rickettsia are obligatory , intracellular , small gram - negative bacteria associated with eukaryotic hosts .
they are traditionally divided into three groups : the spotted fever group , the typhus group and the scrub typhus group .
the spotted fever results from a large group of tick- , mite- and flea - borne zoonotic infections that are caused by closely related rickettsiae .
rickettsia conorii has been identified as the agent causing mediterranean spotted fever ( msf ) .
a variety of geographically distinct types of r. conorii have been described that cause variable clinical presentations different from typical msf .
a 27-year - old primigravida with a 16week history of amenorrhea and respiratory failure was transfered to a tertiary care center .
she had high - grade fever for 8 days prior to the transfer and had developed an erythymatous maculopapular rash on day 4 of the illness , involving the trunk initially , later extending to the palms and soles [ figure 1 ] .
erythematous maculopapular rash in a hand a persistant dry cough , not associated with hemoptysis , was noticed on day 5 .
she developed a progressively worsening dyspnea with bilateral ankle edema not associated with oliguria or orthopnea .
her condition deteriorated rapidly , warranting intubation for respiratory failure and transfer to a tertiary care center . on admission to the tertiary care center icu ,
the patient also had tachycardia ( 128 beats / min ) without any significant st segment changes on the ecg .
the blood urea measured 8.7 mmol / dl with a serum sodium of 140 meq / l and a pottasium of 5.0 meq / l .
full blood count showed neutrophilia of 78% in a total of 14.4  10 l. hemoglobin was 7.4 g / dl with a mild thrombocytopenia of 160,000 l .
the blood picture revealed normochromic normocytic anemia with no evidence of disseminated intravascular coagulation ( dic ) . the international normalized ratio ( inr ) was 0.96 .
the serum glutamate oxaloacetate transaminase ( sgot ) activity was 42 u / l and serum glutamate pyruvate transaminase ( sgpt ) activity was 28
the c - reactive protein ( crp ) level was 6 mg / dl and the antinuclear antibody ( ana ) was negative .
chest x - ray on day 1 at icu , showing diffuse bilateral opacities the patient was started on oral azithromycin , iv cefotaxime , iv hydrocortisone 50 mg 6 hourly .
the patient 's condition deteriorated rapidly on day 3 of icu stay and needed adrenaline , noradrenaline , dobutamine and vasopressin to maintain a blood pressure of 70/50 mmhg .
the urine output dropped and the urine microscopic examination revealed granular casts and dysmorphic red blood cells .
blood urea rose to 12.9 mmol / dl and the electrolytes showed pottasium level of 5.6 meq / l .
on the 4 day at the icu and 12 day of the disease , she devoloped anuria with further increase in blood urea and serum creatinine .
she was hemodynamically unstable with a blood pressure of 60 mmhg even with total inotrope support .
endocardium of the heart showed vegitations on a narrowed mitral valve [ figure 4 ] .
the kidneys were of normal size , but the cortico - medullary demarcations were less clear .
the grossly hemorrhagic lung the heart showing narrowing and vegetations at the mitral valve the histology of the lung showed gross hemorrhage and foci of pneumonia .
the vegetations of the heart were reported as fibrinous with entrapped white cells , but with no bacteria or fungi .
histology of the liver revealed centrilobular necrosis with a tendency to confluence , and a mild fatty change .
a final diagnosis of disseminated r. conorii infection with pulmonary hemorrhage , endocarditis and tubulointerstitial nephritis was made .
r. conorii is an obligate , intracellular , slow - growing , gram - negative bacterium belonging to the spotted fever group of rickettsiae .
unusual rickettsial strains related to r. conorii have been described as belonging to an  r. conorii complex  which includes the indian tick typhus rickettsia ( atcc vr-597 ) with r. conorii subsp .
it is transmitted to humans through the bite of dog ticks ( rhipicephalus sanguineus ) widely prevalent among the  old world  .
it is also known to be transmitted by haemaphysalis ticks , especially in pakistan and kenya .
the infection is transmitted via larvae and nymphs , and the tick bite is usually not felt .
the incubation period ranges from 3 to 15 days depending upon the route of rickettsial entry and the rickettsial load .
after introduction into the skin at the site of the tick bite or through the conjunctiva contaminated by blood or excretions from an infective tick , the primary multiplication occurs . in the skin , the localized multiplication of the rickettsiae in the endothelial cells of the capillaries leads to the formation of a raised red papule .
the inflammation and thrombosis of the affected capillaries lead to necrosis of the center of the papule and the formation of the typical red lesion with a black center , the  tache noire  .
this is followed by the spread of infection through lympho - hematogenous routes throughout the body , causing disseminated vascular lesions in multiple organs .
about 6% of the cases are severe , and fatal cases occur even in young , healthy adults , with a reported death rate of about 2.5% .
old age , alcoholism and glucose-6-phosphate dehydrogenase ( g6pd ) deficiency are known risk factors for severe disease .
the patient described here is from kotagla , a tea estate village in central sri lanka .
the patient reported a history of significant exposure to stray dogs , abundant in any sri lankan village , but not of any tick bites .
the absence of the tachy noire is significant in this case as the clinical diagnosis of msf ( caused by r. conorii subsp .
however , the absence of tache noire has been noted in israeli spotted fever caused by r. conorii subsp .
the fever starts after an incubation period of 7 days followed by a febrile period ( up to 40c , usually continuous ) associated with a maculopapular rash .
the papules of the rash are first noticed on the 3 to 5 day of illness , and they come out in crops and are palpable as small nodules in the skin . in severe cases ,
characteristically , the rash involves the palms of the hands , the soles of the feet and , to a lesser extent , the face . in this patient ,
the rash involved the palms and soles , sparing the face , and was of dusky cyanotic appearence with prominant macules .
the cough and the dyspnea reported in our patient were relatively rare in a case series of msf , with a representation of 10% and 21% , respectively .
renal insufficiency is a known complication in around 6% of the patients and is caused by tubulointerstitial nephritis .
myocarditis had been obseved in 11% of patients and might explain the severe tachycardia with poor response to inotropes in this patient .
the diagnosis of r. conorii infection in this patient is justfied as there is a compatible clinical picture along with a single titer of > 1/512 .
endocarditis is not described as a complication of r. conorii infection . identifying r. conorii as the causative organism of endocarditis in this patient
is supported by the absence of previous heart disease and lack of clinical features to suggest subacute bacterial endocarditis on admission and during prenatal clinics .
the vegetations isolated from this patient as well as the blood cultures did not reveal bacteria or fungi .
this patient was correctly started on oral azithromicin and intravenous chlorampenicol at the tertiary hospital .
a diagnostic scoring system with microbiological , epidemiologic , and clinical parameters has been proposed for msf and it had shown good sensitivity and specificity .
this case highlights the need of clinical suspicion of uncommon diseases based on the geographic and socioeconomic background of a patient .
relatively benign diseases may have severe manifestations resulting in fatality ; therefore , physicians should consider there factors for early diagnosis and intervention .
 rickettsial diseases are common in srilanka . 
 the spotted fever group of rickettsiae presents in many ways , including very severe disease causing significant morbidity and mortality . a regional variation of the rickettsia conorii subspecies and differences in clinical presentations 
 are reported . 
 this case describes disseminated rickettsia conorii infection in a pregnant woman presenting with endocarditis . 