The paddy, the vector and the caregiver: lessons from an ecosystem approach to irrigation and malaria in Northern Côte d'Ivoire

Malaria is one of the most serious public health problems in the world. For the last few decades, numerous studies have focused on the potential links between environmental transformations (such as the expansion of irrigation) and malaria occurrence. Most of these studies have been based on relatively simple models outlining the interactions of the host-vector-parasite triad. In this paper, we investigate the links between the intensification of irrigated rice cultivation and malaria. In an attempt to complement biomedical and entomological approaches we propose a model that recognises the influence of human-vector contacts on transmission processes, but stresses the importance of taking into consideration socio-economic and cultural factors in the management of disease episodes, and how these can be affected by transformations of natural resource management strategies. Using a case study in Northern C?te d'Ivoire, we investigated the complex mechanisms by which agriculture-generated changes in ecosystems and socio-economic organisation influence disease risks and produce new scenarios in the management of disease. Our results show that the socio-economic transformation and gender repositioning induced, or facilitated, by the intensification of lowland irrigated rice cultivation influence the health care system for malaria in the study area. They lead to a reduction of the capacity of women to manage malaria episodes among children and influence their vulnerability to the disease. We argue that these elements contribute to higher malaria prevalence in villages involved in double cropping of rice annually.     

Stent placement or brachytherapy for palliation of dysphagia from esophageal cancer: a prognostic model to guide treatment selection

BACKGROUND: Brachytherapy was found to be preferable to metal stent placement for the palliation of dysphagia because of inoperable esophageal cancer in the randomized SIREC trial. The benefit of brachytherapy, however, only occurred after a relatively long survival. The objective is to develop a model that distinguishes patients with a poor prognosis from those with a relatively good prognosis. METHODS: Survival was analyzed with Cox regression analysis. Dysphagia-adjusted survival (alive with no or mild dysphagia) was studied with Kaplan-Meier analysis. Patient data is from the multicenter, randomized, controlled trial (SIREC, n = 209) and a consecutive series (n = 396). Patients received a stent or single-dose brachytherapy. RESULTS: Significant prognostic factors for survival included tumor length, World Health Organization performance score, and the presence of metastases (multivariable p < 0.001). A simple score, which also included age and gender, could satisfactorily separate patients with a poor, intermediate, and relatively good prognosis within the SIREC trial. For the poor prognosis group, the difference in dysphagia-adjusted survival was 23 days in favor of stent placement compared with brachytherapy (77 vs. 54 days, p = 0.16). For the other prognostic groups, brachytherapy resulted in a better dysphagia-adjusted survival. CONCLUSIONS: A simple prognostic score may help to identify patients with a poor prognosis in whom stent placement is at least equivalent to brachytherapy. If further validated, this score can provide an evidence-based tool for the selection of palliative treatment in esophageal cancer patients.     

Toward the development of a test for growth hormone (GH) abuse: a study of extreme physiological ranges of GH-dependent markers in 813 elite athletes in the postcompetition setting

There is a need to develop a test to detect GH abuse by elite athletes. Measured levels of GH in blood or urine, however, provide little information on the GH-IGF-I axis. Previous studies have identified a series of indirect markers of GH action that are markedly altered by the administration of GH, but to a lesser degree by acute exercise. This study was undertaken to determine the physiological range of these GH-dependent variables in elite athletes after a competitive event to determine whether such values differ from resting values in normal and athletic subjects and to establish whether any adjustments to this range are required on the basis of age, gender, demographic characteristics, or the nature of the exercise performed. Serum samples were collected from 813 elite athletes (537 males and 276 females; age range, 17-64 yr) from 15 sporting disciplines within 2 h of completion of a major competitive event. IGF-I, IGF-binding protein 2 (IGFBP-2), IGFBP-3, acid-labile subunit, and the bone and soft tissue markers, osteocalcin, carboxyl-terminal propeptide of type I procollagen, carboxyl-terminal cross-linked telopeptide of type I collagen, and procollagen type III were measured. Sporting category, gender, age, height, weight, body mass index (BMI), and racial group of the athlete were documented, and results were compared both to normative data and to values obtained from elite athletes under resting conditions. Forty-one percent of IGF-I values in male athletes and 41% of values in female athletes were above the upper limits of 99% reference ranges derived from resting values in a normal population. Postcompetition levels of all variables except carboxyl-terminal propeptide of type I procollagen and carboxyl-terminal cross-linked telopeptide of type I collagen differed from resting values. There was a consistent age-dependent fall in measured levels of all variables (P < 0.0001) with the exception of IGFBP-2, which increased with age (P < 0.0001). BMI, but not height, exerted a small, but significant, influence on several variables. After adjustment for age, there were no significant differences in the levels of any of the measured variables between sporting categories. IGFBP-2 and IGFBP-3 were lower in 35 black athletes compared with those in 35 white athletes matched for age, gender, height, BMI, and sporting category. We have demonstrated that there are predictable age-dependent levels of GH-dependent markers in elite athletes that are consistent even at the extremes of physical exertion and that these are independent of sporting category. Normative data applicable to white athletes are provided. This provides important groundwork for the development of a test for GH abuse, although these values may be specific for the reagents and assays used.     

Gender differences in estimating I-131 thyroid uptake from Tc-99m thyroid uptake for benign thyroid disease

Objective:For radioactive Iodine-131 (¹³¹I) treatments of thyroid diseases, increased efficacy has been reported for personalized dosimetry treatments. The measurement of Iodine-131 thyroid uptake (¹³¹IU) is required in these cases. This study aims to investigate whether ^99mTc thyroid uptake (^99mTcU) may be used in place of ¹³¹IU for implementing personalised treatments.Methods:A retrospective study of 152 benign thyroid disease ¹³¹I treatments was carried out during 2012–2020; 117 treatments were for female patients while 35 were for male patients diagnosed with either Graves’ disease, multinodular goitre or toxic nodules.Results:A statistically significant correlation was found between ¹³¹IU and ^99mTcU data, with the data more correlated for male than female patients (r = 0.71 vs 0.38, p-value < 0.001). Patient age and time difference between the two respective uptake measurements significantly influenced the uptake correlation in females but not for the male cohort, although there was no significant difference between the parameters across gender. Thyroid diagnosis and hormone levels showed a significant correlation with uptakes in both genders. Estimating ¹³¹IU based on ^99mTcU was shown to be predictive for male but not in female patients (R² = 91% vs 16%).Conclusion:Estimating ¹³¹IU based on ^99mTcU is not recommended for females at our centre. Males reported good correlation, but a larger sample would be needed for validation.Advances in knowledge:The initial findings showed a significant gender difference in benign thyroid uptake parameters at our centre, highlighting the potential need for gender consideration when planning ¹³¹IU patient management and when reporting studies results.     

Primary drug resistance in South Africa: data from 10 years of surveys

HIV-1 transmitted drug resistance (TDR) could reverse the gains of antiretroviral rollout. To ensure that current first-line therapies remain effective, TDR levels in recently infected treatment-naive patients need to be monitored. A literature review and data mining exercise was carried out to determine the temporal trends in TDR in South Africa. In addition, 72 sequences from seroconvertors identified from Africa Centre's 2010 HIV surveillance round were also examined for TDR. Publicly available data on TDR were retrieved from GenBank, curated in RegaDB, and analyzed using the Calibrated Population Resistance Program. There was no evidence of TDR from the 2010 rural KwaZulu Natal samples. Ten datasets with a total of 1618 sequences collected between 2000 and 2010 were pooled to provide a temporal analysis of TDR. The year with the highest TDR rate was 2002 [6.67%, 95% confidence interval (CI): 3.09-13.79%; n=6/90]. After 2002, TDR levels returned to <5% (WHO low-level threshold) and showed no statistically significant increase in the interval between 2002 and 2010. The most common mutations were associated with NNRTI resistance, K103N, followed by Y181C and Y188C/L. Five sequences had multiple resistance mutations associated with NNRTI resistance. There is no evidence of TDR in rural KwaZulu-Natal. TDR levels in South Africa have remained low following a downward trend since 2003. Continuous vigilance in monitoring of TDR is needed as more patients are initiated and maintained onto antiretroviral therapy.     

Association of sociocultural factors with initiation of the kidney transplant evaluation process

Although research shows that minorities exhibit higher levels of medical mistrust, perceived racism, and discrimination in healthcare settings, the degree to which these underlying sociocultural factors preclude end‐stage renal disease (ESRD) patients from initiating kidney transplant evaluation is unknown. We telephone surveyed 528 adult ESRD patients of black or white race referred for evaluation to a Georgia transplant center (N = 3) in 2014‐2016. We used multivariable logistic regression to examine associations between sociocultural factors and evaluation initiation, adjusting for demographic, clinical, and socioeconomic characteristics. Despite blacks (n = 407) reporting higher levels of medical mistrust (40.0% vs 26.4%, P < .01), perceived racism (55.5% vs 18.2%, P < .01), and experienced discrimination (29.0% vs 15.7%, P < .01) than whites (n = 121), blacks were only slightly less likely than whites to initiate evaluation (49.6% vs 57.9%, P = .11). However, after adjustment, medical mistrust (odds ratio [OR]: 0.59; 95% confidence interval [CI]: 0.39, 0.91), experienced discrimination (OR: 0.62, 95% CI: 0.41, 0.95), and perceived racism (OR: 0.61; 95% CI: 0.40, 0.92) were associated with lower evaluation initiation. Results suggest that sociocultural disparities exist in early kidney transplant access and occur despite the absence of a significant racial disparity in evaluation initiation. Interventions to reduce disparities in transplantation access should target underlying sociocultural factors, not just race.