Richard L. Sweet

A review of premature birth and subclinical infection

Premature birth causes high rates of neonatal morbidity and mortality. There are multiple causes of preterm birth. This article reviews the evidence linking subclinical infection and premature birth. Although maternal genital tract colonization with specific organisms has been inconsistently associated with preterm birth and/or premature rupture of membranes, some infections have been consistently associated with preterm delivery. The association of histologic chorioamnionitis with prematurity is a consistent finding, but the mechanisms require further study. The relationship between histologic chorioamnionitis infection and the chorioamnionitis of prematurity requires additional research. A varying number of patients in idiopathic preterm labor have positive amniotic fluid cultures (0% to 30%), but it is not clear whether infection preceded labor or occurred as a result of labor. Evidence of subclinical infection as a cause of preterm labor is raised by finding elevated maternal serum C-reactive protein and abnormal amniotic fluid organic acid levels in some patients in preterm labor. Biochemical mechanisms for preterm labor in the setting of infection are suggested by both in vitro and in vivo studies of prostaglandins and their metabolites, endotoxin and cytokines. Some, but by no means all, antibiotic trials conducted to date have reported decreases in prematurity. These results support the hypothesis that premature birth results in part from infection caused by genital tract bacteria. In the next few years, research efforts must be prioritized to determine the role of infection and the appropriate prevention of this cause of prematurity.

Upper Genital Tract Infections

Upper genital tract infection in women has for years been referred to as pelvic inflammatory disease. This term specifies neither the site nor the type of infection. Unfortunately it has become so ingrained in the literature that it has become common medical vernacular. It is preferable to indicate at least the site of infection by using such terms as endometritis, salpingitis, salpingo-oophoritis, or tubo-ovarian abscess. Since these infections often represent a progression from endometritis to salpingitis and ultimately to pyosalpinx, hydrosalpinx, or tubo-ovarian abscess, it may be difficult to find a term that specifies the type and extent of infection. Further specificity can be achieved by referring to these infections as acute or chronic to indicate the severity and course of the infection.

Results of noncomparative studies of cefotetan in the treatment of obstetric and gynecologic infections

In a multicenter trial involving 11 centers, 160 women were enrolled to evaluate the safety and effectiveness of 1 or 2 gm of cefotetan administered every 12 hours in the treatment of obstetric and gynecologic infections. The 133 evaluable patients generally were under 25 years of age, were nonwhite, and had hospital-acquired endometritis or pelvic inflammatory disease caused by both aerobic and anaerobic bacteria. Escherichia coli, Neisseria gonorrhoeae, group D streptococci, Bacteroides sp., and Peptococcus sp. were among the most frequently isolated pathogens. The patients were treated for a mean of 5.6 +/- 1.6 days and received a total dose of 19.27 gm. The signs and symptoms of infection were cleared or improved in 93% of the 133 patients evaluable for clinical response. Of the 116 evaluated bacteriologically, 95% had a satisfactory or presumed satisfactory response; only six patients (5%) were considered to be bacteriologic failures. Differences in the results of several clinical laboratory tests performed before and after treatment were statistically, but not clinically, significant (p less than 0.05). Safety was evaluated in the 158 patients who received cefotetan, and only four (3%) had adverse reactions considered related to the drug. Cefotetan was clearly effective and produced no untoward reactions in these women with obstetric and gynecologic infections caused by both aerobic and anaerobic organisms when administered at 1 or 2 gm every 12 hours.

Comparative Study of Intravaginal Metronidazole and Triple-Sulfa Therapy for Bacterial Vaginosis

OBJECTIVEnWe sought to compare the efficacy of metronidazole gel vs. triple-sulfa cream in the treatment of bacterial vaginosis (BV).nnnMETHODSnIn a double-blinded study, 247 women with symptomatic BV were randomly assigned to receive either 5 g of 0.75% metronidazole gel twice daily for 5 days or triple-sulfa cream twice daily for 5 days. There were 205 (96 treated with metronidazole and 109 treated with triple-sulfa) evaluable patients to compare efficacy at the final visit. Approximately 60% of these patients had been previously treated for BV, reflecting the recurrent nature of the disease in this patient population.nnnRESULTSnAt the first (12-16 days) return visit, 81/103 (79%) patients in the metronidazole group were cured compared with 80/113 (71%) patients in the triple-sulfa cream group (P = 0.333). At the final (28-35 days) return visit, 63/96 (66%) in the 96 metronidazole group remained cured compared with only 51/109 (47%) in the triple-sulfa group (P = 0.02). An intent-to-treat analysis similarly showed that the cure rate with metronidazole was superior to triple-sulfa (P < or = 0.02). The clinical diagnosis demonstrated a high correlation (88%) with the diagnosis made by an independent assessment by Grams stain. The side effects reported by the patients using metronidazole gel were infrequent and mild and were similar to those reported with triple-sulfa.nnnCONCLUSIONSnMetronidazole gel is a safe, effective, and well-tolerated treatment for BV.

Cephalosporins and Cephamycins

The clinician is faced with a veritable explosion in the investigation and introduction of cephalosporin and cephalosporinlike antibiotics. Although very little clinical and in vitro differences exist between the first generation cephalosporins (Fig. 1), there has been a steady proliferation of these agents. Although, the clinical efficacy of this versatile group of first generation cephalosporins, which are broad spectrum bactericidal beta lactam antibiotics, is well established, in fact, they are not the drug of choice for any specific infection. However, they have become the second choice drugs for many bacterial infections. This confusing situation will become even more complex, as the so-called second and third generation cephalosporins receive either widespread use or introduction into clinical medicine. This second generation and third generation of cephalosporins have enhanced broad spectrum antimicrobial activity, which may be of clinical importance. The cephamycin group of antibiotics which are related to he cephalosporins also have come into being.