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The East African : Oct 20th 2014
32 The EastAfrican OUTLOOK OCTOBER 18-24,2014 Continent is fast losing its most A new study says that ove≥ the past 40 yea≥s, the numbe≥ of te≥≥estial mammals has halved due to human activity By JEFF OTIENO The EastAfrican T The Gambian rat. Picture: NYT Scientists in US find ala≥ming bugs in ≥ats PATHOGENS By CARL ZIMMER New York Times News Service IF THE past few years have taught us anything, it’s that our well-being is intimately linked to the health of animals. The current Ebola epidem- ic probably got its start when someone came into contact with an infected animal, perhaps a monkey or a fruit bat. The virus causing Middle East respiratory syndrome appears to spread from camels to humans. Yet animal pathogens remain a scientific terra incognita. Researchers have begun cornering animals in far-flung parts of the world to learn more about what infects them. Recently, a team of pathogen hunters at Columbia University went on an expedition closer to home. They conducted a survey of the viruses and bacteria in Manhattan’s rats, the first attempt to use DNA to catalogue pathogens in any animal species in New York City. “Everybody’s looking all over the world, in all sorts of exotic placess,” said Ian Lipkin, a professor of neurology and pathology at Columbia. “But nobody’s looking right under our noses.” Although the scientists exam- ined just 133 rats, they found plenty of pathogens. Some caused food-borne illnesses. Others, like Seoul hantavirus, had never before been found in New York. Others were altogether new to science. Once the scientists caught the rats, they took samples of blood, urine, faeces and tissues from a number of organs. After extracting DNA from the samples, they sifted through the gene fragments. They discovered bacteria that caused food poisoning, such as salmonella and a strain of E coli known to cause terrible diarrhoea. They also found pathogens that caused fevers, such as Seoul hantavirus and Leptospira. They did not, however, find some of the nastiest germs infecting rats in other parts of the world, such as Yersinia pestis, which causes bubonic plague. In a recent study on rats, scientists discovered: Bacteria that caused food poisoning, such as salmonella and a strain of E coli known to cause terrible diarrhoea. Pathogens that caused fevers, such as Seoul hantavirus and Leptospira. 18 unknown species related to viruses already shown to cause diseases in humans. Then the scientists searched the rats for new species of viruses. So far, they have identified 18 unknown species related to viruses already shown to cause diseases in humans. Two of the new species were similar to the virus that causes hepatitis C. David Patrick, the director of the School of Population and Public Health at the University of British Columbia, called the identification of new viruses “groundbreaking.” “These viruses may or may not have any links to human illness, but it is good to be able to describe them in detail,” he said. The viruses resembling hepa- titis C could prove to be the most important discovery in the survey, not because rats will give us hepatitis C. (They will not.) But scientists may be able to glean clues from the rat viruses to fight the disease, which affects about 150 million people worldwide. Jay Varma, the deputy com- missioner for disease control at the New York City Department of Health, said the study would not lead to any immediate changes in how the city deals with rats, but the data would help health officials better understand how diseases spread. “We live in a world where humans are in the minority,” he said. “We as a society probably haven’t done enough to understand the true ecology of bacteria and viruses.” he population of the world’s terrestrial species compris- ing mammals, birds, reptiles and amphibians has halved in the past 40 years due to increased human activity, a new analysis by environmental scientists reveals. Scientists from the World Wildlife Fund (WWF) who conducted the study on terrestrial species over the past 40 years, say that the global trend shows no sign of slowing down, even though campaigns on environment conservation have been stepped up. The analysis found that Af- rica is among continents where a sharp decline in terrestrial mammals has occurred, raising serious concerns about the future of some of the continent’s most valuable mammals, among them elephants and rhinos. For many years, terrestrial mammals have played a significant role in the continent’s economic growth, attracting millions of tourists who bring in the foreign exchange that countries use to pay for imports. The analysis attributes the loss of wildlife habitat in Africa, as in other parts of the world, to increased human land use, particularly for agriculture, urban development and energy production. Environmental scientists now warn that some of the animals listed as most endangered by the Convention on International Trade in Endangered Species (Cites) may be headed for extinction in the near future if the trend continues. “When habitat loss and deg- radation is compounded by the added pressure of wildlife hunting, the impact on species can be devastating,” the conservation organisation warns in its analysis. The WWF arrived at this damning conclusion after studying population trends for 1,562 species of mammals, birds, reptiles and amphibians from a wide range of habitats. The study helped the scientists calculate the global living planet index (LPI) — which assesses the population of mammals and other living organisms over a given period of time. The forest elephant In Africa, elephants and rhi- nos are among a group of mammals facing extinction due to human activity. In the category of the former, the forest elephant, a sub-species of the African elephant, distributed throughout fragmented forested areas in West and Central Africa, faces the highest risk. Due to the rapid loss of their traditional habitat, with studies showing that forest elephants had been restricted to a mere 67 per cent of their historic range as early as 1984, their numbers too have declined rapidly. “Recent analysis suggests that across the forest elephant’s range, the population size declined by more than 60 per cent between 2002 and 2011 — primarily due to increasing rates of poaching for ivory,” the scientists who conducted the analysis said. In general, according to the United Nations Environment Programme (Unep) the possible number of elephants killed in Africa per year is in the range of 20,000 –25,000. WWF puts Africa’s elephant population at between 470,000 and 690,000. The decline of forest ele- phants has been partly blamed on the Sudanese Janjaweed and the Lord’s Resistance Army (LRA) who continue to poach the mammals throughout Central Africa and neighbouring countries. The Mozambican National Resistance (Renamo) has also been accused of poaching elephants and rhinos to fund its resurgent insurgency. In East Africa, fingers have The forest elephant, a subspecies of the African elephant, faces the highest risk of extinction.” WWF been pointed at the militant group Al Shabaab, who poach the wild animals and sell their tusks, then use the money to buy ammunition and fund terror attacks in the region. Corrupt public officials with connections in Asia have also been linked to poaching. According to the Kenya Wild- life Service (KWS), as at early September this year, the country had lost 116 elephants. Last year, 302 were killed. In Tanzania, though the exact number of elephants killed this year is unknown, it is believed to be higher. Tanzania is one of the countries with the high- At South Af≥ica’s oldest game ≥ese≥ve, By PAUL BURKHARDT Washington Post-Bloomberg ELEPHANTS AT Hluhluwe-iMfolozi Park, South Africa’s oldest game reserve, have begun receiving a contraceptive vaccine to control the pachyderm population. The game reserve is the largest in the programme, which now includes 20 parks, according to a statement by the Humane Society International, an animal conservation organisation. “The immuno-contraceptive pro- gramme allows elephant populations to be managed humanely, especially in small enclosed parks and private conservancies,” said the group, along with Ezemvelo, the conservation authority in KwaZulu-Natal, the province where the park is located. The vaccine, injected remotely into African elephant cows by dart gun, is a non-hormonal treatment that causes an immune response which prevents eggs from being fertilised by a sperm, said the groups. The groups added: “It is also reversible, allowing managers to fine- tune population growth.” While elephants are endangered across much of Africa, in Southern Africa many parks are overpopulated, leading to damage to ecosystems including tearing down of trees. The animals can weigh up to six metric tonnes and stand 310 feet at the 600 Number of elephants at the HluhluweiMfolozi Park in South Africa.
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Oct 27th 2014