January 9, 199/8 Vo l. 46 / Nos. 52 & 53 ENTFORE ONMERARE SCONT RA 1245 Update: Isolation of Avian Influenza - A(H5N1) Viruses from Humans — Hong Kong, 1997-1998 1247 Rubella Among Crew Members of Commercial Cruise Ships 1250 Enhanced Medical Assessment Strategy for Barawan Somali Refugees — Kenya, 1997 1254 Evaluation of HIV Case Surveillance Through the Use of Non-Name MORBIDITY AND MORTALITY WEEKLY REPORT Unique Identifiers — Maryland and Texas, 1994-1996 Update: Isolation of Avian Influenza A(H5N1) Viruses from Humans — Hong Kong, 1997-1998 As of January 6, 1998, a total of 16 confirmed and three suspected cases of human infection with avian influenza A(H5N1) viruses have been identified in Hong Kong. Confirmed cases are those from which an influenza A(H5N1) virus was isolated or in which a seroconversion to influenza A(H5N1) virus was detected by a neutralization assay. Suspected cases are those with influenza-like illness (ILI) and preliminary labo- ratory evidence of influenza A(H5N1) infection. This report summarizes interim find- ings from the ongoing epidemiologic and laboratory investigation of influenza A(H5N1) cases by health officials in Hong Kong and by CDC. The first known case of human infection with influenza A(H5N1) occurred in a 3- year-old boy who died from respiratory failure in May 1997 (7). Of the 15 remaining confirmed cases, five persons had onset of illness in November and 10 in December; all three persons with suspected cases had onset during December. No cases have been identified with onset after December 28, 1997. Ages of persons with confirmed cases ranged from 1 to 60 years (mean age: 17 years) and, for persons with suspected cases, from 3 to 7 years (mean age: 5 years). Nine (47%) cases occurred among per- sons aged <5 years. Four persons with confirmed cases have died, and three remain in critical condition. Testing has been completed of serum samples collected in August as a part of the epidemiologic investigation of the first case of human influenza A(H5N1) infection. Serum samples were obtained from 502 persons who may have had contact with the child or with poultry, including family members, persons who lived in the same neigh- borhood, children and staff of the child-care center the child attended, health-care workers, poultry workers, and persons working on pig farms. Samples of contro! se- rum specimens were obtained from 218 healthy children and 201 healthy adult resi- dents of Hong Kong. These samples were tested for antibody to influenza A(H5N1) virus using a micro-neutralization assay. Of the 502 persons tested who may have had contact with the child or with poultry, elevated neutralization antibody titers to influ- enza A(H5N1) virus were present in nine (2%). These persons included five (17%) of 29 poultry workers, one (2%) of 54 health-care workers, one (2%) of 63 neighbors, one (1%) of 73 laboratory workers, and one (0.4%) of 261 child-care center contacts. Speci- mens were negative for the four family members, 18 persons working on pig farms, and the 419 controls. Seropositivity was not associated with reported ILI. U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES 1246 January 9, 1998 Avian Influenza A Virus — Continued Antigenic and genetic analyses of viral isolates from seven case-patients indicated two closely related but distinguishable groups of influenza A(H5N1) viruses, suggest- ing multiple introductions in humans from poultry sources. All seven of the influenza A(H5N1) viruses analyzed from human cases contained all eight RNA gene segments from avian viruses, indicating that genetic reassortment between avian and human influenza viruses has not occurred. Reported by: TA Saw, FHKAM (Community Medicine), Hong Kong Dept of Health; W Lim, FRCP Virus Unit, Hong Kong Dept of Health; K Shortridge, PhD, The Univ of Hong Kong; J Tam, PhD, Chinese Univ of Hong Kong; KK Liu, DRVS, Dept of Agriculture and Fisheries; KH Mak, FHKAM (Community Medicine); T Tsang, MPH, TK Au, MPH, YY Ho, MSC, TY Lee, MBBS, H Kwong, MMED (Public Health), Hong Kong Dept of Health. Prince of Wales Hospital; Princess Margaret Hospital; Queen Elizabeth Hospital; Queen Mary Hospital; Tuen Mun Hospital; United Christian Hospital; Yan Chai Hospital, Hong Kong. RG Webster, PhD, St. Jude Children’s Research Hospi- tal, Memphis, Tennessee. World Health Organization, Geneva, Switzerland. Influenza Br, Div of Viral and Rickettsial Diseases, National Center for Infectious Diseases, CDC. Editorial Note: The cases reported in Hong Kong represent the first identified in- stances of human illness associated with infection with influenza A(H5N1) viruses. Goals of the ongoing investigation are to detect new cases, determine sources of in- fection and mode(s) of transmission, and identify risk factors for influenza A(H5N1) infection. Except for a cluster of two confirmed and two suspected cases in one family, case-patients are not known to have had contact with each other or a common source of exposure and are geographically distributed throughout Hong Kong. All cases of infection have occurred among residents of Hong Kong, and no cases of infection with influenza A(H5N1) viruses have been identified among persons residing outside Hong Kong. The serologic data obtained as part of the epidemiologic study of the initial case support the preliminary conclusion that persons with high levels of exposure to in- fected poultry or direct exposure to the virus in the laboratory may be at increased risk for infection with influenza A(H5N1) virus. However, the investigation has not ruled out the possibility of person-to-person transmission from exposure to ill and infec- tious persons: two seropositive persons who had contact with the first case-patient included a child-care center classmate and a health-care worker, and the classmate had contact with both the ill child and the same potential environmental source of exposure to ill chickens at the school as the ill child. However, the health-care worker reported no history of exposure to the virus in the laboratory or any recent exposure to poultry, and a history of exposure to the child or to poultry was unknown for a seropositive elderly neighbor. On the basis of the overall low rates of infection among contacts and controls and the lack of seropositivity among family members, at this time, the virus probably is not being efficiently transmitted among humans. Global surveillance for influenza viruses is critical to monitor the circulation of dif- ferent strains and indicates that human influenza type A(H3N2), type A(H1N1), and type B viruses continue to circulate worldwide. Data from the Hong Kong Department of Health’s influenza surveillance system indicate that the number of cases of ILI in Hong Kong is at normal levels for this period; however, during December, the number of human influenza viruses isolated increased. During December, influenza A(H3N2) was the most commonly isolated influenza strain in Hong Kong, although influenza A(H1N1) and B viruses also were identified. The currently available inactivated triva- lent influenza vaccine contains influenza A(H1N1), A(H3N2), and B strains repre- Vol. 46 / Nos. 52 & 53 MMWR Avian Influenza A Virus — Continued sentative of those currently circulating among humans and is recommended for per- sons at increased risk for influenza-related complications (2). Information about influenza A(H5N1) activity in Hong Kong and the United States and international influenza surveillance data are available through CDC's Influenza Branch, Division of Viral and Rickettsial Diseases, National Center for Infectious Dis- eases, World-Wide Web site http://www.cdc.gov/ncidod/diseases/flu/fluvirus.htm. References 1. CDC. Isolation of avian influenza A(H5N1) viruses from humans—Hong Kong, May-December 1997. MMWR 1997;46:1204-7. 2. CDC. Prevention and control of influenza: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR 1997;46(no. RR-9). Rubella Among Crew Members of Commercial Cruise Ships — Florida, 1997 During April-July 1997, two different commercial cruse lines notified CDC of ru- bella outbreaks among crew members. In July 1997, CDC initiated an investigation on one cruise ship to determine the extent of and risk factors for rubella infection among crew members and to assess the potential risk for rubella transmission to passen- gers—particularly rubella-susceptible pregnant women at risk for giving birth to an infant with congenital rubella syndrome (CRS). This report summarizes rubella out- breaks involving two cruise ships and the results of the CDC investigation on one cruise ship, which demonstrate that crew members can serve as a susceptible popu- lation for rubella infection and should be vaccinated with measles-mumps-rubella vaccine (MMR) if they are not immune. Although the outbreaks were limited to crew members, cruise ship travel provides an environment conducive to the potential spread of rubella and other infectious diseases among crew and passengers; there- fore, women of childbearing age, particularly pregnant women, should be immune to rubella before traveling on cruise ships to reduce the risks for rubella infection and CRS. Cruise Ship A On April 7, cruise line A notified CDC about a rash illness in a crew member aboard one of the ships in its fleet. The cruise ship sailed twice a week from Florida on 3-day cruises to the Bahamas, carrying approximately 900 crew members and 2000 passen- gers per cruise. During May and June, rash illnesses were reported in six additional crew members; five of the seven cases were confirmed serologically (by immuno- globulin [lg] M antibodies) as acute rubella infection. A survey of the crew members conducted by the cruise line indicated that a substantial proportion had no documen- tation of rubella vaccination and that at least 95% were not U.S.-born. Because of evi- dence of ongoing transmission of rubella among crew members (many of whom were natives of countries without rubella vaccination programs) and the potential for trans- mission to female crew members and passengers of childbearing age, CDC advised the cruise line to initiate a vaccination campaign with MMR during June. Serologic susceptibility testing was recommended for all crew members ineligible for vaccina- tion, including pregnant women. Cruise line staff and state and local health depart- 1248 January 9, 1998 Rubella — Continued ment personnel vaccinated 865 (96%) of the approximately 900 crew members who had no documented rubella vaccination or immunity. Following the vaccination cam- paign, one additional rash illness was reported in a crew member and subsequently was serologically confirmed to be consistent with acute rubella infection. This crew member had received MMR <2 weeks before the onset of rash. Cruise Ship B On July 25, cruise line B notified CDC about a cluster of rash illnesses among crew members of one of its cruise ships sailing between Florida and the Bahamas. The cruise ship sailed daily from Florida with a crew of 385 and carried approximately 8400 passengers per week. CDC initiated an investigation in July to determine the ex- tent of the outbreak and risk factors for rubella infection among crew members and to assess the potential risk for rubella transmission to passengers, particularly rubella- susceptible pregnant women at risk for serious adverse health outcomes (including CRS). The investigation included review of the ship’s medical logs and interviews and examinations of the 385 crew members. Because approximately 25%-50% of rubella infections are asymptomatic (7), a serosurvey of rubella IgM and IgG antibodies was conducted among 366 consenting crew members. A confirmed case was defined as IgM serology consistent with rubella infection, or signs and symptoms meeting the clinical case definition for rubella and linked epidemiologically to a laboratory- confirmed case with onset during May 30—-August 2. Rubella was confirmed in 16 (4%) crew members; all confirmed cases had IgM serology consistent with rubella infec tion. Of 16 crew members with IgM-confirmed cases, eight (50%) had no symptoms of infection. An additional 25 (7%) of the 366 crew members surveyed were susceptible to rubella at the time of the serosurvey. The crew interviews indicated that approxi- mately 85% of the crew members were not U.S.-born (representing at least 50 coun- tries), and 75% had negative or unknown rubella vaccination histories. Crew members living aboard the ship were more likely to have confirmed rubella than were crew members living ashore (16 of 288 versus zero of 78; relative risk=9.0 [Woolf's esti- mate], p=0.03). To determine demographic characteristics of passengers on cruise ship B and iden- tify pregnant women who, if susceptible to rubella, could be at risk for giving birth to infants with CRS, a questionnaire was administered to passengers sailing on cruises during August 4-8. All passengers (approximately 6000) received a health alert about the rubella outbreak before boarding the ship; 3643 (61%) passengers completed the questionnaire. Among the respondents, approximately 75% of passengers were U.S.- born, 12% were born in the Bahamas, and 13% were born in other countries. A total of 1213 (33%) of the 3643 respondents were women of childbearing age (i.e., 15-44 years); 28 (0.8%) of all respondents were pregnant women, of whom 14 (50%) re- ported being in the first trimester. Although the rubella immune status of these preg- nant passengers was not determined, previous serosurveys in the U.S. population suggest that approximately 10% of women of childbearing age may be susceptible to rubella, and up to 85% of susceptible pregnant women who are infected during their first trimester may give birth to an infant with CRS (2). Reported by: H Heshmati, MD, J Moini, MD, C Krugg, Brevard County Health Dept, Merritt Island; M McMiilan, C Castro, J Griffiths, Broward County Health Dept, Fort Lauderdale; HT Janowski, MPH, Florida Dept of Health. Vessel Sanitation Program, Special Programs Group, Vol. 46 / Nos. 52 & 53 MMWR 1249 Rubella — Continued National Center for Environmental Health; Child Vaccine Preventable Disease Br, Epidemiology and Surveillance Div, National Immunization Program; Miami Quarantine Station, Program Operations Br and Surveillance and Epidemiology Br, Div of Quarantine, National Center for Infectious Diseases, CDC. Editorial Note: Although rubella is typically a mild, self-limited disease in adults, infec- ticn in pregnant women can result in serious adverse health outcomes for the fetus, including CRS, a group of birth defects including deafness, cataracts, heart defects, and mental retardation. In the United States, approximately 10% of young adults are susceptible to rubella; in other countries, some without routine vaccination policies for rubella, susceptibility rates for rubella range from 4% to 68% (3). During 1994- 1996, 12 laboratory-confirmed cases of CRS were reported in the United States (4). Although a definitive quantitation of the risk for transmission of rubella among crew members and passengers on the cruise ships could not be ascertained, risk for infection among those crew members of cruise ship B could be estimated. Results of the serosurvey among crew members indicate that at least 41 (11%) of 366 were acutely infected with or susceptible to rubella at the time of the serosurvey. This sero- survey was conducted after recognition of an ongoing outbreak of rash illnesses among crew members, and it is likely that rubella susceptibility rates at the outset of the outbreak would have been higher. The risk for transmission of infection and an outcome of CRS in pregnant passen- gers in their first trimester of pregnancy on cruise ship B was difficult to determine because 1) the rubella immune status of these pregnant passengers was unknown and 2) the consequences of rubella infection in susceptible pregnant women (i.e., CRS) may not be evident for several months after the exposure. If pregnant passen- gers were exposed, and assuming that approximately 10% of these women were sus- ceptible to rubella and 85% of susceptible pregnant women who are infected during their first trimester will give birth to an infant with CRS, one case of CRS could poten- tially occur each week among passengers sailing during the outbreak. Minimizing or eliminating the risk for rubella exposure among susceptible preg- nant women is important because of the potential for serious adverse health out- comes for the fetus. To interrupt transmission of rubella among crew members and to prevent transmission of infection and CRS among susceptible pregnant women, CDC recommended administration of MMR to all crew members lacking documented im- munity to rubella; serologic testing to determine susceptibility to rubella for all crew members ineligible for vaccination, including pregnant women; active surveillance aboard the ship to detect new rubella infections; prospective notification of the poten- tial risk for rubella exposure to all embarking passengers until 30 days after the last confirmed rubella infection; and retrospective notification to all passengers sailing during the period of potential rubella transmission. These recommendations were ef- fective in interrupting rubella transmission among crew members on cruise ship B: no additional rash ilinesses were identified after their implementation. This report of two clusters of rubella infections on commercial cruise ships demon- strates that crew members—many from ccuntries without routine rubella vaccination programs—are potential groups of susceptible persons at risk for rubella infection. To prevent future rubella outbreaks among such persons, CDC recommends that cruise lines administer MMR to all crew members without documented immunity to rubella. Although reported rubella cases in these two outbreaks were limited to crew mem- 1250 MMWR January 9, 1998 Rubella — Continued bers, cruise ship travel provides a semi-closed environment for crew and passenger interactions, conducive to the potential spread of rubella and many other infectious diseases among crew and passengers. To prevent transmission of rubella infection and subsequent CRS, women of childbearing age, particularly pregnant women, should be immune to rubella before cruise ship excursions or international travel. The outbreaks described in this report illustrate the potential for transmission of infectious disease among persons traveling across international borders, including aboard commercial cruise ships. Previous infectious disease outbreaks reported among crew members and passengers have included diarrheal diseases and other vaccine-preventable diseases such as influenza (5). Approximately 4 million persons travel aboard North American cruise ships each year (CDC, unpublished data, 1998). Ensuring routinely recommended adult vaccinations for all crew members will sub- stantially decrease the potential for future outbreaks of vaccine-preventable illnesses aboard cruise ships. All suspected cases of rubella and other notifiable vaccine- preventable diseases should be reported to the nearest state and local health depart- ment. State health departments should report all suspected cases of rubella to CDC’s Child Vaccine-Preventable Disease Branch, Epidemiology and Surveillance Division, National Immunization Program, telephone (404) 639-8230. References . American Academy of Pediatrics. 1997 Red book: report of the Committee on Infectious Dis- eases. 24th ed. Elk Grove Village, Illinois: American Academy of Pediatrics, 1997. . Miller E, Cradock-Watson JE, Pollock TM. Consequences of confirmed maternal rubella at successive stages of pregnancy. Lancet 1982;2:781-4. . Cutts FT, Robertson SE, Diaz-Ortega JL, Samuel R. Control of rubella and congenital rubella syndrome (CRS) in developing countries, part 1: burden of disease from CRS. Bull World Health Organ 1997;75:55-68. . CDC. Rubella and congenital rubella syndrome—United States, 1994-1997. MMWR 1997; 46:350-4. . CDC. Update: influenza activity—United States, 1997-98 season. MMWR 1997;46:1094-98. Enhanced Medical Assessment Strategy for Barawan Somali Refugees — Kenya, 1997 Each year, approximately 100,000 refugees are resettled to the United States. Be- fore resettlement, these refugees undergo medical screening to identify inadmissible conditions (e.g., infectious tuberculosis and human immunodeficiency virus [HIV] in- fection) among individual refugees. This report describes the implementation and re- sults of an enhanced refugee medical assessment strategy among Barawan Somali refugees in Kenya during July 1997. This strategy employs population-based screen- ing for parasitic infections. The findings indicate that, among these refugees, the prevalences of malaria and intestinal parasites were sufficient to warrant pre- embarkation therapy to improve the health of both individuals and the total refugee population. This therapy also may prevent local transmission of parasitic infections in the resettlement communities in the United States. In May 1997, resettlement began for approximately 4000 Barawan Somali refugees encamped since 1992 near Mombasa, Kenya. In 1993, detection of substantial malaria parasitemia (15%) among Somali refugees from this region prompted recommenda- Vol. 46 / Nos. 52 & 53 MMWR Barawan Somali Refugees — Continued tion of antimalarial treatment before resettlement (7). In addition, high prevalences of malaria (30%) and intestinal parasites (60%-80%) had been reported among residents of Kenya living in the coastal region, including Mombasa (S.K. Sharif, M.D., Ministry of Health, Kenya, personal communication, 1997). Because the prevalence of parasitic infections among the Barawan refugees may reflect those of the local community, the International Organization for Migration (IOM) consulted CDC on appropriate pre- embarkation interventions for Barawan refugees. IOM, a nongovernmental organiza- tion, medically screens more than half of the refugees resettling to the United States. CDC interim recommendations included mass pre-embarkation therapy with single- dose sulfadoxine-pyrimethamine (SP) for malaria parasitemia and mebendazole (100 mg twice a day for 3 days) for intestinal helminths. During July 1997, CDC con- ducted a cross-sectional survey of an approximately 10% sample of refugees during the standard medical screening process to 1) determine the prevalences of malaria and intestinal parasites, 2) reevaluate recommended pre-embarkation therapies, 3) as- sess the effectiveness of the antimalarial regimen, and 4) evaluate the laboratory com- ponent of medical screening. 1OM provided information about two groups: refugees examined during February 3-June 23 (travel-approved population, n=3253) and refugees examined during July 7-17 (survey population, n=390). Basic characteristics of the two groups (i.e., age, sex, country of origin, and size of family unit) were similar. Members of the survey popula- tion were asked about histories of recent illness and use of medications and other antimalarial preventive measures. A local hospital laboratory screened members of the survey population for malaria by using a qualitative buffy-coat (QBC) test followed by confirmation of all QBC-positives using microscopic examination of Field’s-stained blood smears; persons who were positive for malaria were retested 3 and 7 days fol- lowing completion of antimalarial therapy. Stool specimens were screened at a local hospital for intestinal parasites by direct and formalin ether-concentrated smears. CDC performed quality-control assessments for both the malaria smears and stool samples. Malaria Of the 390 survey participants, 26 (7%; 95% confidence interval [Ci]=4%-10%) were positive for malaria. Of the 26 who were positive, 25 had Plasmodium falciparum parasitemia, and one had P ovale parasitemia. Because of the severity of the parasitemia and symptoms, the local hospital treated seven of the 26 malaria-positive persons with halofantrine or artemether. Nineteen received a weight-adjusted dose of SP. One patient receiving SP was lost to follow-up. Of the remaining 18 patients receiv- ing SP, 13 were malaria-negative on day 3 of follow-up, and all were malaria-negative by day 7. Of the surveyed population, recent febrile symptoms were reported by 20% and 37% during initial and follow-up questioning, respectively (Table 1). Use of anti- malarial therapy (chloroquine, halofantrine, SP, or quinine) was common among those refugees reporting fever (71% and 93%, respectively). Ten percent of the sur- veyed refugees reported using any malaria chemoprophylaxis, and most (91%) re- ported using bed nets (Table 1). Of the 229 refugees reporting the condition of their bed nets, 51 (22%) reported holes or tears in the netting (i.e., poor condition). Use of 1252 January 9, 1998 Barawan Somali Refugees — Continued bed nets in poor condition compared with use of bed nets in good condition was as- sociated with malaria parasitemia (odds ratio=9.2; 95% Cl=3.2-27.5). A total of 37 randomly selected blood smears from refugees reported as parasite- negative by the local hospital were reviewed by CDC and confirmed as negative. How- ever, of the 26 refugees reported as parasite-positive, two cases of P falciparum parasitemia could not be confirmed by CDC. The smear diagnosed by the local hospi- tal as P ovale was identified by CDC as P falciparum. Intestinal Parasites Stool specimens were obtained from 331 persons; of these, specimens from 129 (39%) were positive for one or more pathogenic intestinal parasites, including Trichuris trichiura (28%), Ascaris lumbricoides (9%), and other pathogens (Table 2). Sex-specific prevalences were similar (41% for females versus 37% for males, chi- square test=0.47, p=0.49). However, age-specific prevalence was higher for persons TABLE 1. Number of affirmative responses to initial and follow-up questions about malaria symptoms among Barawan Somali refugees, 1997 Affirmative responses Total Survey/Characteristic No. (%) respondents initial survey* Had fever in July 77 (20) 389 Received any antimalarial therapy 54 (71) 76 Follow-up survey$ Had fever during May-July 131 (37) 358 Received any antimalarial therapy' 122 (93) 131 Used chemoprophylaxis 34 (10) 355 Used bed nets 325 (91) 355 Bed nets in poor condition 51 (22) 229 *Survey conducted during July 7-17; n=390. ‘Chloroquine, sulfadoxine-pyrimethamine, quinine, halofantrine, or artemether. Survey conducted July 12 and July 16; n=358. TABLE 2. Number and percentage distribution of selected intestinal parasites among Barawan Somali refugees and comparison of results of stool specimen screening performed by a local hospital and reviewed by CDC, by parasite, 1997 Quality review Survey population* Local hospital cbct _Parasite . (%) No. (%) No. (%) Trichuris trichiura (28) 1 (32) (42) Ascaris lumbricoides ( 9) (17) (17) Giardia lamblia ( 8) (12) (17) Entamoeba histolytica ( 2) ( 5) (10) Hookworms ( 1) ( 2) — Strongyloides stercoralis ( 1) ( 2) ( 2) Hymenolepis nana 3 ( 1) 0 — *Stool specimens from survey population tested at a local hospital during July; n=331. "Quality review by CDC during October; n=41. Vol. 46 / Nos. 52 & 53 MMWR Barawan Somali Refugees — Continued aged <15 years (51%) than for persons aged 215 years (32%) (chi-square test=11.95, p<0.01). CDC reviewed randomly selected negative (n=15) and positive (n=26) stool specimens as determined by the local hospital and found that, for 11 (27%) of these 41 specimens, the local hospital either did mot detect or misclassified pathogens that were present in sufficient numbers to detect. The most commonly undetected patho- gen was T. trichiura, and the most commonly misclassified pathogen was Entamoeba histolytica. Reported by: S Gonzaga, MD, V Keane, MPH, B Gushulak, MD, International Organization for Migration, Geneva, Switzerland. H Boyd, Rollins School of Public Health, Emory Univ, Atlanta, Georgia. Div of Parasitic Diseases and Surveillance and Epidemiology Br, Div of Quarantine, National Center for Infectious Diseases, CDC. Editorial Note: Although the prevalences of parasitic infections among the Barawan refugees were lower than the prevalences of these infections among persons in the surrounding communities, the prevalences of malaria (7%) and intestinal parasites (39%) among Barawan Somali refugees encamped in Kenya were sufficient to warrant pre-embarkation therapies. The strategy of screening for parasitic infections among a subset of refugees before resettlement provided an opportunity to assess the need for public health interventions for the entire Barawan refugee population. This strategy optimized the efficient distribution of these therapies before the refugees were reset- tled to the United States. This screening strategy also may be used to determine the need for other pre-embarkation therapies among future refugee populations. How- ever, because the magnitudes of exposures and risks may vary among different groups, the use of specific interventions may differ by refugee group. CDC oversees refugee health screening in accordance with the Refugee Act of 1980.* The law requires that refugees with medical conditions potentially affecting the public's health be identified and treated; the quality of medical screening and related health services be monitored and assessed; and that health officials in resettlement communities be notified of identified medical conditions. Refugee medical assess- ments previously focused on identifying inadmissible medical conditions. The en- hancement of the medical screening process described in this report emphasizes the expansion of screening to include parasitic diseases with the potential for local trans- mission in the resettlement community (2,3) and a broadening of the focus from the individual to a population. As a result of the findings of the enhanced assessment of Barawan Somali refu- gees, CDC recommended continuation of mass pre-embarkation therapy (day before departure) for malaria infection with SP for all departing refugees who had no contra- indication to therapy (i.e., sulfa allergy). This recommendation was based on three considerations. First, the prevalence of parasitemia (7%) may have been underesti- mated because of the extensive use of presumptive antimalarial therapy for fever. Second, single-dose SP provides adequate cost-effective therapy for P. falciparum. Al- though the small number of refugees treated with SP (n=19) precluded accurate as- sessment of the effectiveness of SP, all refugees were malaria-negative by day 7 following SP therapy (n=18, one lost to follow-up). Third, mass pre-embarkation therapy effectively treats symptomatic persons and reduces asymptomatic malaria parasitemia among the entire refugee population, thereby reducing the risk for im- ported P falciparum malaria. *Public Law 96-212. 1254 January 9, 1998 Barawan Somaii Refugees — Continued Because some Barawan Somali refugees were infected with both helminthic and protozoan pathogens, the interim recommendation for mass pre-embarkation therapy with 3-day mebendazole was changed to single-dose albendazole (400 mg per kg of body weight) for all persons except pregnant women.’ This approach was considered preferable because of the high prevalence of mixed intestinal parasites, the low cost of albendazole, and the ease of single-dose therapy before departure (4-6). The opti- mal choices of agent(s) and duration of therapy for mass treatment of intestinal para- sites among refugee populations remain to be determined. The program of enhanced screening for and management of infectious diseases among this vulnerable refugee population enabled the implementation of population- based interventions before members of this group dispersed to multiple locations in >20 states. CDC is notifying health officials in the states in which refugees are being resettled of the results of the pre-embarkation medical screening and treatment. CDC also is working with IOM and state refugee health programs to develop a shared data- base of refugee medical screening results. References . Slutsker L, Tipple M, Keane V, McCance C, Campbell CC. Malaria in East African refugees re- settling to the United States: development of strategies to reduce the risk of imported malaria. J Infect Dis 1995;171:489-93. . CDC. Malaria in Montagnard refugees—North Carolina, 1992. MMWR 1993;42:180-3. . Gyorkos TW, Frappier-Davignon L, MacLean JD, Viens P. Effect of screening and treatment on imported intestinal parasite infections: results from a randomized, controlled trial. Am J Epidemiol! 1989;129:753-61. . Raccurt CP. Lambert MT, Bouloumie J, Ripert C. Evaluation of the treatment of intestinal helmin- thiases with albendazole in Djohong (North Cameroon). Trop Med Parasitol 1990;41:46-8. . Pungpak S, Singhasivanon V, Bunnag D. Albendazole as a treatment for Giardia infection. Ann Trop Med Parasitol 1996;90:563-5. . Hall A, Nahar Q. Albendazole as a treatment for infections with Giardia duodenalis in children in Bangladesh. Trans R Soc Trop Med Hyg 1993;87:84-6. 'Albendazole is currently approved by the Food and Drug Administration for treatment of neurocysticercosis and hydatid disease. Evaluation of HIV Case Surveillance Through the Use of Non-Name Unique Identifiers — Maryland and Texas, 1994-1996 Notifiable disease reporting laws or regulations in states and territories require re- porting of acquired immunodeficiency syndrome (AIDS) cases, including patient and physician names, to state or local health authorities. As of January 1, 1998, a total of 31 states were conducting name-based human immunodeficiency virus (HIV) case surveillance by using the same methods as surveillance for AIDS. However, because of concerns about name-based HIV surveillance, Maryland and Texas implemented HIV surveillance using non-name unique identifiers (Ul)*. This report summarizes a 3-year collaboration by CDC and these states to evaluate UI surveillance for HIV infec- *Reporting in Maryland is exempted for nonstate residents; persons who are tested at anony- mous test sites; are blood, semen, or tissue donors; and participants of certain research projects. No exemptions to reporting exist in Texas.