What Is Boutonneuse Fever?

Updated on January 8, 2021

In over a century ago, between the year 1910 to 1920, a strange illness was first recorded and detailed in the Mediterranean, in Tunis (present day Tunisia), North Africa and was called Boutonneuse, a translation for “Spotty” in French.

The naming of this not totally known disease was due to the appearance of pimpled-looking skin rash on affected people that follow a severe fever.

The bacteria causing the Boutonneuse fever (a.k.a Mediterranean fever), is mostly found in the Mediterranean regions of Europe and sub-Saharan Africa but the epidemiological distribution and clinical severity of the Boutonneuse fever is rapidly changing and the regions of it been recorded are increasing; Greece, Slovenia, India, Malta, Kenya, Somalia, South Africa and some selected regions surrounding the Black sea; areas like Ukraine and Bulgaria.

Recently, the Boutonneuse fever disease is found in Mediterranean counties between June and September and it is the second most commonly reported spotted fever report among United States patients following international travels after the African tick bite fever.

Scientific classification of Boutonneuse Fever

Common Name: Boutonneuse Fever
Common Vector: Rhipicephalus sanguineus (dog tick)

Causative agent: A bacteria- Rickettsia conorii
Type of Infection: A Rickettsial infection
Specialty: infectious disease

Other Names: Mediterranean spotted fever, Kenya tick typus, Indian tick typus, Marseilles fever, Astrakhan fever.

Some Interesting Facts about Rickettsia conorii (Causative agent)

The Causative Organism or agent of the Boutonneuse fever; the Rickettsia conorii, a bacterium, is a gram-negative type (it does not retain the crystal violet stain during the laboratory Gram staining technique used to identify bacteria).

This Bacterium is an obligate intracellular bacterium that is unable to reproduce or multiply outside the body of a host cell. In other words, if the bacterium does not infect another organism (an insect), it dies out.

So, to ensure its continuous survival, it inhabits the cells of another organism, feeding from the cells and reproducing itself.

Some Interesting Facts about Dog Tick- Rhipicephalus sanguineus (Common Vector)

When a pet especially your dog is discovered scratching itself a lot. As a good owner its worrisome and deciding to investigate the cause of these scratches; most times you discover either a tiny brownish tick (male) or a fairly large grayish tick (female) stuck to its skin, under the fur.

This insect is called the Rhipicephalus sanguineus commonly known as brown dog tick which is found around the world in almost every type of habitat.

Among ticks in Florida, the brown dog tick is distinctively recognized by its color, body shape and hexagonal basis capituli; flat surface where mouthparts are attached.

Unlike many tick species which complete their life cycle indoors (that is carried by indoors by animals), the brown dog tick is a very unusual specie of tick as it is able to complete its life cycle both indoors and outdoors.

Because of this interesting fact, the brown dog tick is able to establish population in colder climates (Dantas-Torres 2008) and also in residences.

Its life cycle includes three active stages (larva, nymph, adult), it feeds only once then leaves the host to digest the blood meals and transforms or molt into the next stage or lay eggs- a fully blood-fed female brown dog tick can lay up to 7000 eggs, 4000 on average.

Although brown dog ticks will feed on a wide variety of mammals, dogs are always top on the menu. Brown dog tick vector several pathogens that causes canine and human diseases, so its management in the environment is very important.

How Boutonneuse Fever infect Humans?

The Boutonneuse fever is carried by the brown dog tick probably exists in nature in the lower animals, but canines (such as dogs) are apparently the major source of infection. People can contract this infection by either been directly bitten by the dog ticks or through dog bites.

When humans are introduced into the cycle, they become dead-end in the transmission chain.

How do you know you have Boutonneuse Fever?

The incubation period lasts around 6 to 10 days, followed by the rapid occurrence of symptoms. Some of the symptoms of the Boutonneuse fever include:

High Fever,

Severe headaches,
Photophobia,
Muscular and articular pains,

Rash- spreading to the palms, soles, scalp, scrotum, retroauricular areas and auxillary regions. These rashes are mostly maculopapular; the rash contains both macules and papules. A macule is a flat discolored area of the skin while a papule is a small, raised bump.
Flu-like symptoms like Running nose, redness of eyes and increased body temperature,
Eschar- uniquely known as “tache noire” is a red sore with a dark dead centre at the bite site.

The above symptoms are present to varying degrees with fever (90% to 100%) and rash (80% to 96%) been the most common symptoms reported.

Boutonneuse fever can be moderately severe or fatal.

Prevention of Boutonneuse Fever

Prevention of infestations in the residence or kennel begins with thorough inspections of dogs living in or entering these facilities.

Adequate utilization of tick control products should be discussed with veterinarian to ensure a healthful selection of appropriate product suitable for use.
Frequent hand picking or manually removing and killing of already attached ticks on dog’s skin thereby avoiding engorgement of the ticks on dogs. This is critical to management of the tick and well-being of the dogs.
Always check dogs for ticks after returning home from kennels, dog parks, groomers, or other frequented locations by dogs. Also tick checking after returning from outdoor activities helps to prevent bites by other tick species.

In homes and dog kennels, cracks and crevices should be sealed, grasses and weeds short be properly maintained.
Wash and dry dog beds and blankets with hot water and high dryer heat because high temperatures can kill ticks hiding between fibers.
Steam also can be used to kill ticks on unwashable items like furniture

Treatment of Boutonneuse Fever

Early detection and prompt adequate treatment of Boutonneuse Fever drastically shortens the disease course and reduces outcome of unprecedented complication tendencies.

The current treatment of choice for all rickettsial infections including Boutonneuse fever infection is doxycycline and this also includes pregnant and pediatric patients.

Treatment is not to be delayed waiting for confirmatory laboratory results. Clinically, adult dosage for administration is 100mg twice a day for 7 to 10 days and 2.2mg/kg twice daily for children under 45kg.

Though doxycycline was previously banned in the pediatric and pregnant population’s treatment due to possible side effects of dental staining in children and the risk of tetragenicity on the developing fetus.

But recently, research have shown relative safety using doxycycline for Boutonneuse fever treatment in these population. Alternatives for doxycycline include; azithromycin, Chloramphenicol.

Conclusion

The earlier the infestation is discovered and addressed, the easier it will be to eliminate. Monitoring and grooming of dogs particularly upon return from outdoor activities or locations where other dogs were present, remains the best way of early detection of infestations.

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