent-driven sampling. Participants underwent antibody testing for HIV and syphilis and interviewer-administered surveys eliciting information on demographics, drug use, sexual behaviors, and socio-environmental influences. Participants were defined as injecting in the hotspot if they most frequently injected within a 3 standard deviational ellipse of the cohort's incident HIV cases. Logistic regression was used to identify individual and structural factors associated with the HIV 'hotspot'.ResultsOf 1031 IDUs, the median age was 36 years; 85% were male; HIV prevalence was 4%. As bivariate analysis indicated different correlates for males and females, models were stratified by sex. Factors independently associated with injecting in the HIV hotspot for male IDUs included homelessness (AOR 1.72; 95%CI 1.14-2.6), greater intra-urban mobility (AOR 3.26; 95%CI 1.67-6.38), deportation (AOR 1.58; 95%CI 1.18-2.12), active syphilis (AOR 3.03; 95%CI 1.63-5.62), needle sharing (AOR 0.57; 95%CI 0.42-0.78), various police interactions, perceived HIV infection risk (AOR 1.52; 95%CI 1.13-2.03), and health insurance status (AOR 0.53; 95%CI 0.33-0.87). For female IDUs, significant factors included sex work (AOR 8.2; 95%CI 2.2-30.59), lifetime syphilis exposure (AOR 2.73; 95%CI 1.08-6.93), injecting inside (AOR 5.26; 95%CI 1.54-17.92), arrests for sterile syringe possession (AOR 4.87; 95%I 1.56-15.15), prior HIV testing (AOR 2.45; 95%CI 1.04-5.81), and health insurance status (AOR 0.12; 95%CI 0.03-0.59).ConclusionWhile drug and sex risks were common among IDUs overall, policing practices, STIs, mobility, and lack of healthcare access were correlated with injecting in this HIV transmission hotspot. Although participants in the hotspot were more aware of HIV risks and less likely to report needle sharing, interventions addressing STIs and structural vulnerabilities may be needed to effectively address HIV risk.

Abstract Background Female sex workers (FSW) are at increased risk for HIV and other STI due to occupation-related risks and exposures. Long-distance truck drivers have been implicated in the spread of HIV, but less is known about HIV/STI risks of FSW servicing truck drivers, especially in North America. As part of an international collaborative pilot study, we interviewed FSWs servicing truck driver clients along two major transportation corridors to explore factors associated with recent STI symptoms. Methods A cross-sectional study of 200 FSW was conducted in Mexico: 100 from Nuevo Laredo (U.S. border); 100 from Ciudad Hidalgo (Guatemalan border). Eligibility criteria included age ≥18 years, speaking English or Spanish, and having ≥1 truck driver client in the past month. The main outcome was reporting any recent STI symptoms, defined as experiencing genital/anal warts, genital ulcers/sores, genital itching, or abnormal vaginal discharge in the past 6 months. Logistic regression was used to identify correlates of recent STI symptoms. Results Median age of FSW was 29 years, 74% were single, 87% had

Abstract Background The geographical congruency in distribution of helminths and Plasmodium falciparum makes polyparasitism a common phenomenon in Sub Saharan Africa. The devastating effects of helminths-Plasmodium co-infections on primary school health have raised global interest for integrated control. However little is known on the feasibility, timing and efficacy of integrated helminths-Plasmodium control strategies. A study was conducted in Zimbabwe to evaluate the efficacy of repeated combined school based antihelminthic and prompt malaria treatment. Methods A cohort of primary schoolchildren (5-17 years) received combined Praziquantel, albendazole treatment at baseline, and again during 6, 12 and 33 months follow up surveys and sustained prompt malaria treatment. Sustained prompt malaria treatment was carried out throughout the study period. Children's infection status with helminths, Plasmodium and helminths-Plasmodium co-infections was determined by parasitological examinations at baseline and at each treatment point. The prevalence of S. haematobium, S. mansoni, STH, malaria, helminths-Plasmodium co-infections and helminths infection intensities before and after treatment were analysed. Results Longitudinal data showed that two rounds of combined Praziquantel and albendazole treatment for schistosomiasis and STHs at 6 monthly intervals and sustained prompt malaria treatment significantly reduced the overall prevalence of S. haematobium, S. mansoni, hookworms and P. falciparum infection in primary schoolchildren by 73.5%, 70.8%, 67.3% and 58.8% respectively (p < 0.001, p < 0.001, p < 0.001, p < 0.001 respectively). More importantly, the prevalence of STH + schistosomes, P. f + schistosomes, and P. f + STHs + schistosomes co-infections were reduced by 68.0%, 84.2%, and 90.7%, respectively. The absence of anti-helminthic treatment between the 12 mth and 33 mth follow-up surveys resulted in the sharp increase in STHs + schistosomes co-infection from 3.3% at 12 months follow up survey to 10.7%, slightly more than the baseline level (10.3%) while other co-infection combinations remained significantly low. The overall prevalence of heavy S. haematobium, S. mansoni and hookworms infection intensities were significantly reduced from: 17.9-22.4% to 2.6-5.1%, 1.6-3.3% to 0.0% and 0.0-0.7% to 0.0% respectively. Conclusion Biannual Integrated school based antihelminthic and sustained prompt malaria treatment has a potential to reduce the burden of helminths-plasmodium co-infections in primary school children. In areas of stable malaria transmission, active case finding is recommended to track and treat asymptomatic malaria cases as these may sustain transmission in the community.

Abstract Background Helminth infection rates in grade three children are used as proxy indicators of community infection status and to guide treatment strategies in endemic areas. However knowledge, attitudes and practices (KAP) of this target age group (8-10 years) in relation to schistosomiasis, soil transmitted helminthiasis (STHs) and malaria is not known at a time when integrated plasmodium - helminth control strategies are being advocated. This study sought to assess KAP of grade 3 children in relation to schistosomiasis, STHs and malaria in order to establish an effective school based health education for disease transmission control. Methods Grade 3 children (n = 172) attending four randomly selected primary schools (one in rural and 3 in the commercial farming areas) in Zimbabwe were interviewed using a pre-tested interviewer administered questionnaire. The urine filtration technique was used to determine S. haematobium infection status. Infection with S. mansoni and STHs was determined using a combination of results from the Kato Katz and formol ether concentration techniques. P. falciparum was diagnosed by examination of Giemsa stained thick blood smears. Results It was observed that 32.0%, 19.2% and 4.1% of the respondents had correct knowledge about the causes of schistosomiasis, malaria and STHs, respectively, whilst 22.1%, 19.2% and 5.8% knew correct measures to control schistosomiasis, malaria and STHs. Sixty-two percent and 44.8% did not use soap to wash hands after toilet and before eating food respectively, whilst 33.1% never wore shoes. There were no functional water points and soap for hand washing after toilet at all schools. There was a high prevalence distribution of all parasites investigated in this study at Msapa primary school - S. haematobium (77.8%), S. mansoni (33.3%) hookworms (29.6%) and P. falciparum (48.1%). Reports that participant had suffered from schistosomiasis and malaria before were significant predictors of these diseases (p = 0.001 and p = 0.042, respectively). Report that participant had blood in urine on the day of examination was a significant predictor of schistosomiasis (p = 0.045). Conclusion There is a critical need for targeting health messages through schools in order to reach the most susceptible schoolchildren. This will empower the schoolchildren with the basic knowledge and skills ultimately protecting them from acquiring schistosomiasis, STHs and malaria.

Abstract Background Sterile syringe access is a critical component of HIV prevention programs. Although retail pharmacies provide convenient outlets for syringe access, injection drug users (IDUs) may encounter barriers to syringe purchase even where purchase without a prescription is legal. We sought to obtain an objective measure of syringe access in Tijuana, Mexico, where IDUs report being denied or overcharged for syringes at pharmacies. Methods Trained "mystery shoppers" attempted to buy a 1 cc insulin syringe according to a predetermined script at all retail pharmacies in three Tijuana neighborhoods. The same pharmacies were surveyed by telephone regarding their syringe sales policies. Data on purchase attempts were analyzed using basic statistics to obtain an objective measure of syringe access and compared with data on stated sales policies to ascertain consistency. Results Only 46 (28.4%) of 162 syringe purchase attempts were successful. Leading reasons for unsuccessful attempts were being told that the pharmacy didn't sell syringes (35.3%), there were no syringes in stock (31.0%), or a prescription was required (20.7%). Of 136 pharmacies also surveyed by telephone, a majority (88.2%) reported selling syringes but only one-third (32.5%) had a successful mystery shopper purchase; the majority of unsuccessful purchases were attributed to being told the pharmacy didn't sell syringes. There was similar discordance regarding prescription policies: 74 pharmacies said in the telephone survey that they did not require a prescription for syringes, yet 10 of these pharmacies asked the mystery shopper for a prescription. Conclusions IDUs in Tijuana have limited access to syringes through retail pharmacies and policies and practices regarding syringe sales are inconsistent. Reasons for these restrictive and inconsistent practices must be identified and addressed to expand syringe access, reduce syringe sharing and prevent HIV transmission.

Background Although previous data indicate that the overall incidence of human leptospirosis in the Peruvian Amazon is similar in urban and rural sites, severe leptospirosis has been observed only in the urban context. As a potential explanation for this epidemiological observation, we tested the hypothesis that concentrations of more virulent Leptospira would be higher in urban than in rural environmental surface waters. Methods and Findings A quantitative real-time PCR assay was used to compare levels of Leptospira in urban and rural environmental surface waters in sites in the Peruvian Amazon region of Iquitos. Molecular taxonomic analysis of a 1,200-bp segment of the leptospiral 16S ribosomal RNA gene was used to identify Leptospira to the species level. Pathogenic Leptospira species were found only in urban slum water sources ( Fisher's exact test; p = 0.013). The concentration of pathogen-related Leptospira was higher in urban than rural water sources (similar to 10(3) leptospires/ml versus 0.5 x 10(2) leptospires/ml; F = 8.406, p < 0.05). Identical 16S rRNA gene sequences from Leptospira interrogans serovar Icterohaemorrhagiae were found in urban slum market area gutter water and in human isolates, suggesting a specific mode of transmission from rats to humans. In a prospective, population- based study of patients presenting with acute febrile illness, isolation of L. interrogans-related leptospires from humans was significantly associated with urban acquisition (75% of urban isolates); human isolates of other leptospiral species were associated with rural acquisition (78% of rural isolates) (chi-square analysis; p < 0.01). This distribution of human leptospiral isolates mirrored the distribution of leptospiral 16S ribosomal gene sequences in urban and rural water sources. Conclusions Our findings data support the hypothesis that urban severe leptospirosis in the Peruvian Amazon is associated with higher concentrations of more pathogenic leptospires at sites of exposure and transmission. This combined quantitative and molecular taxonomical risk assessment of environmental surface waters is globally applicable for assessing risk for leptospiral infection and severe disease in leptospirosis-endemic regions.