BORRELIOSIS RELAPSING FEVER

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BORRELIOSIS (RELAPSING FEVER)

• Other names
• febris recurrens
• tick-borne/louse-borne relapsing fever
• spirillum fever
• vagabond fever
• fowl nest fever (China)
• gharib gez (Iran)
• carapata (Africa)
• kimputu/gorgoya (South America)

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BORRELIOSIS

• Rare in US, but many cases unreported or
  misdiagnosed
• Occurs throughout world numerous deaths in Asia,
  Africa, Central and South America

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BORRELIOSIS
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BORRELIOSIS

• Tick-borne
• Ornithodoros spp (soft-bodied tick)
• O. parkeri, hermsii, moubata, erraticus
• feeding characteristics
• Nocturnal feeders
• Short feeding period (lt 1 hour) organism passed
  within minutes of attachment
• ingest Borrelia with blood meal multiply in
  hemocele (celomic cavity) in 5-8 days

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BORRELIOSIS

• Vector biology ticks
• Transovarial transmission
• Remain infected for life (lifespan 2 yrs)
• Live in caverns, rodent or owl burrows
• transmitted by bite or bite wound contamination
  with coxal fluid expelled during engorgement
• Numerous reservoir hosts (rodents wild and
  domestic animals)

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BORRELIOSIS

• Louse-borne
• Pediculus humanus corporus P h capitus (body
  head louse)
• Species (host) specific
• Infest clothing
• Sensitive to minimal temperature changes (leave
  febrile or dying hosts)
• No transovarial transmission
• No animal reservoir

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BORRELIOSIS

• Vector biology lice
• ingest Borrelia with blood meal, multiply in
  hemocele (celomic cavity) in 5-8 days
• 12 of lice feeding on patient become infected
• remains infected entire life (3 weeks)
• transmitted by crushing (organisms released from
  celomic cavity) not by biting or defecation

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BORRELIOSIS

• Pediculus humanus corporus

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BORRELIOSIS

• Ornithodoros spp.

Adult female
Larva
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BORRELIOSIS

• Biology of Borrelia spp.
• Spirochete, unevenly coiled
• lt 0.1-0.5 ? x 3-25 ?
• Variation in appearance and antigenicity with
  subsequent attacks
• Fibrillar structure and cell body rotate in
  opposite directions

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BORRELIOSIS

• Borrelia spp. fibrillar structure

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BORRELIOSIS

• Borrelia spp. in smear (acridine orange staining)

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BORRELIOSIS

• Epidemiology
• Distribution
• Louse-borne
• US not endemic sporadic imported cases
• Worldwide ubiquitous, particularly in areas of
  war, poverty, overcrowding
• Tick-borne
• U.S. primarily western states from Texas to
  Rocky Mountains to Washington
• Worldwide Mediterranean (Spain), Middle East,
  Africa
• Sex males gt females (60)

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BORRELIOSIS

• Epidemiology
• Occurrence
• Louse-borne
• US rare, sporadic
• Worldwide unknown
• Mortality up to 70 if untreated 1 otherwise
• Tick-borne
• U.S. unknown
• Worldwide unknown
• Mortality lt10 if untreated

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BORRELIOSIS

• Pathogenesis
• Spirochetemia
• Reticuloendothelial cells
• Thrombocytopenia/coagulopathy
• Relapse

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BORRELIOSIS

• Clinical features
• Incubation period 7 days (3-18)
• Abrupt onset of symptoms
• Fever
• Headache
• Myalgia, arthralgia
• Weakness, anorexia
• Vomiting, nausea associated with hepatic/spleen
  involvement more common with louse-borne
• Transitory petechial rash may occur

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BORRELIOSIS

• Clinical features transitory petechial rash
  (tick bites)

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BORRELIOSIS

• Clinical features
• Relapse
• Initial febrile response lasts up to 6 days
• Recurrence of fever in 7-10 days
• Tend to be less severe
• Normally fewer episodes with louse-borne
  tick-borne 3-10
• Entire episode ranges from couple of weeks
  (louse-borne) to longer (tick-borne)

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BORRELIOSIS

• Clinical spectrum
• Clinical illness
• Improvement
• recovery
• Relapse

• Pathogenesis
• Clone formation
• Destroy original
• organisms
• Clone replicates

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BORRELIOSIS

• Diagnosis
• Lab findings
• Anemia and thrombocytopenia
• WBC normal
• Elevated liver enzymes
• Azotemia
• Definitive diagnosis
• Wright or Giemsa stain of blood smear to
  visualize spirochetes
• Xenodiagnosis examination of hemolymph from
  ticks feeding on febrile patient

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BORRELIOSIS

• Prevention
• Rodent control
• Vector control
• de-lousing of clothing
• tick control
• Vaccine not yet available