Achieving global equity for COVID-19 vaccines: Stronger international partnerships and greater advocacy and solidarity are needed.

Peter Figueroa and co-authors advocate for equity in the worldwide provision of COVID-19 vaccines.

Neurological safety and efficacy of darifenacin and mirabegron for the treatment of overactive bladder in patients with history of cerebrovascular accident: A prospective study.

OBJECTIVES: To evaluate the neurological safety and clinical efficacy of darifenacin and mirabegron in patients with a history of cerebrovascular accident (CVA) who had overactive bladder (OAB) symptoms. METHODS: This prospective randomized study, approved by the institute's ethics committee, was carried out at a tertiary care center from December 2018 to June 2020. Treatment naïve adult patients with a past history of CVA with stable neurological status for atleast past 3 months with symptoms of OAB for 3 or more months were included. Eligible patients received either darifenacin or mirabegron for a period of 3 months and various parameters on the 3-day International Consultation on Incontinence Questionnaire (ICIQ) bladder diary, the Montreal Cognitive Assessment-Basic score (MoCA-B), and the adverse events at 3 months posttreatment were compared to that at the baseline. RESULTS: A total of 60 patients were included, 30 in each arm. After 3 months of treatment with darifenacin or mirabegron, the majority of the ICIQ bladder diary parameters improved and there was no deterioration in the cognitive function as noted on the MoCA-B score in either of the arms. On intergroup comparison, the mean change in bladder diary parameters and the MoCA-B scores was similar between the two groups. CONCLUSION: Darifenacin and mirabegron, in the short term, do not adversely affect the cognitive function in patients with a history of CVA with OAB symptoms. Both are safe and effective treatment options in patients with OAB post-CVA.

Genome-wide identification and characterization of Chitinase gene family in Brassica juncea and Camelina sativa in response to Alternaria brassicae.

Chitinases belong to the group of Pathogenesis-related (PR) proteins that provides protection against fungal pathogens. This study presents the, genome-wide identification and characterization of chitinase gene family in two important oilseed crops B. juncea and C. sativa belonging to family Brassicaceae. We have identified 47 and 79 chitinase genes in the genomes of B. juncea and C. sativa, respectively. Phylogenetic analysis of chitinases in both the species revealed four distinct sub-groups, representing different classes of chitinases (I-V). Microscopic and biochemical study reveals the role of reactive oxygen species (ROS) scavenging enzymes in disease resistance of B. juncea and C. sativa. Furthermore, qRT-PCR analysis showed that expression of chitinases in both B. juncea and C. sativa was significantly induced after Alternaria brassicae infection. However, the fold change in chitinase gene expression was considerably higher in C. sativa compared to B. juncea, which further proves their role in C. sativa disease resistance to A. brassicae. This study provides comprehensive analysis on chitinase gene family in B. juncea and C. sativa and in future may serve as a potential candidate for improving disease resistance in B. juncea through transgenic approach.

Cp*Co(iii)-catalyzed annulation of azines by C-H/N-N bond activation for the synthesis of isoquinolines.

Herein, an efficient, atom economic and external oxidant free approach has been disclosed for the synthesis of isoquinolines. Azines were employed for annulation reactions with alkynes via sequential C-H/N-N bond activation using an air-stable cobalt catalyst. The method takes advantage of the incorporation of both the nitrogen atoms of azines into the desired isoquinoline products, offering the highest atom economy. In addition, the developed protocol works under external oxidant as well as silver salt free conditions. Furthermore, the established methodology features a relatively broad substrate scope with high product yields and scalability up to the gram level.

Glaucoma secondary to intraocular tumors: mechanisms and management.

PURPOSE OF REVIEW: Glaucoma secondary to intraocular tumors is important to consider in eyes with a known tumor and those with unilateral or refractory glaucoma. The purpose of this review is to discuss the mechanisms and management of intraocular tumors with related secondary glaucoma. RECENT FINDINGS: Several intraocular tumors can lead to glaucoma, including iris melanoma, iris metastasis, iris lymphoma, trabecular meshwork melanoma, choroidal melanoma, choroidal metastasis, retinoblastoma, and medulloepithelioma. The mechanisms for glaucoma include solid tumor invasion into the angle, tumor seeding into the angle, angle closure, and iris neovascularization. Management of the tumor can lead to resolution of glaucoma. Management of the secondary glaucoma may involve medical therapy, transscleral cyclophotocoagulation, laser trabeculoplasty, and potentially antivascular endothelial growth factor therapy. Minimally invasive glaucoma surgery (MIGS) can be considered for eyes with treated, regressed posterior segment malignancies if there is no iris or ciliary body involvement. Importantly, avoidance of MIGS, filtering, or shunting surgery in eyes with active malignancies is emphasized. SUMMARY: Intraocular tumors can produce secondary glaucoma. Treatment of the primary tumor can sometimes resolve the glaucoma. Topical, oral, or laser therapies can be considered. Avoidance of MIGS, filtering, or shunting surgery is advised until the malignancy is completely regressed.

Light-Triggered, Spatially Localized Chemistry by Photoinduced Electron Transfer.

It is of immense interest to exert spatial and temporal control of chemical reactions. It is now demonstrated that irradiation can trigger reactions specifically at the surface of a simple colloidal construct, obtained by adsorbing polyethyleneimine on fluorescent colloidal particles. Exciting the fluorescent dye in the colloid affords photoinduced electron transfer to spatially proximal amine groups on the adsorbed polymer to form free radical ions. It is demonstrated that these can be harnessed to polymerize acrylic acid monomer at the particle surface, or to break up colloidal assemblies by cleaving a cross-linked polymer mesh. Formation of free radical ions is not a function of the size of the colloid, neither is it restricted to a specific fluorophore. Fluorophores with redox potentials that allow photoinduced electron transfer with amine groups show formation of free radical ions.

When government agencies turn to unregulated drug sources: Implications for the drug supply chain and public health are grave.

OBJECTIVE: To highlight how sourcing practices for lethal injections drugs are undermining state and federal regulatory structures established to preserve the security and integrity of the medicines supply chain in the United States. SUMMARY: Unable to find sources for execution products approved by the U.S. Food and Drug Administration (FDA), some states have started sourcing the required drugs or active ingredients from unapproved foreign manufacturers or have contracted with small compounding pharmacists to compound them. Many states have passed legislation barring the disclosure of information regarding the origin and chain of custody for prisons' stocks of compounded lethal injection drugs. This creates a regulatory vacuum and prevents the responsible authorities (e.g., FDA, Drug Enforcement Agency, state boards of pharmacy) from performing their crucial roles to ensure quality and supply chain transparency for medicines in circulation. CONCLUSION: By purchasing medicines from non-FDA-approved suppliers and enacting lethal injection sourcing secrecy laws, states are undermining the robust enforcement of chain of custody and pharmaceutical supply chain transparency. The secrecy surrounding the execution drug procurement risks creating illicit supply channels. Once an illicit supply channel is established with a supplier, it creates risks that other drug products move through it, particularly in a context where the FDA, Drug Enforcement Agency, and state boards of pharmacy are prevented from performing their usual regulatory duties. Lawmakers have the obligation and authority to step in and close this regulatory gap to promote public health and safety.

CRISPR/Cas9: a promising way to exploit genetic variation in plants.

Creation of variation in existing gene pool of crop plants is the foremost requirement in crop improvement programmes. Genome editing is a tool to produce knock out of target genes either by introduction of insertion or by deletion that disrupts the function of a specific gene. The CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9) system is the most recent addition to the toolbox of sequence-specific nucleases that includes ZFNs and TALENs. The CRISPR/Cas9 system allows targeted cleavage of genomic DNA guided by a small noncoding RNA, resulting in gene modifications by both non-homologous end joining and homology-directed repair mechanisms. Here, we present an overview of mechanisms of CRISPR, its potential roles in creating variation in germplasm and applications of this novel interference pathway in crop improvement. The availability of the CRISPR/Cas9 system holds promise in facilitating both forward and reverse genetics and will enhance research in crops that lack genetic resources.

Rapid diagnostic tests for malaria.

Maintaining quality, competitiveness and innovation in global health technology is a constant challenge for manufacturers, while affordability, access and equity are challenges for governments and international agencies. In this paper we discuss these issues with reference to rapid diagnostic tests for malaria. Strategies to control and eliminate malaria depend on early and accurate diagnosis. Rapid diagnostic tests for malaria require little training and equipment and can be performed by non-specialists in remote settings. Use of these tests has expanded significantly over the last few years, following recommendations to test all suspected malaria cases before treatment and the implementation of an evaluation programme to assess the performance of the malaria rapid diagnostic tests. Despite these gains, challenges exist that, if not addressed, could jeopardize the progress made to date. We discuss recent developments in rapid diagnostic tests for malaria, highlight some of the challenges and provide suggestions to address them.

Le maintien de la qualité, de la compétitivité et de l'innovation dans les technologies de la santé au niveau mondial représente un défi constant pour les fabricants, tandis que l'accessibilité économique, l'accès et l'équité constituent un défi pour les gouvernements et les organismes internationaux. Nous abordons ces questions dans le présent rapport en ce qui concerne les tests de diagnostic rapide du paludisme. Les stratégies visant à enrayer et à éradiquer le paludisme reposent sur un diagnostic précoce et précis. Les tests de diagnostic rapide du paludisme nécessitent peu de formation et de matériel et peuvent être réalisés par des non-spécialistes dans des endroits isolés. L'utilisation de ces tests s'est considérablement répandue au cours des dernières années suite aux recommandations préconisant d'examiner tous les cas présumés de paludisme avant la mise en route d'un traitement et de mettre en œuvre un programme d'évaluation pour mesurer les performances des tests de diagnostic rapide du paludisme. Il demeure, malgré ces avancées, des défis, qui, s'ils ne sont pas surmontés, risquent de compromettre les progrès accomplis jusqu'à présent. Le présent rapport fait état des améliorations récemment apportées aux tests de diagnostic rapide du paludisme, souligne un certain nombre de défis et propose des solutions pour les surmonter.

Mantener la calidad, competitividad e innovación en la tecnología de salud mundial es un desafío constante para los fabricantes, mientras que la asequibilidad, el acceso y la equidad son desafíos para los gobiernos y las agencias internacionales. En este artículo se debaten estas cuestiones con relación a las pruebas de diagnóstico rápido del paludismo. Las estrategias para controlar y eliminar el paludismo dependen de un diagnóstico temprano y preciso. Las pruebas de diagnóstico rápido del paludismo requieren muy poco entrenamiento y equipo y pueden ser llevadas a cabo por no especialistas en lugares apartados. La utilización de estas pruebas se ha expandido significantemente durante los últimos años, tras las recomendaciones de hacer una prueba en todos los casos de posible paludismo antes del tratamiento y la implementación de un programa de evaluación para examinar el rendimiento de las pruebas de diagnóstico rápido del paludismo. A pesar de estos avances, todavía existen desafíos que, si no se abordan, podrían poner en peligro el progreso hecho hasta la fecha. Se debaten los recientes desarrollos de las pruebas de diagnóstico rápido del paludismo, se destacan algunos de los desafíos y se proporcionan sugerencias para tratarlos.

Costing the supply chain for delivery of ACT and RDTs in the public sector in Benin and Kenya.

BACKGROUND: Studies have shown that supply chain costs are a significant proportion of total programme costs. Nevertheless, the costs of delivering specific products are poorly understood and ballpark estimates are often used to inadequately plan for the budgetary implications of supply chain expenses. The purpose of this research was to estimate the country level costs of the public sector supply chain for artemisinin-based combination therapy (ACT) and rapid diagnostic tests (RDTs) from the central to the peripheral levels in Benin and Kenya. METHODS: A micro-costing approach was used and primary data on the various cost components of the supply chain was collected at the central, intermediate, and facility levels between September and November 2013. Information sources included central warehouse databases, health facility records, transport schedules, and expenditure reports. Data from document reviews and semi-structured interviews were used to identify cost inputs and estimate actual costs. Sampling was purposive to isolate key variables of interest. Survey guides were developed and administered electronically. Data were extracted into Microsoft Excel, and the supply chain cost per unit of ACT and RDT distributed by function and level of system was calculated. RESULTS: In Benin, supply chain costs added USD 0.2011 to the initial acquisition cost of ACT and USD 0.3375 to RDTs (normalized to USD 1). In Kenya, they added USD 0.2443 to the acquisition cost of ACT and USD 0.1895 to RDTs (normalized to USD 1). Total supply chain costs accounted for more than 30% of the initial acquisition cost of the products in some cases and these costs were highly sensitive to product volumes. The major cost drivers were found to be labour, transport, and utilities with health facilities carrying the majority of the cost per unit of product. CONCLUSIONS: Accurate cost estimates are needed to ensure adequate resources are available for supply chain activities. Product volumes should be considered when costing supply chain functions rather than dollar value. Further work is needed to develop extrapolative costing models that can be applied at country level without extensive micro-costing exercises. This will allow other countries to generate more accurate estimates in the future.

Melkersson-Rosenthal syndrome with isolated unilateral eyelid edema: an immunopathologic study.

Lymphedema is caused by defective drainage of the lymphatic system. In Melkersson-Rosenthal syndrome, involvement is predominantly of the lumens with blockage of lymphatic channels by histiocytic-epithelioid cell clusters accompanied by dermal granulomas and lymphocytes. It is a localized, painless, nonitching, and nonpitting form of lymphedema. Besides the eyelids, the disease can cause lip edema, facial palsy, and/or fissured tongue. It is rare and has received little attention in the ophthalmic literature, either in its complete triadic form, or more frequently, in its monosymptomatic forms. Pathogenesis is not well understood, and there is no effective therapy. The authors describe a case of Melkesson-Rosenthal syndrome in a 45-year-old Hispanic man with isolated unilateral upper eyelid edema. Histopathological and immunohistochemical evaluations of an eyelid biopsy specimen revealed intravascular and extravascular clusters of histiocytic-epithelioid cells that were CD68/163-positive. Variable numbers of mostly T-lymphocytes were found in the epidermis, dermis, and orbicularis muscle and by virtue of the associated granulomas established the diagnosis of Melkersson-Rosenthal syndrome. CD4 helper and CD8 suppressor T-lymphocytes were equally represented. CD20 B-lymphocytes were exceedingly sparse. Conspicuous CD1a-positive Langerhans' cells were present in the epidermis, sometimes formed subepithelial loose aggregates and were also incorporated in the granulomas. The differential diagnosis includes the far more common condition of acne rosacea. Management of Melkersson-Rosenthal syndrome, and of angioedema in general, is reviewed.

Stereotactic microdebrider in deep lateral orbital decompression for patients with thyroid eye disease.

PURPOSE: Stereotactic navigation systems have been used in neurosurgery and otolaryngology with great success. The current investigation illustrates the novel use of a microdebrider with built-in stereotactic guidance in a series of thyroid orbitopathy patients who underwent deep lateral orbital wall decompression surgery. METHODS: A noncomparative, interventional, retrospective case series of patients who underwent deep lateral deep orbital wall decompression from 2006 to 2013 was conducted in accordance with Institutional Review Board policy and the Declaration of Helsinki. Patient demographics, indications for surgery, pre-, intra-, and postoperative findings along with complications were recorded. RESULTS: One hundred eight deep lateral orbital decompression surgeries were performed in 69 patients using the Straightshot M4 Microdebrider with built-in stereotactic guidance (Medtronics). Seventy-eight cases were in women and 30 cases were in men. The average age was 50.4 years (SD = 11.9 years). Indications for surgery included proptosis, exposure keratopathy, or compressive optic neuropathy. No patient experienced intraoperative complications. Specifically, cerebrospinal fluid leak, visual loss, infection, or unanticipated inflammation were not encountered. The average postoperative follow-up time was 5.35 months. Mean reduction in proptosis was 3.72 mm (SD = 2.1). Visual acuity improved in 32.4% (35/108) of cases. CONCLUSIONS: This surgical instrument combines a single handpiece locator, microdebrider, irrigator, retractor, and suction device into one. It enhances anatomical localization during orbital decompression and, with an integrated tissue guard, may decrease the risk of injury to orbital soft tissues. Stereotactic navigation enhances the surgeon's ability to determine the maximal limits of decompression in real time by confirming depth of bone removal and may potentially increase surgeons' confidence in orbital decompression surgery.

Extruded, partially disintegrated, poly-HEMA orbital implant (AlphaSphere).

A 54-year-old diabetic man underwent enucleation for endophthalmitis. Secondary implantation of a 2-hydroxyethyl methacrylate (HEMA) sphere (AlphaSphere, Addition Technology) was performed 2 weeks later. Six weeks after insertion, noninfectious disintegration of sutured tissue planes represented by Tenon's capsule, rectus muscle, and conjunctiva occurred, requiring removal of the fragmenting implant before uncontrolled extrusion occurred. Histopathologic analysis revealed an absence of infectious pathogens and no tissue necrosis, but rather breakup of the implant material that elicited a granulomatous response with sparse T-lymphocytes and almost no polymorphonuclear leukocytes. This distinctively designed poly-HEMA orbital implant incited a dramatic and irreversible host tissue response. Investigation of other cases will be necessary to determine the frequency of such a complication and should include rigorous histopathologic techniques.

Cadaveric study of anatomical variations of the median nerve and persistent median artery at wrist.

BACKGROUND: Awareness of anatomical variations of the median nerve at wrist is important in repair of traumatic injuries and treatments of compression syndrome because in these situations precise dissection of the nerve is mandatory and such variations are not infrequent. MATERIALS AND METHODS: In this study, 52 hands of 52 fresh cadavers were dissected and median nerve anatomy along with the presence of persistent median artery (PMA) was noted. RESULTS: A total of 26 hands (50%) had the deviation from the standard text book anatomy of the median nerve. There was early division of the median nerve into the medial and lateral branches in 11.53% hands. There was early branching of the 2(nd) common digital nerve in 9.6% hands. The transligamentous motor branch to the thenar muscle was most prevalent (42.3% hands). The single motor branch to the thenar muscles was found in the majority of hands (84.6%). The PMA was present in 11.53% hands and it was associated with variations in the median nerve anatomy in all cases. CONCLUSIONS: This study shows a high percentage of deviation from standard anatomy as well as a high percentage of transligamentous thenar muscle motor branch. The presence of PMA was associated with variations in the median nerve anatomy in all cases. Therefore if PMA is present there are very high chances of associated median nerve anomalies.

Effect of adjunct Vitamin D treatment in vitamin D deficient pulmonary tuberculosis patients: A randomized, double blind, active controlled clinical trial.

BACKGROUND: Since, Vitamin D [1α,25(OH)2D)] enhances antimicrobial activity of Innate immunity and modulate Adaptive immune responses, simultaneously, so it play a potential role for balanced immune activity against Mycobacterium tuberculosis and restricting tissue injuries within the TB patients.(Chun et al., 2011) 9 We aimed to determine the role of adjunct Vitamin D treatment on the outcome of pulmonary tuberculosis patients and evaluated the effect of Vitamin D administration on Differential Leucocyte Count, Erythrocyte Sedimentation Rate, serum Adenosine deaminase, serum C- reactive protein, Oxygen saturation (SpO2) and Body Weight in Vitamin D deficient pulmonary tuberculosis patients. METHODS: We conducted a prospective, interventional, randomized, double blind, parallel group, active controlled clinical trial. Newly diagnosed Vitamin D deficient pulmonary tuberculosis patients were randomly assigned to intervention group (received standard anti-tubercular treatment with adjunct Vitamin D3) and control group (received standard anti-tubercular treatment without adjunct Vitamin D3). Total four doses [each dose of 2.5 mg (100000 IU)] of Vitamin D3 were given, orally. First dose was given within 7 days of starting anti-tubercular treatment and second, third, fourth dose were given at 2, 4 and 6 weeks respectively. At the time of enrollment, we measured all baseline characteristics. During follow-up, we measured the study variables and monitored adverse events at 2, 4, 6, 8 and 12 weeks. Our safety parameter was serum corrected calcium level to assess the risk of hypercalcemia. RESULTS: Total 130 pulmonary TB patients, 65 patients in each group, were analyzed. Our study results showed that decrease in Neutrophil count was statistically significant with small effect sizes at every time point of measurement and increase in Lymphocyte count was statistically significant with small and moderate effect sizes at 4, 6 and 8 week for intervention group than for control group. Decrease in erythrocyte sedimentation rate was statistically significant with small effect sizes at 6 and 8 week, decrease in serum adenosine deaminase and serum C- reactive protein was statistically significant with moderate effect sizes at 4, 6 and 8 week for intervention group than for control group. Increase in Oxygen saturation was statistically significant at 4 week with small effect size and increase in body weight was statistically significant with small effect sizes for intervention group than for control group. No case of hypercalcemia was reported. CONCLUSION: Our findings suggest a potential role of adjunctive Vitamin D3 to accelerate resolution of inflammatory responses and improvement in clinical outcomes of pulmonary TB patients. TRIAL REGISTRATION: This trial is registered with Clinical Trials Registry - INDIA (http://ctri.nic.in) with CTRI Number - CTRI/2021/11/037914. PLACE OF STUDY: Room Number 27, first floor out-patients department (OPD) and inpatient Wards, fourth floor, Department of Respiratory Medicine, Uttar Pradesh University of Medical Sciences, Saifai, Etawah (U.P.), INDIA.

Duragen: A dermal substitute for the management of suboptimal wounds.

Using a flap in a large wound with a very small area of exposed vital structures may be an excessive intrusion and cause unnecessary donor site morbidity. Dermal matrix (DuraGen) was applied onto critical areas where bone or tendons were exposed and a split skin graft was placed thereon. All patients had satisfactory wound closure without the need for a flap. DuraGen appears to be a safe, single-stage alternative, to a flap for the healing of complex wounds.

Median arcuate ligament syndrome: A rare case report from Nepal.

INTRODUCTION: Median arcuate ligament syndrome (MALS) is a rare condition caused by the compression of the celiac trunk by the median arcuate ligament, leading to a typical symptom triad: postprandial abdominal pain, weight loss, nausea, and vomiting. CASE PRESENTATION: A 41-year-old female patient presented to our center with mild postprandial abdominal pain over the epigastric region, and bloating sensation. Ultrasonography of the abdomen showed multiple stones in the gall bladder lumen, and the computed tomography scan showed median arcuate ligament impingement along the proximal aspect of the celiac trunk causing moderate narrowing with post-stenotic dilation. Laparoscopic release of the median arcuate ligament with laparoscopic cholecystectomy was performed. DISCUSSION: The diagnosis of Median Arcuate Ligament Syndrome is based on the classical post-prandial symptoms and abdominal imaging technologies like Doppler ultrasonography, computed tomography angiography, or magnetic resonance angiography. Exclusion of other intestinal disorders should be considered before making the diagnosis. Celiac artery decompression through different means is the principle of treatment of this condition. CONCLUSION: The diagnosis of median arcuate ligament syndrome should be considered in patients with postprandial abdominal pain that does not have an established etiology. Celiac artery decompression by releasing the median arcuate ligament is the treatment.

Characterization of a new begomovirus and a beta satellite associated with the leaf curl disease of French bean in northern India.

Begomoviruses are emerging as serious threat to many crops throughout the world particularly in tropical and sub-tropical regions. A leaf curl disease with symptoms typical of infection by many begomoviruses was observed in French bean (Phaseolus vulgaris) at Kanpur, India, during 2010-2012. The disease caused downward leaf curling and made the plants unproductive. The disease was transmitted from infected to healthy plants through whitefly (Bemisia tabaci). The products of five samples digested with EcoRI yielded DNA fragments of about 2.7 kb. The complete sequence of the Fb1 sample comprised 2,741 nucleotides with genome organization typical of begomoviruses having two ORFs in virion-sense and five ORFs in complementary-sense separated by an intergenic region with begomovirus conserved nonanucleotide sequence, TAATATTAC. The complete DNA-A sequence homology was most closely related to Cotton leaf curl Bangalore virus with 80 % nucleotide sequence identity. Based on the demarcation criteria for identifying a begomovirus species, Fb1 is considered as a distinct begomovirus species, named French bean leaf curl virus and designated as FbLCV-[IN:Knp:12]. The complete sequence of associated satellite DNA-ß comprises 1,379 nucleotides with single ORF and has 80 % identity with Papaya leaf curl beta satellite. There was no evidence of recombination in DNA-A of FbLCV and associated beta satellite DNA molecule.

Diffusion of subsidized ACTs in accredited drug shops in Tanzania: determinants of stocking and characteristics of early and late adopters.

BACKGROUND: Many households in sub-Saharan Africa utilize the private sector as a primary source of treatment for malaria episodes. Expanding access to effective treatment in private drug shops may help reduce incidence of severe disease and mortality. This research leveraged a longitudinal survey of stocking of subsidized artemisinin combination therapies (ACTs), an effective anti-malarial, in Accredited Drug Dispensing Outlets (ADDOs) in two regions of Tanzania. This provided a unique opportunity to explore shop and market level determinants of product diffusion in a developing country retail market. METHODS: 356 ADDOs in the Rukwa and Mtwara regions of Tanzania were surveyed at seven points between Feb 2011 and May 2012. Shop level audits were used to measure the availability of subsidized ACTs at each shop. Data on market and shop level factors were collected during the survey and also extracted from GIS layers. Regression and network based methodologies were used. Shops classified as early and late adopters, following Rogers' model of product diffusion, were compared. The Bass model of product diffusion was applied to determine whether shops stocked ACTs out of a need to imitate market competitors or a desire to satisfy customer needs. RESULTS: Following the introduction of a subsidy for ACTs, stocking increased from 12% to nearly 80% over the seven survey rounds. Stocking was influenced by higher numbers of proximal shops and clinics, larger customer traffic and the presence of a licensed pharmacist. Early adopters were characterized by a larger percentage of customers seeking care for malaria, a larger catchment and sourcing from specific wholesalers/suppliers. The Bass model of product diffusion indicated that shops were adopting products in response to competitor behavior, rather than customer demand. CONCLUSIONS: Decisions to stock new pharmaceutical products in Tanzanian ADDOs are influenced by a combination of factors related to both market competition and customer demand, but are particularly influenced by the behavior of competing shops. Efforts to expand access to new pharmaceutical products in developing country markets could benefit from initial targeting of high profile shops in competitive markets and wholesale suppliers to encourage faster product diffusion across all drug retailers.