#Plague in #SanFrancisco: #rats, #racism and #reform (Nature, summary)

[Source: Nature, full page: (LINK). Summary, edited.]

Plague in San Francisco: rats, racism and reform

Tilli Tansey


An urban outbreak of a deadly infectious disease with no known cause is a disaster planner’s worst nightmare. In his rousing book Black Death at the Golden Gate, journalist David Randall describes just that: the bubonic-plague epidemic that struck San Francisco, California, in 1900. The race to identify, isolate and halt the disease is set against a rich background of official complacency, financial malfeasance, political intrigues and scientific disputes.



Nature 568, 454-455 (2019) / doi: 10.1038/d41586-019-01239-x

Keywords: Plague; USA; California; History.



#Plague-Positive #Mouse #Fleas on Mice Before Plague Induced Die-Offs in Black-Tailed and White-Tailed Prairie Dogs (Vector Borne Zoo Dis., abstract)

[Source: Vector Borne and Zoonotic Diseases, full page: (LINK). Abstract, edited.]

Plague-Positive Mouse Fleas on Mice Before Plague Induced Die-Offs in Black-Tailed and White-Tailed Prairie Dogs

Gebbiena M. Bron, Carly M. Malavé, Jesse T. Boulerice, Jorge E. Osorio, and Tonie E. Rocke

Published Online: 17 Apr 2019 / DOI: https://doi.org/10.1089/vbz.2018.2322



Plague is a lethal zoonotic disease associated with rodents worldwide. In the western United States, plague outbreaks can decimate prairie dog (Cynomys spp.) colonies. However, it is unclear where the causative agent, Yersinia pestis, of this flea-borne disease is maintained between outbreaks, and what triggers plague-induced prairie dog die-offs. Less susceptible rodent hosts, such as mice, could serve to maintain the bacterium, transport infectious fleas across a colony, or introduce the pathogen to other colonies, possibly facilitating an outbreak. Here, we assess the potential role of two short-lived rodent species, North American deer mice (Peromyscus maniculatus) and Northern grasshopper mice (Onychomys leucogaster) in plague dynamics on prairie dog colonies. We live-trapped short-lived rodents and collected their fleas on black-tailed (Cynomys ludovicianus, Montana and South Dakota), white-tailed (Cynomys leucurus, Utah and Wyoming), and Utah prairie dog colonies (Cynomys parvidens, Utah) annually, from 2013 to 2016. Plague outbreaks occurred on colonies of all three species. In all study areas, deer mouse abundance was high the year before plague-induced prairie dog die-offs, but mouse abundance per colony was not predictive of plague die-offs in prairie dogs. We did not detect Y. pestis DNA in mouse fleas during prairie dog die-offs, but in three cases we found it beforehand. On one white-tailed prairie dog colony, we detected Y. pestis positive fleas on one grasshopper mouse and several prairie dogs live-trapped 10 days later, months before visible declines and plague-confirmed mortality of prairie dogs. On one black-tailed prairie dog colony, we detected Y. pestispositive fleas on two deer mice 3 months before evidence of plague was detected in prairie dogs or their fleas and also well before a plague-induced die-off. These observations of plague positive fleas on mice could represent early spillover events of Y. pestis from prairie dogs or an unknown reservoir, or possible movement of infectious fleas by mice.

Keywords: Yersinia pestis; Plague; Fleas; USA.


#Epidemiological characteristics of an #urban #plague #epidemic in #Madagascar, August–November, 2017: an outbreak #report (Lancet Infect Dis., abstract)

[Source: The Lancet Infectious Diseases, full page: (LINK). Abstract, edited.]

Epidemiological characteristics of an urban plague epidemic in Madagascar, August–November, 2017: an outbreak report

Rindra Randremanana, PhD, Voahangy Andrianaivoarimanana, PhD, Birgit Nikolay, PhD, Beza Ramasindrazana, PhD, Juliette Paireau, PhD, Quirine Astrid ten Bosch, PhD, Jean Marius Rakotondramanga, MSc, Soloandry Rahajandraibe, MSc, Soanandrasana Rahelinirina, PhD, Fanjasoa Rakotomanana, PhD, Feno M Rakotoarimanana, MD, Léa Bricette Randriamampionona, MD, Vaoary Razafimbia, MD, Prof Mamy Jean De Dieu Randria, MD, Mihaja Raberahona, MD, Guillain Mikaty, PhD, Anne-Sophie Le Guern, PharmD, Lamina Arthur Rakotonjanabelo, MSc, Prof Charlotte Faty Ndiaye, MD, Voahangy Rasolofo, PhD, Eric Bertherat, MD, Maherisoa Ratsitorahina, MD, Simon Cauchemez, PhD, Laurence Baril, MD, André Spiegel, MD, Minoarisoa Rajerison, PhD

Open Access / Published: March 28, 2019 / DOI: https://doi.org/10.1016/S1473-3099(18)30730-8




Madagascar accounts for 75% of global plague cases reported to WHO, with an annual incidence of 200–700 suspected cases (mainly bubonic plague). In 2017, a pneumonic plague epidemic of unusual size occurred. The extent of this epidemic provides a unique opportunity to better understand the epidemiology of pneumonic plagues, particularly in urban settings.


Clinically suspected plague cases were notified to the Central Laboratory for Plague at Institut Pasteur de Madagascar (Antananarivo, Madagascar), where biological samples were tested. Based on cases recorded between Aug 1, and Nov 26, 2017, we assessed the epidemiological characteristics of this epidemic. Cases were classified as suspected, probable, or confirmed based on the results of three types of diagnostic tests (rapid diagnostic test, molecular methods, and culture) according to 2006 WHO recommendations.


2414 clinically suspected plague cases were reported, including 1878 (78%) pneumonic plague cases, 395 (16%) bubonic plague cases, one (<1%) septicaemic case, and 140 (6%) cases with unspecified clinical form. 386 (21%) of 1878 notified pneumonic plague cases were probable and 32 (2%) were confirmed. 73 (18%) of 395 notified bubonic plague cases were probable and 66 (17%) were confirmed. The case fatality ratio was higher among confirmed cases (eight [25%] of 32 cases) than probable (27 [8%] of 360 cases) or suspected pneumonic plague cases (74 [5%] of 1358 cases) and a similar trend was seen for bubonic plague cases (16 [24%] of 66 confirmed cases, four [6%] of 68 probable cases, and six [2%] of 243 suspected cases). 351 (84%) of 418 confirmed or probable pneumonic plague cases were concentrated in Antananarivo, the capital city, and Toamasina, the main seaport. All 50 isolated Yersinia pestis strains were susceptible to the tested antibiotics.


This predominantly urban plague epidemic was characterised by a large number of notifications in two major urban areas and an unusually high proportion of pneumonic forms, with only 23% having one or more positive laboratory tests. Lessons about clinical and biological diagnosis, case definition, surveillance, and the logistical management of the response identified in this epidemic are crucial to improve the response to future plague outbreaks.


US Agency for International Development, WHO, Institut Pasteur, US Department of Health and Human Services, Laboratoire d’Excellence Integrative Biology of Emerging Infectious Diseases, Models of Infectious Disease Agent Study of the National Institute of General Medical Sciences, AXA Research Fund, and the INCEPTION programme.

Keywords: Yersinia pestis; Plague; Bubonic plague; Pneumonic plague; Madagascar.


#Pneumonic #Plague in a #Dog and Widespread Potential #Human #Exposure in a #Veterinary Hospital, #USA (Emerg Infect Dis., abstract)

[Source: US Centers for Disease Control and Prevention (CDC), Emerging Infectious Diseases Journal, full page: (LINK). Abstract, edited.]

Volume 25, Number 4—April 2019 / Dispatch

Pneumonic Plague in a Dog and Widespread Potential Human Exposure in a Veterinary Hospital, United States

Paula A. Schaffer1, Stephanie A. Brault1, Connor Hershkowitz1, Lauren Harris, Kristy Dowers, Jennifer House, Tawfik A. Aboellail, Paul S. Morley, and Joshua B. Daniels

Author affiliations: Colorado State University, Fort Collins, Colorado, USA (P.A. Schaffer, S.A. Brault, C. Hershkowitz, L. Harris, K. Dowers, T.A. Aboellail, P.S. Morley, J.B. Daniels); Colorado Department of Public Health and Environment, Denver, Colorado, USA (J. House)



In December 2017, a dog that had pneumonic plague was brought to a veterinary teaching hospital in northern Colorado, USA. Several factors, including signalment, season, imaging, and laboratory findings, contributed to delayed diagnosis and resulted in potential exposure of >116 persons and 46 concurrently hospitalized animals to Yersinia pestis.

Keywords: Yersinia pestis; Plague; Pneumonic plague; Dogs; USA; Colorado.


#Plague #vaccine: recent #progress and #prospects (npj Vaccines, abstract)

[Source: npj Vaccines, full page: (LINK). Abstract, edited.]

Review Article | OPEN | Published: 18 February 2019

Plague vaccine: recent progress and prospects

Wei Sun & Amit K. Singh

npj Vaccines, volume 4, Article number: 11 (2019)



Three great plague pandemics, resulting in nearly 200 million deaths in human history and usage as a biowarfare agent, have made Yersinia pestis as one of the most virulent human pathogens. In late 2017, a large plague outbreak raged in Madagascar attracted extensive attention and caused regional panics. The evolution of local outbreaks into a pandemic is a concern of the Centers for Disease Control and Prevention (CDC) in plague endemic regions. Until now, no licensed plague vaccine is available. Prophylactic vaccination counteracting this disease is certainly a primary choice for its long-term prevention. In this review, we summarize the latest advances in research and development of plague vaccines.

Keywords: Yersinia pestis; Plague; Vaccines.


#Global #Disease #Outbreaks Associated with the 2015–2016 #ElNiño Event (Sci Rep., abstract)

[Source: Scientific Reports, full page: (LINK). Abstract, edited.]

Article | OPEN | Published: 13 February 2019

Global Disease Outbreaks Associated with the 2015–2016 El Niño Event

Assaf Anyamba, Jean-Paul Chretien, Seth C. Britch, Radina P. Soebiyanto, Jennifer L. Small, Rikke Jepsen, Brett M. Forshey, Jose L. Sanchez, Ryan D. Smith, Ryan Harris, Compton J. Tucker, William B. Karesh & Kenneth J. Linthicum

Scientific Reports, volume 9, Article number: 1930 (2019)



Interannual climate variability patterns associated with the El Niño-Southern Oscillation phenomenon result in climate and environmental anomaly conditions in specific regions worldwide that directly favor outbreaks and/or amplification of variety of diseases of public health concern including chikungunya, hantavirus, Rift Valley fever, cholera, plague, and Zika. We analyzed patterns of some disease outbreaks during the strong 2015–2016 El Niño event in relation to climate anomalies derived from satellite measurements. Disease outbreaks in multiple El Niño-connected regions worldwide (including Southeast Asia, Tanzania, western US, and Brazil) followed shifts in rainfall, temperature, and vegetation in which both drought and flooding occurred in excess (14–81% precipitation departures from normal). These shifts favored ecological conditions appropriate for pathogens and their vectors to emerge and propagate clusters of diseases activity in these regions. Our analysis indicates that intensity of disease activity in some ENSO-teleconnected regions were approximately 2.5–28% higher during years with El Niño events than those without. Plague in Colorado and New Mexico as well as cholera in Tanzania were significantly associated with above normal rainfall (p < 0.05); while dengue in Brazil and southeast Asia were significantly associated with above normal land surface temperature (p < 0.05). Routine and ongoing global satellite monitoring of key climate variable anomalies calibrated to specific regions could identify regions at risk for emergence and propagation of disease vectors. Such information can provide sufficient lead-time for outbreak prevention and potentially reduce the burden and spread of ecologically coupled diseases.

Keywords: ENSO; Extreme weather; Chikungunya fever; Plague; Cholera; Global Health.


Effects of #Deltamethrin #Treatment on Small #Mammal and #Ectoparasite Population Dynamics and #Plague Prevalence in a North American Mixed-Grass Prairie System (Vector Borne Zoo Dis., abstract)

[Source: Vector Borne and Zoonotic Diseases, full page: (LINK). Abstract, edited.]

Effects of Deltamethrin Treatment on Small Mammal and Ectoparasite Population Dynamics and Plague Prevalence in a North American Mixed-Grass Prairie System

Lauren P. Maestas  and Hugh B. Britten

Published Online: 22 Jan 2019



Sylvatic plague affects many species in North American prairie ecosystems. Deltamethrin is commonly used to manage fleas in potential outbreak areas. Understanding the role of small mammals and their ectoparasites in sylvatic plague maintenance is pertinent to understanding the ecology of plague and its persistence in nature. This study examined the effects of plague management using deltamethrin on communities of small mammals, their flea faunas, and Yersinia pestis prevalence. We trapped small mammals from 2014 to 2016 on the Lower Brule Indian Reservation (LOBR), South Dakota, and analyzed the effects of deltamethrin treatment on small mammal populations, flea loads, and Y. pestis prevalence. We collected higher flea loads from small mammals on sites not treated with deltamethrin (1.10 fleas per animal) than from deltamethrin-treated sites (1.03 fleas per animal). We observed significant negative trends in mean flea load per animal between pre- and post-treatment collections. We detected no significant effects of deltamethrin treatment on animal captures pre- and post-treatment, but observed significant differences in animal captures by experimental unit. We detected no serological evidence for the presence of Y. pestis antibodies in small mammals and 1.2% Y. pestis prevalence across all sampled fleas. Although there is little overlap in the species of fleas infesting small mammals and prairie dogs, the occurrence of flea spillover has been documented. In our study, treatment with deltamethrin reduced flea loads on small mammals by up to 49%. Our data suggest that although the efficacy of deltamethrin on the LOBR—a mixed-grass system—may not be as high as that found in a comparable study in a short-grass system, deltamethrin is still a useful tool in the management of plague.

Keywords: Insecticides; Plague; Yersinia pestis; Wildlife; North America Region; Deltamethrin.