P02-07. High Concentrations of Interleukin-15 and Low Concentrations of CCL5 in Breast Milk are Associated with Protection against Postnatal HIV Transmission

Background: Natural variations in IL-15 concentration have not been investigated for an association with an immune-protection against HIV. Given IL-15's central role in anti-HIV immunity, we hypothesized that higher concentrations of IL-15 in breast milk may protect against postnatal mother-to-child HIV transmission. Methods: In a case-control study nested within a clinical trial in Zambia, we compared IL-15 concentrations in breast milk of 22 HIV-infected women who transmitted HIV to their infants through breastfeeding with those of 72 who did not, as well as 18 HIV-uninfected women. Breast milk HIV RNA quantity, sodium, CXCL12, CCL5, and IL-8 concentrations were measured as well as maternal plasma HIV RNA concentrations and CD4 cell count. We used logistic regression modeling to adjust for potential confounders. Results: Higher concentrations of IL-15 in breast milk (adjusted odds ratio [AOR]: 0.01 per log10 pg/ml increase, 95% confidence interval [CI]: <0.001 to 0.3) were associated with protection against postnatal HIV transmission in univariate analysis and after adjusting for maternal CD4 cell counts, breast milk HIV RNA, CCL5, CXCL12, and IL-8 concentrations. Breast milk IL-15 concentration correlated with breast milk sodium, the other cytokines and HIV RNA concentration. It was inversely correlated with infant birth weight and tended to be higher in 1 week than in 1 month post-partum samples. Breast milk CCL5 concentrations were associated with increased risk of HIV transmission (AOR: 12.7 95% CI: 1.6 to 102.0) in adjusted analysis. Breast milk CXCL12 and IL-8 concentrations were not independently associated with transmission. Conclusion: High concentration of IL-15 were associated with a protection against breastfeeding HIV transmission after adjusting for other pro-inflammatory cytokines, HIV RNA in breast milk, and maternal CD4 cell count. These results corroborate a protective role of IL-15-mediated cellular immunity against HIV transmission during breastfeeding. They are informative for vaccination studies using IL-15 as an adjuvant

Maternal micronutrient status and decreased growth of Zambian infants born during and after the maize price increases resulting from the southern African drought of 2001-2002.

OBJECTIVE: To investigate the effects on maternal micronutrient status and infant growth of the increased maize prices that resulted from the southern African drought of 2001-2002. DESIGN: Longitudinal cohort study. SETTING: A maternal and child health clinic in Lusaka, Zambia. SUBJECTS: Maternal and infant health and nutrition data and maternal plasma were being collected for a study of breast-feeding and postpartum health. Samples and data were analysed according to whether they were collected before (June to December 2001), during (January 2002 to April 2003) or after (May 2003 to January 2004) the period of increased maize price. Season and maternal HIV status were controlled for in analyses. RESULTS: Maize price increases were associated with decreased maternal plasma vitamin A during pregnancy (P = 0.028) and vitamin E postpartum (P = 0.042), with the lowest values among samples collected after May 2003 (vitamin A: 0.96 micromol l(-1), 95% confidence interval (CI) 0.84-1.09, n = 38; vitamin E: 30.8 micromol mmol(-1) triglycerides, 95% CI 27.2-34.8, n = 64) compared with before January 2002 (vitamin A: 1.03 micromol l(-1), 95% CI 0.93-1.12, n = 104; vitamin E: 38.9 micromol mmol(-1) triglycerides, 95% CI 34.5-43.8, n = 47). There were no significant effects of sampling date on maternal weight, haemoglobin or acute-phase proteins and only marginal effects on infant weight. Infant length at 6 and 16 weeks of age decreased progressively throughout the study (P-values for time of data collection were 0.51 at birth, 0.051 at 6 weeks and 0.026 at 16 weeks). CONCLUSIONS: The results show modest effects of the maize price increases on maternal micronutrient status. The most serious consequence of the price increases is likely to be the increased stunting among infants whose mothers experienced high maize prices while pregnant. During periods of food shortages it might be advisable to provide micronutrient supplements even to those who are less food-insecure

Foot and mouth disease in Zambia: Spatial and temporal distributions of outbreaks, assessment of clusters and implications for control

Zambia has been experiencing low livestock productivity as well as trade restrictions owing to the occurrence of foot and mouth disease (FMD), but little is known about the epidemiology of the disease in these endemic settings. The fundamental questions relate to the spatio-temporal distribution of FMD cases and what determines their occurrence. A retrospective review of FMD cases in Zambia from 1981 to 2012 was conducted using geographical information systems and the SaTScan software package. Information was collected from peer-reviewed journal articles, conference proceedings, laboratory reports, unpublished scientific reports and grey literature. A space–time permutation probability model using a varying time window of one year was used to scan for areas with high infection rates. The spatial scan statistic detected a significant purely spatial cluster around the Mbala–Isoka area between 2009 and 2012, with secondary clusters in Sesheke–Kazungula in 2007 and 2008, the Kafue flats in 2004 and 2005 and Livingstone in 2012. This study provides evidence of the existence of statistically significant FMD clusters and an increase in occurrence in Zambia between 2004 and 2012. The identified clusters agree with areas known to be at high risk of FMD. The FMD virus transmission dynamics and the heterogeneous variability in risk within these locations may need further investigation

Restriction of HIV-1 Genotypes in Breast Milk Does Not Account for the Population Transmission Genetic Bottleneck That Occurs following Transmission

BACKGROUND. Breast milk transmission of HIV-1 remains a major route of pediatric infection. Defining the characteristics of viral variants to which breastfeeding infants are exposed is important for understanding the genetic bottleneck that occurs in the majority of mother-to-child transmissions. The blood-milk epithelial barrier markedly restricts the quantity of HIV-1 in breast milk, even in the absence of antiretroviral drugs. The basis of this restriction and the genetic relationship between breast milk and blood variants are not well established. METHODOLOGY/PRINCIPAL FINDINGS. We compared 356 HIV-1 subtype C gp160 envelope (env) gene sequences from the plasma and breast milk of 13 breastfeeding women. A trend towards lower viral population diversity and divergence in breast milk was observed, potentially indicative of clonal expansion within the breast. No differences in potential N-linked glycosylation site numbers or in gp160 variable loop amino acid lengths were identified. Genetic compartmentalization was evident in only one out of six subjects in whom contemporaneously obtained samples were studied. However, in samples that were collected 10 or more days apart, six of seven subjects were classified as having compartmentalized viral populations, highlighting the necessity of contemporaneous sampling for genetic compartmentalization studies. We found evidence of CXCR4 co-receptor using viruses in breast milk and blood in nine out of the thirteen subjects, but no evidence of preferential localization of these variants in either tissue. CONCLUSIONS/SIGNIFICANCE. Despite marked restriction of HIV-1 quantities in milk, our data indicate intermixing of virus between blood and breast milk. Thus, we found no evidence that a restriction in viral genotype diversity in breast milk accounts for the genetic bottleneck observed following transmission. In addition, our results highlight the rapidity of HIV-1 env evolution and the importance of sample timing in analyses of gene flow.National Institute of Child Health and Human Development; National Institutes of Health (R01 HD 39611, R01 HD 40777); International Maternal Pediatric Adolescent AIDS Clinical Trials Group (U01 AI068632-01); National Institutes of Health Cellular, Biochemical; Molecular Sciences Training Program Grant (T 32 067587

The Mucosae-Associated Epithelial Chemokine (MEC/CCL28) Modulates Immunity in HIV Infection

BACKGROUND. CCL28 (MEC) binds to CCR3 and CCR10 and recruits IgA-secreting plasma cells (IgA-ASC) in the mucosal lamina propria (MLP). Mucosal HIV-specific IgA are detected in HIV-infection and exposure. The CCL28 circuit was analyzed in HIV-infected and-exposed individuals and in HIV-unexposed controls; the effect of CCL28 administration on gastrointestinal MLP IgA-ASC was verified in a mouse model. METHODOLOGY/FINDINGS. CCL28 was augmented in breast milk (BM) plasma and saliva of HIV-infected and –exposed individuals; CCR3+ and CCR10+ B lymphocytes were increased in these same individuals. Additionally: 1) CCL28 concentration in BM was associated with longer survival in HIV vertically-infected children; and 2) gastro-intestinal mucosal IgA-ASC were significantly increased in VSV-immunized mice receiving CCL28. CONCLUSIONS. CCL28 mediates mucosal immunity in HIV exposure and infection. CCL28-including constructs should be considered in mucosal vaccines to prevent HIV infection of the gastro-intestinal MLP via modulation of IgA-ASC.Istituto Superiore di Sanita' "Programma Nazionale di Ricerca sull' AIDS"; DG Right to Health and Solidarity Policy; EMPRO and AVIP EC WP6 Projects; Japan Health Science Foundation; National Institutes of Child Health and Human Development (HD 39611, HD 40777

Serological Survey of Foot-and-Mouth Disease Virus in Buffaloes ( Syncerus caffer

A study was conducted to determine the serotypes of foot-and-mouth disease viruses (FMDV) circulating in African buffaloes (Syncerus caffer) from selected areas in Zambia. Sera and probang samples were collected between 2011 and 2012 and analysed for presence of antibodies against FMDV while probang samples were used to isolate the FMDV by observing cytopathic effect (CPE). Samples with CPE were further analysed using antigen ELISA. High FMD seroprevalence was observed and antibodies to all the three Southern African Territories (SAT) serotypes were detected in four study areas represented as follows: SAT2 was 72.7 percent; SAT1 was 62.6 percent; and SAT3 was 26.2 percent. Mixed infections accounted for 68.6 percent of those that were tested positive. For probang samples, CPE were observed in three of the samples, while the antigen ELISA results showed positivity and for SAT1 (n=1) and SAT2 (n=2). It is concluded that FMDV is highly prevalent in Zambian buffaloes which could play an important role in the epidemiology of the disease. Therefore livestock reared at interface with the game parks should be included in all routine FMDV vaccination programmes

Differential Effects of Early Weaning for HIV-Free Survival of Children Born to HIV-Infected Mothers by Severity of Maternal Disease

BACKGROUND. We previously reported no benefit of early weaning for HIV-free survival of children born to HIV-infected mothers in intent-to-treat analyses. Since early weaning was poorly accepted, we conducted a secondary analysis to investigate whether beneficial effects may have been hidden. METHODS. 958 HIV-infected women in Lusaka, Zambia, were randomized to abrupt weaning at 4 months (intervention) or to continued breastfeeding (control). Children were followed to 24 months with regular HIV PCR tests and examinations to determine HIV infection or death. Detailed behavioral data were collected on when all breastfeeding ended. Most participants were recruited before antiretroviral treatment (ART) became available. We compared outcomes among mother-child pairs who weaned earlier or later than intended by study design adjusting for potential confounders. RESULTS. Of infants alive, uninfected and still breastfeeding at 4 months in the intervention group, 16.1% who weaned as instructed acquired HIV or died by 24 months compared to 16.0% who did not comply (p=0.98). Children of women with less severe disease during pregnancy (not eligible for ART) had worse outcomes if their mothers weaned as instructed (RH=2.60 95% CI: 1.06-6.36) compared to those who continued breastfeeding. Conversely, children of mothers with more severe disease (eligible for ART but did not receive it) who weaned early had better outcomes (p-value interaction=0.002). In the control group, weaning before 15 months was associated with 3.94-fold (95% CI: 1.65-9.39) increase in HIV infection or death among infants of mothers with less severe disease. CONCLUSION. Incomplete adherence did not mask a benefit of early weaning. On the contrary, for women with less severe disease, early weaning was harmful and continued breastfeeding resulted in better outcomes. For women with more advanced disease, ART should be given during pregnancy for maternal health and to reduce transmission, including through breastfeeding. TRIAL REGISTRATION. Clinical trials.gov NCT00310726National Institute of Child Health and Human Development (NICHD); National Institutes of Health (R01 HD 39611, R01 HD 40777

Esophageal squamous cell cancer in a highly endemic region

AIM: To identify risk factors associated with esophageal cancer in Zambia and association between dietary intake and urinary 8-iso prostaglandin F2α (8-isoPGF2α). METHODS: We conducted a prospective, case control study at the University Teaching Hospital. Subjects included both individuals admitted to the hospital and those presenting for an outpatient upper endoscopy. Esophageal cancer cases were compared to age and sex-matched controls. Cases were defined as patients with biopsy proven esophageal cancer; controls were defined as subjects without endoscopic evidence of esophageal cancer. Clinical and dietary data were collected using a standard questionnaire, developed a priori. Blood was collected for human immunodeficiency virus (HIV) serology. Urine was collected, and 8-isoPGF2α was measured primarily by enzyme-linked immunosorbent assay and expressed as a ratio to creatinine. RESULTS: Forty five controls (mean age 54.2 ± 15.3, 31 male) and 27 cases (mean age 54.6 ± 16.4, 17 males) were studied. Body mass index was lower in cases (median 16.8) than controls (median 23.2), P = 0.01. Histopathologically, 25/27 (93%) were squamous cell carcinoma and 2/27 (7%) adenocarcinoma. More cases smoked cigarettes (OR = 11.24, 95%CI: 1.37-92.4, P = 0.02) but alcohol consumption and HIV seropositivity did not differ significantly (P = 0.14 for both). Fruit, vegetables and fish consumption did not differ significantly between groups (P = 0.11, 0.12, and 0.10, respectively). Mean isoprostane level was significantly higher in cases (0.03 ng/mg creatinine) than controls (0.01 ng/mg creatinine) (OR = 2.35, 95%CI: 1.19-4.65, P = 0.014). CONCLUSION: Smoking and isoprostane levels were significantly associated with esophageal cancer in Zambians, but diet, HIV status, and alcohol consumption were not

Foot-and-mouth disease control in Zambia: A review of the current situation

Zambia has been experiencing low livestock productivity as well as trade restrictions owing to the occurrence of foot-and-mouth disease (FMD) and contagious bovine pleura pneumonia (CBPP). Foot-and-mouth disease was first recorded in Zambia in 1933 in the Western Province and since then the country has experienced repeated outbreaks. Bearing in mind the pressure that may be existing on the many risk factors for FMD including climate change, there is need to review our knowledge on FMD control. We present the spatial distribution of the FMD outbreaks that have been recorded in Zambia in the last twenty years, and the effect of the vaccinations and movement control that have been applied. We propose further strain characterisation of previous FMD outbreaks, including full sequence of VP1 gene and the 5’UTR site. The data will be geo-coded and populated with risk factor attributes. We also present preliminary findings of the buffalo and cattle probang sampling that was conducted in Lochnivar and Kafue National Park. We further probang sampled 25 buffalo at each interface area in Sioma Ngwezi, Lukusuzi and Lower Zambezi national parks. Villages in close proximity to the buffalo populations as well as those not in close proximity will be multistage cluster sampled for comparison. The data will be geo-coded and populated with risk factor and foot-and-mouth disease virus (FMDV) characterisation attributes. Data collected using a pre-tested structured questionnaire will be geo-coded and populated with identified risk factors and stored in a database and will be spatially modelled to determine their effect on FMD occurrence and control measures. New outbreaks of FMD that may occur will be investigated to find out if there are new strains involved, species affected and predisposing risk factors. The authors conclude that impacts of FMD on livelihoods if appropriate control measures are not put in place are far more devastating especially at community level. Presented with the current poverty levels failure to institute result oriented control measures will exacerbate the already life-threatening situation