Question

Which of the following spirochete-caused diseases is transmitted by an arthropod? A. Leptospirosis B. Pinta C. Relapsing fever D. Yaws E. Syphilis

Short answer

The spirochete-caused disease transmitted by an Arthropod is Relapsing fever.

Step-by-step solution

Identify spirochete-caused diseases

Spirochetes are a group of motile bacteria, of which many types are known to cause diseases. These include Leptospirosis, Pinta, Relapsing fever, Yaws, and Syphilis.

Understand Arthropod-borne diseases

Certain diseases are transmitted by vectors, which are living organisms that can transmit infectious pathogens between humans or from animals to humans. One such group of vectors are arthropods (like ticks and fleas) which can transmit different diseases.

Match diseases with transmission

Out of the given options, for each disease one needs to identify if it is primarily transmitted by an arthropod or not. The following matching can be created: \n Leptospirosis - commonly transmitted by contact with water, soil, or food contaminated with the urine of infected animals. \n Pinta - transmitted through direct skin-to-skin contact. \n Relapsing fever - transmitted by ticks (which are arthropods).\n Yaws - typically spread by direct contact with the fluid from a lesion of an infected person. \n Syphilis - most commonly spread during sexual activity.

Key concepts

Spirochete-caused diseases

Spirochetes are unique bacteria known for their spiral shape and mobility. They swim like corkscrews, enabling them to move through viscous environments. These bacteria are responsible for several diseases in humans:

• Leptospirosis: Typically contracted through exposure to water contaminated with animal urine, this disease can cause a range of symptoms including fever and muscle aches.
• Pinta: Affects the skin, resulting in discoloration and dermatological changes, and is transmitted through direct contact.
• Relapsing Fever: Noted for its recurring fever episodes; transmitted through ticks.
• Yaws: Known for producing lesions; spreads by direct contact with infected lesions.
• Syphilis: Widely recognized for being sexually transmitted and may involve multiple bodily organs if untreated.

These diseases showcase the varied transmission and infection methods of spirochetes, highlighting their adaptability.

Vector transmission

Vector transmission involves the transfer of pathogens through vectors—organisms that carry and transmit viruses, bacteria, or parasites. These living vectors are often arthropods such as:

• Ticks and Fleas: Known to transmit illnesses like Relapsing Fever through bites.
• Mosquitoes: Associated with spreading malaria, Zika, and dengue fever among others.
• Sandflies and Blackflies: Responsible for diseases like leishmaniasis and onchocerciasis.

Vectors play a critical role in disease dynamics by acting as intermediaries that can carry pathogens from one host to another, sometimes across significant distances. This can lead to outbreaks if not properly managed, especially in areas where vector populations are high.

Relapsing fever

Relapsing Fever is primarily caused by the spirochete Borrelia. It manifests with multiple instances of fever, separated by periods of normal temperature. Here are some key aspects of this disease:

• Transmission: The disease is mainly transmitted by arthropods such as ticks. The soft-bodied ticks can latch onto hosts, transferring the pathogen when feeding.
• Symptoms: Characterized by recurring episodes of high fever, chills, headache, and muscle pain. The symptoms recede and then recur, hence the term "relapsing".
• Diagnosis and Treatment: Diagnosis often involves blood tests to identify the bacteria. Treatment is usually with antibiotics, which can effectively clear the infection.

Understanding the transmission and symptoms of Relapsing Fever can aid in prevention and prompt treatment, limiting the spread in areas with tick presence.