The global epidemiology of HIV/AIDS

Co-infection dynamics of COVID-19 and HIV/AIDS

Although there are many results that can be used to treat and prevent Coronavirus Disease 2019 (COVID-19) and Human Immunodeficiency Virus (HIV), these diseases continue to be public health concerns and cause socioeconomic consequences. Following compromised immunity, COVID-19 is considered to be a challenge for people with HIV. People with advanced HIV are considered a vulnerable population at high risk in several case studies that discuss COVID-19 and HIV co-infection. As there is no cure for HIV and there is a chance of contracting COVID-19 again, co-infection continues to pose a problem. The purpose of this study is to investigate the impact of intervention strategies and identify the role of different parameters in risking people living with HIV to death when they get infected with COVID-19. This is achieved through the development and rigorous analysis of a mathematical model that considers a population at risk of death due to COVID-19 and HIV. The model formulation provides a detailed explanation of the transmission dynamics of COVID-19 and HIV co-infection. The solution's invariant region, positivity, and boundedness were established. The reproduction numbers of the sub-models and the co-infection model were determined. The existence and stability of equilibria, including backward bifurcation for the COVID-19 sub-model, were examined. The epidemiological significance of backward bifurcation is that the condition [Formula: see text] less than 1 for eliminating COVID-19, though necessary, is no longer sufficient. Parametric estimation and curve fitting were performed based on data from Ethiopia. Numerical simulations were employed to support and clarify the analytical findings and to show some parameter effects on COVID-19 and HIV co-infection. Accordingly, the simulations indicated that parameters [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text], related to HIV patients' exposure to other diseases and the increase in infectiousness, have a positive role in increasing the number of co-infections. On the other hand, an increase in COVID-19 vaccination ([Formula: see text]) shows the suppression of co-infection cases. In addition, treating co-infected individuals for COVID-19, increasing treatment rates [Formula: see text] and [Formula: see text], reduces the death risk of HIV-infected individuals due to the co-infection burden. It was implied that improving vaccine delivery programs and other medical interventions have important contributions to lowering the risk of COVID-19 infection-related fatalities in HIV patients.

HIV-1 Tat amino acid residues that influence Tat-TAR binding affinity: a scoping review

HIV-1 remains a global health concern and to date, nearly 38 million people are living with HIV. The complexity of HIV-1 pathogenesis and its subsequent prevalence is influenced by several factors including the HIV-1 subtype. HIV-1 subtype variation extends to sequence variation in the amino acids of the HIV-1 viral proteins. Of particular interest is the transactivation of transcription (Tat) protein due to its key function in viral transcription. The Tat protein predominantly functions by binding to the transactivation response (TAR) RNA element to activate HIV-1 transcriptional elongation. Subtype-specific Tat protein sequence variation influences Tat-TAR binding affinity. Despite several studies investigating Tat-TAR binding, it is not clear which regions of the Tat protein and/or individual Tat amino acid residues may contribute to TAR binding affinity. We, therefore, conducted a scoping review on studies investigating Tat-TAR binding. We aimed to synthesize the published data to determine (1) the regions of the Tat protein that may be involved in TAR binding, (2) key Tat amino acids involved in TAR binding and (3) if Tat subtype-specific variation influences TAR binding. A total of thirteen studies met our inclusion criteria and the key findings were that (1) both N-terminal and C-terminal amino acids outside the basic domain (47-59) may be important in increasing Tat-TAR binding affinity, (2) substitution of the amino acids Lysine and Arginine (47-59) resulted in a reduction in binding affinity to TAR, and (3) none of the included studies have investigated Tat subtype-specific substitutions and therefore no commentary could be made regarding which subtype may have a higher Tat-TAR binding affinity. Future studies investigating Tat-TAR binding should therefore use full-length Tat proteins and compare subtype-specific variations. Studies of such a nature may help explain why we see differential pathogenesis and prevalence when comparing HIV-1 subtypes.

Incidence and Predictors of Hypertension Among HIV Patients Receiving ART at Public Health Facilities, Northwest Ethiopia: A One-Year Multicenter Prospective Follow-Up Study

Background

The introduction of highly active retroviral therapy has dramatically reduced mortality and improved survival among HIV patients. However, there is a possible risk of comorbid complications such as hypertension. Little evidence is available regarding the incidence of hypertension among HIV patients receiving anti-retroviral therapy in Ethiopia.

Purpose

To assess the incidence and predictors of hypertension among HIV positive patients receiving ART at Public Health Facilities, Northwest Ethiopia.

Patients and Methods

A one-year prospective follow-up study was conducted among a cohort of 302 new adult individuals initiating on a standard anti-retroviral therapy regimen with a median (IQR) age of 35 years (IQR=30-41). A pretested data extraction checklist was used to extract baseline patient records. The collected data were entered into Epi-Data version 3.1 and exported to STATA version 14 for analysis. The incidence rate was calculated, and a Kaplan-Meier survival curve was used to estimate the survival probabilities of developing hypertension. Cox proportional hazards model was fitted to identify the predictors of hypertension.

Results

About 40 (13.25) new hypertensive cases were observed during the follow-up period, and the remaining 262 (86.75%) were censored. The overall incidence rate of hypertension was 16.35 per 1000 person-month with 2447 patient-month observations. Male sex (AHR = 2.45, 95% CI: 1.02, 6.14), old age (AHR = 2.83, 95% CI: 1.08, 7.45), high BMI (AHR = 6.54, 95% CI: 2.03, 21.13), diabetic comorbidity (AHR = 2.36, 95% CI: 1.07, 5.22), and patients who were on Zidovudine (AZT)-based ART regimen (AHR =3.47, 95% CI: 1.10, 10.94) were significant predictors for the development of hypertension.

Conclusion

The findings of this study revealed that incident hypertension is a common problem among HIV patients receiving ART. Routine monitoring of blood pressure and screening and treating high blood pressure should be an integral part of follow-up for HIV patients in ART clinics.

A Review on Quinoline Derived Scaffolds as Anti-HIV Agents

After restricting the proliferation of CD4+T cells, Human Immunodeficiency Virus (HIV), infection persists at a very fast rate causing Acquired Immunodeficiency Syndrome (AIDS). This demands the vigorous need of suitable anti-HIV agents, as existing medicines do not provide a complete cure and exhibit drawbacks like toxicities, drug resistance, side-effects, etc. Even the introduction of Highly Active Antiretroviral Therapy (HAART) failed to combat HIV/AIDS completely. The major breakthrough in anti-HIV discovery was marked with the discovery of raltegravir in 2007, the first integrase (IN) inhibitor. Thereafter, the discovery of elvitegravir, a quinolone derivative emerged as the potent HIV-IN inhibitor. Though many more classes of different drugs that act as anti-HIV have been identified, some of which are under clinical trials, but the recent serious focus is still laid on quinoline and its analogues. In this review, we have covered all the quinoline-based derivatives that inhibit various targets and are potential anti-HIV agents in various phases of the drug discovery.

Diagnosis and treatment of tuberculosis of the foot and ankle-A literature review

Foot osteoarticular tuberculosis is uncommon. Late diagnosis and sub-optimal management can lead to significant morbidity, deformity and even death. Preservation of life, limb and function can be achieved with prompt diagnosis and treatment. In 1882, Robert Koch published his discovery of mycobacterium tuberculosis as the causative agent of tuberculosis (TB), and showed the disease was infectious rather than inherited. Over two centuries later, TB remains one of the top 10 causes of death worldwide. Whilst in 90% of cases TB infects the respiratory system, in 10% it is extrapulmonary and can infect the skeletal, nervous, lymphatic and genitourinary systems. The spine is the most frequently affected site in the musculoskeletal system and this is known as Pott's disease. The foot and ankle is affected in only 0.13% cases of extrapulmonary TB. A high index of suspicion is thus required. This infrequency in incidence, heterogeneity of its presentation along with the difficulty in early diagnosis often causes significant delays in its treatment and hence results in a considerable disability. The medical treatment is well established but the role of surgery, its usefulness and its correct timing remain controversial. The main diagnostic issues include imaging being non-specific. Plain radiographs remain the first line imaging modality. MRI and CT scans provide greater detail and capture the disease at an earlier stage. Microbiological testing has low sensitivity and specificity becasue TB lesions are paucibacillary. Bone biopsy is of significant diagnostic value as it not only allows histological examination to detect granulomas but enables sensitivity and resistance testing of anti-tuberculous therapy (ATT). Issues relating to treatment include timing, duration, combination of chemotherapy and the challenge of multi drug resistant tuberculosis MDR-TB. The selection and timing of appropriate surgical techniques and optimal duration of follow-up are further points to consider. In this article we aim to review the literature on diagnosis and treatment of foot and ankle TB.

Vaccine-Associated Maintenance of Epithelial Integrity Correlated With Protection Against Virus Entry

To identify the mechanisms by which human immunodeficiency virus type 1 (HIV-1) might penetrate the epithelial barrier during sexual transmission to women and the mechanisms of vaccine-associated protection against entry, we characterized early epithelial responses to vaginal inoculation of simian immunodeficiency virus strain mac251 (SIVmac251) in naive or SIVmac239Δnef-vaccinated rhesus macaques. Vaginal inoculation induced an early stress response in the cervicovaginal epithelium, which was associated with impaired epithelial integrity, damaged barrier function, and virus and bacterial translocation. In vaccinated animals, early stress responses were suppressed, and the maintenance of epithelial barrier integrity correlated with prevention of virus entry. These vaccine-protective effects were associated with a previously described mucosal system for locally producing and concentrating trimeric gp41 antibodies at the mucosal interface and with formation of SIV-specific immune complexes that block the stress responses via binding to the epithelial receptor FCGR2B and subsequent inhibitory signaling. Thus, blocking virus entry may be one protective mechanism by which locally concentrated non-neutralizing Ab might prevent HIV sexual transmission to women.

High antiretroviral therapy service delivery satisfaction and its' associated factors at Midre-genet hospital; Northwest Tigray, Ethiopia

Background

Patient’s satisfaction occurs when patients feel their needs and expectations are being meet by the service delivery they receive in health institutions. The Objective of this research was to assess HIV/AIDS patients’ satisfaction with antiretroviral therapy service delivery and its associated factors at Midre – Genet hospital, Northwest Tigray, Ethiopia.

Methods

Institutional based cross-sectional study was conducted. Four hundred twenty study respondents were selected using systematic random sampling technique. Data was collected using pretested, structured interview questionnaire. Bivariate analysis was conducted to identify potential significantly associated variables and transferred to multivariate logistic regression analysis. P value < 0.05 is used to demarcate significantly associated variables.

Result

The overall HIV/AIDS patients’satisfaction on antiretroviral therapy service delivery at Midre-Genet referral hospital was 75.2%. Multivariate analysis revealed age, marital status, occupation, income, information provision and guidance, privacy, access of toilets and interpersonal communication as significantly associated factors with patient’s satisfaction on ART service delivery.

Conclusion

The overall HIV/AIDS patients’ satisfaction at Midre-Genet referral hospital was high. Age, marital status, occupation and, income was associated factors. Moreover, lack of functional CD4 machine, inaccessibility of toilets and water, waiting time, inadequate counseling services and lack of qualified health worker (Doctor) in the ART clinic were also challenges for ART patients in the hospital.

Electronic supplementary material

The online version of this article (10.1186/s12913-018-3055-4) contains supplementary material, which is available to authorized users.

Substance Abuse and HIV/AIDS in the Caribbean

The Caribbean and Central America represent a formidable challenge for researchers and policy makers in the HIV field, due to their pronounced heterogeneity in terms of social, economic, and cultural contexts and the different courses the HIV epidemic has followed in the region. Such contrasting contexts and epidemics can be exemplified by 2 countries that share the island of Hispaniola, the French Creole-speaking Haiti, and the Spanish-speaking Dominican Republic. Haiti has experienced the worst epidemics outside of sub-Saharan Africa. Following a protracted economic and social crisis, recently aggravated by a devastating earthquake, the local HIV epidemic could experience resurgence. The region, strategically located on the way between coca-producing countries and the profitable North American markets, has been a transshipment area for years. Notwithstanding, the impact of such routes on local drug scenes has been very heterogeneous and dynamic, depending on a combination of local mores, drug enforcement activities, and the broad social and political context. Injecting drug use remains rare in the region, but local drug scenes are dynamic under the influence of increasing mobility of people and goods to and from North and South America, growing tourism and commerce, and prostitution. The multiple impacts of the recent economic and social crisis, as well as the influence of drug-trafficking routes across the Caribbean and other Latin American countries require a sustained effort to track changes in the HIV risk environment to inform sound drug policies and initiatives to minimize drug-related harms in the region.

Exploring the Context and Implementation of Public Health Regulations Governing Sex Work: A Qualitative Study with Migrant Sex Workers in Guatemala

Public health regulations practices surrounding sex work and their enforcement can have unintended consequences for HIV and sexually transmitted infection (STI) prevention and care among sex workers. This analysis was based on qualitative in-depth (n = 33) and focus groups interviews (n = 20) conducted with migrant female sex workers in Tecún Umán and Quetzaltenango, Guatemala, and explored the implementation of sex work regulations and related consequences for HIV prevention and care among migrant sex workers. Sex work regulations were found to have health-related benefits (e.g., access to HIV/STI testing) as well as negative impacts, such as abuse by police and harassment, detention/deportation of migrant sex workers. Whereas public health regulations may improve access to HIV/STI testing, their implementation may inadvertently jeopardize sex workers' health through unintended negative consequences. Non-coercive, evidence-based public health and sex work policies and programs are needed to expand access to HIV/STI prevention and care among migrant sex workers, while protecting their dignity and human rights.

Recent Insights into the HIV/AIDS Pandemic

Etiology, transmission and protection: Transmission of HIV, the causative agent of AIDS, occurs predominantly through bodily fluids. Factors that significantly alter the risk of HIV transmission include male circumcision, condom use, high viral load, and the presence of other sexually transmitted diseases. Pathology/Symptomatology: HIV infects preferentially CD4+ T lymphocytes, and Monocytes. Because of their central role in regulating the immune response, depletion of CD4+ T cells renders the infected individual incapable of adequately responding to microorganisms otherwise inconsequential. Epidemiology, incidence and prevalence: New HIV infections affect predominantly young heterosexual women and homosexual men. While the mortality rates of AIDS related causes have decreased globally in recent years due to the use of highly active antiretroviral therapy (HAART) treatment, a vaccine remains an elusive goal. Treatment and curability: For those afflicted HIV infection remains a serious illness. Nonetheless, the use of advanced therapeutics have transformed a dire scenario into a chronic condition with near average life spans. When to apply those remedies appears to be as important as the remedies themselves. The high rate of HIV replication and the ability to generate variants are central to the viral survival strategy and major barriers to be overcome. Molecular mechanisms of infection: In this review, we assemble new details on the molecular events from the attachment of the virus, to the assembly and release of the viral progeny. Yet, much remains to be learned as understanding of the molecular mechanisms used in viral replication and the measures engaged in the evasion of immune surveillance will be important to develop effective interventions to address the global HIV pandemic.

Sex Exchange and HIV-related Risk Behaviors among Female Heroin Users in China

This study examines differences in demographic characteristics and HIV-related risk behaviors between Chinese female heroin users who exchanged sex for drugs or money and those who were never involved in sex exchange. A sample of 171 female heroin users was recruited from a detoxification center in China. Female heroin users who exchanged sex for drugs or money were more likely to be unemployed and were at higher risk in both sexual behaviors and injection drug use. Number of sexual partners in the previous year, unemployment, and injection drug use were independently associated with exchange of sex for drugs or money; adjusted odds ratios were 1.2, 3.8, and 2.6, respectively. Findings show that HIV-related risk behaviors are common among female heroin users in China and that HIV harm reduction should be focused on female heroin users who exchange sex for drugs or money.

HIV-related hematological malignancies: a concise review

HIV (Human Immunodeficiency Virus) and its consequence, AIDS (acquired immunodeficiency syndrome) are responsible for a human tragedy of incalculable proportions. Patients afflicted by it are susceptible due to an early senescence of the immune system to opportunistic infections and malignancies. Since the introduction in 1996 of highly active anti-retroviral therapy (HAART), the landscape of malignancies associated to HIV/AIDS has changed in a significant manner as a direct result of significant improvement in the morbidity, mortality and life expectancy of HIV infected patients. While there has been a significant decrease in developed countries of malignancies such as Kaposi's sarcoma and Primary CNS lymphomas associated to the pre-HAART HIV-related immunodeficiency, hematological malignancies, particularly non-Hodgkin lymphomas continue to be the most common cancer-related cause of death in HIV infected individuals. This concise review of the subject highlights aspects of the natural history of HIV disease as it relates to the cause of malignancies with emphasis in the management and treatment of HIV-related hematological malignancies.

Providers' perspectives on the best practices for HIV prevention for men who have sex with men in Berlin, Germany: lessons for policy and prevention

Using qualitative data via providers' perspectives, the goal of this study was to identify strengths and weaknesses in the current approaches being used to prevent onward transmission of HIV among men who have sex with men (MSM) in Berlin, Germany. In 2013, 18 participants from 10 organizations who provide direct outreach or services to MSM were interviewed (30-75 minutes). With regard to strategies and services that individuals believed contributed to the organization's success, we identified five themes: (1) Having staff and volunteers to "match" the target population, (2) Embracing homosexuality and gay identity, (3) Being invested in the cause, (4) Coordination of services to avoid overlap and duplication, and (5) Seeing eye-to-eye with the target population. Finally, with regard to areas in which organizations felt they could use improvement (i.e., continuing challenges), we identified three themes: (1) Insufficient funding and resources, (2) Insufficient services, and (3) HIV stigma, homophobia, and shifting attitudes about HIV. This study informs HIV prevention approaches in Berlin, Germany as well as other urban centers where MSM are disproportionally affected by the HIV epidemic.

Prevalence of microalbuminuria and diagnostic value of dipstick proteinuria in outpatients from HIV clinics in Bukavu, the Democratic Republic of Congo

Background

Microalbuminuria is a marker of early kidney disease and high cardiovascular risk in various populations, including HIV positive patients. However, the diagnostic value of qualitative (dipstick) proteinuria and the burden of microalbuminuria in HIV positive patients living in sub-Saharan Africa are relatively unclear.

Methods

In a cross-sectional study, 235 HIV- positive outpatients were screened for proteinuria in 3 HIV-clinics in Bukavu. A spot urine sample from each subject was tested both by a dipstick and albumin-creatinine-ratio (ACR) assay. The performance of dipstick proteinuria exceeding 1+ was compared with that of microalbuminuria (≥30 mg/g creatinine).

Results

The prevalence of microalbuminuria and dipstick proteinuria ≥ (1+), ≥ (2+) and ≥ (3+) was 11%, 41%, 3.5% and 0.7%, respectively.

Compared to microalbuminuria, the dipstick (proteinuria of 1+ or greater) had an overall sensitivity of 60% and a specificity of 61%. The positive predictive value was 15.4% and the negative predictive value 92.8%.

Conclusion

Proteinuria is highly prevalent in HIV positive patients. The limited sensitivity and specificity of the dipstick to detect significant microalbuminuria make it unattractive as a screening tool in HIV positive patients.

Access to antiretroviral therapy and survival in eastern Europe and central Asia: a case study in Armenia

Introduction

Antiretroviral therapy (ART) substantially improves the health of people living with HIV and contributes to preventing new infections. While HIV incidence is decreasing in most regions, the epidemic in eastern Europe continues to rise, as new infections currently outnumber the rate of ART initiation. In this study, we assess ART use in Armenia and its impact on the number of AIDS diagnoses and mortality.

Methods

National surveillance data were obtained from the National Centre for AIDS Prevention, Armenia. Cox-proportional hazard models were used to determine the effect of demographic and clinical risk factors, including access to ART, on AIDS and mortality.

Results

Among people diagnosed with HIV since 2005, approximately 40% per year were diagnosed with CD4<200 cells per mL. Overall, 232 people (57.1%) with AIDS or a low CD4 count had not received ART by the end of 2010. Mortality was 34.1% among people living with HIV who did not initiate ART, and 0.3% among people who received ART. Among people diagnosed with HIV from 1996 to 2010, age at diagnosis, no use of ART, likely mode of transmission, likely place of transmission, low baseline CD4 count and no STI diagnosis at last contact are significantly associated with death.

Discussion

In Armenia, HIV is frequently diagnosed at a late stage of disease, indicating low testing rates. Of people diagnosed with HIV and in need of ART, a large proportion (approximately 60%) either do not provide consent for treatment, or are who migrants who cannot be located.

Conclusions

Globally, the scale-up of ART has resulted in substantial reductions in mortality among individuals initiating therapy. However, in an era of momentum for treatment as prevention, treatment levels are not at adequate levels for preventing morbidities and mortality in some settings. Particular focus should be placed on key at-risk subgroups.

Aligning HIV/AIDS communication with the oral tradition of Africans: a theory-based content analysis of songs' potential in prevention efforts

Despite a growing recognition of songs as a useful HIV/AIDS campaign strategy, little research has investigated their potential and/or actual impact. In this study, through a theory-based content analysis, we have assessed the prevention domains covered and the health-relevant constructs promoted by 23 AIDS songs widely used to aid prevention efforts in Ethiopia. To identify the health-relevant constructs and reveal their potential to facilitate or inhibit positive changes, the Extended Parallel Process Model (EPPM) has been used. The findings revealed that the songs cover most of the prevention domains that constitute the current agenda of behavior change communication in Sub-Saharan Africa. However, although all the EPPM variables have been found in almost every song, there were significantly more efficacy messages than threat messages. This suggests that although the songs may lead to positive changes in HIV/AIDS-related outcomes among audiences who have already perceived the threat posed by HIV/AIDS, they are less likely to motivate and thereby generate responses from audiences who have less or no threat perceptions. It is argued that given their potential as a culturally appropriate strategy in Sub-Saharan Africa where oral channels of communication play significant roles, songs could be harnessed for better outcomes through a theory-based design.

The role of communication inequality in mediating the impacts of socioecological and socioeconomic disparities on HIV/AIDS knowledge and risk perception

INTRODUCTION

Although the link between social factors and health-related outcomes has long been widely acknowledged, the mechanisms characterizing this link are relatively less known and remain a subject of continued investigation across disciplines. In this study, drawing on the structural influence model of health communication, the hypothesis that differences in concern about and information needs on HIV/AIDS, HIV/AIDS-related media use, and perceived salience of HIV/AIDS-related information, characterized as communication inequality, can at least partially mediate the impacts of socioecological (urban vs. rural) and socioeconomic (education) disparities on inequalities in HIV/AIDS knowledge and risk perception was tested.

METHODS

Data were collected from a random sample of 986 urban and rural respondents in northwest Ethiopia. Structural equation modeling, using the maximum likelihood method, was used to test the mediation models.

RESULTS

The models showed an adequate fit of the data and hence supported the hypothesis that communication inequality can at least partially explain the causal mechanism linking socioeconomic and socioecological factors with HIV/AIDS knowledge and risk perception. Both urbanity versus rurality and education were found to have significant mediated effects on HIV/AIDS knowledge (urbanity vs. rurality: β = 0.28, p = .001; education: β = 0.08, p = .001) and HIV/AIDS risk perception (urbanity vs. rurality: β = 0.30, p = .001; education: β = 0.09, p = .001).

CONCLUSIONS

It was concluded that communication inequality might form part of the socioecologically and socioeconomically embedded processes that affect HIV/AIDS-related outcomes. The findings suggest that the media and message effects that are related to HIV/AIDS behavior change communication can be viewed from a structural perspective that moves beyond the more reductionist behavioral approaches upon which most present-day HIV/AIDS communication campaigns seem to be based.

Management of protozoa-related diarrhea in HIV infection

Protozoa infections are an important cause of chronic diarrhea in patients infected with HIV. The introduction of highly active antiretroviral treatment to the management of HIV in the mid 1990s has led to a dramatic reduction in the incidence of these opportunistic infections in Europe and America. In contrast, in the developing world where such treatments are not readily affordable, protozoa-related diarrhea remains a major cause of morbidity and mortality in HIV-infected individuals. In this review, the optimum investigations required to diagnose these pathogens in HIV-related diarrhea, as well as current treatment options, will be discussed.

Health workforce contributions to health system development: a platform for universal health coverage

PROBLEM

In the 1970s, Thailand was a low-income country with poor health indicators and low health service coverage. The local health infrastructure was especially weak.

APPROACH

In the 1980s, measures were initiated to reduce geographical barriers to health service access, improve the health infrastructure at the district level, make essential medicines more widely available and develop a competent, committed health workforce willing to service rural areas. To ensure service accessibility, financial risk protection schemes were expanded.

LOCAL SETTING

In Thailand, district hospitals were practically non-existent in the 1960s. Expansion of primary health care (PHC), especially in poor rural areas, was considered essential for attaining universal health coverage (UHC). Nationwide reforms led to important changes in a few decades.

RELEVANT CHANGES

Over the past 30 years, the availability and distribution of health workers, as well as their skills and competencies, have greatly improved, along with national health indicators. Between 1980 and 2000 coverage with maternal and child health services increased substantially. By 2002, Thailand had attained UHC. Overall health system development, particularly an expanded health workforce, resulted in a functioning PHC system.

LESSONS LEARNT

A competent, committed health workforce helped strengthen the PHC system at the district level. Keeping the policy focus on the development of human resources for health (HRH) for an extended period was essential, together with a holistic approach to the development of HRH, characterized by the integration of different kinds of HRH interventions and the linking of these interventions with broader efforts to strengthen other health system domains.

Media use and HIV/AIDS knowledge: a knowledge gap perspective

Despite the widespread utilization of the mass media in HIV/AIDS prevention, little is known about the knowledge gap that results from disparities in mass media use. This study examined the relationship between HIV/AIDS-related mass media use and HIV/AIDS-related knowledge among urban and rural residents of northwestern Ethiopia. A hierarchical regression analysis indicated that HIV/AIDS-related mass media use has both sequestering and mainstreaming effects in certain segments of the study population, although it was not a significant predictor of HIV/AIDS-related knowledge in the total population. The knowledge gaps between individuals with high and low education and between individuals who experience high and low levels of interpersonal communication about HIV/AIDS narrowed as HIV/AIDS-related media use increased, but the gap between urban and rural residents widened. The widening gap could be explained by differences in perceptions of information salience and several theoretical assumptions. Current mass media information campaigns, which are often prepared and broadcast from urban centers, may not only fail to improve the HIV/AIDS knowledge of the rural populace but also put rural populations at a disadvantage relative to their urban counterparts. Communication interventions informed by socioecological models might be helpful to redress and/or narrow the widening knowledge gap between urban and rural residents.

Determinants of HIV/AIDS-related information needs and media use: beyond individual-level factors

Despite the centrality of information and communication in the fight against HIV/AIDS, little research has investigated the factors associated with HIV/AIDS-related information needs and media use in hard-hit Sub-Saharan Africa. This study explored individual-level and socioecological determinants among urban and rural residents in northwest Ethiopia. Urbanity versus rurality, education, direct experience with HIV/AIDS, perceived salience of HIV/AIDS-related information, and personal health concern were tested as predictors. Regression analyses showed that urbanity versus rurality and education are the major determinants of HIV/AIDS-related information needs and media use. Being urbanite and educated were associated with high concern about and information needs on HIV/AIDS and HIV/AIDS-related mass media use. Moreover, urbanity versus rurality and education significantly predicted preferences for specific types of HIV/AIDS-related information. While rurality and low education were associated with a preference for basic HIV transmission and prevention information, urbanity was associated with a preference for information on HIV/AIDS-related care and support. In most cases, urbanity versus rurality emerged as a substantial predictor and also significantly moderated the effects of other variables. Given the evolving nature of the pandemic and its expansion to rural areas, ruralites' low information needs and media use deserve due attention. Equally, communication interventions targeting urban contexts need to move beyond providing only the ABCs of HIV transmission and prevention and should attend to urbanites' progressive information needs, which seem to have now become more on care and support so as to live and deal with the pandemic.

Geographical and temporal variation of injection drug users in Pakistan

Objectives

We describe the characteristics of injecting drug users (IDU) in Pakistan in 2006 and 2011, and assess the heterogeneity of IDU characteristics across different cities and years as well as factors associated with HIV infection.

Methods

Cross-sectional, integrated behavioural-biological surveys of IDU were conducted in 10 cities across Pakistan in 2006 and 2011. Univariate and multivariable analyses were used to describe the differences in HIV prevalence and risk behaviours between cities and over time.

Results

Large increases in HIV prevalence among injection drug users in Pakistan were observed, with overall HIV prevalence increasing from 16.2% in 2006 to 31.0% in 2011; an increase in HIV prevalence was also seen in all geographic areas except one. There was an increase in risk behaviours between 2006 and 2011, anecdotally related to a reduction in the availability of services for IDU. In 2011, larger proportions of IDU reported injecting several times a day and using professional injectors, and fewer reported always using clean syringes. An increase in the proportion living on the street was also observed and this was associated with HIV infection. Cities differ in terms of HIV prevalence, risk profiles, and healthcare seeking behaviours.

Conclusions

There is a high prevalence of HIV among injection drug users in Pakistan and considerable potential for further transmission through risk behaviours. HIV prevention programs may be improved through geographic targeting of services within a city and for involving groups that interact with IDU (such as pharmacy staff and professional injectors) in harm reduction initiatives.

Role of condom negotiation on condom use among women of reproductive age in three districts in Tanzania

Background

HIV/AIDS remains being a disease of great public health concern worldwide. In regions such as sub-Saharan Africa (SSA) where women are disproportionately infected with HIV, women are reportedly less likely capable of negotiating condom use. However, while knowledge of condom use for HIV prevention is extensive among men and women in many countries including Tanzania, evidence is limited about the role of condom negotiation on condom use among women in rural Tanzania.

Methods

Data originate from a cross-sectional survey of random households conducted in 2011 in Rufiji, Kilombero and Ulanga districts in Tanzania. The survey assessed health-seeking behaviour among women and children using a structured interviewer-administered questionnaire. A total of 2,614 women who were sexually experienced and aged 15-49 years were extracted from the main database for the current analysis. Linkage between condom negotiation and condom use at the last sexual intercourse was assessed using multivariate logistic regression.

Results

Prevalence of condom use at the last sexual intercourse was 22.2% overall, ranging from12.2% among married women to 54.9% among unmarried (single) women. Majority of the women (73.4%) reported being confident to negotiate condom use, and these women were significantly more likely than those who were not confident to have used a condom at the last sexual intercourse (OR = 3.13, 95% CI 2.22-4.41). This effect was controlled for marital status, age, education, religion, number of sexual partners, household wealth and knowledge of HIV prevention by condom use.

Conclusion

Confidence to negotiate condom use is a significant predictor of actual condom use among women in rural Tanzania. Women, especially unmarried ones, those in multiple partnerships or anyone needing protection should be empowered with condom negotiation skills for increased use of condoms in order to enhance their sexual and reproductive health outcomes.

The "brain drain" of health care workers: causes, solutions and the example of Jamaica

Despite much media attention being given to the physician shortage in Canada in recent years, this shortage pales in comparison to that seen in many middle- and low-income countries. A major cause of the shortage in these countries is the migration of health care workers from developing to developed nations, a phenomenon known as the "brain drain". The loss of these workers is having devastating impacts globally, particularly in Sub-Saharan Africa and the Caribbean. Causes of the "brain drain" are numerous and include poor working conditions in poorer countries and active recruitment by richer countries. Jamaica has been one of the countries in the Caribbean hardest hit by mass migration of health care workers. The multiple dimensions of Jamaica's health worker "brain drain" illustrate both the complexity of the issues reviewed in this commentary, and the net loss for low- and middle-income countries. Creative and sustainable solutions to the problem are actively being sought globally, but will require commitment and support from all nations as well as from international funding bodies if meaningful impacts on health are to be realized.

Spatial visualization of multivariate datasets: an analysis of STD and HIV/AIDS diagnosis rates and socioeconomic context using ring maps

OBJECTIVES

We used existing data systems to examine sexually transmitted disease (STD) and HIV/AIDS diagnosis rates and explore potential county-level associations between HIV/AIDS diagnosis rates and socioeconomic disadvantage.

METHODS

Using South Carolina county data, we constructed multivariate ring maps to spatially visualize syphilis, gonorrhea, chlamydia, and HIV/AIDS diagnosis rates; gender- and race-specific HIV/AIDS diagnosis rates; and three measures of socioeconomic disadvantage-an unemployment index, a poverty index, and the Townsend index of social deprivation. Statistical analyses were performed to quantitatively assess potential county-level associations between HIV/AIDS diagnosis rates and each of the three indexes of socioeconomic disadvantage.

RESULTS

Ring maps revealed substantial spatial association in STD and HIV/AIDS diagnosis rates and highlighted large gender and racial disparities in HIV/AIDS across the state. The mean county-level HIV/AIDS diagnosis rate (per 100,000 population) was 24.2 for males vs. 11.2 for females, and 34.8 for African Americans vs. 5.2 for white people. In addition, ring map visualization suggested a county-level association between HIV/AIDS diagnosis rates and socioeconomic disadvantage. Significant positive bivariate relationships were found between HIV/AIDS rate categories and each increase in poverty index category (odds ratio [OR] = 2.03; p=0.006), as well as each increase in Townsend index of social deprivation category (OR=4.98; p<0.001). A multivariate ordered logistic regression model in which all three socioeconomic disadvantage indexes were included showed a significant positive association between HIV/AIDS and Townsend index categories (adjusted OR=6.10; p<0.001).

CONCLUSIONS

Ring maps graphically depicted the spatial coincidence of STD and HIV/AIDS and revealed large gender and racial disparities in HIV/AIDS across South Carolina counties. This spatial visualization method used existing data systems to highlight the importance of social determinants of health in program planning and decision-making processes.

Effect of a healthcare gender gap on progression of HIV/AIDS defined by clinical-biological criteria among adults from Cordoba City (Argentina) from 1995 to 2005

OBJECTIVE

To establish the influence of clinical status at diagnosis and of gender on progression of HIV/AIDS determined by clinical-biological factors in patients from Cordoba City (Argentina) from 1995 to 2005).

METHODS

Gender and clinical and laboratory data were evaluated by descriptive statistics, non-parametric survival analysis, and generalized linear models at the beginning of the study (diagnosis) and at the end (hospital records, n=209).

RESULTS

At diagnosis, women (n=28, 13.4%) had a higher probability of being asymptomatic than men (n=181, 86.6%). High viremia was associated with advanced clinical stages, but was inversely related to CD4 count. Truncated Kaplan-Meier curves were similar for both sexes. The probability of not having AIDS criteria at the end of the study was higher in patients without these criteria at diagnosis. Women had a higher probability of having AIDS at the end of the follow-up than men. In contrast, men had a higher prevalence of venereal diseases (n=38, 21%), dysmetabolic profile (n=14, 7.7%) and positive serology for opportunists (n=31, 17.1%). Marker diseases were mainly represented by internal mycosis and waste syndrome, although less specific findings (anemia, oral lesions) were also associated with progression.

CONCLUSIONS

Using an integrative approach, high viremia was critically linked to clinical and lymphocyte impairment. Early diagnosis was a major determinant of clinical course, with women having a worse prognosis. However, men were diagnosed in clinically advanced stages and with other non-HIV-related entities, which could affect progression. These findings should be integrated into the planning of preventive strategies.

Neighborhood poverty and injection cessation in a sample of injection drug users

Neighborhood socioeconomic environment may be a determinant of injection drug use cessation. The authors used data from a prospective cohort study of Baltimore City, Maryland, injection drug users assessed between 1990 and 2006. The study examined the relation between living in a poorer neighborhood and the probability of injection cessation among active injectors, independent of individual characteristics and while respecting the temporality of potential confounders, exposure, and outcome. Participants' residences were geocoded, and the crude, adjusted, and inverse probability of exposure weighted associations between neighborhood poverty and injection drug use cessation were estimated. Weighted models showed a strong association between neighborhood poverty and injection drug use cessation; living in a neighborhood with fewer than 10%, compared with more than 30%, of residents in poverty was associated with a 44% increased odds of not injecting in the prior 6 months (odds ratio = 1.44, 95% confidence interval: 1.14, 1.82). Results show that neighborhood environment may be an important determinant of drug injection behavior independent of individual-level characteristics.

Rethinking the role of the local community in HIV epidemic spread in sub-Saharan Africa: a proximate-determinants approach

The spread of HIV in sub-Saharan Africa continues largely unabated. To improve prevention interventions, a better understanding of the determinants of HIV infection is required. Conceptual frameworks can guide epidemiological investigation and prevent a misguided focus on single risk factors in isolation. Existing frameworks of HIV infection focus on transmission. However, the transmitting individual is rarely known. By contrast, data on individual HIV acquisition are available from longitudinal studies and tests for recent HIV infection. From the perspective of individuals susceptible to HIV, it is important to distinguish between factors determining the individual's biological disposition and sexual behavior and community-level factors, which can affect both HIV acquisition and the likelihood that a sex partner chosen from a community will be infected with HIV and transmit the infection. We propose a framework that takes the susceptible individual as a starting point and links distal, proximate and biological determinants of HIV infection at both the individual and the community level. We describe three necessary ingredients for the use of the framework (identification of the relevant community, multilevel analysis and methods for causal inference).

Issues of scale and uncertainty in the global remote sensing of disease

Scale and uncertainty are important issues for the global prediction of disease. Disease mapping over the entire surface of the Earth usually involves the use of remotely sensed imagery to provide environmental covariates of disease risk or disease vector density. It further implies that the spatial resolution of such imagery is relatively coarse (e.g., 8 or 1km). Use of a coarse spatial resolution limits the information that can be extracted from imagery and has important effects on the results of epidemiological analyses. This paper discusses geostatistical models for (i) characterizing the scale(s) of spatial variation in data and (ii) changing the scale of measurement of both the data and the geostatistical model. Uncertainty is introduced, highlighting the fact that most epidemiologists are interested in accuracy, aspects of which can be estimated with measurable quantities. This paper emphasizes the distinction between data- and model-based methods of accuracy assessment and gives examples of both. The key problem of validating global maps is considered.

Could the CARE-SHAKTI intervention for injecting drug users be maintaining the low HIV prevalence in Dhaka, Bangladesh?

AIMS

To explore whether the low HIV prevalence observed in Bangladesh results from prevention activities, this study uses mathematical modelling to estimate the impact of a needle/syringe exchange intervention for injecting drug users (IDUs) in Dhaka, Bangladesh.

DESIGN

Epidemiological, behavioural and intervention monitoring data were used to parameterize a dynamic mathematical model, and fit it to National HIV Sero-surveillance data among IDUs (2000-02). The model was used to estimate the impact of the intervention on HIV transmission among IDUs and their sexual partners.

SETTING

Dhaka, Bangladesh, where the HIV prevalence has remained low despite high-risk sexual and injecting behaviours, and growing HIV epidemics in neighbouring countries.

FINDINGS

The model predicts that the intervention may have reduced the incidence of HIV among IDUs by 90% (95% CI 74-94%), resulting in an IDU HIV prevalence of 10% (95% CI 4-19%) after 8 years of intervention activity instead of 42% (95% CI 30-47%) if the intervention had not occurred.

CONCLUSIONS

The analysis highlights the potential for rapid HIV spread among IDUs in Dhaka, and suggests that the intervention may have substantially reduced IDU HIV transmission. However, there is no room for complacency. Sustained and expanded funding for interventions in Dhaka and other regions of Bangladesh are crucial to maintaining the low HIV prevalence.

Estimates of injecting drug users at the national and local level in developing and transitional countries, and gender and age distribution

OBJECTIVE

To present and update available national and subnational estimates of injecting drug users (IDUs) in developing/transitional countries, and provide indicative estimates of gender and age distribution.

METHODS

Literature review of both grey and published literature including updates from previously reported estimates on estimates of IDU population and data sources giving age and gender breakdowns. The scope area was developing/transitional countries and the reference period was 1998-2005.

RESULTS

Estimates of IDU numbers were available in 105 countries and 243 subnational areas. The largest IDU populations were reported from Brazil, China, India, and Russia (0.8 m, 1.9 m, 1.1 m, and 1.6 m respectively). Subnational areas with the largest IDU populations (35,000-79,000) are: Warsaw (Poland); Barnadul, Irtkustk, Nizhny-Novgorod, Penza, Voronez, St Petersburg, and Volgograd (Russia); New Delhi and Mumbai (India); Jakarta (Indonesia), and Bangkok (Thailand). By region, Eastern Europe and Central Asia have the largest IDU prevalence (median 0.65%) (min 0.3%; max 2.2%; Q1 0.39%; Q3 1.32%) [corrected] followed by Asia and Pacific: 0.24% (min 0.004%; max 1.47%; Q1 0.14%; Q3 1.47%) [corrected] In the Middle East and Africa the median value equals 0.2% (min 0.0003%; max 0.35%; Q1 0.11%; Q3 0.23%) [corrected] and in Latin America and the Caribbean: 0.12% (min 0.11%; max 0.69%; Q1 0.04%; Q3 0.13%) [corrected] Subnational areas with the highest IDU prevalence among adults (8-14.9%) were Shymkent (Kazakhstan), Balti (Moldova), Astrakhan, Barnadul, Irtkustk, Khabarovsk, Kaliningrad, Naberezhnyje Chelny, Penza, Togliatti, Volgograd, Voronez, and Yaroslavl (Russia), Dushanbe (Tajikistan), Ashgabad (Turkmenistan), Ivano-Frankivsk and Pavlograd (Ukraine) and Imphal, Manipur (India). 66% (297/447) of the IDU estimates were reported without technical information. Data on the IDU age/gender distributions are also scarce or unavailable for many countries. In 11 Eastern European and Central Asian countries the age group <or=20-29 represented >50% of the total. The proportion of IDU men was 70%-90% in Eastern Europe and Central Asia, and there was a marked absence of data on women outside this region.

CONCLUSION

Unfortunately data on IDU prevalence available to national and international policymakers is of an unknown and probably yet to be tested quality. This study provide baseline figures but steps need to be taken now to improve the reporting and assessment of these critical data.

Microbiology of osteomyelitis in patients infected with the human immunodeficiency virus

Osteomyelitis rarely develops in patients infected with the human immunodeficiency virus despite their immunosuppressed state. In the limited literature available on this subset of patients, the role of opportunistic micro-organisms is controversial. Our purpose is to describe the microbiologic features of osteomyelitis. This is a retrospective review of 20 patients infected with the human immunodeficiency virus who were admitted to our musculoskeletal infection ward with the diagnosis of osteomyelitis. Eleven patients (55%) were intravenous drug users. Medical comorbidities were present in 14 of 20 patients (70%), including tuberculosis in five patients and hepatitis C in three patients. The mean CD4 count was 269/mm (range, 20-539/mm). Osteomyelitis was monomicrobial in 10 patients (50%) and polymicrobial in seven patients (35%) whereas in three patients no organism was cultured. The most common pathogen was Staphylococcus aureus, present in 10 patients (50%). No mycobacterial or fungal pathogens were identified. Infection recurred in 3 of 14 patients (21%) that were available for followup. Despite their immunocompromised status, patients infected with the human immunodeficiency virus did not develop osseous infections with opportunistic pathogens. Staphylococcus aureus was the most common pathogen found; however, a considerable proportion of infections were polymicrobial.

Awareness, acceptance, and action: an emerging framework for understanding AIDS stigmatizing attitudes among community leaders in Barbados

AIDS stigma must be acknowledged and reduced to advance HIV prevention and HIV/AIDS care in a variety of settings worldwide, including in the West Indies where national epidemics are thought to be growing rapidly. Regarded by international health organizations as a formidable barrier to service delivery and receipt, AIDS stigma refers to prejudice and discrimination directed toward people living with HIV/AIDS (PLHA), persons perceived as being at risk for HIV infection, and the informal and formal service providers who care for PLHA. However, there is little evidence of successful antistigma interventions in the literature. Furthermore, beyond studies of willingness in various professions to serve clients or patients with HIV/AIDS, the stigmatizing attitudes and behaviors of service delivery personnel, paraprofessionals and volunteers have been inadequately studied. This paper uses data obtained during an AIDS awareness workshop with sports coaches in Barbados to illustrate principles of an antistigma intervention framework being developed for social service and health personnel. The Awareness/Acceptance/Action Model (AAAM) draws on principles of mindfulness, rooted in ancient Asian traditions, and recently adapted to a range of physical and mental health interventions in Western contexts. Mindfulness techniques encourage awareness of one's current state and environment, acceptance of the implications of one's attitudes and behaviors, and the development of intentional responses rather than habitually patterned reactions. In this initial effort, community leaders were guided through a series of self-reflective exercises focusing AAAM principles on their tendencies toward AIDS stigma, and exploring more compassionate and functional alternatives.

Global overview of injecting drug use and HIV infection among injecting drug users

OBJECTIVE

To provide global estimates of the prevalence of injecting drug use (IDU) and HIV prevalence among IDU, in particular to provide estimates for developing and transitional countries.

METHODS

Collation and review of existing estimates of IDU prevalence and HIV prevalence from published and unpublished documents for the period 1998-2003. The strength of evidence for the information was assessed based on the source and type of study.

RESULTS

Estimates of IDU prevalence were available for 130 countries. The number of IDU worldwide was estimated as approximately 13.2 million. Over ten million (78%) live in developing and transitional countries (Eastern Europe and Central Asia, 3.1 million; South and South-east Asia, 3.3 million; East-Asia and Pacific, 2.3 million). Estimates of HIV prevalence were available for 78 countries. HIV prevalence among IDU of over 20% was reported for at least one site in 25 countries and territories: Belarus, Estonia, Kazakhstan, Russia, Ukraine, Italy, Netherlands, Portugal, Serbia and Montenegro, Spain, Libya, India, Indonesia, Malaysia, Myanmar, Nepal, Thailand, Viet Nam, China, Argentina, Brazil, Uruguay, Puerto Rico, USA and Canada.

CONCLUSIONS

These findings update previous assessments of the number of countries with IDU and HIV-infected IDU, and the previous quantitative global estimates of the prevalence of IDU. However, gaps remain in the information and the strength of the evidence often was weak.

Suppression of HIV-1 viral replication and cellular pathogenesis by a novel p38/JNK kinase inhibitor

OBJECTIVE

To analyze a novel compound, which inhibits serine-threonine protein kinase p38, for its possible bioactivity against HIV-1 infection.

METHODS

Proteins involved in cellular signal transduction pathways represent a novel class of host therapeutic targets for infectious diseases. In this regard the serine/threonine kinase p38 MAPK, a member of the mitogen-activated protein (MAP) kinase superfamily of signal transduction molecules may play an important role in HIV-1 infection. We analyzed the ability of this compound (RWJ67657) to inhibit HIV replication in primary T cells and monocytes. Cellular expression of phospho-p38MAPK was studied by Western blot analysis. Blockade of HIV infection induced apoptosis was measured by Annexin V staining.

RESULTS

p38 inhibitor RWJ67657 was effective in inhibiting HIV-1 replication in both T-cell and monocyte cell lines, irrespective of the coreceptor used by the virus for entry into the cell. Importantly, both reverse transcriptase and protease resistant escape mutant viruses were effectively suppressed by RWJ67657. In addition, the tested compounds block HIV-induced T-cell apoptosis, a critical means of T-cell depletion linked to AIDS progression.

CONCLUSION

Several steps in the HIV-1 virus life cycle appear to depend on cellular activation, including activation of the p38 pathway. Without activation virus replication is thought to be blocked due to incomplete reverse transcription and a lack of proviral DNA integration. The data collectively illustrate that inhibition of the p38 pathway can affect HIV-1 replication. Interruption of HIV infection by p38 inhibitors underscores the value of exploring antiviral drugs that target host cellular proteins.

Contextual determinants of drug use risk behavior: a theoretic framework

Over the past two decades, public health research has emphasized the role of individual risk behaviors, primarily injection and sexual risk behaviors, in the spread of HIV infection. Much less emphasis has been given to understanding the determinants of these risk behaviors. Although individual characteristics are partly responsible for risky injection and sexual behaviors, they do not explain all the interpersonal variability in risk behavior. Contextual factors associated with HIV risk behavior may include structural factors (e.g., availability of services), social norms and attitudes (e.g., social trust), disadvantage (e.g., neighborhood socioeconomic status), and features of the physical environment (e.g., housing quality). This article presents a conceptual framework that incorporates some of the key contextual domains that may affect drug use behavior. It also presents data from a study of street-recruited drug users as an example of the relations between social contextual factors and frequency of injecting drug use, and discusses some methodological challenges in the study of contextual determinants of drug use behavior.

“Typhoid Mary” and “HIV Jane”: Responsibility, Agency and Disease Prevention

The construction of disease risks as knowable, calculable and preventable in dominant social science and public health discourses has fostered a certain kind of logic about individual risk and the responsibility for infection. Disease control measures that have developed out of this logic typically fail to recognise the socio-structural roots of many high-risk behaviours that are linked to the spread of infection. Instead, they hold the disease carrier responsible for managing his/her own risk of infection of others, and rely on constraining the agency of the carrier (e.g. by constraining movement, contact or occupation). In occupations associated with a high risk of infection, the idea of responsibility of the actor implicitly raises issues of "professional responsibility". Using the case of "Typhoid Mary" and a hypothetical case of "HIV Jane", this paper explores some of the problems with making sex workers responsible for the prevention of HIV transmission. It argues that for the notion of "responsibility" to make any sense, the HIV-positive person must be in a position to exercise responsibility, and for this they must have agency.

Novel engineered HIV-1 East African Clade-A gp160 plasmid construct induces strong humoral and cell-mediated immune responses in vivo

HIV-1 sequences are highly diverse due to the inaccuracy of the viral reverse transcriptase. This diversity has been studied and used to categorize HIV isolates into subtypes or clades, which are geographically distinct. To develop effective vaccines against HIV-1, immunogens representing different subtypes may be important for induction of cross-protective immunity, but little data exist describing and comparing the immunogenicity induced by different subtype-based vaccines. This issue is further complicated by poor expression of HIV structural antigens due to rev dependence. One costly approach is to codon optimize each subtype construct to be examined. Interestingly, cis-acting transcriptional elements (CTE) can also by pass rev restriction by a rev independent export pathway. We reasoned that rev+CTE constructs might have advantages for such expression studies. A subtype A envelope sequence from a viral isolate from east Africa was cloned into a eukaryotic expression vector under the control of the CMV-IE promoter. The utility of inclusion of the Mason-Pfizer monkey virus (MPV)-CTE with/without rev for driving envelope expression and immunogenicity was examined. Expression of envelope (gp120) was confirmed by immunoblot analysis and by pseudotype virus infectivity assays. The presence of rev and the CTE together increased envelope expression and viral infection. Furthermore the CTE+rev construct was significantly more immunogenic then CTE alone vector. Isotype analysis and cytokine profiles showed strong Th1 response in plasmid-immunized mice, which also demonstrated the superior nature of the rev+CTE construct. These responses were of similar or greater magnitude to a codon-optimized construct. The resulting cellular immune responses were highly cross-reactive with a HIV-1 envelope subtype B antigen. This study suggests a simple strategy for improving the expression and immunogenicity of HIV subtype-specific envelope antigens as plasmid or vector-borne immunogens.

Investigating the source of hepatitis C virus infection among individuals whose route of infection is undefined: a study of ten cases

Hepatitis C virus (HCV) transmission is predominantly parenteral via infected blood products or shared injecting equipment. Many infected individuals, however, deny these risk factors. This study set out to determine whether an in-depth interview would determine the likely source of infection for those whose route of infection was undefined. Between May 1999 and July 1999, risk factor information was sought, through in-depth interview, from 10 patients whose source of hepatitis C infection was undefined. The clinical notes of the patients were scrutinized to complement the information provided through the questionnaire. Despite undertaking an in-depth interview, it was not possible to establish the likely route of infection for 9 of the 10 individuals studied as they reported several risk events. There is little benefit to interviewing routinely those HCV-infected people who have no history of injecting drugs or having received a contaminated blood/blood product transfusion, to ascertain their likely source or time of infection; at best, such effort might only increase one's confidence that infection was acquired through means other than these 2 routes.

Clinical and virological aspects of hepatitis B co-infection in individuals infected with human immunodeficiency virus type-1

The improved prognosis of HIV-infection that has occurred since the introduction of highly active antiretroviral therapy (HAART) has resulted in renewed emphasis being placed on co-morbidities associated with HIV-infection, and chronic viral hepatitis in particular. Hepatitis B virus (HBV) infection is an important infection in HIV-1 infected individuals because of the influence of HIV-1 co-infection on the natural history of HBV infection. Antiviral therapies with activity against both viruses have enabled targeted therapy in co-infected individuals, however, optimism regarding improved prognosis has been tempered by the development of antiviral resistant HBV. Emerging new classes of HBV therapies herald the possibility of combination HBV therapy.

Evolution of drug resistance in Candida albicans

The widespread deployment of antimicrobial agents in medicine and agriculture is nearly always followed by the evolution of resistance to these agents in the pathogen. With the limited availability of antifungal drugs and the increasing incidence of opportunistic fungal infections, the emergence of drug resistance in fungal pathogens poses a serious public health concern. Antifungal drug resistance has been studied most extensively with the yeast Candida albicans owing to its importance as an opportunistic pathogen and its experimental tractability relative to other medically important fungal pathogens. The emergence of antifungal drug resistance is an evolutionary process that proceeds on temporal, spatial, and genomic scales. This process can be observed through epidemiological studies of patients and through population-genetic studies of pathogen populations. Population-genetic studies rely on sampling of the pathogen in patient populations, serial isolations of the pathogen from individual patients, or experimental evolution of the pathogen in nutrient media or in animal models. Predicting the evolution of drug resistance is fundamental to prolonging the efficacy of existing drugs and to strategically developing and deploying novel drugs.