Tickborne Diseases Abroad

Agent

Rickettsia africae

Where Found

Sub-Saharan Africa, Caribbean (French West Indies), and Oceania

Incubation Period

Typically 5–7 days but may be as long as 10 days

Signs and Symptoms

ATBF is typically a mild-to-moderate disease; no known deaths are attributable to infection with R. africae. ATBF is almost always associated with an inoculation eschar (see R. parkeri rickettsiosis) at the site of tick attachment. Multiple eschars are described in approximately 20–50% of patients with ATBF. Several days after eschar(s) appear, the following can develop:

• Fever
• Headache
• Myalgia
• Regional lymphadenopathy
• Rash (generalized with maculopapular or vesicular eruptions)

General Laboratory Findings

• Similar to other Rickettsia, see R. parkeri rickettsiosis.

Laboratory Diagnosis

Confirmation of the diagnosis is based on laboratory testing, but antibiotic treatment should not be delayed pending laboratory confirmation.

• ATBF can be confirmed using IFA or detection of Rickettsial DNA by PCR of eschar swab, skin biopsy, or whole blood. See R.parkeri rickettsiosis.
• ATBF can be confirmed by comparing acute and convalescent (taken 4–6 weeks following illness onset) samples for evidence of seroconversion in IgG antibodies.

Treatment

See RMSF treatment.

Agents

Borrelia afzelii, B. garinii, B. burgdorferi sensu stricto, and B. bavariensis (previously considered a variant of B. garinii)

Where Found

In Europe, Lyme disease is endemic from southern Scandinavia into the northern Mediterranean countries of Italy, Spain, Portugal, and Greece and east from the British Isles into central Russia. Incidence is highest in Central and Eastern European countries. In Asia, infected ticks occur from western Russia through Mongolia, northeastern China, and Japan; however, human infection appears to be uncommon in some of these areas.

Incubation Period

3–30 days

Signs and Symptoms

Outside of North America, most infections are caused by B. afzelii, B. garinii, B. burgdorferi sensu stricto, and B. bavariensis (previously considered a variant of B. garinii), with each causing somewhat different clinical manifestations.

As in the United States, the erythema migrans (EM) rash is the most common early manifestation; later neurologic, cardiac, and rheumatologic disease may occur. In European Lyme disease, the EM rash may spread more slowly and is less commonly accompanied by systemic symptoms. Atrophic skin lesions (acrodermatitis chronica atrophicans) are a frequent late manifestation of infection with B. afzelii. In Lyme disease caused by B. garinii, some individuals may develop Bannwarth syndrome, a severe neuroborreliosis characterized by radiculopathy, neuropathy, and lymphocytic meningitis.

Laboratory Confirmation

Antibodies to Borrelia species that cause Lyme disease outside the United States may not be reliably detected by all tests used in the United States. Providers who suspect internationally-acquired Lyme disease should use diagnostic tests that have been validated for these species.

Treatment

See Lyme disease treatment.

References

Steere AC, Strle F, Wormser GP, et al. Lyme borreliosis. Nat Rev Dis Primers. 2016;2:16090.

Stone BL, Tourand Y, Brissette CA. Brave new worlds: The expanding universe of Lyme disease. Vector Borne Zoonotic Dis. 2017;17(9):619-629.

Vandekerckhove O, De Buck E, Van Wijngaerden E. Lyme disease in Western Europe: an emerging problem? A systematic review. Acta Clin Belg. 2021;76(3):244-252.

Agent

Tick-borne encephalitis virus

Where Found

Endemic in focal areas of Europe and Asia, extending from western and northern Europe through to northern and eastern Asia. The highest disease incidence has been reported from the Baltic states, Slovenia, and Czech Republic. Asian countries with reported cases or virus activity include China, Japan, Kazakhstan, Kyrgyzstan, Mongolia, and South Korea. TBE may also be acquired by ingestion of unpasteurized dairy products from infected goats, sheep, or cows.

Incubation Period

8 days (range, 4–28 days)

Signs and Symptoms

TBE disease often presents with mild illness but can cause neuroinvasive disease (i.e., aseptic meningitis, encephalitis). The course of illness can be monophasic or biphasic. If biphasic, the two phases are:

• First phase: nonspecific febrile illness with headache, myalgia, and fatigue. Usually lasts for several days and may be followed by an afebrile and relatively asymptomatic period.
• Second phase: central nervous system involvement. Findings depend on the specific presentation but might include meningeal signs, altered mental status, cognitive dysfunction, ataxia, rigidity, seizures, tremors, cranial nerve palsies, and limb paresis.

Laboratory Confirmation

During the first phase of the illness, TBE virus or viral RNA can sometimes be detected in serum samples by virus isolation or RT-PCR. However, by the time neurologic symptoms are recognized, the virus or viral RNA is usually undetectable. Therefore, virus isolation and RT-PCR should not be used to rule out a diagnosis of TBE. Clinicians should contact their state or local health department or CDC’s Division of Vector-Borne Diseases (970-221-6400) for assistance with diagnostic testing.

Treatment

There is no specific antiviral treatment for TBE; therapy consists of supportive care and management of complications.

Prevention

Inactivated TBE vaccine (manufactured as TICOVAC) is licensed and available in the United States. This vaccine is approved for use in people aged 1 years and older and is administered as a three-dose series.

TBE vaccine is recommended for persons who are moving or traveling to a TBE-endemic area and will have extensive exposure to ticks based on their planned outdoor activities and itinerary. In addition, TBE vaccine may be considered for persons traveling or moving to a TBE-endemic area who might engage in outdoor activities in areas ticks are likely to be found.

References

Centers for Disease Control and Prevention. Diagnosis and management of tickborne rickettsial diseases: Rocky Mountain spotted fever and other spotted fever group rickettsioses, ehrlichioses, and anaplasmosis—United States: a practical guide for health care and public health professionals. MMWR 2016;65 (No.RR-2).

Centers for Disease Control and Prevention. Brunette GW, Kozarsky PE, Cohen NJ, et al. CDC Health Information for International Travel 2016 (Yellow Book). New York, NY: Oxford University Press; 2016.

European Centre for Disease Prevention and Control, Tick-borne diseases.

Fournier PE, Jensenius M, Laferl H, et al. Kinetics of antibody responses in Rickettsia africae and Rickettsia conorii infections. Clin Diag Lab Immunol 2002;9(2):324-328.

Goodman JL, Dennis DT, Sonenshine DE, editors. Tick-borne diseases of humans. Washington, DC: ASM Press; 2005.

Jensenius M, Fournier PE, Kelly P, et al. African tick bite fever. Lancet Infect Dis 2003;3(9):557-564.

Parola P, Paddock CD, Socolovschi C, et al. Update on tick-borne rickettsioses around the world: a geographic approach. Clin Microbiol Rev 2013;26(4):657-702.