Helicobacter pylori infection among non-Native educators in Alaska.

OBJECTIVES: To determine seroprevalence of H. pylori infection in non-Native educators residing in urban or rural settings in Alaska, and to determine potential risk factors associated with infection in this population. STUDY DESIGN: A cross-sectional survey of non-Native educators residing in urban or rural settings in Alaska. METHODS: Participants completed a questionnaire detailing aspects of residential life; H. pylori antibody status was determined by a commercial assay. RESULTS: Of the 203 non-Native participants, 49 (24%) had antibody to H. pylori. Univariate analysis demonstrated that the mean age of seropositive participants was higher than of seronegatives (48 vs. 42 years, respectively, p = .001). In addition, participants who had experienced childhood crowding were more likely to test seropositive for H. pylori (p = .058). On multivariate analysis, only age > or = 40 was associated with infection. No difference in median hemoglobin or ferritin levels were noted among seropositive and seronegative participants. There was no increased risk of seropositivity among participants who had lived in an Alaska Native village or in a developing country for > or = 6 months. CONCLUSIONS: Overall, 24% of non-Native educators residing in rural Alaska tested positive by serology for H. pylori. Age > or = 40 years was associated with infection. Median hemoglobin or ferritin levels did not differ significantly among seropositive and seronegative participants.

Incremental effectiveness of 2 doses of measles-containing vaccine compared with 1 dose among high school students during an outbreak.

A measles outbreak occurred among a highly vaccinated population in Alaska during 1998, providing an opportunity to determine the incremental efficacy of >or=2 doses of measles-containing vaccine (MCV) compared with 1 dose. Of 33 confirmed case patients identified, 31 had been vaccinated with 1 dose of MCV, 1 had received 2 doses, and vaccination status was unknown in 1 case. Seventy percent of cases were school-associated; 58% of cases occurred in 2 high schools. Of 3679 students attending the 2 schools, 50.4% and 45.5% had received >or=2 doses of MCV before measles introduction at the schools. The relative risk of developing measles among persons vaccinated with >or=2 doses of MCV compared with 1 dose was 0.06 (95% confidence interval, 0.01-0.44; P<.001), yielding an estimated incremental vaccine efficacy of 94.1% (95% confidence interval, 55.9%-99.2%; P<.001). Rapid implementation of a mandatory second-dose MCV requirement probably limited the extent of this outbreak.

Large summertime influenza A outbreak among tourists in Alaska and the Yukon Territory.

We investigated a large summertime outbreak of acute respiratory illness during May-September 1998 in Alaska and the Yukon Territory, Canada. Surveillance for acute respiratory illness (ARI), influenza-like illness (ILI), and pneumonia conducted at 31 hospital, clinic, and cruise ship infirmary sites identified 5361 cases of ARI (including 2864 cases of ILI [53%] and 171 cases of pneumonia [3.2%]) occurring primarily in tourists and tourism workers (from 18 and 37 countries, respectively). Influenza A viruses were isolated from 41 of 210 patients with ILI at 8 of 14 land sites and 8 of 17 cruise ship infirmaries. Twenty-two influenza isolates were antigenically characterized, and all were influenza A/Sydney/05/97-like (H3N2) viruses. No other predominant pathogens were identified. We estimated that >33,000 cases of ARI might have occurred during this protracted outbreak, which was attributed primarily to influenza A/Sydney/05/97-like (H3N2) viruses. Modern travel patterns may facilitate similar outbreaks, indicating the need for increased awareness about influenza by health care providers and travelers and the desirability of year-round influenza surveillance in some regions.

Two atypical cases of cystic echinococcosis (Echinococcus granulosus) in Alaska, 1999.

Before 1999, clinical experience demonstrated that the sylvatic (or Northern) biotype of Echinococcus granulosus seen in Alaska produced fewer complications and serious sequelae than infection with the pastoral (or European) biotype found in other parts of the world. Two cases of E. granulosus with severe sequelae occurred in Alaska in 1999. The adverse outcomes could have been rare complications that are part of the clinical spectrum of disease caused by sylvatic cystic echinococcus, an indication that the sylvatic biotype, especially when affecting the liver, has potential for severe clinical consequences, or perhaps in one case, infection with a more virulent biotype of E. granulosus contracted during visits to Washington State.

Use of liver function tests to predict the magnitude of an outbreak of hepatitis A.

The results of liver function tests allowed local and state public health professionals in Alaska to accurately predict the magnitude of an outbreak of hepatitis A.