"ව්‍යාප්ත වසංගත" හි සංශෝධන අතර වෙනස්කම්

== Concern about possible future pandemics ==

=== Viral hemorrhagic fevers ===

 

Some Viral Hemorrhagic Fever causing agents like [[Lassa fever]], [[Rift Valley fever]], [[Marburg virus]], [[Ebola|Ebola virus]] and [[Bolivian hemorrhagic fever]] are highly contagious and deadly diseases, with the theoretical potential to become pandemics. Their ability to spread efficiently enough to cause a pandemic is limited, however, as transmission of these viruses requires close contact with the infected vector, and the vector only has a short time before death or serious illness. Furthermore, the short time between a vector becoming infectious and the onset of symptoms allows medical professionals to quickly [[quarantine]] vectors, and prevent them from carrying the pathogen elsewhere. Genetic mutations could occur, which could elevate their potential for causing widespread harm; thus close observation by contagious disease specialists is merited.

 

=== Antibiotic resistance ===

Antibiotic-resistant microorganisms, sometimes referred to as "[[Antibiotic resistance|superbugs]]", may contribute to the re-emergence of diseases which are currently well-controlled. For example, cases of [[tuberculosis]] that are resistant to traditionally effective treatments remain a cause of great concern to health professionals. Every year, nearly half a million new cases of [[multidrug-resistant tuberculosis]] (MDR-TB) are estimated to occur worldwide.<ref>[http://www.who.int/mediacentre/news/releases/2009/tuberculosis_drug_resistant_20090402/en/index.html Health ministers to accelerate efforts against drug-resistant TB]. ''World Health Organization.''</ref> After India, China has the highest rate of multidrug-resistant TB.<ref>[http://www.guardian.co.uk/society/2009/apr/01/bill-gates-tb-timebomb-china Bill Gates joins Chinese government in tackling TB 'timebomb']. ''Guardian.co.uk''. April 1, 2009</ref> The [[World Health Organization]] (WHO) reports that approximately 50 million people worldwide are infected with MDR TB, with 79 percent of those cases resistant to three or more antibiotics. In 2005, 124 cases of [[MDR TB]] were reported in the United States. Extensively drug-resistant tuberculosis ([[XDR TB]]) was identified in Africa in 2006, and subsequently discovered to exist in 49 countries, including the United States. About 40,000 new cases of XDR-TB emerge every year, the WHO estimates.<ref>[http://www.cnn.com/2008/HEALTH/11/17/tb.pandemic/index.html Tuberculosis: A new pandemic?]. CNN.com</ref>

 

 

=== Influenza ===

 

Wild aquatic birds are the natural hosts for a range of [[influenza]] A viruses. Occasionally, viruses are transmitted from these species to other species, and may then cause outbreaks in domestic poultry or (rarely) give rise to a human pandemic. <ref name=sobrino6>{{cite book |chapterurl=http://www.horizonpress.com/avir |author=Klenk et al. |year=2008 |chapter=Avian Influenza: Molecular Mechanisms of Pathogenesis and Host Range |title=Animal Viruses: Molecular Biology |publisher=Caister Academic Press |isbn=978-1-904455-22-6}}</ref><ref name=Kawaoka>{{cite book |author=Kawaoka Y (editor). |title=Influenza Virology: Current Topics |publisher=Caister Academic Press |year=2006 |url=http://www.horizonpress.com/flu |isbn=978-1-904455-06-6}}</ref>

 

==== H5N1 (Avian Flu) ====

 

In February 2004, [[avian influenza]] virus was detected in birds in [[Vietnam]], increasing fears of the emergence of new variant strains. It is feared that if the avian influenza virus combines with a human influenza virus (in a bird or a human), the new subtype created could be both highly contagious and highly lethal in humans. Such a subtype could cause a global influenza pandemic, similar to the [[Spanish Flu]], or the lower mortality pandemics such as the [[Asian Flu]] and the [[Hong Kong Flu]].