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Introduction: Plasmablastic lymphoma (PBL) is an uncommon and aggressive large B-cell lymphoma commonly diagnosed in human immunodeficiency viruses -positive patients. Oral cavity is the most commonly PBL affected site. Most oral PBLs presented as asymptomatic swellings, frequently associated with ulcerations and bleeding. Most cases lacked B-symptoms, suggesting a more local involvement of the disease. No standard treatment is yet for oral PBL. Five-year survival rate recorded no more than 33.5%. Patient concerns: A 39-year-old male presented to Dental Clinic with 1 month swelling of the oral cavity, in absence of any other symptoms or signs. He followed antibiotic therapy just on suspicion of an oral abscess and later oral surgical treatment on suspicion of bone neoplasm. Diagnosis: Surgical specimen analysis highlighted a diffuse infiltrate of large-sized atypical cells with plasmablastic appearance and plasma cell phenotype. Oral cavity PBL was diagnosed. Blood tests recorded mild lymphopenia and positive human immunodeficiency viruses serology. Interventions: Patient underwent chemotherapy including intrathecal methotrexate prophylaxis, in addition to a highly active antiretroviral therapy. Outcomes: At 12 months from diagnosis, patient recorded complete hematological remission. Conclusions: Oral PBL diagnosis requires a high level of suspicion and awareness both by physicians and pathologists. They should be aware of the extent of such disease which is often mistaken as oral abscess or infected tooth, thus leading to delay the most appropriate diagnostic evaluation. As PBL is an aggressive non-Hodgkin lymphoma, a delayed diagnosis might negatively impact on both treatment and survival.

Background: The nutritional status of HIV-infected children is reported to be poor. Diarrhoea and acute respiratory infections tend to be more common and severe in HIV-infected children than in uninfected ones. Deficiencies of micronutrients may result in poor growth and increased risk of diarrhoea and respiratory infections. Micronutrient deficiencies are common in HIV-infected children. The poor growth, diarrhoea and respiratory infections seen in HIV-infected children may be partly due to micronutrient deficiencies. The studies in this thesis had two main objectives: (1) to evaluate the effect of short-term (during hospitalization) and long-term (6 months) multi-micronutrient supplementation on episodes of diarrhoea and respiratory infections in HIV-infected children who are not yet on antiretroviral therapy (ART), and (2) to assess the effects of long-term multi-micronutrient supplementation on appetite and growth performance of HIV-infected who are not on ART. Methods and results: Four studies were conducted. Initially a cross-sectional study was performed in which the duration of hospitalization, weight, length, micronutrient status and appetite of HIV-infected children admitted with diarrhoea or pneumonia was compared with the results of HIV-uninfected children. Duration of hospitalization was 2.8 days (52%) longer in HIV-infected children. Appetite as measured by amount of test food eaten (g per kg body weight) was 26% poorer in HIV-infected children. Mean length-for-age Z-scores were lower in HIV-infected children; there was no difference in level of wasting. Subsequently multi-micronutrient supplementation studies were performed, one short-term and two long-term studies. The effect of supplementation on the duration of hospitalization in HIV-infected children with diarrhoea or pneumonia was assessed in the short-term study. One long-term study assessed the supplement’s impact on growth and frequency of episodes of diarrhoea and of pneumonia in HIV-infected children. The other evaluated the effect of the supplement on the appetite of these children. The supplement contained vitamins A, B complex, C, D, E and folic acid, and the minerals copper, iron, selenium and zinc at levels based on recommended dietary allowances. In the short-term supplementation study HIV-infected children aged 4-24 months who were hospitalized with pneumonia or diarrhoea received the supplement or a placebo until discharge from hospital. The duration of hospitalization was 1.7 days (19%) shorter in the supplement group. Long-term multi-micronutrient supplementation improved the weight-for-age and weight-for-height Z-scores of HIV-infected children aged 4-24 months by 0.4 over the 6-month period. There was no improvement in stunting. Children in the supplement group had substantially fewer episodes of respiratory symptoms per month than the placebo group (0.66 ± 0.51) per month vs (1.01 ± 0.67) (P < 0.05) and marginally fewer episodes of diarrhoea per month (0.25 ± 0.31) vs (0.36 ± 0.36) (P = 0.09). There was no effect on CD4 lymphocytes. Long-term supplementation with micronutrients had benefits on the appetite of HIV-infected children aged 6-24 months as well. Improvements in amount of test food eaten over the 6-month period were much higher among children who received the supplement (4.7 ± 14.7 g/kg body weight) than the changes in those who received the placebo (-1.4 ± 11.6 g/kg body weight). Conclusion: Multi-micronutrient supplementation reduces the duration of diarrhoea and of pneumonia and incidence of diarrhoea and of respiratory symptoms in HIV-infected children who are not yet on ART. Multi-micronutrient supplementation also improves appetite and weight in these children but not height. The results of these studies indicate that multi-micronutrient supplementation should be considered in HIV-infected infant and young children who have not commenced ART.

Background: The nutritional status of HIV-infected children is reported to be poor. Diarrhoea and acute respiratory infections tend to be more common and severe in HIV-infected children than in uninfected ones. Deficiencies of micronutrients may result in poor growth and increased risk of diarrhoea and respiratory infections. Micronutrient deficiencies are common in HIV-infected children. The poor growth, diarrhoea and respiratory infections seen in HIV-infected children may be partly due to micronutrient deficiencies. The studies in this thesis had two main objectives: (1) to evaluate the effect of short-term (during hospitalization) and long-term (6 months) multi-micronutrient supplementation on episodes of diarrhoea and respiratory infections in HIV-infected children who are not yet on antiretroviral therapy (ART), and (2) to assess the effects of long-term multi-micronutrient supplementation on appetite and growth performance of HIV-infected who are not on ART. Methods and results: Four studies were conducted. Initially a cross-sectional study was performed in which the duration of hospitalization, weight, length, micronutrient status and appetite of HIV-infected children admitted with diarrhoea or pneumonia was compared with the results of HIV-uninfected children. Duration of hospitalization was 2.8 days (52%) longer in HIV-infected children. Appetite as measured by amount of test food eaten (g per kg body weight) was 26% poorer in HIV-infected children. Mean length-for-age Z-scores were lower in HIV-infected children; there was no difference in level of wasting. Subsequently multi-micronutrient supplementation studies were performed, one short-term and two long-term studies. The effect of supplementation on the duration of hospitalization in HIV-infected children with diarrhoea or pneumonia was assessed in the short-term study. One long-term study assessed the supplement’s impact on growth and frequency of episodes of diarrhoea and of pneumonia in HIV-infected children. The other evaluated the effect of the supplement on the appetite of these children. The supplement contained vitamins A, B complex, C, D, E and folic acid, and the minerals copper, iron, selenium and zinc at levels based on recommended dietary allowances. In the short-term supplementation study HIV-infected children aged 4-24 months who were hospitalized with pneumonia or diarrhoea received the supplement or a placebo until discharge from hospital. The duration of hospitalization was 1.7 days (19%) shorter in the supplement group. Long-term multi-micronutrient supplementation improved the weight-for-age and weight-for-height Z-scores of HIV-infected children aged 4-24 months by 0.4 over the 6-month period. There was no improvement in stunting. Children in the supplement group had substantially fewer episodes of respiratory symptoms per month than the placebo group (0.66 ± 0.51) per month vs (1.01 ± 0.67) (P < 0.05) and marginally fewer episodes of diarrhoea per month (0.25 ± 0.31) vs (0.36 ± 0.36) (P = 0.09). There was no effect on CD4 lymphocytes. Long-term supplementation with micronutrients had benefits on the appetite of HIV-infected children aged 6-24 months as well. Improvements in amount of test food eaten over the 6-month period were much higher among children who received the supplement (4.7 ± 14.7 g/kg body weight) than the changes in those who received the placebo (-1.4 ± 11.6 g/kg body weight). Conclusion: Multi-micronutrient supplementation reduces the duration of diarrhoea and of pneumonia and incidence of diarrhoea and of respiratory symptoms in HIV-infected children who are not yet on ART. Multi-micronutrient supplementation also improves appetite and weight in these children but not height. The results of these studies indicate that multi-micronutrient supplementation should be considered in HIV-infected infant and young children who have not commenced ART.

This thesis deals with the effectiveness and the capability of microfinance institutions in enhancing women’s livelihood and empowerment, and mitigating the effects of HIV and AIDS on affected women and their households in Côte d’Ivoire. This study was carried out within the framework of the AWLAE (African Women Leaders in Agriculture and Environment) Project. The AWLAE project addresses the theme of the role of women in food systems and effects of HIV and AIDS on rural livelihoods. Microfinance has been recognized as a significant means of economic development in developing countries, especially in Africa where most of the economies are based on agriculture. Microfinance as a credit institution is seen as one of the relevant tools that can provide small loans for poor people especially women who have no access to formal banks. Therefore MFIs have attracted more attention from governments, NGOs, researchers and civil servants since the microcredit summit in 1997 and the nomination of the year 2005 as the International Year of Microcredit by the United Nations General Assembly. Studies have shown that the effects of MFIs on women’s activities differ between countries and between regions within countries according to factors including the environment, and the socio-demographic characteristics of the beneficiaries. This heterogeneity renders the effects of MFIs inconclusive and explains the necessity and the relevance to conduct this empirical study in Côte d’Ivoire. The objective of this study is to gain insight into women’s needs in terms of support for economic activities and empowerment in rural areas and the way in which MFIs address these needs. Specifically, the study aims at assessing whether microfinance services provided for women in Côte d’Ivoire fit their needs in terms of improving their incomes, productivity, decision-making power, human and social capital. Special attention is paid to HIV-affected women. To achieve these objectives, the study tends to respond to four main research questions: 1) What are women’s needs for credit in rural areas? 2) How do women have access to MFI credit in rural areas? 3) What are the effects of participation in microfinance programs on women’s practical and strategic gender needs? 4) What is the relationship between microfinance programs and women coping with HIV/AIDS? These research questions lead to the formulation of hypotheses that are confirmed or rejected. This study uses both a theoretical and empirical approach that represents the interaction of women’s livelihood, microfinance and HIV and AIDS. The empirical analysis consists of an in-depth analysis of microfinance institutions and a survey analysis applied to cross-sectional data collected from 440 women in the Abengourou region located in the Central Eastern part of Côte d’Ivoire. The sample was divided into four categories of women as follows: Non-HIV affected women with and without MFI credit; HIV-affected women with and without credit. This study gives a descriptive analysis of the study country, and the response of the state to promote the microfinance sector and to mitigate the effects of HIV and AIDS on the individual, household and communities in Côte d’Ivoire. Women in the Abengourou region are basically involved in agriculture from which they earn their livelihood and the opportunity to produce food for household consumption. The type of activities carried by women depends on their access to credit. Those who have no access to MFI loans were mainly engaged in farm activities while women with access to credit were mainly traders. They were also able to undertake both agricultural and trade activities. From these results, it appears that women in rural areas need MFI credit for trade purposes and to a lesser extent for agricultural activities. This study found a significant relation between savings and credit, meaning that access to MFI credit was fundamentally conditioned on the provision of savings from the borrowers that most of the rural population did not have. MFIs use savings as collateral to prevent defaults. In addition, MFI membership and the type of activity are also important to obtain MFI credit. Furthermore, access to MFI credit depends on factors linked to the characteristics of female borrowers including, marital status, wealth status of the household, ethnicity and the empowerment of women, and trade activity. These determinants positively affect the probability of obtaining MFI credit in rural areas. The study reveals that MFIs prefer to finance trade activity rather than agricultural activity as the latter is seen as risky and associated with unpredictable income. The use of the propensity score matching method led to the following results. MFIs are found to be effective in enhancing a set of variables including income, the level of farm production, human and social capital. MFI credit has enhanced women’s decision-making power within the households too. However, women’s access and use of MFI credit in rural areas did not significantly increase the value of women’s assets but it did significantly enhance the value of household assets. This result on the value of women’s assets did not confirm the findings of several studies which indicated that the provision of credit enables women to build up and improve the value of their assets (Rahman, 2004; Mayoux, 1999, Van Maanen, 2004). The result also suggested that female borrowers were more likely to use their income earned not to build their own assets, but to contribute to the improvement of the household standard of living. Doing so enables these women to achieve more power in fulfilling their practical and strategic gender needs within the household as indicated by the findings of this study. The effectiveness of MFIs in providing loans for women in rural areas is measured by the loan repayment which is an important indicator for MFI practitioners. It gives insight into the capability of the credit institution to insure its sustainability and to increase its outreach. From our analysis, loan repayment among female borrowers generally was not successful as some borrowers had difficulties to pay back their MFI loan. The non-repayment is mainly explained by the diversion of loans from investment purposes, which has to do with the lack of women’s control over loans. For MFIs, the diversion of loans can endanger their functioning and sustainability and therefore their effectiveness in rural areas. However, this study found the low repayment performance of female borrowers to be contradictory to the positive effect of MFI credit on women’s income and the positive return on investment they achieved. Hence, this study suggests that in addition to the diversion of loans, non-repayment might be linked to other factors especially the unwillingness of the borrowers to repay their loan. The analysis of the interaction between HIV/AIDS, women’s livelihood and MFIs reveals on the one hand that HIV and AIDS negatively affects both human and physical capital of households through morbidity and mortality. The morbidity of affected women results in a direct negative impact on their livelihood activities and an indirect effect on their income and loan repayment. HIV/AIDS has an impact on the morbidity of household members that leads to the loss of family labour, which is difficult to replace due to lack of resources. In addition, the morbidity results in a drop in the level of education as children are forced to stay at home due to illness. On the other hand, the negative effects of HIV and AIDS on female borrowers entail an indirect effect on MFIs through the incapability of affected borrowers to generate more money and inability to payback their loans. This result essentially has to do with the diversion of loans to meet medical expenditures and the process of the provision of loans that appears to be flawed. In line with this deficiency, the functioning and the effectiveness of MFIs to support and extend their outreach among HIV-affected individuals or households are threatened. This study contributes to the existing findings about the socio-economic role of MFIs to support women generating their livelihood. It gives empirical findings in the case of rural areas in Côte d’Ivoire. Such study was not done since the implementation of microfinance institutions in the Abengourou region. The study reveals that the activities carried by women can be influenced by their need to have access to MFIs. This means that women will choose to undertake a particular activity to fit the preferences of microfinance institutions. Another important contribution of this study is to empirically link women’s empowerment to their access to MFI credit. The study reveals that women’s empowerment regarding the demand for and the use of credit make them more reliable and give them more opportunity to obtain MFI credit. With regard to HIV, this study highlights the diversity and the specificity of the way HIV-affected individuals are financially supported by credit institutions. To conclude, the study provides some policy recommendations and interventions in order to make MFIs more effective in offering financial services to individuals and households in general and women in particular in rural areas. Specifically we recommend the provision of loans taking into account the needs of borrowers with respect to the special nature of their activities to be financed. MFIs need subsidies from the state or other potential donors to reinforce the capacity building of MFI credit officers through training and to support the transaction costs linked to the provision of small loans. Doing so will help them to better understand and serve the rural population living in an environment which seems to be complex. The study also recommends further study to be conducted in order to explore the long-run effects of MFI credit in rural Côte d’Ivoire.

This thesis deals with the effectiveness and the capability of microfinance institutions in enhancing women’s livelihood and empowerment, and mitigating the effects of HIV and AIDS on affected women and their households in Côte d’Ivoire. This study was carried out within the framework of the AWLAE (African Women Leaders in Agriculture and Environment) Project. The AWLAE project addresses the theme of the role of women in food systems and effects of HIV and AIDS on rural livelihoods. Microfinance has been recognized as a significant means of economic development in developing countries, especially in Africa where most of the economies are based on agriculture. Microfinance as a credit institution is seen as one of the relevant tools that can provide small loans for poor people especially women who have no access to formal banks. Therefore MFIs have attracted more attention from governments, NGOs, researchers and civil servants since the microcredit summit in 1997 and the nomination of the year 2005 as the International Year of Microcredit by the United Nations General Assembly. Studies have shown that the effects of MFIs on women’s activities differ between countries and between regions within countries according to factors including the environment, and the socio-demographic characteristics of the beneficiaries. This heterogeneity renders the effects of MFIs inconclusive and explains the necessity and the relevance to conduct this empirical study in Côte d’Ivoire. The objective of this study is to gain insight into women’s needs in terms of support for economic activities and empowerment in rural areas and the way in which MFIs address these needs. Specifically, the study aims at assessing whether microfinance services provided for women in Côte d’Ivoire fit their needs in terms of improving their incomes, productivity, decision-making power, human and social capital. Special attention is paid to HIV-affected women. To achieve these objectives, the study tends to respond to four main research questions: 1) What are women’s needs for credit in rural areas? 2) How do women have access to MFI credit in rural areas? 3) What are the effects of participation in microfinance programs on women’s practical and strategic gender needs? 4) What is the relationship between microfinance programs and women coping with HIV/AIDS? These research questions lead to the formulation of hypotheses that are confirmed or rejected. This study uses both a theoretical and empirical approach that represents the interaction of women’s livelihood, microfinance and HIV and AIDS. The empirical analysis consists of an in-depth analysis of microfinance institutions and a survey analysis applied to cross-sectional data collected from 440 women in the Abengourou region located in the Central Eastern part of Côte d’Ivoire. The sample was divided into four categories of women as follows: Non-HIV affected women with and without MFI credit; HIV-affected women with and without credit. This study gives a descriptive analysis of the study country, and the response of the state to promote the microfinance sector and to mitigate the effects of HIV and AIDS on the individual, household and communities in Côte d’Ivoire. Women in the Abengourou region are basically involved in agriculture from which they earn their livelihood and the opportunity to produce food for household consumption. The type of activities carried by women depends on their access to credit. Those who have no access to MFI loans were mainly engaged in farm activities while women with access to credit were mainly traders. They were also able to undertake both agricultural and trade activities. From these results, it appears that women in rural areas need MFI credit for trade purposes and to a lesser extent for agricultural activities. This study found a significant relation between savings and credit, meaning that access to MFI credit was fundamentally conditioned on the provision of savings from the borrowers that most of the rural population did not have. MFIs use savings as collateral to prevent defaults. In addition, MFI membership and the type of activity are also important to obtain MFI credit. Furthermore, access to MFI credit depends on factors linked to the characteristics of female borrowers including, marital status, wealth status of the household, ethnicity and the empowerment of women, and trade activity. These determinants positively affect the probability of obtaining MFI credit in rural areas. The study reveals that MFIs prefer to finance trade activity rather than agricultural activity as the latter is seen as risky and associated with unpredictable income. The use of the propensity score matching method led to the following results. MFIs are found to be effective in enhancing a set of variables including income, the level of farm production, human and social capital. MFI credit has enhanced women’s decision-making power within the households too. However, women’s access and use of MFI credit in rural areas did not significantly increase the value of women’s assets but it did significantly enhance the value of household assets. This result on the value of women’s assets did not confirm the findings of several studies which indicated that the provision of credit enables women to build up and improve the value of their assets (Rahman, 2004; Mayoux, 1999, Van Maanen, 2004). The result also suggested that female borrowers were more likely to use their income earned not to build their own assets, but to contribute to the improvement of the household standard of living. Doing so enables these women to achieve more power in fulfilling their practical and strategic gender needs within the household as indicated by the findings of this study. The effectiveness of MFIs in providing loans for women in rural areas is measured by the loan repayment which is an important indicator for MFI practitioners. It gives insight into the capability of the credit institution to insure its sustainability and to increase its outreach. From our analysis, loan repayment among female borrowers generally was not successful as some borrowers had difficulties to pay back their MFI loan. The non-repayment is mainly explained by the diversion of loans from investment purposes, which has to do with the lack of women’s control over loans. For MFIs, the diversion of loans can endanger their functioning and sustainability and therefore their effectiveness in rural areas. However, this study found the low repayment performance of female borrowers to be contradictory to the positive effect of MFI credit on women’s income and the positive return on investment they achieved. Hence, this study suggests that in addition to the diversion of loans, non-repayment might be linked to other factors especially the unwillingness of the borrowers to repay their loan. The analysis of the interaction between HIV/AIDS, women’s livelihood and MFIs reveals on the one hand that HIV and AIDS negatively affects both human and physical capital of households through morbidity and mortality. The morbidity of affected women results in a direct negative impact on their livelihood activities and an indirect effect on their income and loan repayment. HIV/AIDS has an impact on the morbidity of household members that leads to the loss of family labour, which is difficult to replace due to lack of resources. In addition, the morbidity results in a drop in the level of education as children are forced to stay at home due to illness. On the other hand, the negative effects of HIV and AIDS on female borrowers entail an indirect effect on MFIs through the incapability of affected borrowers to generate more money and inability to payback their loans. This result essentially has to do with the diversion of loans to meet medical expenditures and the process of the provision of loans that appears to be flawed. In line with this deficiency, the functioning and the effectiveness of MFIs to support and extend their outreach among HIV-affected individuals or households are threatened. This study contributes to the existing findings about the socio-economic role of MFIs to support women generating their livelihood. It gives empirical findings in the case of rural areas in Côte d’Ivoire. Such study was not done since the implementation of microfinance institutions in the Abengourou region. The study reveals that the activities carried by women can be influenced by their need to have access to MFIs. This means that women will choose to undertake a particular activity to fit the preferences of microfinance institutions. Another important contribution of this study is to empirically link women’s empowerment to their access to MFI credit. The study reveals that women’s empowerment regarding the demand for and the use of credit make them more reliable and give them more opportunity to obtain MFI credit. With regard to HIV, this study highlights the diversity and the specificity of the way HIV-affected individuals are financially supported by credit institutions. To conclude, the study provides some policy recommendations and interventions in order to make MFIs more effective in offering financial services to individuals and households in general and women in particular in rural areas. Specifically we recommend the provision of loans taking into account the needs of borrowers with respect to the special nature of their activities to be financed. MFIs need subsidies from the state or other potential donors to reinforce the capacity building of MFI credit officers through training and to support the transaction costs linked to the provision of small loans. Doing so will help them to better understand and serve the rural population living in an environment which seems to be complex. The study also recommends further study to be conducted in order to explore the long-run effects of MFI credit in rural Côte d’Ivoire.

In the hard-hit countries by HIV/AIDS, the epidemic has eroded the development gains made in past decades. The spread of HIV is heterogeneous in Sub-Saharan African courtiers, with different peaks which vary geographically and in terms of their distribution among social or economic groups. Thus, there is a pressing need to promote researches and policy making not only at biomedical and behavioural level but also at the underlying social, cultural and economic causes of the epidemic. Although HIV prevention policies and interventions should be based on evidences that show how the disease spreads in the community, however, very few studies have focused on the susceptibility of pastoralists, and therefore there is a great need to acknowledge and document the risk environments which contribute to the spread of HIV/AIDS in pastoral areas to curb the spread of the epidemic. Based on the research in Shinile district of Somali region in Ethiopia, this study aims to identify the risk for the spread of HIV among Shinile pastoralists by looking at the susceptibility factors in the community. In the fieldwork in Ethiopia interviews with 20 people and 3 focus group discussions (FGDs) in the community were conducted. As a tool for identifying susceptibility factors, the study adapted the framework by Tony Barnett and Alan Whiteside and analyzes the research results in terms of identified factors. The research shows that although there is lack of reliable data on the prevalence of the epidemic in the district, HIV/AIDS is a clear and present danger to Shinile pastoral communities. The awareness on HIV/AIDS level in the community are low, the communities have not accepted the presence and the threat associated with the epidemic. The study reveals that migration to urban centers particularly to the neighboring centers with high HIV/AIDS prevalence is likely to be one of the factors which contribute to the spread of the disease to the low risk population. The low awareness and misconceptions on HIV/AIDS compounded by the low access to preventive health services also poses a major risk. In addition, there is a general absence of self- protection among the community, a situation perpetuated by religious and traditional norms. The study also shows that women faces a heightened risk of HIV infection as they have low awareness level due to the ‘women stay home culture’ among pastoralists which limited their access to HIV/AIDS information. Moreover, gender related norms which put women at risk like polygamous marriage, marriage by inheritance, early marriage and female genital mutilation (FGM) are also widely practiced. The striking finding of the research is that being part of pastoral societies, Shinile communities have no experience of violent conflicts among their clan or the neighboring pastoral societies which is known to be common among pastoralists in general. Traditional patterns of sexual networking like wife sharing and multiple sexual partners (pre-marriage and in-marriage) which are promoted in some pastoral societies are not widely acknowledged among Shinile pastoral communities. Finally, the study presents both short term and long term recommendations which contribute towards prevention of HIV spread among the study area. The short term include i) better understanding of the status of the epidemic ii) organise targeted awareness raising campaigns iii) community empowerment to challenge norms and culture on gender issues iv) enhance the involvement of non-governmental organisations (NGOs) and community based organisations( CBOs) in response to the epidemic and v) improve access to preventive health services. The long term recommendations are: i) Policy review on development of pastoral areas and ii) Strengthening and diversifying of pastoral livelihoods.

Background: Type I human immunodeficiency virus (HIV) is characterized by a great genetic variability. There are three groups of virus throughout the world: O, N and M. Group M is responsible for AIDS pandemic and is subdivided in 9 genetic subtypes. Most viral strains in South America are subtype B. Aim: To determine the frequency of HIV subtypes in Chilean patients. Material and methods: Genetic analysis of C2-V3-C3 region of the gene env in HIV strains coming from 77 Chilean subjects infected by different means. DNA heteroduplex mobility assay was used to determine HIV subtypes. Results: Sixty eight cases were infected with subtype B (88.3%) and nine cases were infected with subtype F (11.7%). Conclusions: Subtype B is the predominant HIV in Chile, but subtype F is also present (Rev Méd Chile 2003; 131: 711-8)

Background HIV-1 p24 antigen is a major viral component of human immunodeficiency virus type 1 (HIV-1) which can be used to identify persons in the early stage of infection and transmission of HIV-1 from infected mothers to infants. The detection of p24 is usually accomplished by using an enzyme-linked immunosorbent assay (ELISA) with low detection sensitivity. Here we report the use of two bio-barcode amplification (BCA) assays combined with polymerase chain reaction (PCR) and gel electrophoresis to quantify HIV-1 p24 antigen. Method A pair of anti-p24 monoclonal antibodies (mAbs) were used in BCA assays to capture HIV-1 p24 antigen in a sandwich format and allowed for the quantitative measurement of captured p24 using PCR and gel electrophoresis. The first 1 G12 mAb was coated on microplate wells or magnetic microparticles (MMPs) to capture free p24 antigens. Captured p24 in turn captured 1D4 mAb coated gold nanoparticle probes (GNPs) containing double-stranded DNA oligonucleotides. One strand of the oligonucleotides was covalently immobilized whereas the unbound complimentary bio-barcode DNA strand could be released upon heating. The released bio-barcode DNA was amplified by PCR, electrophoresed in agarose gel and quantified. Results The in-house ELISA assay was found to quantify p24 antigen with a limit of detection (LOD) of 1,000 pg/ml and a linear range between 3,000 and 100,000 pg/ml. In contrast, the BCA-based microplate method yielded an LOD of 1 pg/ml and a linear detection range from 1 to 10,000 pg/ml. The BCA-based MMP method yielded an LOD of 0.1 pg/ml and a linear detection range from 0.1 to 1,000 pg/ml. Conclusions When combined with PCR and simple gel electrophoresis, BCA-based microplate and MMPs assays can be used to quantify HIV-1 p24 antigen. These methods are 3–4 orders of magnitude more sensitive than our in-house ELISA-based assay and may provide a useful approach to detect p24 in patients newly infected with HIV.