Determinants of microbiome composition: Insights from free-ranging hybrid zebras (Equus quagga × grevyi)

The composition of mammalian gut microbiomes is highly conserved within species, yet the mechanisms by which microbiome composition is transmitted and maintained within lineages of wild animals remain unclear. Mutually compatible hypotheses exist, including that microbiome fidelity results from inherited dietary habits, shared environmental exposure, morphophysiological filtering and/or maternal effects. Interspecific hybrids are a promising system in which to interrogate the determinants of microbiome composition because hybrids can decouple traits and processes that are otherwise co-inherited in their parent species. We used a population of free-living hybrid zebras (Equus quagga × grevyi) in Kenya to evaluate the roles of these four mechanisms in regulating microbiome composition. We analysed faecal DNA for both the trnL-P6 and the 16S rRNA V4 region to characterize the diets and microbiomes of the hybrid zebra and of their parent species, plains zebra (E. quagga) and Grevy's zebra (E. grevyi). We found that both diet and microbiome composition clustered by species, and that hybrid diets and microbiomes were largely nested within those of the maternal species, plains zebra. Hybrid microbiomes were less variable than those of either parent species where they co-occurred. Diet and microbiome composition were strongly correlated, although the strength of this correlation varied between species. These patterns are most consistent with the maternal-effects hypothesis, somewhat consistent with the diet hypothesis, and largely inconsistent with the environmental-sourcing and morphophysiological-filtering hypotheses. Maternal transmittance likely operates in conjunction with inherited feeding habits to conserve microbiome composition within species.

The Effect of Stigma on Family Planning and HIV Pre-exposure Prophylaxis Decisions of Young Women Accessing Post-Abortion Care in Kenya

Adolescent girls and young women (AGYW) in Eastern and Southern Africa face parallel epidemics of unintended pregnancy and HIV. Their sexual health decisions are often dominated by intersecting stigmas. In an implementation science project integrating delivery of daily, oral pre-exposure prophylaxis (PrEP) for HIV prevention into 14 post-abortion care (PAC) clinics in Kenya, we enrolled a subset of PrEP initiating AGYW (aged 15 to 30 years) into a research cohort. Utilizing log binomial models, we estimated the effect of PrEP stigma on PrEP continuation (measured via self-report and urine assay for tenofovir) and abortion stigma on contraceptive initiation. Between April 2022 and February 2023, 401 AGYW were enrolled after initiating PrEP through their PAC provider, of which 120 (29.9%) initiated highly-effective contraception. Overall, abortion and PrEP stigmas were high in this cohort. Abortion stigma was more prevalent among those that were adolescents, unmarried, and reported social harm. Among 114 AGYW returning for the month 1 follow-up visit, 83.5% reported continuing PrEP and 52.5% had tenofovir detected. In this subset, higher levels of PrEP stigma were significantly associated with greater likelihood of PrEP adherence, but not PrEP continuation. For abortion stigma, greater scores in the subdomain of isolation were significantly associated with greater likelihood of initiating a highly-effective contraception, while greater scores in the subdomain of community condemnation were significantly associated with reduced likelihood of initiating a highly-effective contraception. Given the burden of stigma documented by our work, PAC settings are a pivotal space to integrate stigma-informed counseling and to empower young women to optimize contraceptive and PrEP decisions.

Effect of differentiated direct-to-pharmacy PrEP refill visits supported with client HIV self-testing on clinic visit time and early PrEP continuation

INTRODUCTION

Delivery of oral pre-exposure prophylaxis (PrEP) is being scaled up in Africa, but clinic-level barriers including lengthy clinic visits may threaten client continuation on PrEP.

METHODS

Between January 2020 and January 2022, we conducted a quasi-experimental evaluation of differentiated direct-to-pharmacy PrEP refill visits at four public health HIV clinics in Kenya. Two clinics implemented the intervention package, which included direct-to-pharmacy for PrEP refill, client HIV self-testing (HIVST), client navigator, and pharmacist-led rapid risk assessment and dispensing. Two other clinics with comparable size and client volume served as contemporaneous controls with the usual clinic flow. PrEP continuation was evaluated by visit attendance and pharmacy refill records, and time and motion studies were conducted to determine time spent in the clinics. Dried blood spots were collected to test for tenofovir-diphosphate (TFV-DP) at random visits. We used logistic regression to assess the intervention effect on PrEP continuation and the Wilcoxon rank sum test to assess the effect on clinic time.

RESULTS

Overall, 746 clients were enrolled, 366 at control clinics (76 during pre-implementation and 290 during implementation phase), and 380 at direct-to-pharmacy clinics (116 during pre-implementation and 264 during implementation phase). Prior to implementation, the intervention and control clinics were comparable on client characteristics (female: 51% vs. 47%; median age: 33 vs. 33 years) and PrEP continuation (35% vs. 37% at 1 month, and 37% vs. 39% at 3 months). The intervention reduced total time spent at the clinic by 35% (median of 51 minutes at control vs. 33 minutes at intervention clinics; p<0.001), while time spent on HIV testing (20 vs. 20 minutes; p = 0.50) and pharmacy (8 vs. 8 minutes; p = 0.8) was unchanged. PrEP continuation was higher at intervention versus the control clinics: 45% versus 33% at month 1, 34% versus 25% at month 3 and 23% versus 16% at month 6. TFV-DP was detected in 85% (61/72) of samples, similar by the study group (83% vs. 85%).

CONCLUSIONS

A client-centred PrEP delivery approach with direct-to-pharmacy PrEP refill visits plus client HIVST significantly reduced clinic visit time by more than one-third and improved PrEP continuation in public health HIV clinics in Kenya.

Structural influences on delivery and use of oral HIV PrEP among adolescent girls and young women seeking post abortion care in Kenya

Background

Adolescent girls and young women (AGYW) in East and southern Africa experience a disproportionate burden of HIV incidence. Integrating HIV pre-exposure prophylaxis (PrEP) within existing programs is a key component of addressing this disparity.

Methods

We evaluated an oral PrEP program integrated into post-abortion care (PAC) in Kenya from March 2021 to November 2022. Technical advisors trained staff at PAC clinics on PrEP delivery, abstracted program data from each clinic, and collected data on structural characteristics. Utilizing a modified Poisson regression, we estimated the effect of structural factors on the probability of PrEP offer and uptake.

Findings

We abstracted data on 6877 AGYW, aged 15-30 years, across 14 PAC clinics. PrEP offers were made to 57.4% of PAC clients and 14.1% initiated PrEP. Offers were associated with an increased probability at clinics that had consistent supply of PrEP (relative risk (RR):1.81, 95% CI: 1.1-2.95), inconsistent HIV testing commodities (RR: 1.89, 95% CI: 1.29-2.78), had all providers trained (RR: 1.65, 95% CI: 1.01, 2.68), and were public (RR: 1.89, 95% CI: 1.29-2.78). These same factors were associated with PrEP uptake: consistent supply of PrEP (RR: 2.71, 95% CI: 1.44-5.09), inconsistent HIV testing commodities (RR: 2.55, 95% CI: 1.39-4.67), all providers trained (RR: 2.61, 95% CI: 1.38-4.92), and were public (RR: 2.55, 95% CI: 1.39-4.67).

Interpretation

Greater success with integration of HIV prevention into reproductive health services will likely require investments in systems, such as human resources and PrEP and HIV testing commodities, to create stable availability and ensure consistent access.

Funding

PrEDIRA 2 was supported by funding from Children's Investment Fund Foundation (R-2001-04433). Ms. Zia was funded by the NIH Ruth L. Kirchstein pre-doctoral award (5F31HD105494-02) and Dr. Heffron was funded by National Institute of Mental Health (K24MH123371).

COMPARISON OF LOSARTAN AND ENALAPRIL EFFECTS ON RENAL FUNCTION IN HYPERTENSIVE ADULTS WITH CHRONIC KIDNEY DISEASE AT A KENYAN REFERRAL HOSPITAL

OBJECTIVE

The objective of this study was to compare renal function in diabetic hypertensive chronic kidney disease patients receiving enalapril or losartan.

DESIGN

This was a retrospective analytic cohort study.

SETTING

Kenyatta National Hospital, Nairobi, Kenya.

SUBJECTS

Two hundred adult patients with hypertension and diabetic nephropathy.

INTERVENTIONS

One hundred and sixteen participants received an enalapril regimen while 84 were on a losartan regimen.

MAIN OUTCOME MEASURES

Time to doubling of serum creatinine and changes in the levels of proteinuria.

RESULTS

There was a higher risk of doubling of serum creatinine with losartan (Adjusted HR = 1.572; [95% CI: 1.015-2.434]; p = 0.043) than enalapril. There was a significant difference in time to doubling between the two arms--losartan 18 months, enalapril 36 month (p = 0.046). The changes in the levels of proteinuria between the two arms were not statistically significant for most of the follow up period except at the 15th month from treatment initiation (p = 0.05).

CONCLUSIONS

Enalapril was found to be more reno-protective compared to losartan. Where feasible, we suggest local use of enalapril as opposed to losartan for diabetic hypertensive chronic kidney disease patients.

Fungal infections among diabetic foot ulcer- patients attending diabetic clinic in Kenyatta National Hospital, Kenya

OBJECTIVE

To isolate and identify fungal pathogens associated with dermatophytoses in diabetic patients and identify the spectrum of yeasts colonising diabetic foot ulcers at Kenyatta National Hospital.

DESIGN

A cross sectional Laboratory based study.

SETTING

The Kenyatta National Hospital diabetic clinic.

SUBJECTS

Sixty one patients with diabetic foot ulcers from August to November 2009.

RESULTS

The five most occurring pathogens were Biopolaris hawaiiensis (5.5%), Trichophyton schoenleinii (3.7%), Aspergillus niger (3.0%), Trichophyton rubrum (3.0%), Fusarium oxysporum (3.0%). Other moulds accounted forless than 3.0%. One suspected case (0.6%) of Penicilium marneffei was isolated although it couldnotbe ascertained due to its high containment requirement. Among the dermatophytes, the most occurring mould was Trichophyton schoenleinii (3.7%) while innon-dermatophyte was Biopolaris hawaiiensis (5.5%). Eight pathogenic yeasts were identified with C. parapsilosis (6.1%) being the most common followed by C. famata (3.0%). Fungal infestation was highest in callus formation (78.6%).

CONCLUSION

Fungal aetiological agents are significant cause of diabetic woundinfection and may require antifungal intervention for successful management of diabetic foot ulcers.

Blood donors in Kenya: a comparison of voluntary and family replacement donors based on a population-based survey

BACKGROUND AND OBJECTIVES

Blood safety and sufficiency are major challenges in Kenya and other sub-Saharan African countries forcing many countries to rely on family replacement donors (FRD). We analysed data from a national AIDS indicator survey to describe blood donors in Kenya and potential risks of transfusion transmissible infections (TTI) comparing voluntary donors and FRD.

MATERIALS AND METHODS

A population-based, cross-sectional survey was conducted in 2007 among 15- to 64-year-olds. Consenting participants were interviewed about blood donation history and were tested for HIV, HSV-2 and syphilis.

RESULTS

Of the 17,940 people surveyed, 445 (2·3%) reported donating blood in the prior 12 months. Sixty-four per cent were voluntary donors, and the rest were FRD. Compared to FRD, the majority of voluntary donors were <25 years old (59% versus 18%), from the highest wealth quintile (57% versus 42%) and single (64% versus 23%). In addition, voluntary donors were less likely to have been sexually active than replacement donors (43% versus 13%). HIV prevalence was lower among voluntary donors than among FRD (2·6% versus 7·4%, P-value=0·07).

CONCLUSIONS

The majority of blood donors in Kenya are voluntary with lower potential risk of TTI.