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Biomedical subjects

L M Huang

Publications and source records attributed to L M Huang.

At least 37 records · Page 2Linked to original sources

Long-term response to hepatitis B vaccination and response to booster in children born to mothers with hepatitis B e antigen.

Hepatitis B (HB) vaccine provides an uncertain duration of protection and the optimal timing of booster vaccine remains unclear. This study examined the immune response at 10 years of 118 children who had developed protective anti-HB surface (anti-HBs) levels after a primary series of HB immunizations in infancy. All of the children were born to hepatitis B e Antigen (HBeAg)-positive hepatitis B surface antigen (HBsAg) carrier mothers. HB markers in all subjects and cellular immune response in some were determined. A booster was given to all subjects after the collection of samples and another blood sample was collected 4 weeks later. The results showed that a total of 39 (33%) of the children were seronegative for anti-HBs. T-cell proliferative response to HBsAg was noted in 47% of children. On HBsAg stimulation, leukocyte samples from a significantly higher proportion of subjects produced cytokines (81% of T cells produced interleukin-2 [IL-2] and 100% produced IL-5). The booster dose of HB vaccine induced the production of a protective level of anti-HBs (>/=10 mIU/mL) in all subjects. Cellular immunity was augmented with a positive rate of 58%, 90%, and 100% for HBsAg-induced T-cell proliferation, IL-2 production, and IL-5 production, respectively. Although 14 (11.9%) of the subjects were HB core antibody positive at 10 years of age, no new HBsAg carrier was detected. The results of this study show that protection afforded by HB vaccination persisted to the age of 10 years in all vaccinees. Immunologic memory was detected in all subjects including those who had lost their anti-HBs seropositivity. These results suggest that no booster vaccination is needed before 10 years of age. The most sensitive marker of immunologic memory is IL-5 production of T cells. (HEPATOLOGY 1999;29:954-959.)

Child↗

Immunogenicity and safety of standard-titer AIK-C measles vaccine in nine-month-old infants.

Because of the interference by maternal antibody before 1 year of age, the Schwarz strain of measles vaccine, which has been routinely used in Taiwan, must be given at 9 months and 15 months of age to ensure an optimal immune response. The AIK-C strain of measles vaccine has been reported to be highly immunogenic. This study evaluated the immunogenicity and safety of the AIK-C vaccine in 9-month-old Taiwanese infants. A total of 135 infants were recruited and were randomly assigned to receive either Schwarz vaccine (68 cases) or AIK-C vaccine (67 cases). Measles antibodies were assayed before and 1 month after the vaccination. Sixty-five (97%) infants who received the AIK-C vaccine seroconverted after the vaccination, whereas the seroconversion rate in those receiving the Schwarz vaccine was 77% (P = 0.001). The incidences of adverse reactions were comparable between the two groups. We conclude that even in 1990s, the failure rate of Schwarz vaccine in 9-month-old infants is still high. The AIK-C vaccine is more immunogenic in infants and its long-term immunogenicity and safety deserve further evaluation.

Antibodies, Viral↗

An evaluation of the safety and immunogenicity of a five-component acellular pertussis, diphtheria, and tetanus toxoid vaccine (DTaP) when combined with a Haemophilus influenzae type b-tetanus toxoid conjugate vaccine (PRP-T) in Taiwanese infants.

OBJECTIVE: Immunologic interference particular to the Haemophilus influenzae type b (Hib) response has been observed with previous acellular pertussis-Hib combination vaccines. To test this hypothesis a clinical trial to assess the safety and immunogenicity of a five-component (pertussis toxoid [PT], filamentous hemagglutinin [FHA], pertactin [PRN], and fimbriae 2 and 3 [FIM]), pertussis vaccine combined with diphtheria and tetanus toxoids (DTaP) when given simultaneously with a lyophilized Hib-tetanus toxoid conjugate vaccine (PRP-T) in infants at 2, 4, 6, and 18 months of age was conducted. The study compared two methods of administration: both vaccines combined in a single syringe and administered as a single injection, or both vaccines administered concurrently but at separate sites of injection. METHODS: Healthy 2-month-old infants were enrolled at the National Taiwan University Hospital. DTaP, PRP-T, and oral poliomyelitis vaccine (OPV) were given at 2, 4, 6, and 18 months. Reaction information was collected by telephone 2 days after each vaccination. Serum was collected at 2, 6, 7, 18, and 19 months of age. RESULTS: One hundred thirty-five healthy infants were enrolled in Taiwan, of which 127 (94%) completed the 18-month booster: 68 received the combined vaccine and 67 the separate vaccines. All vaccines were well tolerated. No differences in rates of local and systemic reactions were seen between the two methods of administration. No serious adverse events were reported. Serologic responses were comparable between the groups. Pertussis responses (enzyme-liked immunoabsorbant assay units [EU]/mL) at 7 months were, for combined versus separate, PT (131 vs 105), FHA (116 vs 116), PRN (100 vs 77), and FIM (922 vs 702). At 19 months, pertussis results were, for combined versus separate, PT (216 vs 182), FHA (203 vs 200), PRN (263 vs 197), and FIM (892 vs 732). Only the 7-month PT response in the combined group was significantly higher (combined 131 EU/mL vs separate 105 EU/mL). After the third dose (age 6 months), all subjects achieved serologic serum antibody levels indicative of protection against Hib, diphtheria, tetanus, and poliovirus types 1, 2, and 3. In fact, 96% of children had anti-PRP levels indicative of protection (>/=0.15 microgram/mL) against Hib after only two doses. At 7 months, anti-PRP geometric mean titer values were 11.8 micrograms/mL in the combined group compared with 13.0 micrograms/mL in the separate group. The anti-PRP geometric mean titers after the 18-month booster were 58.5 micrograms/mL in the combined group versus 55.3 micrograms/mL in the separate group. CONCLUSION: The five-component DTaP vaccine may be combined with PRP-T vaccine without clinically significant immunologic interaction when given in a 2-, 4-, 6-, and 18-month schedule.

Diphtheria↗

Acute respiratory distress syndrome due to tuberculosis in a child after allogeneic bone marrow transplantation for acute lymphoblastic leukemia.

We report the occurrence of tuberculosis in a 10-year-old Taiwanese boy, approximately 4 months after he received a matched-related bone marrow transplantation from his sister for acute T-cell lymphoblastic leukemia. After transplantation, grade III acute graft-versus-host disease developed and the patient was treated with prednisolone and cyclosporine. Marrow failure was noted on day 77 post-transplantation, however, after an episode of herpes zoster infection. Interstitial pneumonia, diagnosed on the basis of chest x-ray and computed tomography findings, occurred on day 120. Histologic examination of an open-lung biopsy specimen showed caseating granulomas and a few acid-fast bacilli. The patient died of acute respiratory distress syndrome, despite immediate implementation of antituberculosis therapy. Sputum cultures grew Mycobacterium tuberculosis 5 weeks later. This report demonstrates that the possibility of tuberculosis needs to be considered in immunocompromised patients, and that appropriate prophylaxis should be instituted in areas where tuberculosis is endemic.

Bone Marrow Transplantation↗

Immunogenicity of oral poliovirus vaccine in Taiwan.

Previous studies have shown that the immune response to trivalent oral poliovirus vaccine (OPV) varies widely from country to country. However, there has been no report on the immunogenicity of this vaccine in Taiwanese children. In this study, 98 children were followed up for 17 months to study the antibody responses following four doses of trivalent OPV. The results showed that, after two doses of vaccine, all children were protected against poliovirus type 1 and 2. All except two children also developed protective antibodies against poliovirus type 3. After three doses, the antibody levels in all subjects were above protective concentrations. The fourth dose, given at 18 months of age, further boosted the antibody titers. These findings show that the OPV currently used in Taiwan is highly immunogenic in Taiwanese children.

Antibodies, Viral↗

Penicillin-nonsusceptible Streptococcus pneumoniae infections in children.

The emergence of penicillin-nonsusceptible Streptococcus pneumoniae (PNSSP) has brought a new clinical challenge. In Taiwan, reports of the prevalence and clinical features of PNSSP infections in children are limited. This study reviewed the resistance patterns of all clinical isolates of S. pneumoniae obtained from patients under 17 years of age from January 1993 through July 1998 in a medical center. Their clinical features and treatment responses were analyzed, with special attention paid to those patients with invasive PNSSP infections. Totally, 170 clinical isolates of S. pneumoniae were obtained from 168 patients aged under 17 years. Among those infections, there were 56 sinusitis (including 4 sinusitis with bacteremia), 44 pneumonia (including 23 pneumonia with bacteremia or empyema), 23 otitis media (including 5 otitis media with bacteremia), 9 simple bacteremia, 9 conjunctivitis, 8 meningitis, 4 peritonitis, 3 skin infections and the other 14 isolates were colonization. One hundred eleven isolates (65.3%) showed reduced penicillin susceptibility by the disk diffusion method. A trend of increasing percentiles of PRSP was noted: 27.3% (3/11) in 1993, 37.5% (9/24) in 1994, 55.5% (10/18) in 1995, 77.5% (31/40) in 1996, 66.0% (31/47) in 1997, and 87.1% (27/31) in 1998. Minimum inhibitory concentration (MIC) determinations by the E-test showed some of the isolates were intermediately resistant. Prior antibiotic usage was associated with a higher incidence of PNSSP infections. However, most children responded well to antimicrobial treatment.

Adolescent↗

Preliminary validation of tumor cell attachment inhibition assay for developmental toxicants with mouse S180 cells.

This study was designed to explore the possibility of using ascitic mouse sarcoma cell line (S180) to validate the mouse tumor cell attachment assay for developmental toxicants, and to test the inhibitory effects of various developmental toxicants. The results showed that 2 of 3 developmental toxicants under consideration, sodium pentobarbital and ethanol, significantly inhibited S180 cells attachment to Concanavalin A-coated surfaces. Inhibition was dependent on concentration, and the IC50 (the concentration that reduced attachment by 50%), of these 2 chemicals was 1.2 x 10(-3) mol/L and 1.0 mol/L, respectively. Another developmental toxicant, hydrocortisone, did not show inhibitory activity. Two non-developmental toxicants, sodium chloride and glycine were also tested and these did not decrease attachment rates. The main results reported here were generally similar to those obtained with ascitic mouse ovarian tumor cells as a model. Therefore, this study added further evidence to the conclusion that cell specificity does not limit attachment inhibition to Con A-coated surfaces, so S180 cell may serve as an alternative cell model, especially when other cell lines are unavailable. Furthermore, after optimal validation, it can be suggested that an S180 cell attachment assay may be a candidate for a series of assays to detect developmental toxicants.

Animals↗

Diphtheria, tetanus and whole cell pertussis vaccine combined with hepatitis B vaccines: a comparison of two doses (10 microg and 5 microg).

BACKGROUND: A combined diphtheria-tetanus-whole cell pertussis-hepatitis B (DTPwHB) vaccine might facilitate the achievement of universal vaccination of infants against hepatitis B. METHODS: A double blind, randomized, two-armed, single center study was undertaken to evaluate the immunogenicity and reactogenicity of combined tetravalent DTPwHB vaccine, with two dosages of hepatitis B component (10 microg and 5 microg). The combined vaccine was tested in the context of a simplified vaccination schedule at 1.5, 3.5 and 6 months of age, to 120 healthy infants born to hepatitis B surface antigen-negative mothers after priming with one dose of hepatitis B vaccine (10 microg) at birth. Antibodies to each antigenic component were measured from blood samples collected immediately after birth, pre- and postvaccination blood samples. RESULTS: The reactogenicity profiles were similar in the two groups. No serious adverse events were reported. One month after completion of the four-dose vaccination schedule, all subjects except one in Group 1 (10 microg) had protective titers of anti-HBs (10 mIU/ml). At this time the geometric mean titer in Group 1 (10 microg) was higher than that observed in Group 2 (5 microg), 696 vs. 488 mIU/ml (P = 0.19). One month after three doses all subjects in both groups had protective antidiphtheria titers and antitetanus titers. The vaccine response rate to the Bordetella pertussis component of the vaccine was 88.0% in Group 1 and 96.2% in Group 2 (P = 0.86). CONCLUSION: Both combined tetravalent vaccines are safe and immunogenic when administered to infants born to a hepatitis B surface antigen-negative mother, with a 10-microg dose of priming hepatitis B vaccine at birth. This combined tetravalent DTPwHB vaccine may play an important role to promote integration of HB vaccine into the Expanded Program of Immunization in hepatitis B-endemic areas.

Antibodies, Bacterial↗

Viral etiology of intussusception in Taiwanese childhood.

BACKGROUND: Adenovirus infection and lymphoid hyperplasia have been associated with childhood intussusception. However, the extent of other viruses involved in this condition remains unclear. This prospective study investigates the relationship between some lymphotropic viruses and current childhood intussusception. METHODS: Patients with intussusception encountered in a pediatric emergency department in a recent 3-year period were studied. Healthy infants and toddlers of comparable age served as controls. Throat and rectal viral cultures were performed in patients and controls. Viral antibodies against adenovirus, cytomegalovirus, human herpesvirus (HHV)-6, HHV-7 and Epstein-Barr virus (EBV) were tested in paired sera from the patients. Acute stage serum from each patient and mesenteric lymph nodes from patients requiring surgery were studied for the presence of adenovirus genome by PCR. RESULTS: Twenty-seven of 61 (44.3%) intussusception patients, but only 2 of 52 (3.8%) healthy controls shed nonenteric adenovirus in throat and rectal specimens (P < 0.001). Of the 27 (74.1%) patients who shed adenovirus, 20 were older than 1 year old, whereas only 1 of 15 (6.7%) similarly aged patients in a previous study from the same area three decades ago did so (P = 0.001). Among 43 patients with available paired sera, acute primary viral infection was found in 17 (39.5%) by adenovirus, 4 (9.3%) by HHV-6, 5 (11.6%) by HHV-7, 2 (4.7%) by EBV and none by cytomegalovirus. Multiple viral infections occurred in 6 patients. Adenovirus genome was detected in 4 of 9 mesenteric lymph nodes and in only 3 of 60 (5%) acute phase sera. CONCLUSIONS: Primary nonenteric adenovirus infection contributes to current childhood intussusception. Acute primary HHV-6, HHV-7 and EBV infections also play etiologic roles.

Acute-Phase Reaction↗

Mononucleosis syndrome and coincidental human herpesvirus-7 and Epstein-Barr virus infection.

Two girls (a 5 year old and a 21 month old) experiencing mononucleosis syndrome with coincidental human herpesvirus (HHV)-7 and Epstein-Barr virus (EBV) infections are described. One patient had primary HHV-7 infection and reactivated EBV infection. The other had primary HHV-7 and EBV infections. These cases indicated that HHV-7 is capable of inducing infectious mononucleosis-like illness. Multiple herpesvirus infection in one of the patients also suggests that interaction among herpesviruses can occur in vivo. The consequence of this interaction may have clinical implications.

Child, Preschool↗

Comparison of once daily cefpodoxime proxetil suspension and thrice daily cefaclor suspension in the treatment of acute otitis media in children.

An open-labeled and randomized trial was conducted to compare the efficacy and safety of once daily cefpodoxime proxetil suspension (10mg/kg/day) and thrice daily cefaclor (45mg/kg/day) in the treatment of acute otitis media in children. A total of 57 children aged from 6 months to 9 years were enrolled; 23 were treated with cefpodoxime and 34 with cefaclor. Satisfactory clinical outcome, either cure or improvement, was achieved at the end of treatment in 90% of patients in the cefaclor group and 95% of patients in the cefpodoxime group (p > 0.05). Clinical recurrence was identified at the follow-up visits in one case of the cefaclor group (3%), and none in the cefpodoxime group (p > 0.05). These drugs were well tolerated by 14/21 (67%) in the cefpodoxime-treated group and 27/32 (84%) in the cefaclor-treated group. The incidence of adverse events was slightly higher in the cefpodoxime group than in the cefaclor group, however the difference did not reach statistical significance (p > 0.05). The daily cost of once-daily cefpodoxime was lower than that of thrice-daily cefaclor. We conclude that cefpodoxime administered once daily is as effective and safe as cefaclor administered thrice daily in the treatment of acute otitis media in children. The less dosing frequency and lower daily price of cefpodoxime provide additional benefits.

Acute Disease↗

Immunogenicity and safety of Haemophilus influenzae type b conjugate vaccine (HibTITER) and a combination vaccine of diphtheria, tetanus, pertussis and HibTITER (TETRAMUNE) in two-month-old infants.

A study was undertaken to evaluate the safety and immunogenicity of a combination vaccine (TETRAMUNE) of conjugate Haemophilus influenzae type b (Hib) vaccine (HibTITER) and DTP (Diphtheria, Tetanus and Pertussis) vaccine. A total of 93 healthy children were randomized to receive either TETRAMUNE (combined group), or DTP and HibTITER administered concurrently (separate group) in separate syringes at approximately 2, 4 and 6 months of age in Taiwan. Serologic responses were largely comparable between the two vaccine groups; almost all subjects were seropositive to Hib PRP (polyribosylribitol phosphate) and were protected against diphtheria and tetanus after 2 doses of vaccine and mounted prominent responses to the components of Bordetella pertussis. Subjects in the combined group did not experience more adverse reactions compared with those in the separate group. We concluded that HibTITER was highly immunogenic and safe when administered concurrently with DTP vaccine to Taiwanese children. TETRAMUNE was also safe and immunogenic and might reduce the number of injections to achieve the same protection.

Antibodies, Bacterial↗

Bacteremia and fungemia in hematological and oncological children with neutropenic fever: two-year study in a medical center.

A retrospective study of bacteremia in children with neutropenic fever admitted to a medical center in Taiwan from Jan. 1994 to Dec. 1995 was performed. There were in total 273 episodes of neutropenic fever during this period, but only 79 pathogens were isolated from blood specimens in 70 episodes. Klebsiella pneumoniae (27.8%), E. coli (10.1%), Staphylococcus aureus (10.1%) and Pseudomonas aeruginosa (7.6%) were the most common pathogens. All the isolates of S. aureus were methicillin sensitive. About half of K. pneumoniae (10/22) was multiple-drug resistant. There were seven infection-related mortality cases, three due to multiple-drug resistant K. pneumoniae, one due to S. aureus, one alpha-hemolytic streptococcus and two fungemia (Cryptococcus neoformans and Fusarium sp.). Vancomycin is not necessary in initial empiric therapy of neutropenic fever, while cefazolin or oxacillin may be included in cases with central venous access device. Antibiotics to cover intestinal flora, especially K. pneumoniae, are paramount in our hospital.

Bacteremia↗

Systemic Penicillium marneffei infection in a child with common variable immunodeficiency.

Penicillium marneffei is rarely pathogenic in humans. Most previously reported cases of P. marneffei infection were from Southeast Asia where patients were usually in an immunocompromised state due to human immunodeficiency virus (HIV) infection. The majority of the patients reported in Western countries were immunocompromised by malignancy, especially Hodgkin's lymphoma. In Taiwan, the first case of P. marneffei infection was reported in 1994 and involved an adult with HIV infection. We report a case of systemic P. marneffei infection in a child with common variable immunodeficiency (CVID). The patient, a 4-year, 5-month-old boy, had a 1-year history of oligoarthritis resembling juvenile rheumatoid arthritis (JRA). He developed a low grade fever (38 degrees C) and hepatosplenomegaly 1 month before admission to the hospital. Although cultures of synovial fluid obtained at the time of onset of oligoarthritis did not grow any organisms, cultures of blood, bone marrow, synovial fluid, and lymph node biopsy samples taken during this admission were positive for P. marneffei. Further immunologic studies revealed a profile characteristic of CVID. The fungal infection was finally eradicated by combined therapy with amphotericin B, fluconazole, itraconazole, and regular immunoglobulin replacement. This case reminds us that JRA or JRA-like arthritis should be differentiated from septic arthritis caused by rare pathogens in immunocompromised patients.

Arthritis, Infectious↗

A simplified schedule to integrate the hepatitis B vaccine into an expanded program of immunization in endemic countries.

OBJECTIVE: To investigate the safety, immunogenicity, and efficacy of a simplified hepatitis B vaccination schedule. METHODS: The second dose of hepatitis B vaccine and the first dose of diphtheria-tetanus-pertussis (DTP) vaccine were given simultaneously at age 6 weeks. The second dose of DTP vaccine was given at age 3.5 months. The third dose of DTP vaccine and the third dose of hepatitis B vaccine were given at age 5.5 months. One hundred three infants (group A) born to mothers without hepatitis B surface antigen (HBsAg) received DTP with whole-cell pertussis vaccine. Fifty-five infants (group B) born to mothers with HBsAg and hepatitis B e antigen received DTP with acellular pertussis vaccine. RESULTS: By age 9 months, none of group A and 4 (7%) group B infants were sero-positive for HBsAg. The protective efficacy against the hepatitis B carrier state in these infants at high risk was 92%. Antibody to hepatitis B surface antigen was 10 mlU/ml or greater in 99 (96%) of group A infants and in 50 (91%) of group B infants. Both the acellular and whole-cell DTP vaccines were immunogenic, and the incidences of adverse reactions were within an expected and acceptable range. CONCLUSIONS: The simplified vaccination schedule to integrate the hepatitis B vaccine into the Expanded Programme of Immunization was safe, Immunogenic, and effective. This schedule may improve vaccine compliance and be applied to DTP and hepatitis B combination vaccines now under investigation.

Antigens↗

Outbreak of scarlet fever at a hospital day care centre: analysis of strain relatedness with phenotypic and genotypic characteristics.

An outbreak of scarlet fever involving 12 children occurred at a hospital day care centre from February to March 1996. Twenty-five throat isolates of Streptococcus pyogenes (GAS, group A streptococcus) available from 24 children, including 10 children with scarlet fever and 14 asymptomatic carriers, and one asymptomatic staff member were studied for the presence of genes encoding streptococcal pyrogenic exotoxin types A (speA), B (speB), and C (speC) and for protease activity. Antimicrobial susceptibilities using the E-test, cluster analysis by cellular fatty acid composition and random amplified polymorphic DNA (RAPD) patterns by means of arbitrarily-primed polymerase chain reaction (APPCR) of the isolates were performed to investigate the outbreak. Only one isolate from an asymptomatic child possessed the speA gene. All isolates possessed the speB gene and 24 (96%) isolates were positive for the speC gene. There was no difference in protease activity between isolates from children with scarlet fever and from asymptomatic carriers. Thirteen isolates (10 recovered from children with scarlet fever, two from asymptomatic children, and one from the staff member) were considered to be the same strain according to the identical antimicrobial susceptibility profile and RAPD patterns and were also considered to be similar by cluster analysis of fatty acid composition. These findings suggest that the outbreak was caused by a unique clone of GAS. We conclude that RAPD typing and cluster analysis by cellular fatty acids composition both provide a powerful tool for epidemiological investigation of GAS infections.

Child Day Care Centers↗

Detection of hepatitis B surface gene mutation in carrier children with or without immunoprophylaxis at birth.

To investigate the clinical significance of mutation in hepatitis B virus (HBV) surface gene, DNA sequence analysis of the "a" determinant was performed on sera from 27 carrier children with immunoprophylaxis, their mothers, and 21 carriers without vaccination. A precore mutant (G to A) at nucleotide 1896 was detected in sera from 11 carriers without vaccination. Mutations in the "a" determinant were detected in 6 (22%) of the vaccinated children. Four HBV strains showed a Gly-to-Arg mutation at the 145th codon of the surface gene. Amino acid substitutions at amino acid 133 and 144 were noted in the other 2 children. Only 1 mother had the same predominant strain of mutant virus as her child. These observations indicate that immune pressure exerted by immunoprophylaxis at birth may select for a mutant virus.

Adolescent↗

Primary infections of human herpesvirus-7 and herpesvirus-6: a comparative, longitudinal study up to 6 years of age.

In order to understand the infection status of human herpesvirus 7 (HHV-7) in Taiwan and clarify the serological cross-reactivity between HHV-7 and HHV-6, a longitudinal study was carried out in 52 infants from whom 9 sera were available from birth to 6 years of age. All sera were tested for antibodies against HHV-6 and HHV-7 by indirect immunofluorescence assay. HHV-7 infection was not seen before 6 months of age and gradually emerged thereafter, reaching a cumulative rate of 28.8%, 67.3%, 73.1%, 78.8%, 82.7%, and 86.5% by the ages of 1, 2, 3, 4, 5 and 6 years, respectively. Primary HHV-6 infection induced a reactive HHV-7 antibody in 10/28 (35.7%) cases with a titre of no more than 10. Twenty-eight children (53.8%) were infected by HHV-6 earlier than HHV-7, while eight (15.4%) were infected by HHV-7 earlier than HHV-6. In summary, HHV-7 infected children later than HHV-6. A one-way cross-reaction of HHV-7 serology by HHV-6 was revealed and a titre of 20 is appropriate for defining HHV-7 infection.

Adolescent↗