Conducting population behavioral health surveillance by using automated diagnostic and pharmacy data systems.

INTRODUCTION: The Walter Reed Army Institute of Research used the Electronic Surveillance System for the Early Notification of Community-Based Epidemics (ESSENCE) to conduct population-based behavioral health surveillance among military-health-system beneficiaries. The study analyzed the effectiveness of using prescribing patterns of psychotropic medications to monitor changes in a community's behavioral health status. OBJECTIVES: The objectives of this study were to 1) determine the feasibility of tracking psychiatric illnesses by monitoring prescriptions for psychiatric medications; 2) assess how often psychiatric medications are prescribed for patients with no record of psychiatric illness; 3) determine at what types of clinics these medications are prescribed most often and what other diagnoses are attributed to these patients; and 4) analyze data for potential changes in the population's mental health after high-stress events. METHODS: Correlation analysis and calculations of sensitivity and specificity were used to determine how well prescription medications correlate with outpatient diagnoses and how well they serve as proxies for outpatient diagnoses. A descriptive analysis was conducted of the types of clinics (e.g., primary care, behavioral health, or other specialty clinics) treating patients and the associated percentage of concurrence between prescriptions and diagnostic codes. RESULTS: In military treatment facilities, a diagnosis of depression or anxiety correlated significantly (r = 0.82) with antidepressant or anxiolytic prescriptions. Sensitivity of prescriptions when compared with outpatient visits was 0.76, and specificity was 0.94. Among those patients who visited a primary care clinic either the day before or the same day as an antidepressant or anxiolytic prescription was filled, 60.1% did not receive a diagnosis of any mental health disorder. Behavioral health clinics had the highest correlation between diagnoses and prescriptions; specialty clinics had the lowest. CONCLUSIONS: Behavioral health trends in a population can be monitored by automated analysis of prescribing patterns alone. This method might be a rapid indicator of needed mental health interventions after acute stress-inducing events and be more sensitive than tracking diagnoses alone.

Epidemiology of acute hepatitis in the Stann Creek District of Belize, Central America.

Hepatitis is common in the Stann Creek District of southern Belize. To determine the etiologies, incidence, and potential risk factors for acute jaundice, we conducted active surveillance for cases. Cases of jaundice diagnosed by a physician within the previous 6 weeks were enrolled. Evaluation included a questionnaire and laboratory tests for hepatitis A, B, C, D, and E, a blood film for malaria, and a serologic test for syphilis. Etiologies of jaundice among 62 evaluable patients included acute hepatitis A, 6 (9.7%), acute hepatitis B, 49 (79.0%), hepatitis non-A-E, 2 (3.2%), and malaria, 5 (8.1%). There were no cases of acute hepatitis E. One patient each with antibody to hepatitis C and D were detected. The annualized incidence of hepatitis A was 0.26 per 1,000. All cases of hepatitis A were in children 4-16 years of age. The annualized incidence of hepatitis B, 2.17 per 1,000, was highest in adults aged 15-44 years (4.4 per 1,000) and was higher in men (36 cases; 3.09 per 1,000) than women (13 cases; 1.19 per 1,000). Four (31%) of the women with hepatitis B were pregnant. The annualized incidence was significantly higher in Mestizo (6.18 per 1000) and Maya (6.79 per 1,000) than Garifuna (0.38 per 1,000) or Creole (0.36 per 1,000). Persons with hepatitis B were significantly more likely to be born outside of Belize (82%), had been in Belize < 5 years (73%), and lived and worked in rural areas (96%) than was the general population. Of those > or = 14 years of age with hepatitis B, only 36% were married. Few persons admitted to transfusions, tattoos, IV drug use, multiple sexual partners, visiting prostitutes, or sexually transmitted diseases. Only 1 of 49 had a reactive test for syphilis. Six patients were hospitalized (including 3 with acute hepatitis B and one with hepatitis A), and none to our knowledge died. Acute hepatitis B is the most common cause of viral hepatitis in the Stann Creek District, but the modes of transmission remain obscure. Infants, women attending prenatal clinics, and new workers are potential targets for immunization with hepatitis B vaccine.

Hepatitis B virus, human immunodeficiency virus type-1, and syphilis among women attending prenatal clinics in Belize, Central America.

Women and their infants may benefit from therapeutic interventions when hepatitis B, human immunodeficiency virus (HIV), or syphilis are detected during the prenatal period. We initiated hepatitis B and HIV screening of women attending prenatal clinics in Belize. Risk factor assessment information for hepatitis B infection and demographic data were determined by interview. Of 543 evaluable women, 81 (14.9%) were seropositive for hepatitis B core antibody (anti-HBc); one woman had asymptomatic hepatitis B surface antigenemia. Antibodies to HIV-1 were detected in one woman. Reactive syphilis serologies were detected in 15 (2.8%) women. Anti-HBc seroprevalence varied by district (range 3.1-43.5%) and by ethnicity (range 0.0-40.9%). Significant identified risks for anti-HBc seropositivity from univariate analyses included being of the Garifuna ethnic group, residence or birth in the Stann Creek or Toledo districts, a reactive syphilis serology, a household size of eight or greater, and five or more lifetime sexual partners. Multivariate analyses identified ethnicity and a reactive rapid plasma reagin as the best predictors of anti-HBc seropositivity. Highly variable differences in anti-HBc prevalence by district may permit the targeting of limited public health resources for education, screening, and prevention programs.

PIP: A cross-sectional study of 543 pregnant women attending prenatal clinics in Belize's 6 districts in a 6-week period in 1993 detected highly variable prevalences of hepatitis B virus (HBV) markers. 81 sera specimens (14.9%) were positive for anti-hepatitis B core antigen (anti-HBc); one woman had asymptomatic hepatitis B surface antigenemia. No HBV markers were detected in the sera of the 1 woman with human immunodeficiency virus (HIV)-1 infection. 15 women (2.8%) had reactive syphilis serologies. Serologic evidence of exposure to HBV was significantly associated with the following sociodemographic factors: single status, age 30-34 years, household size exceeding 8, 5 or more lifetime sexual partners, geographic location (residence in the Stann Creek or Toledo districts), and ethnicity (Garifuna, Creole, and Mayan). In the multivariate analysis, ethnicity and a reactive syphilis result were the only independent predictors of anti-HBc seroprevalence. Anti-HBc seroprevalence varied by district from 3.1-43.5%, with the highest rate in Stann Creek, and by ethnicity from 0 to 40.9%, with the highest rate among the Garifuna. Prevalences were substantially lower among Mestizo-Spanish from the northern and western districts of Orange Walk, Corozal, and Cayo. The overall low prevalence of HBsAg does not support a nationwide prenatal screening program, especially given limited public health care resources. However, this study's findings suggest the feasibility of HBV screening of pregnant women among the Garifuna, Creole, Mayan, and immigrant populations of Belize's Stann Creek and Toledo districts.

Seroprevalence of hepatitis B virus among school-age children in the Stann Creek District of Belize, Central America.

Adults in the Stann Creek District of Belize have a high prevalence of hepatitis B virus (HBV) infection, but the age of onset of these infections is unclear. We conducted a seroprevalence study of hepatitis B markers among Stann Creek school-age children to provide information for planning a hepatitis B vaccine program. The overall prevalence in 587 students was high for antibody to hepatitis B core antigen (anti-HBc) (43.3%) and hepatitis B surface antigen (HBsAg) (7.7%). There was marked variation of anti-HBc by school and by the predominant ethnic groups attending those schools. Maya had the highest prevalence (76%), followed by Mestizo (50%), Garifuna (37%), and Creole (25%). Children less than nine years of age attending the rural primary schools (mostly Mayan and Mestizo) had significantly higher prevalence of anti-HBc than did children attending the urban primary school (mostly Garifuna and Creole) (P < 0.05). Anti-HBc was found in 42% and 36% of students at the two high schools. Of the five schools tested, only at the urban primary school did anti-HBc positivity increase with age. Based on an analysis of the cost of serologic screening before immunization compared with mass vaccination, preimmunization serologic screening resulted in vaccine program cost savings in four of the five schools. Because most children in the rural areas contract hepatitis B before entering school, immunization against HBV should be integrated into the routine infant immunization program.

Characterization of Anopheles darlingi (Diptera: Culicidae) larval habitats in Belize, Central America.

Surveys for larvae of Anopheles darlingi Root were conducted in April, May, and August 1994 in riverine habitats of central Belize (Cayo and Belize districts). An. darlingi was present during both the dry and wet seasons. Larvae were encountered most frequently in patches of floating debris along river margins. The floating mats were often formed by bamboo hanging over the banks and dense submersed bamboo roots. Larvae were found less frequently in lake margins, small lagoons, and ground pools with submersed roots and patches of floating leaves or vegetation. In addition to their association with floating debris, larvae of An. darlingi were associated positively with shade and submersed plants in riverine environments. Samples from river habitats showed the larvae of Anopheles albimanus Wiedemann to be strongly associated with sun-exposed sites containing green or blue-green algae. Unlike An. darlingi, An. albimanus was an ubiquitous mosquito, the immatures of which occurred in a wide variety of riverine and nonriverine aquatic habitats. Based on published reports and our experience, the association of An. darlingi with river systems was verified, and its distribution in Central America and Mexico was mapped.

Prevalence of hepatitis B virus among health care workers in Belize, Central America.

A seroprevalence survey of hepatitis B virus (HBV) markers was conducted among health care workers in Belize to help determine the epidemiology of hepatitis B and to determine if screening before immunization might lower vaccine costs. Of the 330 workers tested, 94 (29%) were positive for antibody to HBV core antigen (anti-HBc) and three (1%) had HBV surface antigen. The presence of anti-HBc increased significantly with age from 12% in those 18-24 years old to 52% in those > or = 50 years old. The rate was 17% of 48 men compared with 30% of 282 women (P = 0.05). Rates increased with years of medical service and were higher among nurses (69 of 228; 30%) and nonprofessional staff (15 of 44; 34%) than among physicians (0 of 20). The presence of anti-HBc also differed significantly among ethnic groups: Mestizo, 4%; Creole, 33% and Garifuna, 57%. Rates differed by district ranging from 3% in a northern district (mostly Mestizo) to 67% in a southern district (mostly Garifuna). Parental exposure to hepatitis B through needle stick injuries and blood transfusions was not associated with anti-HBc. Multiple logistic regression analysis confirmed ethnicity, district of residence, and age as the best predictors of anti-HBc in health care workers. Cost analysis suggests that because of regional differences in exposure, testing of health care workers for anti-HBc in the Belize and Stann Creek districts in southern Belize before hepatitis B immunization would result in vaccine program cost savings.

Randomized comparison of 5 and 10 microgram doses of two recombinant hepatitis B vaccines.

UNLABELLED: The high cost of hepatitis B vaccines remains an obstacle to their use. Since the recommended adult dose of Recombivax HB (MSD) is 10 micrograms and that of Engerix B (SKB) is 20 micrograms, we sought to determine if 10 microgram doses of each vaccine are equally immunogenic. Further, since 5 microgram doses of Recombivax are routinely used in those < or = 29 years of age in the US military, we sought to compare this dose with 5 microgram doses of Engerix B. Lower doses of Engerix would result in vaccine cost savings. METHODS: members of the Belize Defence Force who were > or = 18 years of age (median 24) without detectable anti-HBc were randomly assigned to receive Recombivax, 5 or 10 micrograms, or ENgerix, 5 or 10 micrograms IM at 0, 1, and 6 months. Randomization was weighted toward Engerix. RESULTS: after 3 doses, geometric mean concentrations (GMC) of anti-HBs were highest among those receiving Recombivax 10 micrograms (n=22) or 5 micrograms (n=46) with GMC anti-HBs of 744 and 570 mIU ml-1, respectively. Similar proportions in the two groups developed > or = 10 mIU m-1 anti-HBs (100 and 98%). Among the 91 people who received Engerix 10 micrograms, the GMC anti-HBs was 325 mIU ml-1 and 91% developed > or = 10 mIU ml-1. The 87 people who received Engerix 5 micrograms had the lowest GMC, 177 mIU ml-1 (p < 0.05 compared with either Recombivax group). Only 86% attained > or = 10 mIU ml-1 anti-HBs (p > 0.05 compared with other regimens). The proportion attaining > or = 100 mIU ml-1 was lower in the 5 microgram Engerix group (63%) compared with 80% in the 5 microgram or 95% in the 10 microgram Recombivax groups (p < 0.05). CONCLUSIONS: Engerix administered in 5 microgram doses is less immunogenic than 5 or 10 microgram doses of Recombivax. In healthy populations < 30 years of age, regimens of half the recommended adult dose (5 micrograms of Recombivax or 10 micrograms of Engerix) are highly immunogenic and may result in significant vaccine cost savings.

The prevalence of hepatitis A, B and C infection among different ethnic groups in Belize.

Little is known about the prevalence of infection with hepatitis viruses in Belize, Central America. We conducted a serologic survey among members of the Belize Defence Force (BDF), which is composed of the five major ethnic groups in Belize, to estimate prevalence rates of hepatitis A, B, and C among military-aged men and women in Belize. Of approximately 600 men and women in the BDF, 492 (82%) completed a questionnaire and blood collection. Antibody to hepatitis A was found in 94%, with similar rates by age, sex, rank, and ethnicity. Antibody to hepatitis B core antigen (anti-HBc) was found in 31%. Rates of anti-HBc varied significantly among the ethnic groups with the lowest rates in Mestizo (5%) and Mayan Indians (9%), and significantly higher rates among Creoles (30%) and Garifuna (56%). Rates increased with increasing age from 28% in those 18-24 years old to 35% in those > or = 35 years old (P = 0.07, by chi-square test for trend). Hepatitis B surface antigen was found in 21 (4%) overall. Antibody to hepatitis C was found in two (0.4%). In this young healthy population, exposure to hepatitis A before the age of 18 is almost universal, while exposure to hepatitis B is related to age and ethnic origin.