Marine Hospital Quarantine and Isolation Strategies

Isolation Strategies: Social Distancing, Quarantine, and Barriers

Antiseptic Kisses in Hollywood

  • In 1937, during a flu epidemic, movie kisses were rehearsed behind antiseptic masks to prevent the spread of germs.
  • It was estimated that this would prevent four out of five flu germs from spreading, as each kiss was rehearsed about 20 times.
  • A picture from "LOOK" magazine featured Stanley Morton and Betty Furness.
  • The effectiveness of masks might not have been as high as the image suggests.

R0 and R

  • R0R_0 (Basic Reproductive Number): The expected number of infections generated by an infectious individual at the beginning of an outbreak.
  • RR (or R<em>tR<em>t): Reproductive number at a later stage, generally lower than R</em>0R</em>0.

Factors Affecting R

  • In general, R < R_0 because:
    • The number of susceptible individuals decreases.
    • The number of contacts between individuals decreases.
      • Non-symptomatic individuals sometimes avoid symptomatic individuals.
      • Symptomatic individuals are less social (e.g., asked to stay at home).
      • Systematic isolation, quarantine, and other types of barriers are put in place.

Example: Syphilis in Baboons

  • In humans, syphilis is a sexually-transmitted infection (STI) caused by Treponema pallidum, a bacterium.
  • In olive baboons, the mode of transmission of T. pallidum is unknown, but genital lesions suggest it could also be an STI.
  • Reference: Paciencia et al, Science Advances, 2019

Baboon Study Details

  • GHS: Genital Health Status
  • NU: Non-ulcerated
  • NUF: Non-ulcerated Female
  • NUM: Non-ulcerated Male
  • ULF: Ulcerated Female
  • ULM: Ulcerated Male
  • UL: Ulcerated

Baboon Mating Behavior

  • Female avoids the male.
  • Female mates with the male.
  • When a male has genital ulcerations, non-ulcerated females are less likely to accept mating attempts.
  • Reference: Paciencia et al, Science Advances, 2019

Example: Intestinal Protozoa in Mandrills

  • Reference: Poirotte et al, Science Advances, 2017
  • Individuals receiving an anti-parasitic treatment receive more grooming.
  • Feces from parasitized individuals are avoided.
  • Feces from parasitized individuals likely have a distinct odor that other individuals use to reduce their exposure to parasites.

Symptomatic Individuals and Social Behavior

  • Sickness behavior: Behavioral changes that develop in sick individuals, including sleepiness, inactivity, reduced food intake, postures that reduce heat loss, decrease in self-grooming, etc.
  • In humans, sick individuals often isolate themselves intentionally to fasten recovery and reduce the risk to infect others.

Isolation vs. Quarantine

  • Isolation: Separates sick people with a contagious disease from people who are not sick (CDC.gov).
  • Quarantine: Separates and restricts the movement of people who were exposed to a contagious disease to see if they become sick (CDC.gov).

Historical Examples of Isolation

  • Leviticus 13:46 (ca. 300-500 BCE): People with diseases must live alone outside the camp.
  • Hansen’s disease (leprosy): Endemic in Europe around 1000 CE.