Douglas J. Passaro

Postoperative Serratia marcescens Wound Infections Traced to an Out-of-Hospital Source

From 25 August to 28 September 1994, 7 cardiovascular surgery (CVS) patients at a California hospital acquired postoperative Serratia marcescens infections, and 1 died. To identify the outbreak source, a cohort study was done of all 55 adults who underwent CVS at the hospital during the outbreak. Specimens from the hospital environment and from hands of selected staff were cultured. S. marcescens isolates were compared using restriction-endonuclease analysis and pulsed-field gel electrophoresis. Several risk factors for S. marcescens infection were identified, but hospital and hand cultures were negative. In October, a patient exposed to scrub nurse A (who wore artificial fingernails) and to another nurse-but not to other identified risk factors-became infected with the outbreak strain. Subsequent cultures from nurse As home identified the strain in a jar of exfoliant cream. Removal of the cream ended the outbreak. S. marcescens does not normally colonize human skin, but artificial nails may have facilitated transmission via nurse As hands.

Broad-range bacterial detection and the analysis of unexplained death and critical illness.

Broad-range rDNA polymerase chain reaction (PCR) provides an alternative, cultivation-independent approach for identifying pathogens. In 1995, the Centers for Disease Control and Prevention initiated population-based surveillance for unexplained life-threatening infections (Unexplained Death and Critical Illness Project [UNEX]). To address the causes of UNEX cases, we examined 59 specimens from 46 cases by using broad-range bacterial 16S rDNA PCR and phylogenetic analysis of amplified sequences. Specimens from eight cases yielded sequences from Neisseria meningitidis (cerebrospinal fluid from two patients with meningitis), Streptococcus pneumoniae (cerebrospinal fluid from one patient with meningitis and pleural fluid from two patients with pneumonia), or Stenotrophomonas maltophilia (bone marrow aspirate from one patient with pneumonia). Streptococcus pneumoniae rDNA sequence microheterogeneity was found in one pleural fluid specimen, suggesting the presence of multiple strains. In conclusion, known bacterial pathogens cause some critical illnesses and deaths that fail to be explained with traditional diagnostic methods.

Surveillance for Unexplained Deaths and Critical Illnesses Due to Possibly Infectious Causes, United States, 1995-1998

Population-based surveillance for unexplained death and critical illness possibly due to infectious causes (UNEX) was conducted in four U.S. Emerging Infections Program sites (population 7.7 million) from May 1, 1995, to December 31, 1998, to define the incidence, epidemiologic features, and etiology of this syndrome. A case was defined as death or critical illness in a hospitalized, previously healthy person, 1 to 49 years of age, with infection hallmarks but no cause identified after routine testing. A total of 137 cases were identified (incidence rate 0.5 per 100,000 per year). Patients’ median age was 20 years, 72 (53%) were female, 112 (82%) were white, and 41 (30%) died. The most common clinical presentations were neurologic (29%), respiratory (27%), and cardiac (21%). Infectious causes were identified for 34 cases (28% of the 122 cases with clinical specimens); 23 (68%) were diagnosed by reference serologic tests, and 11 (32%) by polymerase chain reaction-based methods. The UNEX network model would improve U.S. diagnostic capacities and preparedness for emerging infections.

Helicobacter pylori and epidemic Vibrio cholerae 01 infection in Peru.

Summary Summary In a cross-sectional study of the 1991 Peruvian cholera epidemic, Vibrio cholerae 01 infection was associated with Helicobacter pylori infection, particularly in young children. These data support the hypothesis that hypochlorhydria induced by H pylori is important in the pathogenesis of diarrhoeal disease.

Enhanced Control of an Outbreak of Mycoplasma pneumoniae Pneumonia with Azithromycin Prophylaxis

There are currently no recommended epidemic-control measures for Mycoplasma pneumoniae pneumonia outbreaks in closed communities. Previous studies have suggested the usefulness of chemoprophylaxis administered to close contacts of case-patients. To evaluate the effectiveness of various epidemic-control measures during an institutional outbreak, an observational study was undertaken during a very large outbreak of M. pneumoniae pneumonia at a facility for developmentally disabled residents (n = 142 cases). Control measures evaluated included no control, standard epidemic-control measures, and targeted azithromycin prophylaxis (500 mg on day 1, 250 mg/day on days 2-5) plus standard epidemic-control measures. The combined use of azithromycin prophylaxis and standard epidemic-control measures was associated with a significant reduction in the secondary attack rate. This study suggests that the addition of antibiotic prophylaxis to standard epidemic-control measures can be useful during institutional outbreaks of M. pneumoniae pneumonia.

Natural history of grade 1 cervical intraepithelial neoplasia in women with human immunodeficiency virus.

OBJECTIVE: We sought to estimate rates of progression and regression of grade 1 cervical intraepithelial neoplasia (CIN 1) among women with human immunodeficiency virus (HIV). METHODS: In a multicenter prospective cohort study, HIV-seropositive and HIV-seronegative women were evaluated colposcopically after receiving an abnormal cytology test result between November 1994 and September 2002. Women with CIN 1 were included, except those who had undergone hysterectomy, cervical therapy, or had CIN 2–3 or cervical cancer. Those women who were included were followed cytologically twice yearly, with colposcopy repeated for atypia or worse. RESULTS: We followed 223 women with CIN 1 (202 HIV seropositive and 21 HIV seronegative) for a mean of 3.3 person-years. Progression occurred in 8 HIV-seropositive women (incidence density, 1.2/100 person-years; 95% confidence interval [CI] 0.5–2.4/100 person-years) and in no HIV seronegative women. Regression occurred in 66 (33%) HIV-seropositive women (13/100 person-years, 95% CI 10–16/100 person-years) versus 14 (67%) seronegative women (32/100 person-years, relative risk 0.40, 95% CI 0.25–0.66; P < .001). In multivariate analysis, regression was associated with human papillomavirus (HPV) detection (hazard ratio [HR] for low risk 0.28, 95% CI 0.13–0.61, P = .001; and for high-risk 0.34, 95% CI 0.20–0.55, P < .001 versus no HPV detected) and Hispanic ethnicity (HR 0.48, 95% CI 0.230.98; P = .04); HIV serostatus was only marginally linked to regression (HR 0.52, 95% CI 0.27–1.03; P = .06), but seropositive women were less likely to regress when analysis was limited to 146 women with HPV detected at CIN 1 diagnosis (HR 0.18, 95% CI 0.05–0.62; P = .006). CONCLUSION: Grade 1 cervical intraepithelial neoplasia infrequently progresses in women with HIV. Thus, observation appears safe absent other indications for treatment. LEVEL OF EVIDENCE: II-1

Growth slowing after acute Helicobacter pylori infection is age-dependent

Objective Most Helicobacter pylori infections occur during childhood, but the health effects of childhood infection are poorly understood. We investigated whether growth decreases in the 2 months after acute H. pylori seroconversion. Methods We performed a nested case-control study among children 6 months to 12 years of age in a community on the outskirts of Lima, Peru. Health interviews were completed daily. Anthropometric measurements were taken monthly. Sera were collected every 4 months and tested for H. pylori immunoglobulin G. Two-month height and weight gains of seroconverters were compared with gains of sex, age, and size-matched seronegative controls. Results In the 2 months after H. pylori infection, 26 seroconverters gained a median of 24% less weight than 26 matched controls (interquartile range, 63% less to 21% more). In multivariate analysis, H. pylori infection attenuated weight gain only among children aged 2 years or older. This decrease was not explained by increased diarrhea. Conclusions H. pylori seroconversion is associated with a slowing of weight gain in children aged 2 years or older. Reasons for this finding merit additional study.

Helicobacter pylori: Consensus and Controversy

Helicobacter pylori is uniquely adapted to colonize the human stomach. Infection leads to a range of subclinical and clinical outcomes that depend on properties of the infecting strain, the host, and the environment. Eradication therapy is indicated for infected persons who develop peptic ulcer disease or gastric lymphoma or who are beginning long-term treatment with nonsteroidal anti-inflammatory drugs. However, treatment may worsen gastroesophageal reflux disease and increase the risk of esophageal cancer. H. pylori infections can be diagnosed noninvasively and can be eradicated with approximately 85% success by a variety of multidrug, 7-14-day regimens. Unfortunately, antibiotic resistance is affecting treatment effectiveness in the United States and abroad. A more complete understanding of the variation in H. pylori pathogenesis should lead to clearer recommendations about treatment for infected persons who have neither peptic ulcer disease nor gastric lymphoma.

The public health imperative for a neonatal herpes simplex virus infection surveillance system.

About 1 in 5 sexually active adults in the United States has serologic evidence of genital herpes caused by herpes simplex virus type-2. Neonatal herpes simplex virus infection is a serious consequence of genital herpes infection. Herpes infection in neonates causes significant morbidity and neurologic damage and generally has a case-fatality ratio untreated of 60%. It is estimated that 440 to 1320 cases of neonatal herpes infections occur in the United States per year (11–33 cases occur per 100,000 live births). Given the challenges in surveillance for genital herpes due to the large number of asymptomatic infections and infrequent laboratory-based diagnosis, we recommend that to begin an effective national control program for herpes infections, a mandatory national surveillance system for neonatal herpes be implemented. Such a system would help assure appropriate therapy, help monitor trends and understand the burden of disease, identify risk determinants, and evaluate prevention efforts.

Outcome after negative colposcopy among human immunodeficiency virus-infected women with borderline cytologic abnormalities

Objective: To estimate the risk of and risk factors for progression among human immunodeficiency virus (HIV)-seropositive women with abnormal cervical cytology but negative colposcopy. Methods: In a prospective cohort study, 391 HIV-seropositive and 103 seronegative women with cervical cytology read as atypical squamous cells (ASC) or low-grade squamous intraepithelial lesion (LSIL) but negative colposcopy were followed up for a mean of 4.0 years with cytology at 6-month intervals. Colposcopy was prescribed for any epithelial abnormality. Results: Progression to CIN2, CIN3, high-grade SIL/severe dysplasia, or cancer occurred in 47 (12%) HIV-seropositive women and 4 (4%) HIV-seronegative women (P = .02). Progression to CIN1 was seen in an additional 12 HIV-seropositive women and 1 seronegative woman. In multivariate analysis, high-risk but not low-risk HPV detection (hazard ratio [HR] 2.46–95% confidence interval [CI] 1.18–5.12, P = .02 for high risk, HR 1.41, 95% CI 0.62–3.21, P = .42 for low risk), satisfactory colposcopy (HR 2.01, 95% CI 1.11–3.65, P = .02), and non-Hispanic African-American ethnicity (HR 5.08, 95% CI 1.72–14.98, P = .003) were the only factors associated with progression, while HIV serostatus was marginally significant (HR 2.53, 95% CI 0.85–7.50, P = .09). Conclusion: Human immunodeficiency virus–seropositive women with negative colposcopy after borderline cytology face a higher risk of progression than seronegative women, but the absolute risk is low and becomes nonsignificant after controlling for HPV risk type, ethnicity, and colposcopic findings. Observation is appropriate. Level of Evidence: II-2