News / Science & Technology

    Sex Matters for Sleeping Sickness Microbes

    Dead tsetse flies are seen in a laboratory run by the International Livestock Research Institute in Ghibe Valley, 115 miles southwest of Addis Ababa, Ethiopia, June 1, 2002. (AP Photo/Sayyid Azim)
    Dead tsetse flies are seen in a laboratory run by the International Livestock Research Institute in Ghibe Valley, 115 miles southwest of Addis Ababa, Ethiopia, June 1, 2002. (AP Photo/Sayyid Azim)

    Multimedia

    Audio
    Joe DeCapua
    Scientists are keeping a close eye on the mating habits of microscopic organisms, including those that cause African sleeping sickness. They say what happens between two parasites can have major consequences for humans


    Researcher Wendy Gibson said when it comes to single-cell parasites known as trypanosomes, sex matters. They had once been thought to reproduce by splitting in half. But scientists say they have a sex life. 

    “This is important because if they can mate, it means that they can swap genes around. For example, if you’ve got a strain of parasite that’s resistant to a drug and it mates with one that isn’t, then it can swap that gene into the one that’s sensitive to the drug. And then, of course, you’ve got a new parasite, effectively, that is also resistant to the drug. That’s dangerous,” she said.

    Gibson is professor of protozoology at the University of Bristol.

    “Sleeping sickness is a very nasty disease. It’s carried by tsetse flies in tropical Africa. And now, fortunately, the numbers, as recorded by the World Health Organization, have dropped to less than 10,000 recorded cases. But years ago it used to really devastate large populations,” she said.

    She explained how the illness got its name.

    “It’s called sleeping sickness because the parasite gets into the brain and causes people to go into a sort of semi-comatose state. So that they just appear to be sleeping all the time. And that stage of the disease you can only treat with some very unpleasant drugs. One of them is based on arsenic. So you can imagine that that doesn’t do you any good”

    Sleeping sickness has been on the decline due to early diagnosis, thorough treatment and better control of the tsetse fly population. That’s good news. But Gibson said that a resurgence is always possible.

    “A colleague once described sleeping sickness to me as the sleeping dragon. It never goes away because the problem is that there are animal reservoirs of the disease. So even if you haven’t got humans with the disease in an area, it may still be circulating in animals, for example, cattle or wild animals. And of course the tsetse fly is feeding on those in keeping that cycle of transmission going. And it may then, if you’re unlucky, transfer back into the human population,” she said.

    Gibson said it’s important to understand sexual reproduction in microbes.

    “It’s one of the reasons why we’re worried about the next influenza outbreak because influenza is caused by viruses, but they also recombine. OK, it’s not the same sexual reproduction process as we get in these parasites, but it’s the same intrinsic mechanism that you’ve got recombination of genes. And, of course, with flu, you get new recombinant strains. We don’t know how virulent they are and what kind of disease they’ll cause and how quickly they’ll spread.”

    The study of mating microbes helps explain how diseases spread and how new strains are formed. That’s why what’s happening in Uganda is being closely watched.

    “You’ve got in the north of the country the West African form of the disease and in the southeast you’ve got the East African form. The East African form has been spreading northwards. And one of the worries is that it will overlap with the West African form of the disease. Now, if those two parasites then mate together, obviously, we’re worried that they’ll create some sort of superbug that maybe cause more serious disease,” said Gibson.

    Trypanosomes are part of a group of organisms known as protozoa. They also include microbes that cause such illnesses as leishmaniasis, which affects internal organs – giardiasis, an intestinal disorder – and trichomoniasis, which is a sexually transmitted disease.

    You May Like

    California Republicans Mull Choices in Presidential Race

    Ted Cruz tells state's Republican Convention delegates campaign will be 'battle on the ground, district by district by district,' ahead of June 7 primary

    Video Kurdish Football Team Helps War-Torn City Cope

    With conflict still raging across much of Turkey’s predominantly Kurdish southeast, many Kurds are trying to escape turmoil by focusing on success of football team Amedspor

    South African Company Designs Unique Solar Cooker

    Two-man team of solar power technologists introduces Sol4, hot plate that heats up so fast it’s like cooking with gas or electricity

    Featured Videos

    Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
    Turkish Kurd Islamist Rally Stokes Tensionsi
    X
    April 29, 2016 12:28 AM
    In a sign of the rising power of Islamists in Turkey, more than 100,000 people recently gathered in Diyarbakir, the main city in Turkey’s predominantly Kurdish southeast, to mark the birthday of the Prophet Muhammad. The gathering highlighted tensions with the pro-secular Kurdish nationalist movement. Dorian Jones reports from Diyarbakir.
    Video

    Video Turkish Kurd Islamist Rally Stokes Tensions

    In a sign of the rising power of Islamists in Turkey, more than 100,000 people recently gathered in Diyarbakir, the main city in Turkey’s predominantly Kurdish southeast, to mark the birthday of the Prophet Muhammad. The gathering highlighted tensions with the pro-secular Kurdish nationalist movement. Dorian Jones reports from Diyarbakir.
    Video

    Video Pakistani School Helps Slum Kids

    Master Mohammad Ayub runs a makeshift school in a public park in Islamabad. Thousands of poor children have benefited from his services over the years, but, as VOA's Ayesha Tanzeem reports, roughly 25 million school-age youths don't get an education in Pakistan.
    Video

    Video Florida’s Weeki Wachee ‘Mermaids’ Make a Splash

    Since 1947, ‘mermaids’ have fascinated tourists at central Florida’s Weeki Wachee Springs State Park with their fluid movements and synchronized ballet. Performing underwater has its challenges, including cold temperatures and a steady current, as VOA’s Lin Yang and Joseph Mok report.
    Video

    Video Somali, African Union Forces Face Resurgent Al-Shabab

    The Islamic State terror group claimed its first attack in Somalia earlier this week, though the claim has not been verified by forces on the ground. Meanwhile, al-Shabab militants have stepped up their attacks as Somalia prepares for elections later this year. Henry Ridgwell reports there are growing frustrations among Somalia’s Western backers over the country’s slow progress in forming its own armed forces to establish security after 25 years of chaos.
    Video

    Video Bangladesh Targeted Killings Spark Wave of Fear

    People in Bangladesh’s capital are expressing deep concern over the brutal attacks that have killed secular blogger, and most recently a gay rights activist and an employee of the U.S. embassy. Xulhaz Mannan, an embassy protocol officer and the editor of the country’s only gay and transgender magazine Roopban; and his friend Mehboob Rabbi Tanoy, a gay rights activist, were hacked to death by five attackers in Mannan’s Dhaka home earlier this month.
    Video

    Video Documentary Tells Tale of Chernobyl Returnees

    Ukraine this week is marking the 30th anniversary of the world's worst nuclear accident, at the Chernobyl nuclear power plant. Soviet officials at first said little about the accident, but later evacuated a 2,600-square-kilometer "exclusion zone." Some people, though, came back. American directors Holly Morris and Anne Bogart created a documentary about this faithful and brave community. VOA's Tetiana Kharchenko reports from New York on "The Babushkas of Chernobyl." Carol Pearson narrates.
    Video

    Video Nigerians Feel Bite of Buhari Economic Policy

    Despite the global drop in the price of oil, Nigerian President Muhammadu Buhari has refused to allow the country's currency to devalue, leading to a shortage of foreign exchange. Chris Stein reports from Lagos businessmen and consumers are feeling the impact as the country deals with a severe fuel shortage.
    Video

    Video  Return to the Wild

    There’s a growing trend in the United States to let old or underused golf courses revert back to nature. But as Erika Celeste reports from one parcel in Grafton, Ohio, converting 39 hectares of land back to green space is a lot more complicated than just not mowing the fairway.
    Video

    Video West Urges Unity in Libya as Migrant Numbers Soar

    The Italian government says a NATO-led mission aimed at stemming the flow of migrants from Libya to Europe could be up and running by July. There are concerns that the number of migrants could soar as the route through Greece and the Balkans remains blocked. Western powers say the political chaos in Libya is being exploited by people smugglers — and they are pressuring rival groups to come together under the new unity government. VOA's Henry Ridgwell reports.
    Video

    Video Russia’s TV Rain Swims Against Tide in Sea of Kremlin Propaganda

    Russia’s media freedoms have been gradually eroded under President Vladimir Putin as his government has increased state ownership, influence, and restrictions on critical reporting. Television, where most Russians get their news, has been the main target and is now almost completely state controlled. But in the Russian capital, TV Rain stands out as an island in a sea of Kremlin propaganda.

    Special Report

    Adrift The Invisible African Diaspora