1 / 15

Lecture 22 : Other Emerging Infections Overview

Lecture 22 : Other Emerging Infections Overview. NEWLY RECOGNISED INFECTIOUS DISEASES Known slow burners Heart diseases Peptic ulcer Cancers Other diseases DELIBERATELY CAUSED INFECTIOUS DISEASES ASSESSMENT OF RISKS Endemic diseases. Newly Recognised Infections.

nydia
Download Presentation

Lecture 22 : Other Emerging Infections Overview

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Lecture 22 : Other Emerging Infections Overview NEWLY RECOGNISED INFECTIOUS DISEASES Known slow burners Heart diseases Peptic ulcer Cancers Other diseases DELIBERATELY CAUSED INFECTIOUS DISEASES ASSESSMENT OF RISKS Endemic diseases

  2. Newly Recognised Infections • The term is used to describe diseases traditionally thought to be degenerative (i.e. non-infectious), but now thought to be caused by a biological agent (e.g. bacteria, virus). • Not necessarily on the increase – it is the causes that are ‘emerging’.

  3. ‘Slow Burners’ • Some infectious diseases are known to be ‘slow burners’ (i.e. long incubation period). • Chicken pox is caused by the varicella zoster virus, which then becomes dormant, but may cause shingles in later life. • Mycobaterium tuberculosis can hide within the immune system, but break out if the immune system becomes compromised to cause active tuberculosis. • Creutzfeld-Jacob disease (CJD) was long thought to be degenerative, but is now known to be caused by a prion.

  4. Heart Diseases • Streptoccous pyrogenes causes scarlet fever in childhood (now much milder than in the past), but it can develop into rheumatic fever, which in turn may result in rheumatic heart disease. • Trypanosoma cruzi causes Chaga’s disease, which is the leading cause of heart disease in Latin America. • Chlamydia pneumoniae is a suspected factor in atheroma, hypertension and corononary heart disease. • Porphyromonas gingivalisis also a suspect.

  5. Cancers and Ulcers • Helicobacter pylori is now a known cause of peptic ulcers. • Also suspected cause of gastric cancer. • Infections are suspected in other cancers: • Liver (hepatitis B virus); • Cervix (human papilloma virus); • Anus, vagina, penis, mouth and throat (human papilloma virus); • Liver (Aspergillus flavus).

  6. Other Diseases • Other diseases suspected of being caused by infections include: • Appendicitis; • Multiple sclerosis; • Leukaemia; • Type 2 diabetes; • Schizophrenia.

  7. Summary Causality is difficult to prove because: a) Long latency period; b) Agent does not always produce the disease; c) Agent is not the only cause of the disease. New discoveries will increase the likelihood of vaccines or effective therapeutic responses.

  8. Biological Weapons(1) • An epidemic might be started on purpose. • Long history: e.g. Kaffa (plague), British in the French and Indian War (1756-63) – smallpox • Japaneses in World War II against the Russians (typhoid), Chinese (plague and cholera). Chinese deaths estimated at 400,000 and 580,000. • Scottish island of Gruinard contaminated by anthrax in 1942. Only fully decontaminated in 1990.

  9. Gruinard

  10. Biological Weapons(2) • Signatories of the 1972 Biological Weapons Convention agreed not to develop biological weapons. • Soviet Biopreparat programme employed 30,000. • Accident at Sverdlovsk 1979 (the biological Chernobyl) killed at least 100 from Anthrax, but full death toll is thought to have been about 1000.

  11. St. Petersburg Kirov Sergiyev Posad Novosibirsk Sverdlovsk Moscow

  12. Biological Weapons(3) • Russians had one of two repositories of smallpox samples. These are believed to have been used for mass production of smallpox, which may now have found its way to North Korea and Iran. • Other countries believed to have biological weapons include Israel, Syria, Libya, Iraq, India, China, Taiwan, and S. Africa. • Biggest fear is they might be used by terrorist groups. The US was attacked by anthrax in 2001.

  13. Endemic Diseases • Antibiotic resistance will make more bacterial diseases harder to treat. • McKeown argued that therapeutic medicine contributed little to the decline in mortality from infectious diseases. If correct, overall impact of antibiotic resistance may not be too serious. • Improvements due to public health are likewise unlikely to be seriously reversed. • There is a growing population that has never been exposed to infectious diseases. Non-takeup of vaccines presents new risks. • Summary: we are not facing a crisis, but there are signs of complacency.

More Related