Magnitude and Features of Scrub Typhus and Spotted Fever in Children in India

Rickettsiae and Orientia tsutsugamushi are intracellular bacteria that cause fever associated with variable clinical severity. These infections are re-emerging in the Indian subcontinent [1, 2]. A study was therefore undertaken during the period November 2003 to November 2004, to find out the magnitude of the problem in children aged up to 14 years and admitted with acute febrile illness of five to 30 days in a hospital in South India. Children who did not have an etiology for fever identified at the end of routine investigations for malaria, typhoid fever, urinary tract infections, pneumonia and blood stream infections were screened for rickettsial infections by Weil Felix test and one specific test i.e. either enzyme-linked dot immunoassay (Multi test Dip-s-sticks, Panibo inc; Columbia, USA) or microimmunofluorescence assay (done at Unite des Reckettsies Marseille, France). A total of 43 (24 per cent) children were diagnosed to have either typhus or spotted fever among 180 consecutive children screened. Of these, 27 (62.8 per cent) had scrub typhus, 14 (32.6 per cent) had spotted fever and 2 (4.7 per cent) had infection with R. typhi. The disease had an equal distribution among girls (51.2 per cent) and boys (48.8 per cent). The mean age was 5.9 yrs. Seventy percent of the cases occurred during June-December, the cooler months in this region. The clinical and laboratory features of the infected children are shown in Table 1. Eschar was relatively uncommon (14 per cent). One of the two children with R. typhi infection had generalized maculopapular rash, splenomegaly, leucocytosis and evidence of coagulopathy while the other had fever without any localizing signs. Clinical and laboratory profile in 41 children with scrub typhus and spotted fever Clinical and laboratory profile in 41 children with scrub typhus and spotted fever Only 21/43 (49 per cent) of the infected children were identified by Weil Felix test. However positive predictive value of the test was 100 per cent and 91 per cent for scrub typhus and spotted fever respectively; in this group where other infective etiology was excluded prior to selection. The mean duration of hospital stay for children with scrub typhus was 6.7 days, compared to three days for spotted fever. Of 31 (71 per cent) children given doxycycline, 21 (67 per cent) became afebrile by 24 h and nine by 48 h. One child with spotted fever did not respond to doxycycline but only to chloramphenicol. Six children received chloramphenicol of whom two (33.3 per cent) became afebrile by 24 h and two (33.3 per cent) others by 48 h, and the remaining two children (one each with spotted fever and Scrub typhus) expired. Of four children who received ciprofloxacin one (25 per cent) became afebrile by 24 h and the remaining 3 (75 per cent) by 72 h. One child received no treatment but recovered. Complications needing intensive care occurred in nine (21 per cent) children. Two children succumbed and the mortality rate therefore was 4.7 per cent in the series studied. Our data shows that approximately one quarter of acute febrile illnesses, after excluding common causes of fever in children requiring hospitalization, are either due to rickettsial or O. tsutsugamushi infections. However, the protean manifestations make clinical diagnosis difficult [3, 4]. Weil Felix test was found to lack sensitivity. Doxycycline and chloramphenicol remain the antibiotics of choice although non responsiveness was observed [5]. High index of suspicion and prompt specific therapy can significantly reduce the mortality associated with this infection. The authors wish to thank The Christian Medical College for the funding provided. Departments of aChild health, cMedicine, dClinical Microbiology, Christian Medical Collage and Hospital, Tamilnadu, India and bUnite des reckettsies CNRS UMR-A 6020, IFR 48 Faculte de Medecine, Universite de Mediterranee, Marseille, France