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Biomedical subjects

H R Harrison

Publications and source records attributed to H R Harrison.

At least 19 recordsLinked to original sources

Sociocultural factors in puerperal infectious morbidity among Navajo women.

From 1980 to 1982, a sample of 968 pregnant Navajo women in New Mexico was enrolled in a prospective study of biologic and sociocultural factors in puerperal infectious morbidity. Past studies have independently implicated both genital infection and psychosocial stressors in perinatal complications, but, to the authors' knowledge, no previous work has concurrently investigated the interactive effects of genital pathogens and psychosocial processes. Endocervical cultures for Mycoplasma hominis and Chlamydia trachomatis were obtained during prenatal visits, and structured interviews were conducted assessing social support and the degree of cultural traditionality, in this context a proxy measure of acculturative stress. The incidences of postpartum fever, endometritis, and premature rupture of membranes were significantly associated with the concurrence of two factors: the presence of genital tract M. hominis and a highly traditional cultural orientation. When demographic and conventional obstetric risk factors were controlled for, women with both M. hominis and high traditionality experienced infectious complications at a rate twice that of women with either factor alone. Among the plausible explanations for this result is the possibility that acculturative stress undermines physiologic resistance to infectious genital tract disease.

Adolescent

The Tucson Children's Respiratory Study. I. Design and implementation of a prospective study of acute and chronic respiratory illness in children.

The Tucson Children's Respiratory Study, Tucson, Arizona, has been established as a long-term, longitudinal, prospective study of the risk factors for acute lower respiratory tract illnesses in early childhood and for chronic obstructive airways disease in later life. A total of 1,246 newborns were enrolled into the study between May 1980 and January 1984, representing 78% of eligible infants. Cord blood for immunologic studies, neonatal blood specimens for blood counts and differentials, and blood specimens at nine to 15 months of age for immunologic studies, blood counts, and differentials have been obtained on the majority of enrolled children. Pre-illness physiologic and more detailed immunologic studies have also been done on large subgroups of subjects. The majority of lower respiratory tract illnesses suffered by these children in the first three years of life have been assessed in detail for etiologic agents by means of culture and serologic techniques; 1,052 illnesses have been evaluated thus far. The type of illness and nature of etiologic agents are very similar to those reported in other epidemiologic studies. Thus, this group of enrolled infants and their family members constitute an appropriate population for the long-term study of risk factors for acute and chronic respiratory disorders.

Acute Disease

The Tucson Children's Respiratory Study. II. Lower respiratory tract illness in the first year of life.

Lower respiratory tract illnesses occurring during the first year of life in 1,179 healthy infants enrolled in the Children's Respiratory Study, Tucson, Arizona, are described. The children, who use the pediatricians of a health maintenance organization, were enrolled into the study between May 1980 and January 1984. Data were collected on signs, symptoms, and diagnosis for each illness; nasopharyngeal and throat swabs were collected at the acute visit for viral, chlamydial, and mycoplasmal cultures. The cumulative incidence of illness in the first year of life was 32.88 per 100 children. Of the 348 initial lower respiratory tract illnesses occurring in these infants, 60% were diagnosed as bronchiolitis. At least one infecting agent was identified in 66% of the specimens collected at the time of the first illness. Respiratory syncytial virus was the most common isolate; 12 other agents were also identified. There was a strong (p less than 0.0001) relation between agent identified, symptoms reported, and diagnosis; bronchiolitis was predominantly associated with respiratory syncytial virus and croup with parainfluenza viruses. Sex and ethnicity were unrelated to illness experience or to characteristics of the first illness. Lower respiratory tract illness occurrence in the Children's Respiratory Study appears to be similar to patterns observed elsewhere, suggesting that diagnoses (and infecting agents) have changed little over the past decades.

Humans

The epidemiology of infection with the human herpesviruses in Navajo children.

Investigations of serum antibody status to the five human herpesviruses--herpes simplex virus type 1, herpes simplex virus type 2, cytomegalovirus, Epstein-Barr virus, and varicella-zoster virus--were conducted on 197 Navajo children, aged 1-15 years, at a reservation pediatric outpatient clinic in Crownpoint, New Mexico, from 1981-1984. To determine the severity of infection with the human herpesviruses, the authors reviewed lifetime medical records of 166 of the children for evidence of herpesvirus-related diseases, and to illuminate potential modes of transmission of the viruses, they completed home interviews on the families of 87 of the children. The investigation showed that the children had a high prevalence of antibody to herpes simplex virus type 1 (73% of total sample), cytomegalovirus (78%), Epstein Barr virus (98%), and varicella-zoster virus (77%), and that prevalence tended to increase with age. None of the children demonstrated herpes simplex virus type 2 antibodies. The medical records showed that 30% of the children had suffered from gingivostomatitis prior to the study. When age was controlled for, the study showed herpes simplex virus type 1 seropositivity to be associated with children who slept in the same bed as their parents during infancy (p = 0.003) and with frequent attendance at community events (p = 0.02); cytomegalovirus seropositivity was shown to be associated with female sex (p = 0.007) and with living in a traditional Navajo dwelling (p = 0.007). The Navajo children also demonstrated a greater frequency of symptomatic oral herpes simplex virus type 1 infection than is usually recorded. The findings suggest a relation between certain patterns of cultural behavior and transmission of herpesvirus infections.

Adolescent

Factors related to genital Chlamydia trachomatis and its diagnosis by culture in a sexually transmitted disease clinic.

The authors cultured 2,320 patients who attended the Denver Metro Health Clinic for Sexually Transmitted Diseases from September 1981 to June 1983 to determine clinical and epidemiologic factors associated with genital chlamydial infection. Among consecutive heterosexual men with urethral discharge, 226 of 849 (27%) had positive urethral cultures, with rates significantly lower among those with profuse (18%) or purulent (19%) discharges, and higher (37%) among those with symptoms for more than seven days. In a subgroup of men without gonococci, those who had polymorphonuclear leukocytes on smear had higher isolation rates (33%) than those who did not (3%). Among consecutive female patients, 172 of 1,031 (17%) had positive cervical cultures, with rates significantly lower in those who were white (13%), married (7%), or using a diaphragm (0 of 77), and higher in those who were positive for Neisseria gonorrhoeae (38%). There was a marginally significant increased rate of chlamydial isolation among oral contraceptive users only for women aged 20 years or younger. Younger age was significantly associated with chlamydial isolation in both men and women after controlling for sexual activity and other factors. Various patient characteristics can be combined to define subgroups of men and women, with rates of isolation ranging from under 4% to over 60%. These results can be useful in deciding whom to test and whom to treat presumptively in a public health setting.

Adult

Low birth weight, prematurity, and postpartum endometritis. Association with prenatal cervical Mycoplasma hominis and Chlamydia trachomatis infections.

We studied associations of Mycoplasma hominis, Ureaplasma urealyticum, and Chlamydia trachomatis genital infections with pregnancy outcomes, controlling by logistic and multiple linear regression for known risk factors and for the presence of the other two infections. A sample of 1204 Navajo women enrolling for prenatal care had endocervical C trachomatis, M hominis, and U urealyticum cultures and serum samples taken at enrollment and when possible after 30 weeks. Low birth weight (less than 2500 g) was associated with M hominis infection among women with a history of spontaneous abortion. Mycoplasma hominis infection was also associated with postpartum endometritis, but only among women undergoing a cesarean section (odds ratio, 4.7; 95% confidence intervals, 1.22 to 18.3). Although women with recent C trachomatis infection (IgM titer greater than 1:32 on either sample or IgG seroconversion) were at greater risk of low birth weight (19% [3/16]) than women with chronic infection (4.5% [6/133]; relative risk, 4.2), this subgroup at risk was small (11% of women with classifiable C trachomatis infection). Mycoplasma hominis and C trachomatis infections may be important preventable causes of adverse pregnancy outcomes in identifiable subgroups of women.

Cervix Uteri

Western blot analysis of the human serum response to Mycoplasma hominis.

Mycoplasma hominis is a human genital pathogen with importance in postpartum pregnancy complications (postpartum fever/endometritis). Previous research has suggested that serum antibody levels to M. hominis are important in predicting which groups of women are at risk. M. hominis strain PG21 was examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blots to determine which protein antigens would be good candidates for use in serologic tests. Western blots of strain PG21 were probed with acute and convalescent human sera from patients with culture-confirmed M. hominis infections, animal sera directed against strain PG21 and other M. hominis strains, and sera from patients with confirmed infections from other sexually transmitted diseases (STD). Western blot analysis showed that the prenatal (Groups I, II, III) and convalescent (Group IV) M. hominis human sera reacted with proteins with apparent MWs of 106, 67, 46, and 40 kilodaltons (kDa). Only the convalescent sera (Group IV) and the prenatal sera (Group III) reacted with proteins having apparent MWs of 58 and 50 kDa. Animal antisera directed against all strains of M. hominis examined showed that these proteins were reactive in all strains, and other STD human sera did not react with proteins in strain PG21 corresponding to the apparent MWs of 50 and 58 kDa. Preliminary evidence suggested that proteins with the apparent MWs of 50 and 58 kDa may be viable candidates for use in serologic tests for the detection of human anti-M. hominis antibodies and help to eliminate cross-reactivity observed with whole-cell lysates.

Adult

Treatment of sexually transmitted chlamydial infections.

Tetracycline hydrochloride, 500 mg orally four times a day for seven days, remains the treatment of choice for C trachomatis infections in men and nonpregnant women. Either erythromycin, 500 mg orally four times daily for seven days, or an equivalent dosage of another erythromycin product is an alternative treatment for patients who cannot tolerate tetracycline and for pregnant women. These two treatment regimens can be generalized to include nongonococcal urethritis and mucopurulent cervicitis. However, other treatment regimens that are effective against C trachomatis may not be effective for treating nongonococcal urethritis or mucopurulent cervicitis not caused by C trachomatis. The optimal treatment for pregnant women with C trachomatis infections and women with acute PID has not been established. Additional treatment trials with both groups of patients are needed to determine the effectiveness of antimicrobial agents in addition to those currently used, to establish the appropriate dose of each antimicrobial agent, and to clarify the appropriate duration of treatment. All individuals who are sexual partners of patients with nongonococcal urethritis, mucopurulent cervicitis, and acute PID (within the 30 days prior to onset of their symptoms or time of positive clinical evaluation findings) should be examined for sexually transmitted disease and treated promptly with a regimen effective against uncomplicated gonorrhea and chlamydial infections. Prompt treatment of sexual partners reduces the rate of treatment failure due to reinfection, reduces the transmission of infection, and reduces the frequency of occurrence of adverse sequelae of infection.

Acute Disease

Acute Chlamydia trachomatis respiratory infection in childhood. Serologic evidence.

Serum samples from 184 infants and children whose blood was drawn during a clinic visit were tested for antibody to Chlamydia trachomatis, Epstein-Barr virus, and cytomegalovirus. Lifetime illness history was obtained from clinic records. Fifteen percent had anti-C trachomatis IgM antibody. Anti-C trachomatis IgM without IgG was significantly associated with upper respiratory tract syndromes within the 14 days prior to phlebotomy in 6- to 10-year-old patients. This association was not due to polyclonal activation from Epstein-Barr virus infection. A definitive study of chlamydial illness in children rather than infants appears to be indicated.

Acute Disease

Social and cultural factors in pregnancy complications among Navajo women.

A population of 968 pregnant Navajo women was followed in a prospective study conducted from 1980 to 1983 at the Indian Health Service Hospitals in Gallup and Crownpoint, New Mexico. The purpose of the study was to examine social and cultural influences on obstetric and neonatal complications. The extent of traditional cultural practices and the availability of social support were ascertained in structured interviews completed during each woman's first prenatal visit. In a subsample of women, the occurrence of stressful life events was also measured during a final prenatal visit in the third trimester of pregnancy. Controlling for a variety of conventional risk factors and other potential confounders, traditional women sustained complications at a rate greater than twice that of the least traditional, most acculturated women (approximate relative risk = 2.1; p = 0.001). Social support and life events were modestly associated with maternal complications (approximate relative risk = 0.7, 0.8, respectively; p = 0.07), with poorer outcomes found among those with low social support and low numbers of life events. It is proposed that the relationship of maternal complications to all three sociocultural variables--traditionality, social support, and life events--may reflect the influences of social isolation on the course and outcomes of pregnancy.

Adolescent

Cervical Chlamydia trachomatis infection in university women: relationship to history, contraception, ectopy, and cervicitis.

Endocervical Chlamydia trachomatis infection was found in 13 of 162 volunteer female university students (8%). Infection was correlated with younger age (p less than 0.05), less than or equal to 4 years of intercourse (p less than 0.05), a history of gonorrhea (p less than 0.01), and exposure to a partner with urethritis (p less than 0.01). Women who used intrauterine or barrier contraception had less infection (2%) than did women who used oral contraception (14.3%, p less than 0.05) or none at all (10.7%, p less than 0.05). Infection was strongly associated with a cervicitis score calculated from erythema, ectopy, discharge, and secretions that contained white blood cells (p less than 0.0001). By multivariate analysis, a proposed clinical approach was arrived at for testing for chlamydial organisms all women with cervicitis who were not using barrier contraception. The positive predictive value of this approach for chlamydial infection was 28%, and the negative predictive value 98.4%. Cervical ectopy was increased in women who used oral contraception (p less than 0.01), and infection was increased in women with ectopy, regardless of their contraceptive method (p less than 0.001). These results will aid in more rapid diagnosis of endocervical chlamydial infection and in the choice of contraception in young women and high-prevalence groups.

Adolescent

Illnesses in infants born to women with Chlamydia trachomatis infection. A prospective study.

Chlamydia trachomatis is known to cause infant pneumonitis and conjunctivitis and is a suspected cause of otitis media and gastroenteritis. To identify infections associated with exposure to C trachomatis, infant illnesses were studied through a "blinded" review of medical records of 244 infants born to women cultured antenatally for cervical C trachomatis, 25% of whom had C trachomatis-positive cultures. Compared with unexposed infants, infants exposed to C trachomatis had twice the rate of both pneumonitis and recurrent otitis media in the first six months. Infants who were exposed to C trachomatis and who had pneumonitis had higher subsequent rates of gastroenteritis than either unexposed infants or exposed infants without pneumonitis. These results suggest that appreciable outpatient infant morbidity may be associated with maternal infection with C trachomatis, and that it may either cause or promote the occurrence of early, recurrent otitis media and gastroenteritis.

Bronchitis

Infection with Chlamydia trachomatis immunotype J associated with trachoma in children in an area previously endemic for trachoma.

Chlamydia trachomatis immunotype J was isolated from the eye of a five-year-old Navajo child with trachoma. This is the first such isolate from a patient in an area previously endemic for trachoma. Chlamydial infection of the genitals among the Navajo Indians is common, and we have isolated immunotype J from the genital tract of women in this area. This most recent case points to the occurrence of "genital" trachoma. This occurrence adds evidence to the assertion that trachoma may be caused by the "genital" immunotypes of C. trachomatis. Therefore, the traditional distinction between ocular and genital strains may be artifactual.

Antibodies, Monoclonal

In vitro activity of clindamycin against strains of Chlamydia trachomatis, Mycoplasma hominis, and Ureaplasma urealyticum isolated from pregnant women.

Chlamydia trachomatis, Mycoplasma hominis, and Ureaplasma urealyticum are genital agents that are being increasingly implicated in infectious pregnancy complications and abnormal pregnancy outcomes. We measured the in vitro activity of clindamycin against strains of these three agents which were isolated from pregnant women. For 30 strains of C. trachomatis, the median minimal inhibitory concentration was 1.0 microgram/ml (range, 0.25 to 2.0 micrograms/ml). For 27 strains of M. hominis, the median minimal inhibitory concentration was 0.12 microgram/ml (range, 0.06 to 0.25 microgram/ml) and the median minimal bactericidal concentration was 0.5 microgram/ml (range, 0.06 to 2.0 micrograms/ml). For 27 strains of U. urealyticum, the mean minimal inhibitory concentration was 4 micrograms/ml (range, 1.0 to 32.0 micrograms/ml) and the mean minimal bactericidal concentration was 32.0 micrograms/ml (range, 4.0 to 128 micrograms/ml). Thus in vitro clindamycin would appear to be highly active against pregnancy-associated strains of M. hominis, less active against strains of C. trachomatis, and least active against strains of U. urealyticum. Since M. hominis has been strongly linked to postabortal fever and to postpartum fever and endometritis, our results indicate that clindamycin should be evaluated in treatment trials in pregnancy aimed at prevention of M. hominis-induced morbidity as well as in treatment of the complications themselves.

Chlamydia Infections

Establishment of genital tract infection in the CF-1 mouse by intravaginal inoculation of a human oculogenital isolate of Chlamydia trachomatis.

A human oculogenital strain of Chlamydia trachomatis was instilled intravaginally in the outbred CF-1 mouse to establish cervical infection. The mice were neither hormonally nor immunologically manipulated before inoculation. Duration of chlamydial excretion varied from two to ten days. In the culture-positive animals, IgG and IgM antibody titers were elevated in 38% and 17%, respectively. Neither intracytoplasmic inclusions nor elementary bodies of C. trachomatis were detected in genital tissues. Infection was limited primarily to the cervix and only rarely extended into the uterus. Chlamydial infection could only be established during specific periods of the estrus cycle (metestrus-2, diestrus, and proestrus; P less than .001), stages when leukocytes are present in the vaginal smear. Thus, chlamydial infection of the cervix is cycle-dependent in the mouse. In summary, infection of the cervix of the mouse has been established with a human oculogenital strain of C. trachomatis and may be useful as a model of human chlamydial cervicitis.

Animals