11 years old female child presented to our clinic with complaints of

Fever for 24 days,

cough for 15 days

less appetite for 10 days

pain abdomen for 7 days

headache for 5 days

swelling of both lower limbs for 3-4 days

On examination;

Temperature 103 dF,pallor +,icterus+

Pulse rate 56/m regular(relative bradycardia)

Respiratory rate 26/minute ,regular

Generalised lymphadenopathy

bilateral pedal edema

Abdomen-not distended,no tenderness,hepatosplenomegaly+

Chest-bilateral equal breath sound,bilateral vesicular breath sound,bilateral crackles

CVS-NAD

CNS-NAD

Following diagnoses were suspected

Malaria

Typhoid

Viral hepatitis with secondary bacterial infection

Disseminated tuberculosis

Leptospirosis

Scrub typhus

Investigations were planned and done accordingly.

Hb 9 gm/dl

TLC 6800/cmm,P56,L34,E03,M07,B00,Platelet 90000/cmm

SGPT-102,SGOT146,ALP 200,S.BIL 3.8mg/dl

Serum Sodium 130mE/L,Serum potassium 4.4mE/dl

Serum widal-negative

Malaria antigen-negative

Chest X-Ray -bilateral reticulonodular opacities with bilateral pleural effusion

Mantoux test-negative

GA for CBNAAT -negative

The child was emperically treated as enteric fever with cefixime but there was no response.Then the child was treated emperically for malaria and again there was no response.

At this point of time,it was suspected that the child may be suffering from scrub typhus as the child travelled to Uttrakhand during last month.

IgM ELISA for scrub typhus was sent and it came to be positive and the child responded well to doxycycline.

DISCUSSION

:Rickettsia is intracellular ,gram negative proteobacteria with coccobacillar shapes.The disease caused by it is called Rickettsiosis.It is a zoonosis ,transmitted into human by mites(chiggers),ticks or fleas and rodents. Humen are the incidental host.No human to human transmission has been observed.

This disease is frequently seen in Uttrakhand,Rajsthan,assam.West Bengal ,Jammu and Kashmir,Maharashtra Tamil Nadu and Kerala region of India and many countries out of India.

pathogens causing disease in human have been broadly classified into three groups

1.Spotted fever group

2.Typhus group

3.Scrub typhus group

Scrub typhus is causing a health impact in Asia

Pathogenesis;The principle pathogenetic mechanism is vasculitis involving medium and small vessels.It causes increased vascular permeability by disrupting the endothelial tight junctions due to the bacterial load and tumour necrosis factor.Main cause of mortality is pulmonary edema and cerebral edema.

CLINICAL FEATURES OF SCRUB TYPHUS WHICH IS COMMON IN INDIA:

The usual incubation period is 10-12 days with a variability of 6-21 days.Symptoms varies from mild self limiting to severe causing death.

After the period of approximately 5-6 days of bite by mites,there occurs the formation of ESCHAR(shown in the figure) at the site of inoculation of the mite.It is a painless necrotic lesion over skin resembling a cigarette burnt skin surface.The usual sites are groin,axilla,back,neck and other exposed parts of the body.Eschar, if visibl,e makes a clear cut diagnosis of scrub typhus without any investigation.But it is not ususally seen in children.Its prevalence varies from 7-80%.

After about 5-7 days flu like symptoms occurs.In most of the cases fever has been observed with  severe headache.

There may be myalgia,weakness,pain abdomen,vomiting,diarrhoea,cough.

O/E There may be relative bradycardia,generalised lymphadenopathy,generalised body rashes and pedal edema

On systemic examination:there may be hepatosplenomegaly

On investigation:

BLOOD-there may be anemia,thrombocytopenia,raised liver enzymes,raised serum bilirubin,hyponatremia,raised blood urea and serum creatinine

Chest X-Ray may show reticulonodular opacities,features of pulmonary edema,bilateral pleural effusion

ECG may shows features of myocarditis with nonspecific ST-T  changes,features of heart block

LUMBAR PUNCTURES :CSF pictures are indicative of meningoencephalitis.The CSF picture is similar to Tuberculous meningitis with lymphocytic pleocytosis and raised protein.

DIAGNOSIS; The gold standard is INDIRECT IMMUNOFLUORECENT ANTIBODY TEST(IFA), but it is not available everywhere.The next best is IgM ELISA which is widely available and should be done as the sensitivity of Weil-Felix test is very poor.

TREATMENT.The drug of choice is doxycycline,oral or i.v. in the dose of 2.2 mg/kg 12 hourly below 40 kg of weight and 100 mg b.d. above 40 kg of weight,for a period of 7 days of 3 days after the fever subsides.Now it has been recommended for children of any age to treat Rickettsial diseases as it has not caused enamel hypoplasia or teeth staining even after multiple courses.

Alternative medicine is Azithromycin in the dose of 10 mg/kg/day

Other drugs which may be used in special cases are -clarithromycin.chloramphanicol and Rifampicin

Mortality is above 50% if not recognised and treated timely

COMPLICATIONS.HLH(hemophagocytic lymphohistiocytosis and it is very serious complication.

REFERENCES:

AbdadMY,Abou AbdallahR,FoumierP-E,StenosJ,Vasoo S.Aconcise review of the epidemiology and diagnostics of rickettsioses:Rickettsia and Orientia spp.J clin Microbiol.2018;56:eo1728-17

IssacR,VargheseGM,MathaiE,et al.Scrub typhus:prevalence and diagnostic issue in rural southern India.Clin infect dis.;2004:39;1395-6

Rathi N ,Kulkarni A ,Yewale V;Indian Academy of Pediatrics Guidelines on Rickettsial diseases in children committee.IAP Guideline on Rickettsial disesase in children.Indian Pediatr.2017;54:223-9

Elisabeth BN,Cristina S,DidIer R,Phillipe P.Treatment of Ricketssial spp.infections:a review.Exp rev anti infect Ther.2012;10:1425-37