Mary R. Reichler

An Epidemic of Pneumococcal Disease in an Overcrowded, Inadequately Ventilated Jail

BACKGROUND In the United States many correctional facilities now operate at far over capacity, with the potential for living conditions that permit outbreaks of respiratory infections. We investigated an outbreak that was identified in an overcrowded Houston jail after two inmates died of pneumococcal sepsis on the same day. Outbreaks of pneumococcal disease have been rare in the era of antibiotics. METHODS We assessed risk factors for pneumococcal disease in both a case-control and a cohort study. Ventilation was evaluated by measuring carbon dioxide levels and air flow to the living areas of the jail. The extent of asymptomatic infection was determined by culturing pharyngeal specimens from a random sample of inmates. Type-specific immunity was determined with an enzyme immunoassay. RESULTS Over a four-week period, 46 inmates had either acute pneumonia or invasive pneumococcal disease due to Streptococcus pneumoniae serotype 12F. The jails capacity had been set at 3500 inmates, but it housed 6700 at the time of the outbreak; the inmates had a median living area of only 34 ft2 (3.2 m2) (interquartile range, 28 to 56 ft2 [2.6 to 5.2 m2]) per person. There were significantly fewer cases of disease among inmates with 80 ft2 (7.4 m2) per person or more (P = 0.030). Carbon dioxide levels ranged from 1100 to 2500 ppm (acceptable, < 1000), and the ventilation system delivered a median of only 6.1 ft3 of outside air per minute per person (interquartile range, 4.4 to 8.5 ft3; recommended, > or = 20 ft3). The attack rate was highest among inmates in cells with the highest carbon dioxide levels and the lowest volume of outside air delivered by the ventilation system (relative risk, 1.94; 95 percent confidence interval, 1.08 to 3.48). Of underlying medical conditions, intravenous drug use was most strongly associated with disease (odds ratio, 4.50). The epidemic strain (serotype 12F) was cultured from 7 percent of the asymptomatic inmates. Of 11 case patients tested with the enzyme immunoassay, 9 (82 percent) lacked preexisting immunity to this strain. CONCLUSIONS Severe overcrowding, inadequate ventilation, and altered host susceptibility all contributed to this outbreak of pneumococcal disease in a large urban jail.

Risk factors for treatment default in close contacts with latent tuberculous infection.

OBJECTIVE 1) To characterize risk factors for non-completion of latent tuberculous infection treatment (LTBIT), and 2) to assess the impact of LTBIT regimens on subsequent risk of tuberculosis (TB). METHODS Close contacts of adults aged ⩾15 years with pulmonary TB were prospectively enrolled in a multi-center study in the United States and Canada from January 2002 to December 2006. Close contacts of TB patients were screened and cross-matched with TB registries to identify those who developed active TB. RESULTS Of 3238 contacts screened, 1714 (53%) were diagnosed with LTBI. Preventive treatment was recommended in 1371 (80%); 1147 (84%) initiated treatment, of whom 723 (63%) completed it. In multivariate analysis, study site, initial interview sites other than a home or health care setting and isoniazid preventive treatment (IPT) were significantly associated with non-completion of LTBIT. Fourteen TB cases were identified in contacts, all of whom initiated IPT: two TB cases among persons who received ⩾6 months of IPT (66 cases/100 000 person-years [py]), and nine among those who received 0-5 months (median 2 months) of IPT (792 cases/100 000 py, P < 0.001); data on duration of IPT were not available for three cases. CONCLUSION Only 53% (723/1371) of close contacts for whom IPT was recommended actually completed treatment. Close contacts were significantly less likely to complete LTBIT if they took IPT. Less than 6 months of IPT was associated with increased risk of active TB.

HIV counseling and testing in tuberculosis contact investigations in the United States and Canada

BACKGROUND Determining the human immunodeficiency virus (HIV) status of tuberculosis (TB) patients and contacts is important. Despite existing guidelines, not all patients are tested, and testing of contacts is rarely performed. METHODS In a study conducted at nine US/Canadian sites, we introduced formal procedures for offering HIV testing to TB patients and contacts. Data were collected via interviews and medical record review. Characteristics associated with offering and accepting HIV testing were examined. RESULTS Of 651 TB patients, 601 (92%) were offered testing, 511 (85%) accepted, and 51 (10%) were HIV-infected. Of 4152 contacts, 3099 (75%) were offered testing, 1202 (39%) accepted, and 24 (2%) were HIV-infected. Contacts aged 15-64 years, non-Whites, foreign-born persons, smokers, those with positive TB screening, and household contacts were more likely to be offered testing, whereas contacts exposed to HIV-negative patients were less likely to be offered testing. Contacts aged 15-64 years, smokers, drug/alcohol users, diabetics, and those with positive TB screening were more likely to accept testing. Foreign-born persons, Blacks, Hispanics, and contacts exposed to HIV-positive patients were less likely to accept testing. CONCLUSIONS High rates of HIV were detected among patients and contacts. Despite structured procedures to offer HIV testing, some patients and most contacts did not accept testing. Strategies are needed to improve testing acceptance rates.

Household Transmission of Ebola Virus: Risks and Preventive Factors, Freetown, Sierra Leone, 2015

Background Knowing risk factors for household transmission of Ebola virus is important to guide preventive measures during Ebola outbreaks. Methods We enrolled all confirmed persons with Ebola who were the first case in a household, December 2014-April 2015, in Freetown, Sierra Leone, and their household contacts. Cases and contacts were interviewed, contacts followed prospectively through the 21-day incubation period, and secondary cases confirmed by laboratory testing. Results We enrolled 150 index Ebola cases and 838 contacts; 83 (9.9%) contacts developed Ebola during 21-day follow-up. In multivariable analysis, risk factors for transmission included index case death in the household, Ebola symptoms but no reported fever, age <20 years, more days with wet symptoms; and providing care to the index case (P < .01 for each). Protective factors included avoiding the index case after illness onset and a piped household drinking water source (P < .01 for each). Conclusions To reduce Ebola transmission, communities should rapidly identify and follow-up all household contacts; isolate those with Ebola symptoms, including those without reported fever; and consider closer monitoring of contacts who provided care to cases. Households could consider efforts to minimize risk by designating one care provider for ill persons with all others avoiding the suspected case.