Acute Flaccid Paralysis Syndrome Associated With West Nile Virus Infection—Mississippi and Louisiana, July-August 2002 FREE

MMWR. 2002;51:825-828

1 table omitted

West Nile virus (WNV) infection can cause severe, potentially fatal neurologic illnesses including encephalitis and meningitis.^1,2 Acute WNV infection also has been associated with acute flaccid paralysis (AFP) attributed to a peripheral demyelinating process (Guillain-Barré Syndrome [GBS]),³ or to an anterior myelitis.⁴ However, the exact etiology of AFP has not been assessed thoroughly with electrophysiologic, laboratory, and neuroimaging data. This report describes six cases of WNV-associated AFP in which clinical and electrophysiologic findings suggest a pathologic process involving anterior horn cells and motor axons similar to that seen in acute poliomyelitis. Clinicians should evaluate patients with AFP for evidence of WNV infection and conduct tests to differentiate GBS from other causes of AFP.

In July 2002, a previously healthy man aged 56 years from Mississippi was admitted to a local hospital with a 3-day history of fever, chills, vomiting, confusion, and acute painless weakness of the arms and legs. On physical examination, he had tremor and areflexic weakness in both arms and asymmetric weakness in the legs with hypoactive reflexes; sensation was intact. Laboratory abnormalities included a mildly elevated protein in the cerebrospinal fluid (CSF). An evolving stroke was diagnosed, and the patient was treated with anticoagulant therapy; subsequently, the illness was attributed to GBS, and intravenous immune globulin (IVIG) therapy was initiated. A computerized tomography (CT) scan and magnetic resonance imaging (MRI) of the brain and cervical spine were normal. Electromyography and nerve-conduction studies (EMG/NCS) were indicative of a severe asymmetric process involving anterior horn cells and/or their axons. An acute WNV infection was considered probable on the basis of the presence of virus-specific IgM antibody in serum.

In July 2002, a man aged 57 years from Mississippi was admitted to a local hospital with a 3-day history of fever, chills, vomiting, and headache. Laboratory abnormalities indicated an elevated protein and pleocytosis in the CSF. The patient subsequently had acute respiratory failure requiring intubation. On physical examination, rigidity in all extremities was observed with no spontaneous movement. Following extubation, bilateral facial and areflexic, asymmetric weakness was observed in all extremities; sensory examination was normal. Brain MRI was normal. EMG/NCS were indicative of a severe asymmetric process affecting anterior horn cells and/or their axons. IgM and neutralizing antibody test results confirmed an acute WNV infection.

In July 2002, a man aged 56 years from Louisiana with a history of hypertension and coronary artery disease was hospitalized with a 4-day history of fever, vomiting, and painless asymmetric leg weakness. On examination, the patient had a flaccid areflexic right leg and a weak, hyporeflexic left leg; strength and reflexes in the arms were normal. The patient had decreased sensation in a stocking-and-glove distribution and a coarse upper extremity action tremor. A lumbar puncture revealed a CSF pleocytosis. He was admitted with a diagnosis of postviral demyelination syndrome and treated with antimicrobial medication, IVIG, and dexamethasone. MRI of the spine revealed mild cervical spinal stenosis and homogeneous enhancement of the cauda equina consistent with meningitis. EMG/NCS were indicative of a severe asymmetric process affecting anterior horn cells and/or their axons. IgM and neutralizing antibody test results confirmed an acute WNV infection.

In August 2002, a woman aged 69 years from Louisiana with a history of diabetes and degenerative disc disease was hospitalized with a 1-day history of vomiting, lethargy, confusion, fever, and painless right arm weakness. On examination, the patient had nuchal rigidity and a coarse tremor in the chin, left arm, and both legs. The right arm was flaccid and areflexic; strength and reflexes in the other extremities were normal. She was admitted with a diagnosis of meningoencephalitis with associated focal motor radiculitis versus monoplegia secondary to cerebrovascular ischemia. Head CT and brain MRI showed chronic microvascular ischemic changes; MRI of the cervical spine displayed mild narrowing of the spinal cord and the right neural foramina at the C5-6 level. EMG/NCS indicated a severe, asymmetric process affecting anterior horn cells and/or their axons. IgM and neutralizing antibody test results confirmed an acute WNV infection.

In August 2002, a previously healthy man aged 50 years from Mississippi was hospitalized with vomiting and headache. He had flaccid, areflexic weakness in the right arm; sensation in all extremities was normal. An acute stroke was diagnosed, and the patient received anticoagulant therapy. EMG/NCS were indicative of a severe, asymmetric process affecting anterior horn cells and/or their axons in the right upper extremity. IgM and neutralizing antibody test results confirmed an acute WNV infection.

In August 2002, a man aged 46 years from Louisiana with a history of coronary artery disease was admitted to a hospital with fever, chills, fatigue, and leg weakness. He had a plegic and areflexic right leg and mild left leg weakness; sensation was intact. Laboratory abnormalities included a lymphocytic pleocytosis in CSF. The patient was admitted with a diagnosis of GBS and treated with IVIG and antibiotics. An enhanced MRI of the spine revealed findings suggestive of meningitis involving the conus medullaris and cauda equina. EMG/NCS indicated a severe, asymmetric process affecting anterior horn cells and/or their axons. IgM and neutralizing antibody test results confirmed an acute WNV infection.

A Leis, MD, D Stokic, MD, J Polk, MD, V Dostrow, MD, M Winkelman, MD, Methodist Rehabilitation Center, Jackson; R Webb, MD, S Slavinski, DVM, M Currier, MD, State Epidemiologist, Mississippi State Dept of Health. J Van Gerpen, MD, Ochsner Clinic, New Orleans; E Brewer, MD, R Ratard, MD, State Epidemiologist, Louisiana Office of Public Health. J Sejvar, MD, Div of Viral and Rickettsial Diseases; L Petersen, MD, A Marfin, MD, G Campbell, MD, Div of Vector-Borne Infectious Diseases, National Center for Infectious Diseases; B Tierney, MD, M Haddad, MSN, S Montgomery, DVM, A Vicari, DVM, EIS officers, CDC.

The clinical, laboratory, and electrophysiologic findings of these six patients suggest that WNV-associated AFP is a polio-like syndrome with involvement of the anterior horn cells of the spinal cord and motor axons. All six patients had acute onset of asymmetrical weakness without pain or sensory loss. All but one of those with CSF drawn had pleocytosis. Investigation of these patients is continuing.

A polio-like syndrome has been associated with flaviviruses other than WNV,⁵ and anterior myelitis has occurred with WNV infection.⁴ Investigations of primates⁶ and other vertebrates infected with WNV have documented involvement of spinal motor neurons and lesions in the ventral gray matter of the spinal cord, with an absence of lesions in peripheral nerves.

Previous case series have attributed WNV infection–associated AFP to a peripheral neuronal process similar to GBS; acute poliomyelitis might simulate GBS, causing diagnostic confusion.⁷ Clinical, laboratory, and electrophysiologic features of these cases might help differentiate poliomyelitis from GBS. In comparison with the asymmetric AFP observed in these patients, GBS syndrome is more often symmetric, generally involves sensory changes or paresthesias, and is associated with an elevation of CSF protein in the absence of pleocytosis. Additional features of typical GBS include an onset several days following signs of acute infection and a generally favorable outcome with rapid improvement in strength. In addition, EMG/NCS typically suggest a predominantly demyelinating picture, or a combined axonal and demyelinating process. A pure motor axonal variant of GBS⁸ might be confused with polio; however, this GBS variant is typically characterized by symmetric, distally prominent weakness and subclinical sensory nerve involvement on EMG/NCS.

Treatment modalities used for patients with GBS include anticoagulation, IVIG, plasmapheresis, and high-dose corticosteroids. These therapies have no beneficial effect for poliomyelitis and can have significant morbidity.^9,10 In areas where WNV transmission is occurring, clinicians should suspect acute WNV infection and conduct appropriate diagnostic tests in patients presenting with acute, painless, asymmetric weakness, particularly in the setting of an acute febrile illness with CSF pleocytosis. In addition, CSF analysis, thorough EMG/NCS, and neuroimaging should be strongly considered before initiating therapies for GBS or other peripheral inflammatory processes.

Continued surveillance and public health investigation is needed to fully define the scope of neurologic illnesses associated with WNV infection. Health-care providers who are aware of patients with acute WNV infection and AFP should contact their state or local health departments and CDC, telephone 404-639-4657; e-mail, zea3@cdc.gov.

This report is based on information contributed by S Kemmerly, MD, K Baumgarten, MD, Ochsner Clinic; M Rosenblum, MD, K Landry, Touro Infirmary, New Orleans; P Vaccaro, P Mussarat, MD, North Oaks Hospital, Hammond; J Lefran, MD, G Reddy, MD, T Croney, Slidell Memorial Hospital, Slidell, Louisiana. P Collins, Div of Vector-Borne Infectious Diseases, National Center for Infectious Diseases, CDC.

References: 10 available

MMWR. 2002;51:853-856

After declining steadily for 10 years, the number of reported cases of primary and secondary (P&S) syphilis more than doubled in New York City (NYC) from 117 in 2000 to 282 in 2001.¹ The increases have occurred primarily among men who have sex with men (MSM). Of particular concern is the high proportion of syphilis cases among MSM who also have human immunodeficiency virus (HIV). This report summarizes 2001 P&S syphilis data for NYC and compares it with surveillance data for 1999 and 2000; findings indicate a substantial increase in the number of syphilis cases among MSM. These data suggest increases in high-risk sexual behavior among some MSM and underscore the importance of coordinating efforts between the MSM community public health officials, and health-care providers to strengthen HIV-prevention efforts.

Syphilis cases are reported to the NYC Department of Health and Mental Hygiene (NYCDOHMH) by private health-care providers, health-care institutions, and laboratories in accordance with New York state and NYC laws. NYCDOHMH reports confirmed syphilis cases to CDC. NYCDOHMH interviews persons with syphilis of <1 year duration to obtain demographic and risk-behavior data and to provide disease-intervention counseling, which facilitates locating and treating sex partners in addition to treating patients.

A case of P&S syphilis was defined as darkfield-positive lesions or reactive serologic tests for syphilis and accompanying symptoms in a person residing in NYC. For this analysis, patients were classified as MSM if they reported having sex with another man during the time when syphilis might have been acquired or transmitted to a sex partner. This time is based on stage of disease at the time of treatment. For primary syphilis, this period is defined as 3 months before the date of onset of a syphilitic lesion through the date of treatment, and for secondary syphilis, from 6½ months before onset of associated symptoms (e.g., rash, mucocutaneous lesions, lymphadenopathy, and fever) through the date of treatment. Behavioral data collected from male patients included sexual behavior, HIV status, number and sex of sex partners, frequency of condom use, alcohol and recreational drug use, and venues for meeting sex partners. HIV status was determined by self-reports or by laboratory-confirmed tests from specimens collected at the time of the interview or treatment.

During 2001, a total of 282 cases of P&S syphilis were reported to NYCDOHMH; 263 (93%) were in males. The overall P&S syphilis rate in 2001 (3.5 per 100,000 population) was the highest since 1995, and the rate among males (6.9) was the highest since 1994 (Figure 1). The male:female case ratio for P&S syphilis increased from 3.6:1 in 1999 to 13.8:1 in 2001.

The median age of male patients in 2001 was 35 years (range: 16-64 years); mean age was similar to that during previous years (Table 1). The number of cases among males increased in all racial/ethnic groups in 2001. Among males whose race/ethnicity was known, the proportion of cases that occurred among whites increased in 2001 (33%), compared with the proportion in 2000 (23%) and in 1999 (24%). In comparison, the proportion of cases among black males was less in 2001 (36%) and 2000 (38%) than in 1999 (47%). A greater proportion of cases was reported from private health-care providers and private hospitals in 2000 and 2001 than in 1999. The proportion of male patients residing in Manhattan was greater in 2000 and 2001 than in 1999.

Information about sex partners was obtained for 188 males in 2001; of these, 79% were classified as MSM compared with 77% in 2000 and 42% in 1999. HIV status was known for 86 MSM in 2001; of these, 48% were HIV-infected compared with 49% in 2000 and 20% in 1999 (Table 1).

Behavioral data from interviews of 103 MSM patients in 2001 indicated that during the interval when syphilis could have been transmitted or acquired, 77 (75%) reported having more than one sex partner, and 37 (36%) reported using alcohol or other recreational drugs. The venues cited most frequently for meeting sex partners were nightclubs and bars (31%), public cruising sites (22%), Internet chat rooms (14%), and bathhouses (11%). A total of 5% of MSM patients reported exchanging sex for money.

C de Luise, MPH, S Blank, MD, J Brown, S Rubin, A Meyers, MPH, L Neylans, MPA, STD Control Program, New York City Dept of Health and Mental Hygiene, New York, New York. G Paz-Bailey, MD, L Markowitz, MD, Div of STD Prevention, National Center for HIV, STD, and TB Prevention, CDC.

The findings in this report indicate an increasing rate of P&S syphilis among males in NYC, particularly among MSM, a pattern seen in several urban areas of the United States.^2-4 Data obtained from case interviews indicated high-risk behavior among male patients, including having multiple sex partners, substance use, and frequenting venues in which they were likely to meet sex partners. A high proportion of patients with syphilis were infected with HIV. Transmission of HIV is enhanced by syphilis and other sexually transmitted diseases (STDs). Syphilis outbreaks often have affected economically disadvantaged minority groups with poor access to health care and have been commonly associated with heterosexual transmission, drug use, and exchange of sex for money or drugs. In comparison, urban outbreaks, including that in NYC, involve whites and minority groups, MSM, and persons who use private health-care services.

The increasing rate of MSM cases is not unique to NYC; since 1997, syphilis outbreaks among MSM have occurred in other U.S. cities, including Seattle, Chicago, San Francisco, Los Angeles, and Miami.^2-4 In each of these outbreaks, high rates of HIV co-infection were documented, ranging from 20% to 73%. Increases in gonorrhea among MSM also have been observed in the United States⁵ and internationally.⁶ Several factors might be associated with increased high-risk sexual behavior among MSM, including the availability of highly active antiretroviral therapy (HAART).⁷ HAART has had a substantial impact on the decline in AIDS-related mortality and is responsible for improved physical well-being, allowing higher rates of sexual activity than before treatment. Increased sexual risk taking might also be related to "AIDS burnout," which is associated with years of exposure to prevention messages and long-term efforts to maintain safer sex practices.⁸ Other factors described among young MSM include alcohol and drug use, unrecognized HIV infection, and misperception of risk.⁹

In response to the outbreak, NYCDOHMH has enhanced syphilis surveillance, intensified education about prevention and treatment of syphilis to affected communities, strengthened partnerships with community-based organizations, and encouraged health-care providers to increase screening of patients at high risk for other STDs and HIV. Despite these efforts, increases in syphilis rates, including among MSM, have continued in 2002.¹ A similar pattern has been observed in Los Angeles, where, despite extensive efforts to control a syphilis outbreak among MSM, syphilis transmission in this group has continued for several years.¹⁰

The findings in this report are subject to at least two limitations. First, information from public health records and from interviews was not collected systematically; variation occurred in data collection and recording. Second, behavioral data were not available for all patients.

The increasing rate of syphilis among MSM reflects increased sexual risk-taking behavior among subpopulations of MSM, many of whom have HIV. Such behavior increases the risk for STDs and HIV and threatens the health of MSM. Public health officials, the MSM community, and others should continue to develop and implement new, effective prevention approaches to reduce the risk for STDs and HIV among MSM.

References: 10 available

MMWR. 2002;51:856-859

1 table omitted

Unprotected sexual intercourse places young persons at risk for human immunodeficiency virus (HIV) infection, other sexually transmitted diseases (STDs), and unintended pregnancy. Responsible sexual behavior among adolescents is one of the 10 leading health indicators of the national health objectives for 2010 (objective 25.11).¹ To examine changes in sexual risk behavior that occurred among high school students in the United States during 1991-2001, CDC analyzed data from six national Youth Risk Behavior surveys (YRBS). This report summarizes the results of the analysis, which indicate that, during 1991-2001, the percentage of U.S. high school students who ever had sexual intercourse and the percentage who had multiple sex partners decreased. Among students who are currently sexually active, the prevalence of condom use increased, although it has leveled off since 1999. However, the percentage of these students who used alcohol or drugs before last sexual intercourse increased. Despite decreases in some sexual risk behaviors, efforts to prevent sexual risk behaviors will need to be intensified to meet the national health objective for responsible sexual behavior.

YRBS, a component of CDC's Youth Risk Behavior Surveillance System, measures the self-reported prevalence of health risk behaviors among adolescents through representative national, state, and local surveys. The six biennial national surveys conducted during 1991-2001 used independent, three-stage cluster samples to obtain cross-sectional data representative of students in grades 9-12 in all 50 states and the District of Columbia. During 1991-2001, sample sizes ranged from 10,904 to 16,296 students, school response rates ranged from 70% to 79%, student response rates ranged from 83% to 90%, and overall response rates ranged from 60% to 70%.

For each cross-sectional survey, students completed an anonymous, self-administered questionnaire, which included identically worded questions about sexual intercourse, number of sex partners, condom use, and alcohol or drug use before last sexual intercourse. Sexual experience was defined as ever having had sexual intercourse. Having multiple sex partners was defined as having had four or more sex partners during one's lifetime. Current sexual activity was defined as having had sexual intercourse during the 3 months preceding the survey. Condom use was defined as having used a condom at last sexual intercourse among currently sexually active students. Alcohol or drug use was defined as having used alcohol or drugs before last sexual intercourse among currently sexually active students. Race/ethnicity-specific trends are presented only for non-Hispanic black, non-Hispanic white, and Hispanic students because the numbers of students from other racial/ethnic groups were too small for meaningful analysis.

Data were weighted to provide national estimates, and SUDAAN was used for all data analysis. Overall temporal changes were analyzed by using logistic regression analyses that assessed linear and quadratic time effects simultaneously and that controlled for sex, race/ethnicity, and grade. Similarly, temporal changes for sex, race/ethnicity, and grade subgroups were analyzed by using separate logistic regression analyses that assessed linear and quadratic time effects in one type of subgroup while holding the other two constant. Quadratic trends indicated a significant but nonlinear trend in the data over time. When a significant quadratic trend accompanied a significant linear trend, the data demonstrated some nonlinear variation (e.g., leveling off or change in direction) in addition to a linear trend.

During 1991-2001, the prevalence of sexual experience decreased 16% among high school students. Logistic regression analysis indicated a significant linear decrease overall and among female, male, 10th-grade, 11th-grade, 12th-grade, black, and white students. Among 11th-grade students, a significant quadratic trend also was detected, indicating that the prevalence of sexual experience declined during 1991-1997 and then leveled off. Prevalence of sexual experience did not decrease significantly among 9th-grade or Hispanic students.

During 1991-2001, the prevalence of multiple sex partners decreased 24%. A significant linear decrease was detected overall and among male, 11th-grade, 12th-grade, black, and white students. Prevalence of multiple sex partners did not show a significant linear decrease among female, 9th-grade, 10th-grade, or Hispanic students.

During 1991-2001, the overall prevalence of current sexual activity did not change. However, the prevalence of current sexual activity decreased 12% among 11th-grade students and 23% among black students. Among students who are currently sexually active, a significant linear and quadratic trend was observed in the overall prevalence of condom use, indicating an increase in condom use during 1991-1999 and then a leveling off by 2001. A similar pattern was detected among female, 10th-grade, 12th-grade, and black students with the prevalence of condom use peaking in 1997 or 1999 and then leveling off. A significant linear increase in condom use was detected among male, 9th-grade, 11th-grade, Hispanic, and white students.

During 1991-2001, the prevalence of alcohol or drug use before last sexual intercourse among students who are currently sexually active increased 18%. Logistic regression analysis indicated a significant linear increase overall and among male, 11th-grade, 12th-grade, black, and Hispanic students. Among 9th-grade students, a significant quadratic trend was detected, indicating that the prevalence of alcohol or drug use before last sexual intercourse increased during 1991-1997 and then decreased. Prevalence of alcohol or drug use before last sexual intercourse did not show a significant linear increase among female, 10th-grade, or white students.

N Brener, PhD, R Lowry, MD, L Kann, PhD, L Kolbe, PhD, Div of Adolescent and School Health; J Lehnherr, Div of Reproductive Health, National Center for Chronic Disease Prevention and Health Promotion; R Janssen, MD, Div of HIV/AIDS Prevention; H Jaffe, MD; Div of STD Prevention, National Center for HIV, STD, and TB Prevention, CDC.

During 1971-1979, the percentage of females aged 15-19 years living in metropolitan areas nationwide who ever had sexual intercourse increased from 30% to 50%²; during 1982-1988, the percentage of females aged 15-19 years nationwide who ever had sexual intercourse increased from 47% to 53%.³ The findings in this report indicate that, during 1991-2001, the percentages of high school students who ever had sexual intercourse and multiple sex partners decreased, and the percentage of sexually active students who used a condom at last sexual intercourse increased and then leveled off. Overall, fewer high school students are engaging in behaviors that might result in pregnancy and STDs, including HIV infection. This decrease in health risk behaviors corresponds to a simultaneous decrease in gonorrhea, pregnancy, and birth rates among adolescents.^4-7 These improvements in health outcomes probably resulted from the combined efforts of parents and families, schools, community organizations that serve young persons, health-care providers, religious organizations, the media, and government agencies to reduce sexual risks among young persons. For example, the percentage of high school students who received HIV-prevention education in school increased from 83% in 1991 to 92% in 1997 and then leveled off to 89% in 2001 (CDC, unpublished data, 2002).

The findings in this report are subject to at least two limitations. First, these data pertain only to adolescents who attend high school. In 1998, 5% of those aged 16-17 years were not enrolled in a high school program and had not completed high school.⁸ Second, although the survey questions demonstrate good test-retest reliability,⁹ the extent of underreporting or overreporting in YRBS cannot be determined.

One of the national health objectives for 2010 is to increase from 85% to 95% the proportion of adolescents in grades 9-12 who have never had sexual intercourse, have had sexual intercourse but not during the preceding 3 months, or used a condom the last time they had sexual intercourse during the preceding 3 months.¹ In 2001, 86% of high school students met this objective, compared with 80% in 1991. Efforts to prevent sexual risk behaviors will need to be intensified to meet the 2010 objective; to sustain decreases in gonorrhea, pregnancy, and birth rates among adolescents; and to reduce HIV infections and other STDs among young persons. In 1998, the birth rate in the United States was 52.1 per 1,000 females aged 15-19 years, four times higher than the average rate among nations in the Organization for Economic Cooperation and Development.¹⁰ In addition, interventions are needed to reverse the increasing percentage of sexually active high school students who used alcohol or drugs before their last sexual intercourse.

References: 10 available

MMWR. 2002;51:864

CDC has released an updated version of the post-event Smallpox Response Plan and Guidelines. This is the second revision to these guidelines since they were released in November 2001.

Version 3 of the guidelines contains an important addition—the "Smallpox Vaccination Clinic Guide." This guide provides the operational and logistical considerations associated with implementing a large-scale, voluntary vaccination program as part of a multifaceted response to a confirmed smallpox outbreak. Following a confirmed smallpox outbreak within the United States, rapid, voluntary vaccination of a large segment of the population might be required to (1) supplement priority surveillance and containment control strategies in areas with smallpox cases, (2) reduce the at-risk population for additional intentional releases of smallpox virus if the probability of such occurrences is considered significant, and (3) address heightened public concerns about access to voluntary vaccination.

The most important component of smallpox containment is the rapid identification, isolation, and vaccination of close contacts of infected patients and contacts of their contacts (i.e., ring vaccination). This strategy involves identification of infected persons through intensive surveillance, isolation of infected persons, vaccination of household contacts and other close contacts of infected persons (i.e., primary contacts), and vaccination of household and other potential contacts of the primary contacts (i.e., secondary contacts).

The clinic guide will assist planning for larger-scale, post-event vaccination when exposure circumstances indicate the need to supplement the ring vaccination approach with broader protective measures. The clinic guide describes the activities and staffing needs associated with large-scale smallpox vaccination clinics, including suggested protocols for vaccine safety monitoring and treatment. The clinic guide provides an example of a model smallpox clinic and provides samples of pertinent clinic consent forms and patient information sheets that would be used at a clinic.

The clinic guide and the Smallpox Response Plan and Guidelines, Version 3 are available at http://www.cdc.gov/smallpox. CDC will take additional steps to increase preparedness to respond to a smallpox exposure of any magnitude, including updates to the Smallpox Response Plan and Guidelines. Updates on infection control, in-hospital isolation recommendations, post-event vaccination protocols, and outbreak response strategies are under way and will be posted on the CDC website.