Crediting his critics' concerns: Remaking John Snow's map of Broad Street cholera, 1854

Few cases in the history of epidemiology and public health are more famous than John Snow's investigation of a neighborhood cholera outbreak in the St. James, Westminster, area of London in 1854. In this study Snow is assumed to have proven that cholera was water rather than airborne through a methodology that became, and to a great extent remains, central to the science and social science of disease studies. And yet, Snow's work did not satisfy most of his contemporaries who considered his proof of a solely waterborne cholera interesting but unconvincing. Uniquely, this paper asks whether the caution of Snow's contemporaries was reasonable, and secondly, whether Snow might have been more convincing within the science of the day. The answers significantly alter our understanding of this paradigmatic case. It does so in a manner offering insights both into the origins of nineteenth century disease analysis and more generally, the relation of mapping in the investigation of an outbreak of uncertain origin. The result has general relevance—pedagogically and practically—in epidemiology, medical geography, and public health.     

Novel Reassortant Influenza A(H5N8) Viruses among Inoculated Domestic and Wild Ducks,South Korea, 2014

An outbreak of highly pathogenic avian influenza, caused by a novel reassortant influenza A (H5N8) virus, occurred among poultry and wild birds in South Korea in 2014. The aim of this study was to evaluate the pathogenesis in and mode of transmission of this virus among domestic and wild ducks. Three of the viruses had similar pathogenicity among infected domestic ducks: the H5N8 viruses were moderately pathogenic (0%–20% mortality rate); in wild mallard ducks, the H5N8 and H5N1 viruses did not cause severe illness or death; viral replication and shedding were greater in H5N8-infected mallards than in H5N1-infected mallards. Identification of H5N8 viruses in birds exposed to infected domestic ducks and mallards indicated that the viruses could spread by contact. We propose active surveillance to support prevention of the spread of this virus among wild birds and poultry, especially domestic ducks.     

Pharmacovigilance in Russia: current state of affairs,challenges, and prospects

This review outlines current issues of the pharmacovigilance (PV) system in the Russian Federation, namely the present state of regulatory aspects, regulatory requirements in both Russia and the Eurasian Economic Union, and review of causes of under-reporting of adverse drug reactions. Specific attention will be focused on how the system is designed to monitor drug safety functions, reporting and accountability of pharmaceutical products, their manufacturers and medical staff, the role played by regional centers for drug-safety monitoring, and insufficient understanding of the part taken by patients in the system of PV. The prospects of the Russian PV system and its harmonization with global practice will also be discussed.     

Outbreak of Puumala Virus Infection, Sweden

An unexpected and large outbreak of Puumala virus infection in Sweden resulted in 313 nephropathia epidemica patients/100,000 persons in Västerbotten County during 2007. An increase in the rodent population, milder weather, and less snow cover probably contributed to the outbreak.     

Response of Colorado River runoff to dust radiative forcing in snow

The waters of the Colorado River serve 27 million people in seven states and two countries but are overallocated by more than 10% of the river’s historical mean. Climate models project runoff losses of 7–20% from the basin in this century due to human-induced climate change. Recent work has shown however that by the late 1800s, decades prior to allocation of the river’s runoff in the 1920s, a fivefold increase in dust loading from anthropogenically disturbed soils in the southwest United States was already decreasing snow albedo and shortening the duration of snow cover by several weeks. The degree to which this increase in radiative forcing by dust in snow has affected timing and magnitude of runoff from the Upper Colorado River Basin (UCRB) is unknown. Here we use the Variable Infiltration Capacity model with postdisturbance and predisturbance impacts of dust on albedo to estimate the impact on runoff from the UCRB across 1916–2003. We find that peak runoff at Lees Ferry, Arizona has occurred on average 3 wk earlier under heavier dust loading and that increases in evapotranspiration from earlier exposure of vegetation and soils decreases annual runoff by more than 1.0 billion cubic meters or ∼5% of the annual average. The potential to reduce dust loading through surface stabilization in the deserts and restore more persistent snow cover, slow runoff, and increase water resources in the UCRB may represent an important mitigation opportunity to reduce system management tensions and regional impacts of climate change.     

Role of macroscopic particles in deep-sea oxygen consumption

Macroscopic particles (>500 μm), including marine snow, large migrating zooplankton, and their fast-sinking fecal pellets, represent primary vehicles of organic carbon flux from the surface to the deep sea. In contrast, freely suspended microscopic particles such as bacteria and protists do not sink, and they contribute the largest portion of metabolism in the upper ocean. In bathy- and abyssopelagic layers of the ocean (2,000–6,000 m), however, microscopic particles may not dominate oxygen consumption. In a section across the tropical Atlantic, we show that macroscopic particle peaks occurred frequently in the deep sea, whereas microscopic particles were barely detectable. In 10 of 17 deep-sea profiles (>2,000 m depth), macroscopic particle abundances were more strongly cross-correlated with oxygen deficits than microscopic particles, suggesting that biomass bound to large particles dominates overall deep-sea metabolism.     

Pediatric and adolescent injury in skiing

ABSTRACT

This review examines risks that accompany child and adolescent participation in downhill skiing. Falls and non-collision events were the most common mechanism of injury, but significant data implicate head injuries, blunt abdominal trauma, and spinal trauma as the leading causes of morbidity and mortality in this population. School-aged children and youth (7–14 years) are more likely to sustain an injury, compared to children (0–6 years) and older teenagers (15–17 years). Knee injuries were the most common injury, reported as 10.3%-47.7% of all lower limb injuries. The literature supports helmet use as protective against injury with a reduced risk of head, neck, or face injury in children under 13 years. Future studies are necessary to evaluate injury and risks in the backcountry given the rapid increase of adolescents traveling outside ski areas. Research examining risk factors and preventive measures in youth skiing is also warranted.     

Persistent and Repetitive Visual Disturbances in Migraine: A Review

Visual disturbances in migraineurs, such as visual aura, are typically episodic, that is, associated with the headache attack, and overlaid by head pain and other symptoms that impact the patient. In some patients, however, visual symptoms are dominant due to frequency (migraine aura status), duration (persistent migraine aura and other persistent positive visual phenomena), or complexity (visual snow syndrome). These syndromes are more rare and challenging to classify in clinical practice resulting in a lack of systematic studies on pathophysiology and treatment. We aim at describing clinical features and pathophysiological concepts of typical migraine aura with a focus on cortical spreading depression and differentiation from non‐typical migraine aura. Additionally, we discuss nomenclature and the specifics of migraine aura status, persistent migraine aura, persistent positive visual phenomena, visual snow, and other migrainous visual disturbances. The term migraine with prolonged aura might be a useful bridge between typical aura and persistent aura. Further studies would be necessary to assess whether a return of the classification category eventually helps diagnosing or treating patients more effectively. A practical approach is presented to help the treating physician to assign the correct diagnosis and to choose a medication for treatment that has been successful in case reports of these rare but disabling conditions.     

A new photographic method for mapping spatio-temporal receptive field using television snow stimulation

A means was devised to measure simultaneously spatial as well as temporal characteristics of visual receptive fields by stimulating the retina with the noise obtained on an unused television channel. The input, television snow, and the output, neural response, were recorded on a video tape. The tape was played back to obtain the (linear) spatio-temporal Wiener kernel by cross-correlating the input with the output. This method can be applied to extract the linear part of the visual responses in time and space.