Cockroaches

1
Cockroaches

• And Disease

2
Basics

• Order Blattaria
• 4000 species worldwide
• 57 species in the U.S.
• 18 species have become serious domestic pests
• The most important medically are
• Blattella germanica (German cockroach)
• Blatta orientalis (Oriental cockroach)
• Periplanta americana (American cockroach)
• Supella longipalpa (Brown-banded cockroach)

3
Biology

• Like warmth (climate plays a role)
• Cold Climates
• Warm Climates
• Nocturnal
• Omnivorous
• Live for 5-10 weeks without water
• Live many months without food
• Not a limiting factor
• Nymphs often die 7-10 days

4
Life Cycle

• Hemimetabolous
• Eggs are laid encased in a capsule called an
  ootheca
• Typically 18-40
• Deposited or cemented to surfaces
• 4-90 ootheca
• Nymphs
• Hatch after 1-3 months
• Wingless
• Number of nymphal stages and length varies with
  species.
• Adults
• 2 year lifespan or more

5
Medical Importance

• (1) Get into our food supplies
• (2) Odor (Some stink!)
• (3) They feed on humans
• (4) Allergies
• (5)Transmit pathogens?
• We tend to call cockroaches insects of sanitary
  importance.
• Synanthropic species

6
American CockroachPeriplaneta americana

• Originally from Africa.
• Like damp environments.
• Sewers, around pipes, ships.
• Basement or first floor in buildings.
• Nymphal stage 10-14 months long.

7
German CockroachBlattella germanica

• Most common species in WY.
• Originally from Africa.
• Smaller than American.
• Basement and first floors in buildings.
• Carries egg capsule.
• Nymphal stage 2-3 months long.

8
Oriental CockroachBlatta orientalis

• Shiny black, common in WY.
• Found in sewers, likes basement.
• More tolerant of cooler temps.
• Males have short wings, females are long.
• Nymphal stage 12-15 months long.

9
Brown-Banded CockroachSupella longipalpa

• Originally from Cuba.
• 2 broad bands across dorsum.
• All rooms in house.
• Likes high places versus low.
• Big problem in the Southern U.S.
• Glue eggs to things.
• Often ships in with Furniture.

10
Control

• Be clean!
• Insecticidal spraying
• E.g. malathion, carbamates
• Pyrethroids
• E.g. permethrin
• Boric Acid Powder (borax)
• Contact insecticide and stomach poison.
• Organophosphates and Carbamate Insecticides
• 1-2 added to baits of food
• Insect Growth Regulators (IGRs)
• E.g fenoxycarb, hydrophen, methoprene.
• Pheromones and sticky traps

11
TRUE BUGS

• Bed bugs and Triatomine bugs

12
Basics

• Order Hemiptera
• 80,000 known species most in tropics.
• Worldwide distribution
• The most sucessful of the Hemimetabolic insects.
• Divided into two groups the Heteroptera and the
  Homoptera.

13
Family Cimicidae(Bed bugs, poultry bugs, bat
bugs)

• 20 different genera
• Name given for host they feed on.
• Nocturnal.
• Host specific, but will cross over it no natural
  host is available.
• Three main species
• Oeciacus spp. (swallow bugs)
• Cimex hemipterus (Tropical Bed Bug)
• Cimex lectularius (Bed Bug)

14
Life Cycle

• Egg ? Nymph (5 instars) ? Adult
• Both sexes take blood meals.
• Can live up to one year without meal.
• Visit host only for bloodmeal then leave.
• Females lay 2-3 eggs a day (150-200 in lifetime).
• Adults can live up to 4 years.

15
Medical Importance

• Hep. B Virus and other pathogens.
• No evidence can transmit to humans.
• Not considered vectors!
• Reaction to bites can be severe.
• Annoyance may cause sleepless nights.
• Anemia in infants.

16
Diagnosis

• Can detect by presence of live bugs, nymphal
  skins, hatched and unhatched eggs.
• Small dark brown or black marks may be visible on
  bed sheets or mattress.
• No wings, do not spread far.
• Usually, introduced with furniture and bedding.

17
Control

• Insect repellents
• Pyrethroid-impregnated bed-nets.
• Spray floors, walls, furniture with 5 DDT
  emulsion (Tropical countries)
• Malathion, diazinon, carbaryl, pyrethrins.
• Mattresses and wooden slates across beds can be
  sprayed or dusted with insecticides.
• Fumigate.

18
Family Reduviidae(Assassin bugs, Kissing bugs)

• Sub-family Triatominae
• More than 130 species in 16 genera.
• Evolved into a blood feeder that feeds on a wide
  variety of hosts.
• Why called kissing bug?

19
Chagus Disease

• Host Variety of vertebrates.
• Vector Triatoma spp.
• Triatoma infestans
• Triatoma dimidiata
• Triatoma brasiliensis
• Rhodnius prolixus
• Panstrongylus megistus
• Etiologic Agent Trypanosoma cruzi (protozoan)
• Reservoir Wild animals (opossums, armadillos,
  rodents, monkeys, etc).
• Chagus disease is a zoonosis, a parasite of wild
  animals.

20
Distribution

• Most Triatoma occur in the Americas.
• From the Great Lakes of the U.S. to Southern
  Argentina.
• 13 species are found in the Old World tropics.
• All medically important species are confined to
  the Southern U.S., Central and South America.

21
Life Cycle of the Vector

• Hemimetabolous
• Egg ? Nymph ? Adult (6-10 months
• Eggs
• Deposited in or near the habitation of host.
• Nymph
• Hatch after 10-15 days
• Stay hidden for 2-3 days
• 5 instars (each requires 1 blood-meal)
• Can ingest 6-12 times their weight in blood.
• wingless
• Adult
• 1-2 eggs laid each day 200-300 over lifetime
• Ingest 300-400 mg of blood every 4-9 days!
• Nocturnal, feeding lasts 10-25 minutes.

22
Life Cycle
23
Transmission

• People can become infected with Chagas by
• unknowingly touching their eyes, mouth, or open
  cuts after having come into contact with
  infective triatome bug feces
• bugs directly depositing infected feces in their
  eyes
• eating uncooked food contaminated with triatome
  bug feces
• receiving infection from mother during pregnancy
  or at birth
• receiving an infected blood transfusion or organ
  transplant
• Animals can become infected in the same way, or
  they might eat an infected bug.

24
Medical Importance

• Affects an estimated 16-18 million people
  throughout South and Central America and Mexico.
• 50,000 die each year!
• In the United States only 5 cases have been
  reported in humans.
• Domestic transmission cycle, Southern Texas USA.

25
Case Study San Benito, Texas

• Three pet dogs died from Chagas cardiomyopathy.
• Blood drawn from dogs and owners.
• A follow-up serologic survey was conducted.
• Inspection of the residence.
• Triatoma gerstaeckeri
• Domestic transmission cycle.

26
Signs and Symptoms

• There are three stages of infection in Chagas
  disease.
• (1) Acute Stage 1 of cases
• Romaña's sign a person's eye on one side of the
  face swells, usually at the bite wound or where
  feces were deposited or accidentally rubbed into
  the eye.
• fatigue, fever, enlarged liver or spleen, swollen
  lymph glands

27
Signs and Symptoms

• (2) Indeterminate Stage
• 8-10 weeks after infection
• Once it begins it may last many years
• people do not have symptoms.
• (3) Chronic Stage
• 10-40 years after infection 20-30 of infected
  people may develop the most serious symptoms of
  Chagas disease.
• Cardiac problems, including an enlarged heart
  altered heart rate or rhythm heart failure or
  cardiac arrest.
• enlargement of the esophagus or large bowel,
  which results in problems with swallowing or
  severe constipation.

28
Diagnosis/Treatment

• Xenodiagnosis
• Medication for Chagas disease is usually
  effective when given during the early acute stage
  of infection. Once the disease has progressed to
  later stages, medication may be less effective.
• In the late chronic stages of infection,
  treatment focuses on managing the symptoms
  associated with the disease.

29
Prevention and Control

• Avoid sleeping in thatch, mud, or adobe houses.
• Use insecticides
• In some countries, the blood supply may not
  always be screened for Chagas disease.
• Bed Net with insecticides.
• Camp under cover.

30
Prevention and Control

• Control is based on spraying residual
  insecticides inside houses on walls, floors and
  roofs.
• Insecticidal Smoke Bombs
• Make the houses unattractive resting sites for
  bugs.
• Plaster walls to cover up cracks.
• Cost is high for rehousing.