Introduction of Ebola virus into a remote border district of Sierra Leone, 2014: use of field epidemiology and RNA sequencing to describe chains of transmission.

In early October 2014, 7 months after the 2014-2015 Ebola epidemic in West Africa began, a cluster of reported deaths in Koinadugu, a remote district of Sierra Leone, was the first evidence of Ebola virus disease (Ebola) in the district. Prior to this event, geographic isolation was thought to have prevented the introduction of Ebola to this area. We describe our initial investigation of this cluster of deaths and subsequent public health actions after Ebola was confirmed, and present challenges to our investigation and methods of overcoming them. We present a transmission tree and results of whole genome sequencing of selected isolates to identify the source of infection in Koinadugu and demonstrate transmission between its villages. Koinadugu's experience highlights the danger of assuming that remote location and geographic isolation can prevent the spread of Ebola, but also demonstrates how deployment of rapid field response teams can help limit spread once Ebola is detected.

Geospatial analysis of household spread of Ebola virus in a quarantined village - Sierra Leone, 2014.

We performed a spatial-temporal analysis to assess household risk factors for Ebola virus disease (Ebola) in a remote, severely-affected village. We defined a household as a family's shared living space and a case-household as a household with at least one resident who became a suspect, probable, or confirmed Ebola case from 1 August 2014 to 10 October 2014. We used Geographic Information System (GIS) software to calculate inter-household distances, performed space-time cluster analyses, and developed Generalized Estimating Equations (GEE). Village X consisted of 64 households; 42% of households became case-households over the observation period. Two significant space-time clusters occurred among households in the village; temporal effects outweighed spatial effects. GEE demonstrated that the odds of becoming a case-household increased by 4·0% for each additional person per household (P < 0·02) and 2·6% per day (P < 0·07). An increasing number of persons per household, and to a lesser extent, the passage of time after onset of the outbreak were risk factors for household Ebola acquisition, emphasizing the importance of prompt public health interventions that prioritize the most populated households. Using GIS with GEE can reveal complex spatial-temporal risk factors, which can inform prioritization of response activities in future outbreaks.

Estimating the prevalence of active Helicobacter pylori infection in a rural community with global positioning system technology-assisted sampling.

We investigated a possible outbreak of H. pylori in a rural Northern Plains community. In a cross-sectional survey, we randomly sampled 244 households from a geocoded emergency medical system database. We used a complex survey design and global positioning system units to locate houses and randomly selected one eligible household member to administer a questionnaire and a 13C-urea breath test for active H. pylori infection (n = 166). In weighted analyses, active H. pylori infection was detected in 55·0% of the sample. Factors associated with infection on multivariate analysis included using a public drinking-water supply [odds ratio (OR) 12·2, 95% confidence interval (CI) 2·9-50·7] and current cigarette smoking (OR 4·1, 95% CI 1·7-9·6). People who lived in houses with more rooms, a possible indicator of decreased crowding in the home, were less likely to have active H. pylori infections (OR 0·7, 95% CI 0·5-0·9 for each additional room).

Added value of a household-level study during an outbreak investigation of Salmonella serotype Saintpaul infections, New Mexico 2008.

In 2008, nationwide investigations of a Salmonella serotype Saintpaul outbreak led first to consumer warnings for Roma and red round tomatoes, then later for jalapeño and serrano peppers. In New Mexico, where there were a large number of cases but no restaurant-based clusters, the NM Department of Health and the Indian Health Service participated with CDC in individual-level and household-level case-control studies of infections in New Mexico and the Navajo Nation. No food item was associated in the individual-level study. In the household-level study, households with an ill member were more likely to have had jalapeño peppers present during the exposure period and to have reported ever having serrano peppers in the household. This report illustrates the complexity of this investigation, the limitations of traditional individual-level case-control studies when vehicles of infection are ingredients or commonly eaten with other foods, and the added value of a household-level study.

Burden of tuberculosis in indigenous peoples globally: a systematic review.

BACKGROUND: The burden of tuberculosis (TB) in the estimated 370 million indigenous peoples worldwide is unknown. OBJECTIVE: To conduct a literature review to summarize the TB burden in indigenous peoples, identify gaps in current knowledge, and provide the foundation for a research agenda prioritizing indigenous health within TB control. METHODS: A systematic literature review identified articles published between January 1990 and November 2011 quantifying TB disease burden in indigenous populations worldwide. RESULTS: Among the 91 articles from 19 countries included in the review, only 56 were from outside Australia, Canada, New Zealand and the United States. The majority of the studies showed higher TB rates among indigenous groups than non-indigenous groups. Studies from the Amazon generally reported the highest TB prevalence and incidence, but select populations from South-East Asia and Africa were found to have similarly high rates of TB. In North America, the Inuit had the highest reported TB incidence (156/100000), whereas the Metis of Canada and American Indians/Alaska Natives experienced rates of <10/100000. New Zealand's Maori and Pacific Islanders had higher TB incidence rates than Australian Aborigines, but all were at greater risk of developing TB than non-indigenous groups. CONCLUSION: Where data exist, indigenous peoples were generally found to have higher rates of TB disease than non-indigenous peoples; however, this burden varied greatly. The paucity of published information on TB burden among indigenous peoples highlights the need to implement and improve TB surveillance to better measure and understand global disparities in TB rates.

Completing the circle: follow-up screening of STD patients in three clinics of the United States Indian Health Service.

We reviewed charts of newly diagnosed STD patients in three health facilities to determine the proportion who received follow-up STD screening. In a 12-month period, the three facilities had 140 STD cases. STD screening was not indicated for 50 (36%) patients. Among the 90 remaining STD patients, 29 (32%) were screened and 61 (68%) not screened. Among non-screened patients, 36% (22/61) were tested, but outside the time parameters allowed by the audit. The remaining 64% (39/61) received no screening at all, and represented clinical missed opportunities; in this group, nearly all (95%) had chlamydia but were not screened for HIV or syphilis. Linking chlamydia patients with a screen for HIV and syphilis using a clinical reminder in the facilities' electronic health record (EHR) or other tool, would eliminate 95% of the missed opportunities in this sample.

Controlling tuberculosis in an urban emergency department: a rapid decision instrument for patient isolation.

OBJECTIVES: This study examined whether data routinely available in emergency departments could be used to improve isolation decisions for tuberculosis patients. METHODS: In a large emergency department in New York City, we compared the exposure histories of tuberculosis culture-positive and culture-negative patients and used these data to develop a rapid decision instrument to predict culture-positive tuberculosis. The screen used only data that are routinely available to emergency physicians. RESULTS: The method had high sensitivity (.96) and moderate specificity (.54). CONCLUSIONS: The method is easily adaptable for a broad range of settings and illustrates the potential benefits of applying basic epidemiologic methods in a clinical setting.

Propoxyphene-induced wide QRS complex dysrhythmia responsive to sodium bicarbonate--a case report.

Propoxyphene overdose is known to cause widening of the QRS complex on ECG. We report a case of a 54-year-old female who ingested approximately 100 propoxyphene hydrochloride tablets in a suicide attempt. She developed a wide complex dysrhythmia which responded to sodium bicarbonate therapy. Propoxyphene-induced wide complex dysrhythmia responsive to sodium bicarbonate therapy has not been previously reported in the literature.