If there is anything scientists are certain of when it comes to bats and their supposed role in causing human disease, it is that they still have a lot to learn.
Aside from well-established things like rabies virus, SARS coronavirus (the virus that causes severe acute respiratory syndrome) and Marburg virus (an extremely dangerous but rare hemorrhagic fever pathogen), bats appear to carry a plethora of other germs with unclear effects, if any, on human health.
And even some commonly believed bat paradigms may be incorrect. For example, some speculate that bats play a role in the transmission of Ebola simply because Ebola and Marburg are related pathogens. But scientific evidence to support such speculation is scant, at best.
A lack of evidence that bats are key reservoirs of human disease has not prevented their vilification or efforts to exterminate bat colonies where threats are presumed to lurk.
“The fact is that they provide important ecosystem services – insect control, pollination and seed dispersal, to name a few – and we want them around,” says Tony Goldberg, a University of Wisconsin-Madison epidemiologist and virus hunter. “But bats are also increasingly acknowledged as hosts of medically significant viruses. I have mixed feelings about that.”
To better understand the dynamics of bats and potential threats to human health, Goldberg and his colleagues explored the relationship of an African forest bat, a novel virus and a parasite. Their work, described in a report published July 13 in Nature Scientific Reports, identifies all three players as potentially new species, at least at the molecular level as determined by their genetic sequences.
Many viral pathogens often have more than one or two hosts or intermediate hosts needed to complete their life cycles. The role of bat parasites in maintaining chains of viral infection is little studied, and the new Wisconsin study serves up some intriguing insights into how viruses co-opt parasites to help do the dirty work of disease transmission.
The parasite in the current study is an eyeless, wingless fly, technically an ectoparasite. It depends on the bat to be both its eyes and wings. And it plays host to a virus, as the current study shows. For the virus, the fly plays the role of chauffeur. “From a virus’s perspective, an ectoparasite is like Uber. It’s a great way to get around – from animal to animal – at minimal expense and effort,” Goldberg explains.
The bat in the study belongs to the megabat suborder. It is a fruit bat and was trapped, tested and released by Goldberg’s colleague and study co-author Robert Kityo of Uganda’s Makerere University in Kampala.
The bat fly, according to the new study, was infected with a newly discovered rhabdovirus dubbed Kanyawara virus, a distant relative of the rabies virus. “These things were chock-full of the virus,” says Goldberg, a professor of pathobiological sciences at UW-Madison’s School of Veterinary Medicine. That said, he adds that “we don’t know if this virus is transmitted beyond the ectoparasite. We couldn’t find it in the bat. Maybe it is an insect virus.”
However, it is well known that ectoparasites transmit disease, says the Wisconsin epidemiologist, noting that things like ticks and fleas harbor important pathogens like typhus, bubonic plague, Lyme disease and Rocky Mountain spotted fever.
“Bat flies bite people if given the chance,” Goldberg says of the parasite, which he described as “shockingly large, leggy and fast – a parasite from hell.”
The report published this week notes that rare cases of human infection with bat-associated viruses remain enigmatic. The study cites the 1969 case of a British dockworker bitten by an unknown insect while unloading peanuts from Nigeria, and who was subsequently infected by Le Dantec virus, a relative of the virus Goldberg and his colleagues found in abundance in the bat flies they sampled. “Was the dockworker bitten by a bat fly? We’ll never know.”
The subtext of the research, according to Goldberg, is Ebola and the ecology of disease. Scientists are beginning to understand that serious pathogens like Ebola and SARS don’t come out of nowhere. They are already lurking in the environment, and the leap from an animal to a human can be just a matter of time and an organism’s ability to shift from one host to another.
“The big picture relevance of the research is that if we’re going to understand the diversity of viruses in the world, we need to look in unusual places,” Goldberg says. “We have a lot to learn about the basic distribution of species on the planet.”
By Terry Devitt, UW-Madison/ July 13, 2017
This story was originally posted July 10 by the African Studies Program
Over the 4th of July holiday our 2017 Mandela Washington Fellows joined in the celebration of American independence with a bit of BBQ, baseball, and fireworks. Afterwards, three fellows took a moment to reflect on the commemorations of independence in their home countries and to explain the meaning of these celebrations.
Emerencia Nguarambuka: Celebrating freedom in Namibia on March 21st
Independence is freedom, democracy and growth. It means being able to live peacefully, and coexist in harmony, respect for fellow human beings and fighting for equal rights for all humanity, regardless of sex, creed, race, color, religion, etc. It also means having equal access to resources, closing the inequality and poverty gap.
Independence means a second chance and making use of all opportunities the right way. This is especially important to me because prior to an independent Namibia, we were not allowed education, work, free movement, and so much other social stuff. Now we have a chance to redefine our future, and let our children grow up in a better environment with greater opportunities.
In Namibia, independence is celebrated on the 21st of March. Namibia gained independence from South Africa in 1990. We were colonized since the late 19th century. From 1884, Namibia was a German colony known as German South West Africa. After the First World War, South Africa was mandated to administer Namibia as a colony/territory.
To celebrate the holiday, traditional performances and artists provide music and dance throughout the day and after the main event. There are parades by the Defense Force (army), Air Force and the marines, which are inspected by the President and given honors. Previous heroes and heroines are also honored and receive special badges in honor of their role for the fight of independence.
School children also have plays and parades at the Independence Day, which adds more color to the event. At times we also have parachutes as part of the celebrations. The Government will provide small promotional materials such as paper flags and t-shirts to the public for free. Each five year independence (I.e. 5, 10, 15, 20, 25 years) is always a bigger celebration held in the capital city Windhoek and the President invites dignitaries and international friends from countries which helped Namibia attain independence.
After the big event, other regions can also hold delayed independence celebrations for those people who could not travel all the way to the capital city. Food and entertainment is provided. Normally various Ministers will be assigned to these regions to deliver the President’s independence message.
Free Transport is normally provided to all who want to attend the celebrations in order to attract as many people as possible.
Prior to independence celebrations, all media normally carries news and video articles related to independence, focusing on development in the country, as well as interviewing heroes and heroines who can tell their stories of their time fighting for independence.
Marcio Brito: An independent Cape Verde honors Amilcar Cabral on July 5
Cape Verde received its independence from Portugal on the 5th of July in 1975. On the 4th of July, young people host parties in anticipation of the July 5th holiday, people meet up with family and share meals. There’s also a festival and military parade where the president gives medals to officers. Independence celebrations in Cape Verde are about commemorating the birth of a liberated country. They’re also about celebrating the father of Cape Verde – Amilcar Cabral.
Cabral was born on the 12th of September (another national holiday) in Bafata, Guinea-Bissau and was assassinated in 1973, two years before Cape Verde gained independence. His efforts, along with members of the African Party of Independence of Guinea and Cape Verde (P.A.I.G.C.) helped instill dignity in a population who recognized the evident discrimination against them by Portugal, despite the country’s claims that its colonies could “never be separate.”
After the 1974 death of the Portuguese president and dictator and a military coup, the years 1974-1976 marked the independence of the former Portuguese colonies, with Guinea-Bissau being the first nation to receive its independence.
Since its independence, Cape Verde has grown from having a population where 80% of its citizens were unschooled to its current place as a nation with an educated population of 95% gaining access to a basic right that had been denied by the imperial Portuguese powers.
Omari Mahiza: From two countries to one independent Tanzania on December 9th
I am from Tanzania. My independence day is on the 9th of December. Before Independence day – before Tanzania – there were two different counties. One is an island, that is Zanzibar and the other one is the mainland, that was called Tanganyika. So these two places came together and together (in 1964) they formed the country now that is known as Tanzania. So, that day these two countries came together – that’s called Union Day. It’s usually on the 26th of April. But, there is another date that is known as Revolution Day, which is celebrated in Zanzibar. They went through a revolution before their independence. This is known as Revolution Day which is on the 12th of January.
Starting with Independence day, usually there’s a big parade, usually there is an announcement of where the year’s celebration is going to take place so we all know where we need to gather. Usually, it takes place in the National Stadium in Dar el Salaam. Recently it’s been moved around so it can be anywhere, really. People go dressed in flags. You find that all the armed forces are there – the police, army, the navy – everyone will be there. There’ll be a parade, where all those forces pass in front of the president. They salute the president and put on a show for everyone. It’s free, so everyone can attend.
There’s a speech from the president who might wait a whole year to say something specifically for Independence day with regards to workers rights or something which is big. Usually it’s just a celebration of where we’ve been, so we remind ourselves where we were – we got our independence in 1961 from the British. So usually we remind ourselves where we were, where we are right now, and where we want to go.
Fifty-something years after independence I think we’re still struggling with the same things that we were struggling with like fifty years ago. Some of the issues have actually become worse than they were fifty years ago, if you can imagine that. So, what independence means to me, is at least, more freedom of expression these days. I think mostly it means the freedom of expression – people can say I am this – and most of the time not being persecuted. It’s still a challenge, there are certain issues where we are not there yet, but you can see that we are trying. Freedom of speech, freedom of expression is what independence should be.
Emerencia Nguarambuka (Namibia) is an Executive Assistant to the Permanent Secretary at the Ministry of ICT and does her own charity work in her community by assisting poor, young vulnerable women and children through donations of basic items.
Márcio Brito (Cabo Verde) works in the ‘Rádio e Tecnologias Educativas ‘ RTE’ where he produces and presents a daily program from 8 to 11 o’clock in the morning from Monday to Friday.
Omari Mahiza (Tanzania) is a doctor employed by the government to work at Amana Hospital in the pediatrics department.
-by Hiwot Adilow