Chapter 9 Diseases And Human Evolution Summary

Bacterial pathogen Mycobacterium tuberculosis causes tuberculosis a complex granulomatous disease which is a global health concern. It is a very slow growing bacteria, thus is extremely time consuming to culture in laboratory. It can survive the attack of the immune arsenal of our body; can successfully hide inside the macrophage. This makes long periods of uninterrupted antibiotic treatment necessary for the patients with tuberculosis and contributes to drug resistance very quickly [WHO 2014]. All this poses an extreme challenge to the scientists and the medical community to develop effective drug, monitor and treat this disease across globe. Before the discovery of anti-tubercular drugs, this disease was one of the most dreaded diseases. In absence of any drugs the only form of treatment recommended was healthy diet, rest and fresh air. Patients were sent to Tuberculosis sanatorium hoping that they might survive. The origin of this pathogen is traced back to Africa around 70,000 years ago and they successfully coevolved with humans as they migrated out of Africa and settled across the globe. Nearly 10,000 years ago there was a sudden change in human demography and the human population density increased suddenly, this is termed as Neolithic Demographic Transition. Genomic data of Mycobacterium across

“Tuberculosis (TB), a multisystem disease with myriad presentations and manifestations, is the most common cause of infectious disease–related mortality worldwide. Although TB rates are decreasing in the United States, the disease is becoming more common in many parts of the world. In addition, the prevalence of drug-resistant TB is increasing worldwide. TB is caused by M tuberculosis, a slow-growing obligate aerobe and a facultative intracellular parasite. The organism grows in parallel groups called cords (as seen in the image below). It retains many

Tuberculosis has been part of human history for a long time but how long is a long time? Recent research using genetic data has allowed us to know that the tuberculosis progenitor has been on this planet for about 3 million years affecting even our earlier ancestors (Gutierrez et al, 2005). Additionally this research showed that the bacilli from tuberculosis are capable of mixing sections of their genome with other strains and giving the pathogen a composite assembly, which resulted from ancient horizontal exchanges before its clonal expansion. This quality provided tuberculosis a big advantage that even now a days allows the organism to evade, adapt and create resistance to treatments that were once successful. In order to fix current and

Tuberculosis is considered to be another surfacing disease. According to the Institute of Medicine, they believe the sole reason of the resurgence of tuberculosis is the increase in immunosuppressed populations. In industrialized countries, peoples

Chapter 10 of Disease and Human Evolution discusses leprosy. What initially stood out to me is that leprosy isn’t actually the official name of the disease. It was renamed Hansen’s Disease after Dr. Hansen, who discovered the real cause of leprosy. This is where I saw the first evolutionary mechanism. The mycobacterium that causes leprosy, Mycobacterium leprae, can shed its cell wall. This allows it to adapt to a variety of environments, including our body, allowing it to infect as many individuals as possible. I think this is a great example of part of the evolutionary synthesis, that heritable variation will be systematically biased. This says that variation will be biased towards adaptive and well-integrated variants. This mycobacterium certainly did that in evolving the mechanism to shed its cell wall so it can integrate into any organism’s system. I also found it incredibly interesting that this bacteria can also infect armadillos of all animals. While Barnes also discussed that chimpanzees and monkeys can be infected, it stood out to me that armadillos specifically can be infected, as we typically just learn about livestock and non-human primates can be infected with the disease.

Tuberculosis, TB (tubercle bacillus) or MTB (mycobacterium tuberculosis) is a widespread, and in numerous cases fatal, communicable disease produced by a variety of forms of mycobacteria. The disease is distributed within the air when individuals who are infected with active TB infection sneeze, cough, or pass on breathing fluids throughout the air. Generally infections are asymptomatic, meaning they feel or show no symptoms, and dormant, but then again approximately one in ten dormant infections in the long run move on to the active disease. If left untouched, active TB is fatal to more than half of those infected.

Tuberculosis (TB) is a CDC (Centers for Disease Control) notifiable disease which is caused by an infectious bacterium that was discovered by a man named Robert Koch in 1882. This infectious bacterium that causes Tuberculosis is called Mycobacterium tuberculosis (Mtb), and is also known as Koch 's Bacillus. According to the National Institute of Allergy and Infectious Diseases (2015), Mtb is a small, slow-growing bacterium that can live only in people. It is not found in other animals, insects, soil, or other non-living things. Mtb is an aerobic bacterium, which means

One of the top infectious diseases world wild, tuberculosis has plagued humanity for centuries. Tuberculosis is caused by a bacterium, that bacteria attacks the lungs but can also attack and spread to other body parts. Prior to medical advances not much was known about this tuberculosis disease. It is believed that Tuberculosis (or TB for short) has been around for six thousand years. Scientist theorized that TB could have first infected humans roughly five thousand years ago, from contact with infected domesticated animals and spreading along trade routes. Evidence of TB causing bacterium has

In terms of etiology, the bacterium behind tuberculosis as discovered by Koch is a very stubborn one. In his work to determine the cause of tuberculosis he describes how the bacteria shows many distinct characteristics that make them so dynamic. They are rod-shaped, thin, only one-half as long as the diameter of hemoglobin but once in a while, they are able to get as long as the diameter of a cell and belong to a group of Bacilli. In addition, they are also described to possess a form and size that resembles that of the leprosy bacillus that exists in large numbers in everywhere they exist, usually in tissue cells and also outside cells. (Koch, 1882)

TB has been found to come from the genus Mycobacterium. It was first thought that through the taming and keeping of cattle around 10,000-25,000 years ago allowed the bacteria to transfer from the livestock and infect humans. This would be where the bacteria would grow and evolve in the new host and become close to the bacterial species that we see today that can develop into Tuberculosis (Smith, 2003). Although, further research has shown

In many cases, Mycobacterium tuberculosis usually develops because of inconsistent consumptions of drugs. Most of the time, most people don’t even know they are infected until symptoms occur because this pathogen is easily transmitted through air exchange (Medline Library, 2005). Although this pathogen usually remains inactive even when it is in the immune system, it becomes

Tuberculosis, often referred to as TB is one of the world’s oldest infections. It is a chronic, airborne, highly contagious infection, which is caused by Mycobacterium tuberculosis. It is treatable and preventable, but yet causes increasing morbidity and mortality (Battle, 2009,). It re-emerged in the mid-1980s as a major public health concern. Tuberculosis is one of the leading causes of death globally, especially in low and middle income countries. Tuberculosis has been implicated as comorbidity in other diseases like HIV/AIDS and diabetes. It is numbered among the top fifteen diseases by World Health Organization and the sixth Millennium Development Goal. Robert Koch, one of the fathers of Microbiology, first discovered M. tuberculosis as the causative agent of tuberculosis in 1882 (Adams & Koch, 2010). Tuberculosis is the most common bacterial infection worldwide.

Tuberculosis (TB) is infectious disease caused by bacterial pathogens from Mycobacterium tuberculosis Complex. Tuberculosis affects various organs of the body forming granulomas at the site of infection. The pulmonary TB is the most common form (Anon, 2015).Only the pulmonary form is infectious with aerosol transmission after a sneeze or cough from an infected individual. Once an individual is infected with Mycobacterium tuberculosis Complex, clinically, it can either lead to a TB infection (Latent/Inactive TB) or an Active TB. In TB infection, the bacteria reside in the body in an inactive state without causing any symptoms or being contagious. This is due to the immune system of the body which prevents the bacteria from multiplying and causing local damage in the body. The active TB is contagious and is characterized by the common clinical symptoms like, prolonged cough with or without blood and sputum (weeks-months), unintentional weight loss, chronic fatigue, low grade fever (on and off for weeks-months), and night sweats. A Latent TB can become active if there is a compromise in the immune system of the body. The time period between infection and clinical symptoms vary from weeks to years again depending upon the immune system of the body. In vulnerable groups, the symptoms appear after a few months of infection (Mayoclinic.org, 2015).

Mycobacterium tuberculosis, which has possibly caused more fatalities than any other microbial pathogen, has a long-standing worldwide history. Research has shown that an early precursor of the bacteria may have been present in East Africa as long as three million years ago. The current form of Mycobacterium tuberculosis is thought to be a descendant from a bacterium that existed about 20,000 to 15,000 years ago, but the variety of tuberculosis forms present today probably appeared between 250 and 1,000 years ago. Historical evidence for the presence of tuberculosis in ancient times can be obtained through certain skeletal abnormalities that are associated with tuberculosis. For example, Egyptian mummies dating over 5,000 years old have been found to contain the Pott’s deformity (Daniel, 2006). This deformity entails a compressed and deformed spinal cord that results from progressed

Tuberculosis is among the fatal diseases that are spread through the air. It’s contagious, meaning that it spreads from one infected individual to another, and at times it spreads very fast. In addition to being contagious, the disease is an opportunist infection as it takes advantage of those with weak defense mechanism, and especially the ones with terminal diseases like HIV and AIDS. Tuberculosis is therefore among the major concerns for the World Health Organization due to its contagious nature (World Health Organization 1).