Tissue-specific localization of tick-borne pathogens in ticks collected from camels in Kenya: insights into vector competence

Background

Tick-borne pathogen (TBP) surveillance studies often use whole-tick homogenates when inferring tick-pathogen associations. However, localized TBP infections within tick tissues (saliva, hemolymph, salivary glands, and midgut) can inform pathogen transmission mechanisms and are key to disentangling pathogen detection from vector competence.

Methods

We screened 278 camel blood samples and 504 tick tissue samples derived from 126 camel ticks sampled in two Kenyan counties (Laikipia and Marsabit) for Anaplasma, Ehrlichia, Coxiella, Rickettsia, Theileria, and Babesia by PCR-HRM analysis.

Results

Candidatus Anaplasma camelii infections were common in camels (91%), but absent in all samples from Rhipicephalus pulchellus, Amblyomma gemma, Hyalomma dromedarii, and Hyalomma rufipes ticks. We detected Ehrlichia ruminantium in all tissues of the four tick species, but Rickettsia aeschlimannii was only found in Hy. rufipes (all tissues). Rickettsia africae was highest in Am. gemma (62.5%), mainly in the hemolymph (45%) and less frequently in the midgut (27.5%) and lowest in Rh. pulchellus (29.4%), where midgut and hemolymph detection rates were 17.6% and 11.8%, respectively. Similarly, in Hy. dromedarii, R. africae was mainly detected in the midgut (41.7%) but was absent in the hemolymph. Rickettsia africae was not detected in Hy. rufipes. No Coxiella, Theileria, or Babesia spp. were detected in this study.

Conclusions

The tissue-specific localization of R. africae, found mainly in the hemolymph of Am. gemma, is congruent with the role of this tick species as its transmission vector. Thus, occurrence of TBPs in the hemolymph could serve as a predictor of vector competence of TBP transmission, especially in comparison to detection rates in the midgut, from which they must cross tissue barriers to effectively replicate and disseminate across tick tissues. Further studies should focus on exploring the distribution of TBPs within tick tissues to enhance knowledge of TBP epidemiology and to distinguish competent vectors from dead-end hosts.

Prospects and Perspectives of Health Impact Assessment: A Systematic Review of the Peer-Reviewed Literature From June 2007 to January 2023

Objectives

In 2008, an analysis investigating health impact assessment (HIA) practice found that only 6% of HIA-related peer-reviewed publications had a focus on low- and medium-developed countries, whereas 94% were conducted in countries with a high or very high development state. We aimed to update and deepen these observations.

Methods

We conducted a systematic review, searching PubMed and Web of Science for HIA-related papers published in the scientific literature from June 2007 to January 2023. Only applied HIA and papers with HIA as a subject were included.

Results

The search yielded 3,036 publications and the final selection consisted of 1,019 publications. The annual number of total publications increased considerably over the past 15 years. Whereas research-driven HIA (n = 460) showed a steep increase, step-by-step HIA (n = 71) did not show a clear trend.

Conclusion

The gap between the number of HIA-related peer-reviewed publications focusing on low/medium and high/very high developed countries has diminished from 6/94 to 11/89. There is a growing tendency to apply the terminology HIA for health impact modelling studies and quantitative health risk assessments.

Examining the Utilization of Social Capital by Ghanaians When Seeking Care for Chronic Diseases: A Personal Network Survey

Objectives: With limited social security and health protection in Ghana, intergenerational support is needed by those living with NCDs, who incur recurrent costs when seeking NCD care. We measured the level of informal support received by NCD patients and identified factors that influence support provision. Methods: We surveyed 339 NCD patients from three hospitals in Ghana, who listed their social ties and answered questions about their relationship and support frequency. We analyzed the relationship between social support, demographic and health information, characteristics of social ties, and network characteristics. Results: Participants described 1,371 social ties. Nearly 60% of respondents reported difficulties in their usual work or household duties due to chronic illness, which was also the strongest predictor of support. Patients with higher wellbeing reported less social support, while older age and having co-habitant supporters were negatively associated with support, indicating caregiver burnout. Conclusion: Ghanaian NCD patients receive support from various caregivers who may not be able to handle the increasing healthcare and social needs of an aging population. Policies should therefore enhance resource pooling and inclusiveness for old age security.

Agro-morphological and nutritional assessment of chenopod and quinoa germplasm-Highly adaptable potential crops

Quinoa belongs to the family Chenopodiaceae, a pseudo-grain having high nutritional value and is considered an underexploited vegetable crop with the potential to improve the nutritional security of millions. Therefore, assessing genetic diversity in Chenopodium germplasm to untap nutritional and site-specific adaptation potential would be of prime importance for breeders/researchers. The present study used 10 accessions of two Chenopodium species, that is, C. quinoa and C. album. Quantitative and qualitative phenotypic traits, proximate composition, minerals, and amino acids profiles were studied to compare the differences in nutritional value and extent of genetic diversity between these two species. Our results showed significant variation existed in yield attributing agro-morphological traits. All the traits were considered for hierarchical clustering and principal components analysis. Large genetic variability was observed in traits of Chenopodium accessions. The protein, dietary fiber, oil, and sugar content ranged from 16.6% to 19.7%, 16.8% to 26%, 3.54% to 8.46%, and 3.74% to 5.64%, respectively. The results showed that C. album and C. quinoa seeds had good nutritional value and health-promoting benefits. The C. quinoa was slightly ahead of than C. album in terms of nutritional value, but C. album accession IC415477 was at par for higher test weight, seed yield (117.02 g/plant), and other nutritional parameters with C. quinoa accessions. IC415477 and other potential accessions observed in this study may be taken up by breeders/researchers in the near future to dissect nutritional value of Chenopodium and related species for dietary diversity, which is imperative for the nutritional security of the ever-growing world's population.

Informal Support Networks of Tanzanians With Chronic Diseases: Predictors of Support Provision and Treatment Adherence

Objectives: To examine the role of NCD patients' social ties as informal caregivers and whether receiving their support is associated with engagement in care. Methods: NCD outpatients (N2 = 100) in rural Tanzania completed a cross-sectional questionnaire to characterize the support role of their social ties (N1 = 304). Bivariate analyses explored predictors of social support and whether social support is associated with engagement in care. Results: This study found that 87% of participants had health insurance, yet 25% received financial support for financing healthcare. Patient gender, age and marital status were found to be important predictors of social support, with NCD-related disability and disease severity being predictive to a lesser degree. Monthly receipt of both material and non-material support were associated with increased odds of adherence to prescribed medications. Conclusion: These findings indicate that patients' social ties play an important role in filling the gaps in formal social health protection and incur substantial costs by doing so. The instrumental role of even non-material social support in promoting engagement in care deserves greater attention when developing policies for improving this population's engagement in care.

Assessing Potential Environmental Impacts of Pesticide Usage in Paddy Ecosystems: A Case Study in the Deduru Oya River Basin, Sri Lanka

Rice paddies are unique ecosystems that provide rich wetland habitat. Their enduring existence across vast stretches of land has led them to evolve into unique systems serving a diverse assemblage of organisms and sustaining a staple grain for many people. With food demand rising, agricultural intensification through agrochemical application is a common practice used to boost food production in developing countries, including Sri Lanka. The aim of the present study was to assess the concentration of pesticide residues in water in rice ecosystems and discover their potential impacts on both environmental health and the most common fauna groups across a cropping year in Sri Lanka. A total of 270 water samples from waters associated with paddy fields within a watershed were analyzed for 20 commonly used pesticides; in addition, local farm holders were surveyed to assess pesticide usage details in three selected paddy tracts. We then used the Cornell University environmental impact quotient (EIQ) calculator and the ECOTOX Knowledgebase to determine the exposure risk associated with individual pesticides relative to their application rates and aquatic concentrations. Survey results demonstrate that several pesticides were overapplied at rates 1.2-11 times the recommended application, and the EIQ demonstrated high environmental risk of two of the agrochemicals detected, 2-methyl-4-chlorophenoxyacetic and diazinon. Fish, amphibians, insects, and beetles were found to have a wide range of potential adverse outcomes from exposure to diazinon, captan, thiamethoxam, and chlorantraniliprole. To balance the trade-offs between food security and ecosystem sustainability, the present study recommends that adoption of quantifiable environmental health indicators be considered as part of the national policy regulating pesticide use. Environ Toxicol Chem 2022;41:343-355. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.