Monitoring Environmental Disease—United States, 1997 FREE

MMWR. 1998;47:522-525

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ONE OF the national health objectives for 2000 (HP2000) is to establish and monitor nonoccupational "sentinel" environmental diseases, including asthma, heatstroke, hypothermia, heavy metal poisoning, pesticide poisoning, carbon monoxide poisoning, acute chemical poisoning, and methemoglobinemia, in at least 35 states (baseline: 0 states in 1990) (objective 11.16).¹ To assess progress toward this objective, the Council of State and Territorial Epidemiologists (CSTE), the Association of Schools of Public Health, and CDC conducted a telephone survey of environmental epidemiologists in each of the 50 states, the District of Columbia, and Puerto Rico during June-August 1997. This report summarizes the results of that survey, which indicate that progress is being made toward the HP2000 objective.

Approximately 2-3 weeks before the telephone survey was conducted, a questionnaire on environmental disease surveillance systems in each jurisdiction was sent to the epidemiologist responsible for environmental health to allow time for gathering of information. The questionnaire inquired about each jurisdiction's surveillance activities, sources of surveillance data, funding, and goals. Each jurisdiction was asked to describe its surveillance activities from among the following: data collection only; data collection and review; or data collection, review, and case investigation. No additional definitions were provided, and interpretation of the three classifications was left to the respondent.

Responses were obtained from all 52 environmental epidemiologists. The telephone survey identified 174 environmental public health surveillance systems from 51 jurisdictions. The mean number of systems per jurisdiction was three; the median was two (range: zero to 12). Of the 174, a total of 79 (45%) systems monitored lead exposure, with most systems monitoring childhood blood lead levels (BLLs) (51 [65%] of 79). The remaining 28 systems monitored nonoccupational adult lead exposures. The environmental diseases least frequently monitored were heatstroke and hypothermia (four systems each). One jurisdiction (Missouri) had surveillance systems for all 12 of the environmental public health conditions covered by the survey. One jurisdiction did not have any surveillance systems.

Using the description for each disease monitoring system described in this report, 15 (9%) of the surveillance systems collected data only, 46 (27%) collected data and conducted reviews, and 110 (64%) collected data and conducted both reviews and case investigations. Asthma was the only condition for which no systems conducted case investigations.

Data about environmental disease surveillance were collected from numerous sources. Of the 79 lead exposure surveillance systems, 76 (96%) provided information about primary source of data. Of these, 71 (93%) used laboratory data as the primary source of information. Laboratory reporting was mandatory in jurisdictions covered by 65 (86%) of 76 systems. Data about BLLs were gathered electronically by 35 (46%) systems. Five lead surveillance systems used electronic reporting exclusively.

Of the remaining 95 nonlead environmental disease surveillance systems, three did not provide information about primary source of data. The sources of data for the other 92 systems included laboratories (37 [40%]), clinicians (19 [21%]), hospitals (14 [15%]), poison-control centers (seven [8%]), and other sources (15 [16%]). Laboratory reporting was mandatory in the jurisdictions covered by 27 (72%) of 37 systems gathering data from laboratories, and reporting by clinicians was mandatory in 15 (79%) of the 19 systems gathering data from clinicians. No nonlead surveillance systems received information electronically.

Thirty-six (71%) of 51 childhood lead monitoring systems and 14 (50%) of 28 adult lead monitoring systems were either entirely or largely dependent on federal funds for their operation. Twenty-one (23%) of 95 nonlead environmental disease monitoring systems received any federal funding.

P Zeitz, Rollins School of Public Health, Emory Univ; H Anderson, III, MD, B Hughes, PhD, Council of State and Territorial Epidemiologists, Atlanta, Georgia. Surveillance and Programs Br, Div of Environmental Hazards and Health Effects, National Center for Environmental Health; and an EIS Officer, CDC.

The findings in this report indicate that childhood lead poisoning was the only "sentinel environmental disease" for which HP2000 objective 11.16 has been achieved.¹ Although not every system met the requirement to be identified as a surveillance system (ongoing collection, analysis, and use of health data), most of the childhood lead monitoring systems collected, reviewed, and took appropriate action based on the data.

The findings in this report are subject to at least two limitations. First, jurisdiction-based surveillance systems can have different case definitions. For example, although CDC recommends using BLLs ≥10 µg/dL to identify children with elevated BLLs, some jurisdictions used higher values. Jurisdiction-specific case definitions may be necessary because of limited resources and other considerations. CDC, in collaboration with other agencies and organizations, is developing definitions for several environmental diseases such as carbon monoxide poisoning and asthma. Using a standard case definition may allow data from numerous jurisdictions to be more easily summarized and compared. However, each jurisdiction will base its environmental health priorities on its own needs and available resources. Second, >90% of the systems identified in the 1997 survey reviewed the data collected, and in most cases implemented activities based on the data. This survey did not collect information about the frequency or extent of data review or of follow-up activities. Usefulness of routinely collected environmental disease data depends on timely analysis of the data followed by dissemination of information to persons who "need to know," such as policy makers and program managers.^2- 7

Surveillance systems should be simple, sensitive, representative, and timely to be most effective in controlling and preventing disease.⁸ Surveillance systems at the local, state, and national levels are useful for assessing case investigations, implementing control activities, evaluating interventions, monitoring trends, and identifying risk factors. A comprehensive integrated public health surveillance system that combines local, state, and national surveillance activities can best achieve the primary goal of public health surveillance, namely a reduction in disease morbidity and mortality.³ Progress toward the HP2000 objective is evident from the results of this survey. Adequate resources and increased public awareness about the value of surveillance systems in preventing and controlling disease are necessary to fully achieve the objective.²

MMWR. 1998;47:526-528

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THE DISSOLUTION of the Former Soviet Union (FSU) has resulted in the disruption of the health infrastructure in many of the republics, as indicated in part by increases in infectious diseases that were previously controlled (e.g., diphtheria, typhoid, and hepatitis A). In 1994, the Ministry of Health (MOH) of Armenia (1995 population: 3.5 million) detected the first locally acquired case of malaria since the 1940s; the number of imported cases (15) was approximately twice the annual average during 1986-1989 (seven). In 1995, although no locally acquired cases were reported, the number of imported cases increased to 502. In 1996 and 1997, the total (locally acquired and imported) number of reported cases of malaria was 347 and 841, respectively. This report summarizes surveillance for malaria in Armenia during 1996-1997.

Cases were initially identified based on clinical suspicion; confirmation was based on microscopic examination of blood smears by the national laboratory. All cases were caused by Plasmodium vivax. Local clinics and hospitals gathered data and reported this information to the regional public health offices, which in turn reported to the national level.

From 1996 to 1997, the incidence rate (IR) for all reported cases of malaria increased from nine to 22 per 100,000 population. Locally acquired cases accounted for 567 (67%) of the 841 cases reported in 1997. Although 30 (37%) of 81 districts recorded malaria cases, seven (9%) reported locally acquired infections. In 1997, the Masis district registered 527 (63%) of the total and 505 (89%) of the locally acquired cases (IR=592 and 567 cases per 100,000 population, respectively). The seasonal peak for locally acquired cases occurred in September (132 [23%]); 416 (73%) cases were reported during July-October.

To identify possible vectors, the MOH took a convenience sample of mosquitos using standard trapping techniques. Anopheles maculipennis was identified as the most common vector species captured (98%).

V Davidiants, MD, National Information and Analytic Center; M Mannrikian, MD, Sanitary Epidemiologic Svcs; G Sayadian, MD, Health Care System; A Parunakian, MD, Republican Sanitary and Epidemiologic Svc; B Davtian, MD, Ararat Regional Health Dept, Ministry of Health, Armenia. World Health Organization, European Region, Copenhagen. Capacity Development Br, Div of International Health, Epidemiology Program Office; Malaria Section, Epidemiology Br, Div of Parasitic Diseases, National Center for Infectious Diseases; and an EIS Officer, CDC.

The World Health Organization (WHO) estimates that malaria causes 300 to 500 million illness episodes and 1.5 to 2.7 million deaths worldwide each year.¹ From 1945 to 1986, FSU-wide malaria eradication efforts (including mosquito vector control, case detection and treatment, and chemoprophylaxis) curtailed transmission in Armenia, one of the 15 Newly Independent States of the FSU. During 1988-1995, severe financial constraints and the war with Azerbaijan contributed to cessation of vector-control activities in Armenia (which had included the use of mosquito-larvivorous fish [Gambusia affinis], insecticide spraying, and the reduction of mosquito breeding sites). These circumstances, combined with an eroding health infrastructure, may have hindered new malaria cases from being diagnosed, treated, and reported properly during this period. Displaced persons returning from the war with Azerbaijan during the cease-fire accounted for many of the imported cases in 1995; the resurgence of locally transmitted malaria probably resulted from persons with imported cases transmitting infection to the increased density of vectors.

In December 1992, the MOH and CDC, with the support of the U.S. Agency for International Development, began restructuring the health information systems (HIS) in Armenia. The reform began with the development of an emergency surveillance system designed to detect acute health risks.^2,3 By 1996, through additional training and technical support, the MOH adopted a countrywide, comprehensive, and sustainable HIS reform program.* The prompt detection of this malaria epidemic highlights the success of this Armenian HIS reform.

The magnitude of the increase in malaria may be underestimated because surveillance relied on clinical suspicion. Because few cases were seen until recently, physicians may not have suspected malaria and submitted blood smears for laboratory confirmation.

The next steps for malaria control and prevention in Armenia should focus on surveillance, clinical practice, public education, and environmental control. Enhanced surveillance will include (1) initiating active, case-based surveillance; (2) establishing a regional surveillance network because malaria is endemic in neighboring countries; and (3) conducting epidemiologic and entomologic studies to characterize the affected population, determine risk factors for acquisition and transmission, and target interventions. Improving clinical practice will require continuing medical education for physicians in the early diagnosis and treatment of malaria and improved microscopic diagnostic capabilities for rapid and accurate diagnosis. Such capabilities will be essential if P. falciparum malaria emerges, because treatment recommendations depend on the species detected. Community health education about recognizing malaria symptoms should be provided. Vector control should be conducted in the Masis district, especially during the peak transmission season (July to October). Efforts led by WHO are under way to institute some of these control measures during the next malaria season; additional control measures may be taken if resources become available.

References 3 available.

*Armenian Prikaz (administrative directive) no. 550, July 30, 1996.