Category Archives: Lassa Fever

WHO | Lassa Fever – Nigeria

Lassa fever is an acute viral haemorrhagic fever illness. Lassa fever is transmitted to humans via contact with food or household items contaminated with rodent urine or faeces. Person-to-person infections and laboratory transmission can also occur.

Source: WHO | Lassa Fever – Nigeria

104 deaths have been reported since the onset of the current Lassa fever outbreaks season in December 2016

Link between deforestation and ebola a lesson in habitat encroachment | Stuff.co.nz

“We wondered if it was just because people were there, but we tested [and] it was actually due to the fragmented forest with people present … as people start to encroach.”Fruit bat populations increase in fragmented forest conditions, while their contact with humans also increases.Deforestation is increasing in West Africa to provide land to grow cocoa and palm oil and in central Africa, where other ebola outbreaks have occurred, to meet demand for hardwoods.”It shows there’s different implications in how you encroach in the environment. We in very rich countries, what are we doing that’s encouraging deforestation and habitat encroachment?

Source: Link between deforestation and ebola a lesson in habitat encroachment | Stuff.co.nz

Artificial intelligence reveals undiscovered bat carriers of Ebola and other filoviruses | Science Codex

David Hayman of Massey University notes, “The model allows us to move beyond our own biases and find patterns in the data that only a machine can. Instead of predicting where Ebola and other filovirus outbreaks will occur by looking at the last spillover event, it forecasts risk based on the intrinsic traits of filovirus-positive bat species.”Those traits include: early maturity, having more than one pup per year (most bats only have one), offspring that are large at birth, and a tendency to live in large groups. Compared to other bats, filovirus-positive species also have broader geographic ranges that overlap with a higher diversity of mammal species per square kilometer.When data on the world’s 1116 bat species were searched using this filovirus-positive bat profile, machine learning identified new potential hosts based on their traits. Once mapped, these bats were more widely distributed than the team expected. While many potential bat hosts are found in sub-Saharan Africa, they also range across Southeast Asia and Central and South America.Han explains, “Our results corroborate studies in Africa that have predicted the environmental niche of Ebola spans the primary tropical rainforest. But in a departure from past research, we identified several hotspots in Southeast Asia where up to 26 potential reservoir species overlap, notably in Thailand, Burma, Malaysia, Vietnam, and northeast India.”John Drake of the University of Georgia concludes, “Maps generated by the algorithm can help guide targeted surveillance and virus discovery projects. We suspect there may be other filoviruses waiting to be found. An outstanding question for future work is to investigate why there are so few filovirus spillover events reported for humans and wildlife in Southeast Asia compared to equatorial Africa.”

Source: Artificial intelligence reveals undiscovered bat carriers of Ebola and other filoviruses | Science Codex

Avian Flu Diary: Germany’s RKI Statement On Lassa Fever Cluster In Cologne – Oops!

The Nigerian Federal Ministry of Health provides only spotty updates on the outbreak, but two days ago CNN reported in Lassa fever death rates in Nigeria higher than expected): NCDC’s latest report, dated 14 March 2016, the total number of reported cases is 254 (129 of which confirmed by lab tests) and the total number of deaths (suspected, probable and confirmed) is 137, with a Case Fatality Rate (CFR) of 53.9%. Remarkable because last year (2015),  Nigeria reported 250 cases (likely a substantial under count) and only 8 deaths. Normally, 80% who are infected only experience mild symptoms, and the overall mortality rate is believed to be in the 1% to 2% range (although it runs higher (15%-20%) among those sick enough to be hospitalized). The Lassa virus is commonly carried by multimammate rats, a local rodent that often likes to enter human dwellings. Exposure is typically through the urine or dried feces of infected rodents, although human-to-human transmission is possible. Over the years we’ve seen a number of imported cases of Lassa fever to Europe, and into the United States (see here and here). Despite the potential for H-2-H transmission, we’ve never seen a cluster of cases outside of Africa. Until now.  About 10 days ago the medical director of a missionary hospital in Togo, who had been transferred to a hospital in Cologne, Germany, died of Lassa fever.  Yesterday German authorities announced that three contacts of his – including the mortician who prepared his body – have been diagnosed with Lassa.

Source: Avian Flu Diary: Germany’s RKI Statement On Lassa Fever Cluster In Cologne

Avian Flu Diary: FDA On Proposed Oxitec Mosquito Trials In The Florida Keys – Que  this is the end, my friends?

{Mosquitoes are not pests! They are one of nature’s vectors for passing on diseases whose purposes are to rebalance unbalanced ecologies or ecologies that have been dramatically disturbed. Most of the imbalances are caused by human expansion into new areas, deforestation, and industrialized monocultures of grains, fruits, vegetables. The really bad news? If we zap this vector rather than adjust how we disrupt the environment, another vector will take its place with perhaps a more deadly disease.}

Now, with the spread of Dengue, CHIKV and Zika in the Americas – along with the growing degree of insectacide resistance around the world – suddenly GM mosquitoes, Wolbachia, and other novel control methods are getting a lot of attention again.

Source: Avian Flu Diary: FDA On Proposed Oxitec Mosquito Trials In The Florida Keys

Anya Groner: The Public Is Us – Guernica / A Magazine of Art & Politics {Fear and Infectious Diseases}

Fear isn’t useless. It’s essential that we maintain the tension between individual liberties and community health, and expressing fears, particularly competing fears, is one way that’s done. Public skepticism helps ensure decision-makers do enough to minimize disease without abusing power or diminishing civil liberties. Still, it’s vital to keep paranoia in check. The theorist Eve Sedgwick posits that, like typhoid and measles, paranoia is communicable. We pass it along to those we interact with. This happened when the media responded to Dr. Spencer’s Ebola infection and it continues to happen in the ongoing debate about childhood vaccinations and measles. Paranoia distorts decision-making, which is part of the reason that a hundred years after Mary Mallon’s isolation began on North Brother Island, we still struggle to conceptualize the relationship between community and individual health. When it comes to disease, whether we acknowledge it or not, we’re part of the public. The public isn’t an abstraction. It’s us.

Source: Anya Groner: The Public Is Us – Guernica / A Magazine of Art & Politics

Ebola virus: wild and domestic animals, plants and insects…

Initial Ebola virus (EBOV) infection of humans is a rare zoonotic spillover event.  

 
Hypsignathus monstrosus, Epomops franqueti and Myonycteris torquatebats, all fruit-eating megabats of the familyPteropodidae, are considered to be important reservoir hosts, yet they do not show signs of disease.1 
 
While a great deal remains unknown about the identity and spectrum of natural ebolavirus hosts,1zoonoses appear to co-occur with bat pregnancy.2
 

 

Animals that have died from ebolavirus infections include 3,4:

 

  • Duiker (Cephalophus sp.; an antelope) 
  • Gorilla (Gorilla gorilla) 
  •  Chimpanzee (Pan troglodytes)

 

Living animals found to harbour infectious EBOV include:

 

  • Cynomolgus macaque monkey (Macaca fascicularis
  • Franquet’s epauletted fruit bat (Epomops franqueti) 
  • Hammer-headed bat (Hypsignathus monstrosus
  • Little collared fruit bat (Myonycteris torquata)
Those animals with only antibodies to EBOV in the absence of infectious virus, suggesting past exposure include 5,6:

 

  • Domestic dogs (Canis lupus familiaris
  • Peter’s lesser epauletted fruit bat (Micropterus pusillus; fruit-eating) 
  • Angolan free-tailed bat (Mops condylurus; insect-eating) 
  • Giant roundleaf bat (Hipposideros gigas; insect-eating) 
  • Egyptian fruit bat (Roussetus aegyptiacus; fruit-eating) 
  • Geoffrey’s rousette (Rousettus amplexicaudatus; a bat species; fruit-eating) 
  • Lord Derby’s scaly-tailed squirrel (Anomalurus derbianus)

 

Porcupines (Hystrix cristata) have been implicated as a source for human EBOV exposure but virus-positive animals have not been documented.4 
Between nine and 25% of 337 domestic dogs from various towns and villages in Gabon during an EBOV outbreak in 2001-2002 were identified as possible hosts for EBOV when found to be seropositive. 7,8 It was not known when they became seropositive nor has it been experimentally determined that dogs are able to host an active EBOV infection.9,10 Dogs were observed in contact with suspected virus-laden fluids and with other animals during the Gabon outbreak but seropositive dog specimens did not contain EBOV antigen or viral RNA. Three specimens from these seropositive dogs did not yield infectious virus in cell culture either and thus there remains no documented evidence for a canine source of human EBOV infection. In 2014, two dogs owned by human cases of EBOV/Mak in Spain (euthanized without testing 11) and the United States of America (tested negative for EBOV 12,13) did not exhibit any signs of disease. 
Domestic pigs have been found to be a natural host for the Reston ebolavirus 9,14 and antibodies to EBOV have also been found in guinea pigs, an animal that can also be experimentally infected.15Domestic dogs and guinea pigs appear to become infected without symptoms.6,7 Horses, mice, guinea pigs and goats have been experimentally inoculated with EBOV to produce antisera or test therapeutic preparations.16,17 
Pigs experimentally infected with a member of the Zaire ebolavirus become symptomatic.8 NHP, guinea pigs and mice have been used to examine aspects of disease progression and exhibit various degrees of disease when experimentally infected.18,19 
On a few occasions in one study into possible hosts, a low viral load of EBOV could be sporadically recovered after inoculation of a snake (up to 11 days post inoculation), a mouse (up to nine days later) and a spider (21 days later) but the authors of this study concluded that these results could have represented residual inoculum.21
Plants, arthropods, cows, cats and sheep have not been found to naturally carry or host ebolavirus infection but only small numbers of some species have been examined. 3,20-22

 

References…

 

 

  1. Leroy EM, Kumulungui B, Pourrut X, et al. Fruit bats as reservoirs of Ebola virus. Nature 2005;438:575-6.
  2. Plowright RK, Eby P, Hudson PJ, et al. Ecological dynamics of emerging bat virus spillover. Proc Biol Sci 2015;282:20142124.
  3. Olson SH, Reed P, Cameron KN, et al. Dead or alive: animal sampling during Ebola hemorrhagic fever outbreaks in humans. Emerg Health Threats J 2012;5
  4. Lahm SA, Kombila M, Swanepoel R, Barnes RF. Morbidity and mortality of wild animals in relation to outbreaks of Ebola haemorrhagic fever in Gabon, 1994-2003. Trans R Soc Trop Med Hyg 2007;101:64-78.
  5. Marsh GA, Haining J, Robinson R, et al. Ebola Reston virus infection of pigs: clinical significance and transmission potential. J Infect Dis 2011;204 Suppl 3:S804-9.
  6. Gonzalez JP, Herbreteau V, Morvan J, Leroy EM. Ebola virus circulation in Africa: a balance between clinical expression and epidemiological silence. Bull Soc Pathol Exot 2005;98:210-7.
  7. Allela L, Boury O, Pouillot R, et al. Ebola virus antibody prevalence in dogs and human risk. Emerg Infect Dis 2005;11:385-90.
  8. Weingartl HM, Nfon C, Kobinger G. Review of Ebola virus infections in domestic animals. Dev Biol (Basel) 2013;135:211-8.
  9. Stansfield SK, Scribner CL, Kaminski RM, Cairns T, McCormick JB, Johnson KM. Antibody to Ebola virus in guinea pigs: Tandala, Zaire. J Infect Dis 1982;146:483-6.
  10. Connolly BM, Steele KE, Davis KJ, et al. Pathogenesis of experimental Ebola virus infection in guinea pigs. J Infect Dis 1999;179 Suppl 1:S203-17.
  11. Why Dallas Won’t Kill The Dog Of The Texas Nurse With Ebola. Business Insider, 2014. (Accessed 27/4/2015, at http://bitly.com/1IxqyQI )
  12. Starting today, Dallas Animal Services will begin testing Nina Pham’s year-old dog Bentley for Ebola. The Dallas Morning News, 2014. (Accessed 17/4/2015, at http://bitly.com/1GSGqbU.)
  13. EBOLAVIRUS, ANIMAL RESERVOIR (05): USA, DOG, NOT. 2014. (Accessed 01/05/2015, at http://bitly.com/1IxqAIf )
  14. Barrette RW, Metwally SA, Rowland JM, et al. Discovery of swine as a host for the Reston ebolavirus. Science 2009;325:204-6.
  15. Rouquet P, Froment JM, Bermejo M, et al. Wild animal mortality monitoring and human Ebola outbreaks, Gabon and Republic of Congo, 2001-2003. Emerg Infect Dis 2005;11:283-90.
  16. Kudoyarova-Zubavichene NM, Sergeyev NN, Chepurnov AA, Netesov SV. Preparation and use of hyperimmune serum for prophylaxis and therapy of Ebola virus infections. J Infect Dis 1999;179 Suppl 1:S218-23.
  17. Bray M, Davis K, Geisbert T, Schmaljohn C, Huggins J. A mouse model for evaluation of prophylaxis and therapy of Ebola hemorrhagic fever. J Infect Dis 1998;178:651-61.
  18. Ebihara H, Takada A, Kobasa D, et al. Molecular determinants of Ebola virus virulence in mice. PLoS Pathog 2006;2:e73.
  19. Geisbert TW, Young HA, Jahrling PB, Davis KJ, Kagan E, Hensley LE. Mechanisms underlying coagulation abnormalities in ebola hemorrhagic fever: overexpression of tissue factor in primate monocytes/macrophages is a key event. J Infect Dis 2003;188:1618-29.
  20. Turell MJ, Bressler DS, Rossi CA. Short report: lack of virus replication in arthropods after intrathoracic inoculation of Ebola Reston virus. Am J Trop Med Hyg 1996;55:89-90.
  21. Swanepoel R, Leman PA, Burt FJ, et al. Experimental inoculation of plants and animals with Ebola virus. Emerg Infect Dis 1996;2:321-5.
  22. Ebola haemorrhagic fever in Sudan, 1976. Report of a WHO/International Study Team. Bull World Health Organ 1978;56:247-70.

(News, Status, or Profit Seeking?) Was Ebola the culprit in the ancient Plague of Athens? – The Washington Post

Powel Kazanjian, a professor of history and infectious diseases at the University of Michigan.

In a new paper, Kazanjian suggests that an Ebola virus may have been the culprit in the Plague of Athens, a five-year epidemic that began in 430 B.C., whose cause has long been a matter of conjecture. Not only was the famed historian Thucydides, who chronicled the Peloponnesian War between Athens and Sparta, a witness to the Athenian disease, he also contracted it himself and survived.

via Was Ebola the culprit in the ancient Plague of Athens? – The Washington Post.