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Viruses are defined as “ small highly specialized infectious agent”. This definition has been common for the last decades or century to define nature’s microorganisms, which tend to infect most living organisms from humans down to bacteria. Now, it seems that the definition would be widened to include even these little malicious computer codes –that they used to call worms– but now the word virus would seem more appropriate.

In July 2010, a malicious code was discovered and assigned the name “Stuxnet” the powerful virus, and –unlike the previous ones– this one simulates the biological virus in the way it acts. Speaking biologically, a common flu virus would enter the human body through the respiratory tract, bind to special receptors and infect the entire respiratory tract causing the common flu symptoms, this could have been applied to older computer viruses. The new Stuxnet virus, however, would resemble a more specialized biological viruses as hepatitis viruses or HIV; the Stuxnet virus gains entrance to the computer via “Universal Serial Bus“ –commonly known as “USB port”– and then spreads like wild fire in the entire network its device is connected to.

Up to this part, Stuxnet would be a common garden-variety computer virus, but this is not enough for Stuxnet. Just like HIV searches for CD4 cells and hepatitis virus searches for hepatic cells, the malicious code Stuxnet searchs the infected computer for its target, which is a special control program called “Supervisory Control and Data Acquisition (SCADA) developed by Siemens Co. for operation of industrial systems, and used to control manufacturing processes from centralized locations, for example it can be used to alter the motor work rate of a machine on a factory floor, or the pressure in a pipeline, so typical environments could be oil pipelines and power plants.

This highly specialized virus is also unique in its mode of action; the sophisticated virus uses a four “zero-day” vulnerabilities –zero-day vulnerability or zero-day attack is a security hole or breach in a program which the developer is unaware of. Using four of these zero-day vulnerabilities is quite weird because these zero-days are of great value ( for hacker and malware makers )and using 4 of them in a single code is quite odd. Again the code still surprises us with its resemblance to biological viruses, for examples, like flu virus that has the ability to mutate and change forms via multiple ways, and like any bacterium that acquires resistance through plasmids or other pathways, Stuxnet can upgrade itself via peer-to-peer architecture (p2p, a distributed application architecture that partitions tasks or workloads between peers) allowing it to be updated after the initial command and control server (the initial computer) is disabled.

Symantec Corp., one of the world computer security leaders, estimates that 45.000 computers have been infected, and like biological threats and biological warfare viruses, Symantec also estimates nearly 30.000 of these infected computers in Iran only, and earlier today (27 September 2010) undisclosed Iranian sources said the nuclear plant have indeed been hit by Stuxnet with no damage to the plant.

I guess Arnold Schwarzenegger (The terminator) wasn’t lying after all when he said “I’ll be back!! “



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So, we thought the worse was over; we thought we are done fighting the bad guys, HIV, SARS and H1N1A, but now it seems that a new menace is eminent. Our chaotic and rather foolish use of antibiotics have created this unknown danger that could add a new chapter to the history of medicine and fighting infectious diseases. This danger is called New Delhi metallo Beta-Lactamase -1, AKA NDM-1

Meet the Bug

In December 2009, a super villain appeared on the scene; he’s violent, resistant and determined to do as much damage as he could. Our super villain is the NDM-1 (New Delhi metallo beta lactamase – 1), a newly emerging beta-lactam resistance enzyme including carbapenems, which are one of few alternatives used for antibiotic-resistant bacterial infections. The NDM-1 gene is classified as a Carbapenemases . The enzyme is named after the city in which it first appeared, New Delhi, the Indian capital. In December 2009, a Swedish patient in India acquired an antibiotic resistant infection. Being unsuccessfully treated in India, the patient was further transferred to Sweden. The carbapenem-resistant Klebsiella pneumoniae was identified carrying the novel NDM-1 gene. A later study in India found that carbapenem-resistant strains from patients in India carried the NDM-1.

The Spread

In May 2010, an E. coli expressing the NDM-1 gene was isolated from a patient in the UK, the patient was of Indian origin and had visited India 18 months ago where he had been undergoing dialysis. According to CDC Morbidity and Mortality Weekly Report (MMWR) , as of June 2010, three Enterobacteriaceae isolates carrying the NDM-1 gene were discovered in the U.S., which were E. coli, Klebsiella pneumoniae, and Enterobacter cloacae, NDM-1 provided the three isolates with resistance to all antibiotics except for Aztreonam. Fortunately to the bacteria but unfortunately to our patient, the isolates conferred resistance even to Aztreonam by different mechanism other than the NDM-1, and the MMWR established that all the three U.S. isolates were related to patients who had medical care in India.

Furthermore, a team in India in July 2010, reported cases of Acinetobacter baumannii carrying the NDM-1 in India. A recent study by a multinational team published in “The Lancet Infectious Diseases, September 2010” reported that the isolation of 44 isolates with NDM-1 in Chennai, 26 in Haryana, 37 in the UK, and 73 in other sites in India and Pakistan. NDM-1 was mostly found among E. coli (36) and Klebsiella pneumoniae (111), which were highly resistant to all antibiotics. Luckily, all the studies have confirmed that all NDM-1 isolates were susceptible to the antibiotics tigecycline (the FDA-approved glycylcycline antibiotic developed by Francis Tally and marketed by Wyeth under the brand name Tygacil®), and colistin (polymyxin E antibiotic, which causes nephrotoxicity and neurotoxicity at high dose IV). Some unconfirmed reports indicate the NDM-1 appearing in Canada and Japan earlier this month (Sep 2010).

First Victim

In June 2010, patient zero –the first reported death– was a Belgian man who had a car accident in Pakistan, first being treated in a hospital in Pakistan and he became infected with the Bug carrying the NDM-1. He was further transferred to Belgium where he was hospitalized with major leg injury, and despite being administered colistin, the patient died!

We now face a new challenge. Could this superbug mean the end of the beta-lactam antibiotics era?!


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