Chapter 21 Homework
What are the symptoms of the early or catarrhal stage of pertussis?
cold symptoms and most notably a runny nose
What is the major reservoir for Hantavirus?
the deer mouse as well as other rodents that can harbor one of the multiple strains of hantavirus
What stage of pertussis is characterized by severe and uncontrollable coughing?
the second stage of pertussis is called the paroxysmal stage
How is tuberculosis diagnosed?
In the US, by one of two tests recommended by the CDC; the tests given are either a skin or blood test called the interferon-gamma release assay (IGRA); in the developing world, TB is tested by a PCR test or sputum smear test
What is FluMist?
The FluMist is a vaccine that was made available in 2003; it is a nasal mist vaccine consisting of three strains of influenza virus in live attenuated form
Formation of a pseudomembrane in the back of the throat is seen in cases of what disease?
This is seen in cases of Diphtheria. Pseudomembrane forms on the tonsils or pharynx. The membrane is formed by the bacteria and consists of bacterial cells, fibrin, lymphocytes, and dead tissue cells and may be quite extensive. It adheres to tissues and cannot easily be removed. It may eventually completely block respiration.
Do secondary bacterial infections occur with the common cold?
Yes
Do pertussis outbreaks still occur in the US?
Yes in the US and elsewhere
What is the primary transmission route for acquiring agents of the common cold?
by direct contact of droplets as well as indirect contact; it is by contact with hands and fomites contaminated with the nasal discharges of an infected person.
How is pertussis transmitted?
by droplet contact (respiratory droplets); it is highly contagious during both the catarrhal and paroxysmal stages
How long can Mycobacterium tuberculosis survive in fine aerosol particles?
8 months
What is the causative organism of whooping cough?
Bordetella pertussis which is a very small gram-negative rod
What vaccination is used to prevent pertussis?
DTaP an acellular vaccine with important B. pertussis antigens; a single booster with Tdap after the age of 11 is especially important to maintain immunity against this disease
What is the most common mode of transmission of sinusitis?
It is common for patients suffering from the common cold to develop sinusitis caused by bacteria or fungi. Viral infection is probably the most common cause of mild sinusitis. Its most common mode of transmission is direct and indirect contact.
Which disease involves transmission by aerosolized water from whirlpool spas, air conditioners, cooling towers, and supermarket vegetable misters?
Legionella is widely distributed in aqueous habitats as diverse as tap water, cooling towers, spas, ponds, and other freshwaters; t is resistant to chlorine; it is released during aerosol formation and can be carried for long distances
What feature of the respiratory system protect it from infection?
Nasal hairs serve to trap particles. Cilia on the epithelium of the trachea and bronchi propel particles upward and out of the respiratory tract. Mucus on the surface of the mucous membranes lining the respiratory tract is a natural trap for invading microorganisms. Once the microorganisms are trapped, involuntary responses can move them out of the sensitive areas. Responses include: sneezing, coughing, and swallowing. These are first line defenses.
What enzyme associated with the influenza virus hydrolyzes (breaks down) the protective mucous coating of the respiratory tract?
Neuramindase
What causes the bright red rash and fever associated with scarlet fever?
Scarlet fever is the result of infection with S. pyogenes strain that is itself infected with a bacteriophage. This lysogenic virus confers on the streptococcus the ability to produce erthrogenic toxin.
How can diphtheria be prevented?
a series of vaccinations with toxoid, usually given as part of a mixed vaccine against tetanus and pertussis as well, called the DTaP, in the routine childhood vaccination program
What is the constant mutation of viral glycoproteins exhibited by influenza virus called?
antigenic drift.
What is the exchange of a viral gene with that of another influenza virus strain called?
antigenic shift
How are cold viruses transmitted?
droplet contact, but indirect transmission may be more common, such as a healthy person touching a fomite and then touching one of his or her own vulnerable surfaces, such as the mouth, nose or an eye. In some cases, the viruses can remain airborne in droplet nuclei and aerosols and can be transmitted via the respiratory route.
What are the signs and symptoms of severe acute respiratory syndrome (SARS)?
fever (above 100.4) and body aches as well as an overall feeling of malaise
Normal biota of the respiratory tract can cause disease in what types of patients?
in immunocompromised individuals. The normal biota include: Streptococcus pyogenes, Haemophilus influenza, Streptococcus pneumoniae, Neisseria meningitides, and Staphylococcus aureus
What results do the exotoxins produced by Bordetella pertussis have on the respiratory system?
it leads to the production of a host of cytokines that have direct and indirect effects on physiological processes and on the host response
What are the signs of sinusitis caused by allergy?
itchy and watery eyes
In general, what is the affect of the influenza vaccine? How effective is it?
overall effectiveness of 70 to 90%; annual vaccination is considered the best way to avoid the infection
How many strains of influenza are generally present in the vaccine?
three strains of influenza in it; usually there are two influenza A strains and one influenza B strain
What is the function of normal biota of the respiratory tract?
to perform the important function of microbial antagonism. It reduces the chances of pathogens establishing themselves in the same area by competing with them for resources and space.
What individuals are at greatest risk for pneumococcal infections?
young infants, people without a spleen, the elderly and those with underlying lung disease and viral infections