One significant class of vector-borne illnesses is rickettsial infections, which are brought on by obligatory intracellular bacteria. Mites, ticks, fleas, and lice are among the arthropod vectors that spread them[1]. Because of their generic clinical presentation, rickettsial diseases especially scrub typhus, which is caused by Orientia represent a significant cause of severe febrile illness in India and may go undiagnosed.

Prolonged fever, headache, myalgia, vomiting, abdominal discomfort, and rash are frequent symptoms in children with rickettsial fever[2]. Although it is not always present, an eschar is thot to be a typical clinical feature in scrub typhus. Therefore, the diagnosis should not be ruled out if there is not an eschar.

Multiple organ systems may be affected by a severe rickettsial infection. There have been reports of hepatitis, meningoencephalitis, acute renal injury, pneumonia, myocarditis, shock, and hematological anomalies. Thrombocytopenia, increased hepatic transaminases, hyponatremia, and elevated inflammatory markers are common laboratory results[3-4].

Because the early clinical signs are similar to those of other tropical febrile disorders such dengue, malaria, and enteric fever, diagnosis can be difficult. Although sensitivity may vary depending on the stage of sickness, serological testing offers helpful supporting data. Although molecular techniques are helpful, they might not always be accessible in environments with limited resources[5].

Antimicrobial medication must be started as soon as possible since untreated illness might worsen quickly. While azithromycin may be administered in certain patients, doxycycline is still a crucial treatment choice for rickettsial infections[6-7].

In order to evaluate the clinical profile, laboratory abnormalities, complications, treatment response, and outcome of children with rickettsial fever admitted to a tertiary care facility, the current study was conducted[8].

 Aim: To study the clinical profile and outcome of rickettsial fever among children admitted to a tertiary care centre.

 Objectives:

1. To describe the demographic and clinical characteristics of children with rickettsial fever.
2. To evaluate the common laboratory abnormalities.
3. To determine the frequency and pattern of complications.
4. To assess treatment response and clinical outcome.

This prospective observational study was conducted in the Department of Pediatrics of a tertiary care teaching hospital. A total of 50 children diagnosed with rickettsial fever were included. Children aged 1–18 years presenting with acute febrile illness and subsequently diagnosed with Rickettsial infection were enrolled.

 Inclusion criteria

Children were included if they:

• were aged 1–18 years;
• had fever for ≥5 days;
• had clinical features suggestive of rickettsial infection;
• had supportive rickettsial serology; and
• had informed consent from parents or legal guardians.

 Exclusion criteria

Children were excluded if they had:

• confirmed malaria, dengue or enteric fever;
• another documented bacterial infection;
• chronic liver or renal disease;
• immunodeficiency;
• incomplete medical records; or
• refusal of consent.

 Clinical assessment

A detailed history was obtained regarding duration of fever, headache, vomiting, abdominal pain, myalgia, rash, cough, altered sensorium, seizures and other systemic symptoms. History of outdoor exposure, contact with vegetation or animals and possible arthropod exposure was also recorded.

Physical examination included assessment for rash, eschar, lymphadenopathy, hepatosplenomegaly, neurological abnormalities, respiratory distress and signs of shock.

 Laboratory investigations

Complete blood count, platelet count, liver function tests, renal function tests, serum electrolytes and C-reactive protein were performed. Investigations for malaria, dengue and other infections were performed whenever clinically indicated.

Rickettsial infection was diagnosed on the basis of compatible clinical features and supportive rickettsial IgM serology.

 Treatment

Patients received supportive management including hydration, antipyretics, nutritional support and treatment of organ dysfunction where required. Appropriate antimicrobial treatment was initiated following clinical suspicion and/or confirmation. Doxycycline was used in most children, while azithromycin was used in selected cases according to clinical status and treating physician preference.

Children with severe complications were managed in a high-dependency or intensive care setting when required.

 Statistical analysis

Categorical variables were expressed as frequencies and percentages, while continuous variables were expressed as mean ± standard deviation. Associations between categorical variables were evaluated using chi-square or Fisher's exact test. Continuous variables were compared using Student's t test. A p value <0.05 was considered statistically significant.

Ethical approval was obtained from the institutional ethics committee, and informed consent was obtained from parents or legal guardians.

A total of 50 children with rickettsial fever were included. The mean age was 8.6 ± 4.1 years. Twenty-nine (58%) children were male and 21 (42%) were female.

Children aged 6–12 years constituted the largest age group (46%), followed by those aged 13–18 years (30%) and 1–5 years (24%). The mean duration of fever before hospital presentation was 7.3 ± 2.5 days.

Headache was the most frequent symptom after fever, occurring in 31 (62%) children. Vomiting was present in 24 (48%), rash in 22 (44%), abdominal pain in 20 (40%) and myalgia in 18 (36%). Respiratory symptoms were present in 11 (22%). An eschar was identified in 7 (14%) children.

Table 1: Demographic and clinical profile of children with rickettsial fever (n=50)

Thrombocytopenia was the commonest hematological abnormality, occurring in 27 (54%) children. Elevated AST/ALT was observed in 24 (48%), while leukocytosis was present in 15 (30%). Hyponatremia occurred in 14 (28%) and elevated C-reactive protein in 36 (72%).

Table 2: Laboratory abnormalities among children with rickettsial fever (n=50)

Fourteen children (28%) developed one or more complications. Hepatitis was the most frequent complication, occurring in 7 (14%), followed by meningoencephalitis in 3 (6%), acute kidney injury in 3 (6%) and pneumonia/respiratory involvement in 2 (4%). One child had more than one complication. Children who developed complications had a significantly longer duration of fever before admission than those without complications (9.0 ± 2.3 versus 6.6 ± 2.0 days, p<0.001). Thrombocytopenia, elevated AST/ALT and hyponatremia were also significantly more frequent among children who developed complications.

Table 3: Comparison of children with and without complications

Most children showed clinical improvement within 48–72 hours after appropriate antimicrobial treatment. The mean duration of hospitalization was 6.1 ± 2.5 days. Six children required high-dependency or intensive care monitoring.

Forty-eight (96%) children achieved complete recovery. One child required prolonged hospitalization because of neurological complications. One child with severe multisystem involvement and refractory shock died. Overall mortality was therefore 2%.

Table 4: Treatment and clinical outcome among children with rickettsial fever (n=50)

Due to its vague clinical symptoms, rickettsial fever a significant cause of acute febrile illness in children may go unnoticed. 50 children with rickettsial fever were assessed in this study, which showed a wide range of clinical symptoms from simple fever to serious multisystem illness[9].

The majority of the youngsters were school-age, with a mean age of 8.6 years. Males made up 58% of the study population, indicating a male predominance. Numerous pediatric and hospital-based investigations have revealed similar patterns, but the distribution may differ depending on exposure patterns and local epidemiology[10].

Every study participant had a fever. The most common concomitant symptoms were myalgia, headache, vomiting, rash, and abdominal pain. These results align with the established clinical spectrum of rickettsial illness. In youngsters, gastrointestinal symptoms may be very noticeable and might cause diagnostic confusion with viral illnesses or enteric fever[11].

Of the children, 44% had a rash. Rash is a crucial clinical indicator, although it does not rule out rickettsial infection. Just 14% of the children in our research had an eschar. This comparatively low incidence highlights the fact that doctors should not base their diagnosis solely on the discovery of an eschar.

Thrombocytopenia was the most prevalent laboratory abnormality, occurring in 54% of children. The hematological abnormalities commonly described in scrub typhus and other rickettsial infections are consistent with this finding. In endemic areas, thrombocytopenia may also cause diagnostic overlap with dengue illness.

48% of individuals had elevated hepatic transaminases. Rickettsial illness frequently causes hepatic involvement, which can range from moderate biochemical increase to clinically severe hepatitis. Children experiencing complications were substantially more likely to have high transaminases in our research[12].

28% of children had hyponatremia, which was strongly linked to problems. Previous reports have linked hyponatremia to severe rickettsial disease, which may be the result of incorrect antidiuretic hormone release, disturbed fluid balance, or systemic inflammation.

Complications occurred in 14 children (28%). Meningoencephalitis, acute renal injury, pulmonary involvement, and hepatitis were the most frequent complications. With the right supportive and antibiotic medication, the majority of affected children recovered, despite the relatively high overall percentage of problems[13].

The correlation between delayed presentation and problems was a particularly significant finding. Compared to children without issues, children with complications had a mean fever length of 9.0 days before to admission, while children without complications had a mean fever duration of 6.6 days. There was a statistically significant difference (p<0.001). The results highlight the significance of early diagnosis and intervention[14].

Complications were also strongly linked to thrombocytopenia, high AST/ALT, hyponatremia, and elevated CRP. As a result, these metrics may assist medical professionals in identifying kids who are more susceptible to serious illness and directing closer observation.

Within 48 to 72 hours, the majority of youngsters responded to antimicrobial medication. Eighty percent of patients received doxycycline, and twenty percent received azithromycin. The high clinical response rate is in line with the established efficacy of suitable antibiotic treatment for rickettsial infections[15].

96% of the kids made a full recovery, thus the overall result was positive. One youngster had to stay in the hospital for a long time, and another died from refractory shock and severe multisystem involvement. The 2% death rate highlights that while the majority of juvenile rickettsial illnesses respond well to therapy, severe illness can be fatal.

There are several restrictions on the study. It was performed at a single tertiary care centre and involved a relatively modest number of youngsters. Molecular confirmation was not available for all individuals, and the diagnosis was primarily supported by serological tests. Additionally, because this was an observational trial, clinical judgment rather than randomization was used to choose the course of treatment[16].

Notwithstanding these drawbacks, the study identifies clinically significant characteristics that could help doctors identify rickettsial fever early. Rickettsial infection should continue to be a crucial differential diagnosis for children with persistent, unexplained fever in areas where dengue, malaria, and enteric fever are prevalent.

Rickettsial fever is an important cause of acute febrile illness among children and may present with diverse clinical manifestations. Headache, vomiting, rash, abdominal pain and myalgia were common presentations, while thrombocytopenia and elevated liver enzymes were frequent laboratory abnormalities. Complications occurred in 28% of children and were significantly associated with prolonged fever before admission, thrombocytopenia, elevated transaminases, hyponatremia and elevated inflammatory markers. The presence of an eschar was uncommon and therefore should not be considered essential for diagnosis.

Early diagnosis and timely antimicrobial treatment were associated with favorable outcomes, with 96% of children achieving complete recovery. Pediatricians should maintain a high index of suspicion for rickettsial fever in children with prolonged undifferentiated fever and multisystem manifestations, particularly in endemic areas.

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