Letters to the Editor

Abstract

16 June 2008 Dear Editor, TRIPLE INFECTION IN A CHILD Enteric fever, malaria and urinary tract infection are, individually, common infections in children of the tropical and the sub-tropical world. Co-infection with two disease-causing organisms may be more common than usually recognised because of the overlapping systemic manifestations. It is, however, unusual for an immunocompetent child to have three concomitant infections at a given time. The present communication is intended to report on a 4-year-old immunocompetent boy, with simultaneous enteric fever, Escherichia coli (E. coli) urinary tract infection and Plasmodium vivax (P. vivax) malaria. A 4-year-old, otherwise healthy, boy presented with high-grade intermittent fever associated with chills and rigor of 6-day duration. He also had increased frequency of micturition and pain in the abdomen for 3 days. The family and the past medical history were non-contributory. On physical examination, he was febrile (temperature: 103.5°F) and dehydrated. Intravenous fluids corrected the dehydration. He was a normally developing child with age-appropriate anthropometry. Mild pallor with cervical lymphadenopathy without evidence of malnutrition was noted. The abdomen was soft without concomitant tenderness. The spleen and the liver were palpable 2.5 cm and 2 cm below left and right costal margins, respectively. Suprapubic without renal angle tenderness was present. The other systems were normal. The laboratory tests showed: hemoglobin 8 g/dL; white blood cells: 4800/mm3 (52% neutrophils, 46% lymphocytes), platelets: 350 000/mm3. Serum urea and creatinine were normal. The urinary sediment analysis was significant for pus cells and leukocytes. The blood cultures and Widal test were positive (To 1:320) for Salmonella typhi. Ceftriaxone injection was started for enteric fever. The urine and stool cultures for the same organism were negative. The cultures of the urine, however, grew E. coli which was sensitive to ofloxacin. Thus, ofloxacin injection was added. The fever failed to subside by day 4 of therapy. Repeat urine culture at the end of 4 days was sterile. The child became increasingly anorectic and the organomegaly persisted. A Giemsa-stained peripheral blood smear showed trophozoites and schizonts of P. vivax, with parasitaemia quantitatively reported as 10–40 parasites per 100 fields. The antigen test (optiMAL) for P. vivax was positive while that for Plasmodium falciparum was negative. Chloroquine was administered using the naso-gastric tube. Oral primaquine was given as per the recommendation. There was dramatic improvement in the general condition of the child with subsidence of fever within the next 36 h. Ceftriaxone injection was given for 7 days followed by 5 days of oral cefixime. Five days of injection followed by another 5 days of oral ofloxacin was administered. The Enzyme-Linked ImmunoSorbent Assay (ELISA) for HIV-I and II and the tuberculin test were negative. He was discharged on the 10th day, having made a full clinical and microbiologic recovery. He was normal on evaluation at the end of 2 weeks. The co-occurrence of three infections in an immunocompetent child is a rare event in children belonging to the developed world. It may sometimes occur in children of the tropics and the sub-tropics because of the high prevalence of several common infections. Because constitutional symptoms like fever, anorexia and vomiting are common manifestations of most of the infections, they may not always be diagnosed individually. Furthermore, administration of broad-spectrum antimicrobial therapy may be effective for more than one organism responsible for the disease manifestations, thereby masking the presence of co-infection/s. The reported child was presumed to be immunocompetent because he had no history of life-threatening infections in the past and he was developing normally. The ELISA for HIV-I and II and the tuberculin test were non-reactive which further supports the immunocompetency of the child. The laboratory tests for the cellular and humoral immunity was not carried out. Studies from Malawi indicate that malarial parasitaemia is relatively common in children with non-typhoidal salmonella (NTS) bacteraemia.1, 2 The prevalence of any bacteraemia and of NTS bacteraemia was highest in children with severe malarial anaemia, compared with the prevalence in children with cerebral malaria associated with anaemia and in those with cerebral malaria alone.3 The authors recommended antibiotic therapy for NTS infection if bacteraemia was suspected in children with severe malarial anaemia.3 More than two-thirds of NTS episodes coincided with the peak malaria transmission season.2 The incidence of malarial parasitaemia was particularly high when the co-infecting organism was NTS than other infecting organisms. Younger age at presentation and concomitant malnutrition were two prominent risk factors predisposing to co-infection.2 A study in Kenyan children, found NTS bacteraemia to be more common in children with a recent history of malaria but not with current malarial infection.4 We reiterate the importance of ruling out mixed infections in children responding sub-optimally to therapy for a diagnosed infective condition, especially in children of the tropics and the sub-tropics.