Published Version

All known Rift Valley fever virus outbreaks in East Africa from 1950 to May 1998, and probably earlier, followed periods of abnormally high rainfall. Analysis of this record and Pacific and Indian Ocean sea surface temperature anomalies, coupled with satellite normalized difference vegetation index data, shows that prediction of Rift Valley fever outbreaks may be made up to 5 months in advance of outbreaks in East Africa. Concurrent near-real-time monitoring with satellite normalized difference vegetation data may identify actual affected areas.

Hepatitis A virus infection is often described as mild or asymptomatic, particularly in children. The failure of most adults who are found to be immune to remember symptoms of an illness suggestive of hepatitis A virus supports this belief. In 1982, two large outbreaks occurred in well documented populations of military personnel. These outbreaks were each extensively studied epidemiologically and serologically. It was found that 28/29 (96.6%) hepatitis A infections recognized prior to immune serum globulin in Outbreak A and 35/46 (76.1%) infections in Outbreak A were symptomatic. Symptomatic cases failed to occur beyond eight days of immune serum globulin administration to these predominantly susceptible groups. Between 40 and 70% of patients were icteric. Apparent contrasts in symptoms associated with hepatitis A infection in adults and children suggest a basic age-dependent difference in immune response to such infection.

No abstract

The 1996 production halt of adenovirus types 4 and 7 vaccines prompted concerns about the resurgence of large respiratory disease outbreaks among US military basic trainees. This serosurvey was conducted to assess the current susceptibility of the trainee population to these viruses. A stratified, random sample (n=303) of trainees' sera was tested using a quantitative colorimetric microneutralization assay to demonstrate antibody titers considered to provide immunologic protection against each adenovirus type. Results were analyzed for relationships between susceptibility and 4 demographic factors-gender, race, prior military service, and age. Results showed that 66% and 73% of trainees were susceptible to serotypes 4 and 7, respectively. Nearly 90% were susceptible to at least one serotype. Susceptibility was significantly (P<.05) related to lack of prior military service and younger age. Consistent with a serosurvey conducted 20 years ago, these results demonstrated significant susceptibility to two vaccine-preventable causes of disease. These findings may have civilian implications.