Question

Incubation period of Treponema pallidum is about
(a)2 to 14 days
(b)7 to 21 days
(c)1 to 2 weeks
(d)3 to 4 weeks

Answer 1

The incubation period is the amount of time period between the entry of pathogens inside the body and the onset of symptoms for that disease. For some organisms like Mycobacterium leprae, the incubation period is 5 years and can even be 20 years in some extreme cases.

Complete answer:
Treponema pallidum is a spirochaete bacterium that causes syphilis among humans. It affects only humans. It is helically coiled and shows the minimal activity as it lacks most of the major pathways of respiration including Krebs cycle and electron transport system ETS.
The incubation period for this bacterium is 3-4 weeks.

Additional Information: Let us study the disease which is caused by Treponema pallidum i.e. syphilis.
Syphilis is a sexually transmitted disease. But it can also spread by shared needles and from mother to child during pregnancy. The most common symptoms of this disease include cancer(painless ulcer of skin) and sores near the genitals. In extreme cases, the sores cover the entire body. If left untreated this disease can cause serious damage to the brain.
Using condoms during sexual intercourse and proper disposal of used needles are some of the best ways to prevent this disease.
So, the correct option is ‘3 to 4 weeks’.

Note: -The test used to detect syphilis is called FTA-ABS (Fluorescent Treponemal Antibody Absorption Test). It confirms positive after detecting antibodies for Treponema pallidum in the blood.
-Penicillin is most commonly used for the treatment of syphilis.
-Syphilis is completely curable but STDs like hepatitis B, genital herpes, and AIDS are not curable.
-Inoculum dose: It is the minimum amount of pathogen that needs to enter the body to successfully cause an infection.