Advantages and challenges of using census and multiplier methods to estimate the number of female sex workers in a Chinese city

Investigating the influence of language teachers' constructivist self-efficacy on their practice of constructivism in Ghanaian language and culture instruction

The education system in Ghana is undergoing a transition from a behaviorist instructional philosophy to a constructivist one, aiming to produce learners who can actively contribute to nation-building. Nonetheless, given the heavy demands on teachers regarding this abrupt shift into constructivist teaching, there is a need to examine teachers' sense of efficacy in relation to the enactment of the core principles of this novel instructional philosophy-i.e., social, cognitive, and critical constructivism- laid down in the newly introduced standards-based curriculum. An explanatory sequential mixed method was used to obtain data from basic school teachers in the Sunyani-West Municipal of Bono Region, Ghana. Using adapted teacher self-efficacy and constructivist learning environment scales, quantitative data were gathered from 104 teachers. Qualitative data were also gathered from 15 conveniently sampled language teachers to augment the quantitative findings. Using partial least squares structural equation modelling, a significant positive association was discovered between teachers' efficacy and the practice of social and cognitive constructivism. Nonetheless, teachers' efficacy did not statistically predict their practice of critical constructivism. The qualitative results showed that sociocultural concerns probably accounted for the insignificant association between efficacy and critical constructivism. It was therefore concluded that sociocultural norms designed for bringing up a child in Ghana tend to inhibit the enactment of critical constructivism. The study recommends that the National Council for Curriculum and Assessment, in partnership with the Ghana Tertiary Education Commission, should update teacher professional development programs in universities and colleges of education to incorporate constructivist principles, particularly critical pedagogy, aiming to produce competent teachers capable of fostering learners' autonomy, critical thinking, and problem-solving skills as outlined in the Standards-Based Curriculum (SBC).

Estimating the Number of HIV+ Latino MSM Using RDS, SS-PSE, and the Census

This paper presents a method for estimating the overall size of a hidden population using results from a respondent driven sampling (RDS) survey. We use data from the Latino MSM Community Involvement survey (LMSM-CI), an RDS dataset that contains information collected regarding the Latino MSM communities in Chicago and San Francisco. A novel model is developed in which data collected in the LMSM-CI survey serves as a bridge for use of data from other sources. In particular, American Community Survey Same-Sex Householder data along with UCLA's Williams Institute data on LGBT population by county are combined with current living situation data taken from the LMSM-CI dataset. Results obtained from these sources are used as the prior distribution for Successive-Sampling Population Size Estimation (SS-PSE) - a method used to create a probability distribution over population sizes. The strength of our model is that it does not rely on estimates of community size taken during an RDS survey, which are prone to inaccuracies and not useful in other contexts. It allows unambiguous, useful data (such as living situation), to be used to estimate population sizes.

Size Estimation of high-risk groups for hiv infection in india based on data from national integrated bio-behavioral surveillance and targeted interventions

Background

Targeted interventions (TIs) are one of the most effective strategies to control HIV/AIDS transmission, especially among the high-risk groups (HRGs). Implementation of HIV/AIDS control strategies relies heavily on estimation of the size of HRG population. Size estimation for key populations such as female sex workers (FSWs), men who have sex with men (MSM), and injecting drug users (IDUs) is a crucial component of national HIV strategic planning.

Objective

The objective of this study was to estimate the size of FSWs, MSM, and IDUs in various states of India.

Methods

The program multiplier method was used to estimate the size of FSWs, MSM, and IDUs across the country using two distinct but overlapping data sources - Integrated Bio-Behavioral Surveillance and TI program from the same geographical area at the same time period.

Results

In India, as on 2018-2019, there were nearly 18.2 lakhs estimated FSWs accounting to 0.53% among female population aged 15-49 years, with a highest in West Bengal (4.5 lakhs); 5.7 lakhs estimated MSM accounting to 0.16% among male population aged 15-49 years, with a highest in Gujarat (0.7 lakh); and 3.9 lakhs estimated IDUs accounting to 0.11% among male population aged 15-49 years, with a highest in Uttar Pradesh (0.5 lakh).

Conclusions

The current size estimates on HRGs will support the development of projections and estimations of the HIV epidemic at national and state levels. These estimates also help in framing national guidelines such as HIV strategic planning, program design, allocation of resources, prioritizing the interventions, and monitoring and evaluation.

Indirect estimation of student marijuana consumers population in Hamadan using PRM and NSU methods

Background: Finding social causes of a particular disease or specific health problem in groups or hidden illnesses, such as drug misuse is difficult. To estimate the population size, it should be taken into account that under enumeration usually occurs in direct estimation of population of certain high-risk groups. The present study used indirect methods to accurately estimate the population of students who have once experienced marijuana abuse. Methods: This cross sectional research was conducted on 461 students in Hamadan. Two indirect methods, the Network Scale-up (NSU) and proxy respondent method (PRM), were used. Data were analyzed by statistical tests and SPSS version 16 and Excel. Results: The mean age (standard deviation) was 22.51 (4.19 years), and the prevalence of marijuana misuse was 1.94%, 4.12%, and 2.6%, respectively, in girls and 14.57%, 12.58%, and 10.4% in boys using NSU, PRM, and direct method. Conclusion: Direct and NSU methods had higher bias than PRM, the frequency of PRM was closer to reality, and the once use prevalence of marijuana was higher in the young male population than in the female.

Assessing Bias in Population Size Estimates Among Hidden Populations When Using the Service Multiplier Method Combined With Respondent-Driven Sampling Surveys: Survey Study

BACKGROUND

Population size estimates (PSEs) for hidden populations at increased risk of HIV, including female sex workers (FSWs), are important to inform public health policy and resource allocation. The service multiplier method (SMM) is commonly used to estimate the sizes of hidden populations. We used this method to obtain PSEs for FSWs at 9 sites in Zimbabwe and explored methods for assessing potential biases that could arise in using this approach.

OBJECTIVE

This study aimed to guide the assessment of biases that arise when estimating the population sizes of hidden populations using the SMM combined with respondent-driven sampling (RDS) surveys.

METHODS

We conducted RDS surveys at 9 sites in late 2013, where the Sisters with a Voice program (the program), which collects program visit data of FSWs, was also present. Using the SMM, we obtained PSEs for FSWs at each site by dividing the number of FSWs who attended the program, based on program records, by the RDS-II weighted proportion of FSWs who reported attending this program in the previous 6 months in the RDS surveys. Both the RDS weighting and SMM make a number of assumptions, potentially leading to biases if the assumptions are not met. To test these assumptions, we used convergence and bottleneck plots to assess seed dependence of RDS-II proportion estimates, chi-square tests to assess if there was an association between the characteristics of FSWs and their knowledge of program existence, and logistic regression to compare the characteristics of FSWs attending the program with those recruited to RDS surveys.

RESULTS

The PSEs ranged from 194 (95% CI 62-325) to 805 (95% CI 456-1142) across 9 sites from May to November 2013. The 95% CIs for the majority of sites were wide. In some sites, the RDS-II proportion of women who reported program use in the RDS surveys may have been influenced by the characteristics of selected seeds, and we also observed bottlenecks in some sites. There was no evidence of association between characteristics of FSWs and knowledge of program existence, and in the majority of sites, there was no evidence that the characteristics of the populations differed between RDS and program data.

CONCLUSIONS

We used a series of rigorous methods to explore potential biases in our PSEs. We were able to identify the biases and their potential direction, but we could not determine the ultimate direction of these biases in our PSEs. We have evidence that the PSEs in most sites may be biased and a suggestion that the bias is toward underestimation, and this should be considered if the PSEs are to be used. These tests for bias should be included when undertaking population size estimation using the SMM combined with RDS surveys.

Programmatic mapping to determine the size and dynamics of sex work and injecting drug use in Mauritius

HIV in Mauritius is in a concentrated phase. Most HIV infection is among key populations (KPs) including female sex workers (FSW), people who inject drugs (PWID), men who have sex with men (MSM), and transgender sex workers (TGSW). The objective of this research was to use geographical mapping to determine the precise locations, typologies and population estimates of each KP in Mauritius. From May to July 2014 a programmatic mapping approach determined national estimates and information on the specific locations, "hotspots", frequented by KPs in Mauritius. Data were collected through multiple levels of activity. Key informants provided information about hotspots where KPs congregated and were actively engaged in risky behaviours. Validation of hotspots was done by engaging KPs. A total of 17 248 KP members were estimated spread over 1 964 hotspots in Mauritius. The largest KP was PWID with an estimate of 7 598 (range: 4 091-6 223), followed by 6 223 (range: 5 090-7 456) FSWs, spread over 694 and 731 hotspots respectively. A total of 2 020 (range: 1 595-2 446) MSM and 294 geographic MSM hotspots, and 1 407 TGSWs (range: 1 165-1 649) distributed over 245 hotspots. This research provided Mauritius with validated KPs size estimations and provided the first national data on KP hotspots and operational dynamics. The use of these data will strengthen HIV prevention, intervention, and programme planning in the country through focusing efforts to systematically target high-risk areas.

Estimating the number of sex workers in South Africa: rapid population size estimation

Although recognized as a vulnerable population, there is no national population size estimate for sex workers in South Africa. A rapid sex worker enumeration exercise was undertaken in twelve locations across the country based on principles of participatory mapping and Wisdom of the Crowd. Sites with a range of characteristics were selected, focusing on level of urbanisation, trucking, mining and borders. At each site, sex worker focus groups mapped local hotspots. Interviews with sex workers at identified hotspots were used to estimate the numbers and genders of sex workers working in each. Estimates provided in the literature were combined with enumeration exercise results to define assumptions that could be applied to a national extrapolation. A working estimate was reached of between 131,000 and 182,000 sex worker in South Africa, or between 0.76 and 1 % of the adult female population. The success of the exercise depended on integral involvement of sex worker peer educators and strong ethical considerations.

Predictors of condom use behaviors based on the Health Belief Model (HBM) among female sex workers: a cross-sectional study in Hubei Province, China

BACKGROUND

HIV infection related to commercial sexual contact is a serious public health issue in China. The objectives of the present study are to explore the predictors of condom use among female sex workers (FSWs) in China and examine the relationship between Health Belief Model (HBM) constructs.

METHODOLOGY/PRINCIPAL FINDINGS

A cross-sectional study was conducted in two cities (Wuhan and Suizhou) in Hubei Province, China, between July 2009 and June 2010. A total of 427 FSWs were recruited through mediators from the 'low-tier' entertainment establishments. Data were obtained by self-administered questionnaires. Structural equation models were constructed to examine the association. We collected 363 valid questionnaires. Within the context of HBM, perceived severity of HIV mediated through perceived benefits of condom use had a weak effect on condom use (r=0.07). Perceived benefits and perceived barriers were proximate determinants of condom use (r=0.23 and r=-0.62, respectively). Self-efficacy had a direct effect on perceived severity, perceived benefits, and perceived barriers, which was indirectly associated with condom use behaviors (r=0.36).

CONCLUSIONS/SIGNIFICANCE

The HBM provides a useful framework for investigating predictors of condom use behaviors among FSWs. Future HIV prevention interventions should focus on increasing perceived benefits of condom use, reducing barriers to condoms use, and improving self-efficacy among FSWs.

Burden of HIV among female sex workers in low-income and middle-income countries: a systematic review and meta-analysis

BACKGROUND

Female sex workers are a population who are at heightened risk of HIV infection secondary to biological, behavioural, and structural risk factors. However, three decades into the HIV pandemic, understanding of the burden of HIV among these women remains limited. We aimed to assess the burden of HIV in this population compared with that of other women of reproductive age.

METHODS

We searched PubMed, Embase, Global Health, SCOPUS, PsycINFO, Sociological Abstracts, CINAHL (Cumulative Index to Nursing and Allied Health Literature), Web of Science, and POPLine for studies of female sex workers in low-income and middle-income countries published between Jan 1, 2007, and June 25, 2011. Studies of any design that measured the prevalence or incidence of HIV among female sex workers, even if sex workers were not the main focus of the study, were included. Meta-analyses were done with the Mantel-Haenszel method with a random-effects model characterising an odds ratio for the prevalence of HIV among female sex workers compared with that for all women of reproductive age.

FINDINGS

Of 434 selected articles and surveillance reports, 102 were included in the analyses, representing 99,878 female sex workers in 50 countries. The overall HIV prevalence was 11·8% (95% CI 11·6-12·0) with a pooled odds ratio for HIV infection of 13·5 (95% CI 10·0-18·1) with wide intraregional ranges in the pooled HIV prevalence and odds ratios for HIV infection. In 26 countries with medium and high background HIV prevalence, 30·7% (95% CI 30·2-31·3; 8627 of 28,075) of sex workers were HIV-positive and the odds ratio for infection was 11·6 (95% CI 9·1-14·8).

INTERPRETATION

Although data characterising HIV risk among female sex workers is scarce, the burden of disease is disproportionately high. These data suggest an urgent need to scale up access to quality HIV prevention programmes. Considerations of the legal and policy environments in which sex workers operate and actions to address the important role of stigma, discrimination, and violence targeting female sex workers is needed.

FUNDING

The World Bank, UN Population Fund.

Contributions of international cooperation projects to the HIV/AIDS response in China

BACKGROUND

For 20 years, China has participated in 267 international cooperation projects against the HIV/AIDS epidemic and received ∼526 million USD from over 40 international organizations. These projects have played an important role by complementing national efforts in the fight against HIV/AIDS in China.

METHODS

The diverse characteristics of these projects followed three phases over 20 years. Initially, stand-alone projects provided technical support in surveillance, training or advocacy for public awareness. As the epidemic spread across China, projects became a part of the comprehensive and integrated national response. Currently, international best practices encourage the inclusion of civil society and non-governmental organizations in an expanded response to the epidemic.

RESULTS

Funding from international projects has accounted for one-third of the resources provided for the HIV/AIDS response in China. Beyond this strong financial support, these programmes have introduced best practices, accelerated the introduction of AIDS policies, strengthened capacity, improved the development of grassroots social organizations and established a platform for communication and experience sharing with the international community. However, there are still challenges ahead, including integrating existing resources and exploring new programme models. The National Centre for AIDS/STD Control and Prevention (NCAIDS) in China is consolidating all international projects into national HIV prevention, treatment and care activities.

CONCLUSION

International cooperation projects have been an invaluable component of China's response to HIV/AIDS, and China has now been able to take this information and share its experiences with other countries with the help of these same international programmes.

Seroprevalence of blood-borne infections and population sizes estimates in a population of injecting drug users in Croatia

Similar to some other Central European countries, Croatia has low HIV prevalence among injecting drug users (IDUs) but high hepatitis C (HCV) prevalence. This may indicate different patterns of risk behaviour in this region than in other parts of Europe. The main objectives of this study were to assess the seroprevalence of HIV and hepatitis B and C and related risk factors among IDUs in the three largest Croatian cities (Zagreb, Split, Rijeka) and within the national prison system, as well as to apply a multiplier-method population size estimation of IDUs in Zagreb, Split and Rijeka. Recruitment sites were selected in collaboration with the local public health institutes, NGOs, Centers for treatment municipalities and the judiciary system. Participants were recruited during September and October 2007. Trained peer-recruiters were used to recruit IDU participants at treatment and harm reduction centres as well as pre-identified social, commercial and street based venues. Participants completed the study questionnaire and provided venous blood samples for HIV, hepatitis B and hepatitis C testing. The study included 601 participants, of whom 121 were recruited in Split, 130 in Zagreb, 150 in Rijeka and 200 in the prison system. The prevalence of positive anti-HCV tests was 65% in Split, 51% in Zagreb, 29% in Rijeka and 44% in the prisons. The prevalence of anti-HBcAg was 31% in Split, 13% in Zagreb, 9% in Rijeka and 24% in prison. No case of HIV infection was found. The estimated IDUs population sizes were 2,805 for Zagreb area, 3,347 for Split and 1,370 for Rijeka area, however confidence intervals were very large, indicating the need for larger samples. A high frequency of positive markers on hepatitis B virus and C virus in the population of injecting drug users in Croatia has been confirmed with this research, as well as a low prevalence of HIV infection. This may be related to relatively low levels of injecting risk behaviour and injecting frequency although it is not possible to make strong conclusions on risk behaviour, as participants were mostly recruited in harm reduction programmes. This research should be followed by targeted activities for reducing risks of infectious diseases among injecting drug users in the Republic of Croatia and future research at the national level.

The HIV/AIDS Surveillance Project mapping approach: an innovative approach for mapping and size estimation for groups at a higher risk of HIV in Pakistan

OBJECTIVE

We developed a mapping approach to gather data on distribution, number of settings, operational typologies and estimated size of female sex workers (FSWs), male sex workers, hijra sex workers and injection drug users in Pakistan.

METHODS

Data were collected across 12 major cities in Pakistan. Broader methodological steps involved dividing each target city into smaller geographical units and collecting data within each zone from secondary and tertiary key informants, also known as level 1. Level 2 ensured involvement of the communities themselves in validating these estimates, followed by triangulation of the finalized results. Rates for each subgroup per 1000 adult men or women were computed and rolled up into provincial estimates to be summed up into national estimates.

RESULTS

FSWs formed the largest group reported, with estimates of 79 127 and five different subtypologies. Injection drug users were the second largest group, followed by male sex workers and hijra sex workers with estimates of 31 555, 19 320 and 14 702, respectively. We estimated approximately 167 501 FSWs in Pakistan, with an overall national rate of 4. 4 FSWs per 1000 adult women. A total of 71 911 male sex workers in addition to 39 262 hijra sex workers were calculated with rates of 1.7 and 0.9 per 1000 men, whereas injection drug users had an overall estimate of 102 042.

CONCLUSION

This relatively simple methodology provides a scientific and systematic approach, which can be used in the region to estimate population sizes, understand geographical distribution of these groups and recognize the various operational typologies and dynamics of these populations for developing effective prevention strategies.

Appropriateness and execution challenges of three formal size estimation methods for high-risk populations in India

OBJECTIVES

To describe formal, external to programme methods for size estimation of high-risk populations and compare execution challenges and validity of results.

DESIGN

A cross-sectional HIV risk behavioural and biological survey was implemented among 24, 10 and five female sex workers, high-risk men who have sex with men and injecting drug user survey groups, respectively. Size estimates were calculated using three formal methods: capture-recapture, the multiplier method and the reverse tracking method (RTM), a new method.

METHODS

Estimates were compared with each other and programme data.

RESULTS

In general, when appropriately executed, formal methods produced smaller estimates to programme data, although the RTM tended to be closer to programme estimates.

CONCLUSIONS

Capture-recapture requires some knowledge of site location. It can be used as a community mobilization measure at the initiation of a programme. The multiplier method presumes the existence of high quality external data and requires care in selecting the appropriate multiplier. All size estimation methods require careful planning and a full understanding of population dynamics and limitations of data. Before selecting a size estimation method, one must be aware of the strengths, weaknesses and applicability of each method. Use of size estimation methods in large-scale programmes should be considered carefully with adequate importance given to planning and implementation.

Permanent silencing of NKG2A expression for cell-based therapeutics

Natural killer (NK) and T-cell cytotoxicity is significantly reduced by signaling via CD94/NKG2A receptors. High levels of NKG2A on NK cells have been shown to compromise the graft-versus-leukemia effect in hematopoietic stem cell transplantation. We therefore evaluated the functional relevance of NKG2A silencing for the cytotoxic potential of genetically engineered NK and T cells. Lentiviral vectors containing short hairpin RNA (shRNA) sequences targeting NKG2A transcripts were used to transduce NKG2A(+) primary NK and T cells. NKG2A expression levels were measured by flow cytometry and real-time PCR. The effect of NKG2A silencing on the cytolytic potential of NK and T cells was evaluated in cytotoxicity assays using K562 and B lymphoblastoid cells as targets. Granzyme B mRNA transcript levels were detected by real-time PCR. The transduction of inducible RNAi cassettes containing the sequences for shRNAs targeting NKG2A reduced protein expression in NK and T cells by up to 95%. The cytotoxicity assays demonstrated that NKG2A silencing effectively enhanced NK and CD8+ T-cell lysis by up to 40% and 15%, respectively. However, lysis of K562 cells which lack human leukocyte antigen-E, the ligand of NKG2A, was associated with an upregulation of the natural cytotoxicity receptor NKp30 in NKG2A-silenced NK cells. Our data suggest that RNAi-mediated silencing of NKG2A in effector cells could improve the efficacy of cell-based immunotherapies but also show that indirect effects of NKG2A knockdown exist that have to be considered when designing therapeutic protocols with genetically engineered NK or T cells.