Mediterranean spotted fever
Mediterranean spotted fever (MSF), also known as Boutonneuse fever, is an infectious disease caused by the bacterium Rickettsia conorii, typically transmitted through the bite of the brown dog tick, Rhipicephalus sanguineus. This disease is mainly found in regions bordering the Mediterranean and Black Seas, as well as parts of Africa and India, with cases on the rise in the twenty-first century, potentially linked to global climate change. The incubation period for MSF is generally five to seven days, with common symptoms including fever, headache, chills, muscle and joint pain, and a characteristic black spot at the tick bite site.
Complications can occur, particularly in vulnerable populations such as older individuals or those with weakened immune systems, potentially leading to serious health issues like vasculitis and organ failure. Diagnosis is typically based on symptomatology and confirmed through immunofluorescence assays. Treatment often involves antibiotics like doxycycline, and preventative measures focus on minimizing contact with ticks, such as wearing protective clothing and using insect repellent. Understanding MSF is crucial for those living in or traveling to endemic areas to mitigate risks associated with this disease.
Mediterranean spotted fever
- ANATOMY OR SYSTEM AFFECTED: All
- ALSO KNOWN AS: Boutonneuse fever, Marseilles fever
Definition
Mediterranean spotted fever (MSF) is caused by the bacterium Rickettsia conorii and is transmitted through a tick bite. In the spring and summer, MSF is endemic to countries bordering the Mediterranean and Black Seas and to parts of Central Africa, South Africa, and India. MSF has been identified in an increasing number of places in the twenty-first century, and its geographic expansion may be related to global climate change. In a few cases, MSF is particularly serious and can lead to death.
Causes
MSF is usually transmitted by the bite of the brown dog tick, Rhipicephalus sanguineus, although it can be transmitted through the skin or eyes when an infected tick is crushed. Rickettsia conorii is considered a parasite because it can survive only within the cells of a host insect, animal, or human. The parasite is usually found in the cells lining the blood vessels.
Risk Factors
The risk factors are contact with a brown dog tick and living in areas where MSF is endemic. Farmers and persons who participate in outdoor activities, such as hiking and camping, are at increased risk for contact with ticks. Another risk factor is crushing a tick between one’s fingers.
Symptoms
MSF has a five-to-seven-day incubation period. The usual symptoms of the condition are the characteristic black spot at the site of the tick bite and fever, headache, chills, muscle and joint pain, malaise, anorexia, nausea and vomiting, diarrhea, rash on the palms of the hands and the soles of the feet, conjunctivitis, and visual problems. If treatment is delayed, MSF can cause vasculitis, difficulty breathing, nerve and brain damage, kidney failure, enlarged liver, Guillain-Barré syndrome, and death. The severe form of MSF is more common in older people, in alcoholics, in persons with glucose-6-phosphatase dehydrogenase deficiency, and in persons with a suppressed immune system.
Screening and Diagnosis
There is no routine screening for MSF. A diagnosis of MSF is suspected based on the presence of the symptoms. It is usually confirmed by immunofluorescence assay, which identifies the antibodies to R. conorii. Cultures of R. conorii may be taken from the bloodstream.
Treatment and Therapy
MSF is treated with doxycycline (200 milligrams daily) orally or intravenously for ten to fourteen days. If the central nervous system is involved, the antibiotic josamycin may be used because doxycycline may not penetrate it. Josamycin is most commonly used in cases where there is a threat to the central nervous system, a pregnant woman, or a child. Other antibiotics that can be used are Levaquin and Cipro, although their effectiveness has yet to be scientifically established. Clarithromycin may also be used when the patient does not respond to first-line antibiotics.
Prevention and Outcomes
MSF can be prevented by avoiding contact with the brown dog tick. This means avoiding wild dogs that may be carrying ticks. When working in fields or when hiking or camping, one should wear long pants and high socks. Also, one should apply DEET (N,N-diethyl-meta-toluamide) spray.
Bibliography
Bratton, R. L., and G. R. Corey. "Tick-Borne Disease." American Family Physician, vol. 71, 2005, p. 2323.
Colomba, Claudia, et al. "Mediterranean Spotted Fever: Clinical and Laboratory Characteristics of 415 Sicilian Children." BMC Infectious Diseases, vol. 6, 2006, p. 60, doi.org/10.1186/1471-2334-6-60. Accessed 28 Sept. 2024.
Hechemy, Karim E., et al., editors. Rickettsiology and Rickettsial Diseases. New York: Blackwell, 2009.
Raoult, Didier, and Philippe Parola, editors. Rickettsial Diseases. New York: Informa Healthcare, 2007.
Rovery, Clarisse, et al. "Questions on Mediterranean Spotted Fever a Century After Its Discovery." Emerging Infectious Diseases, vol. 14, no. 9, 2008, pp. 1360-1367, doi.org/10.3201/eid1409.071133. Accessed 28 Sept. 2024.
Spernovasilis, Nikolaos, et al. "Mediterranean Spotted Fever: Current Knowledge and Recent Advances." Tropical Medicine and Infectious Disease, vol. 6, no. 4, 2021, doi.org/10.3390/tropicalmed6040172. Accessed 28 Sept. 2024.