Update on hantavirus in Oklahoma: are we missing cases?

Hantavirus Pulmonary Syndrome (HPS) was first recognized in 1993. Through July 6, 2005, 396 cases have been reported in the US, including 50 from Kansas, Texas, and Oklahoma. We report the second case of HPS in Oklahoma and present data from rodent testing to support the presence of hantaviruses across Oklahoma. We examined Oklahoma death certificates for 1999-2003 for possible unreported HPS cases. The rate of death in young adults 15-49 years due to acute respiratory distress syndrome was 69% higher and the death rate due to unspecified respiratory failure was three times higher in the grassland area of Oklahoma as compared to the non-grassland. It appears the highest risk of HPS is in the Oklahoma grasslands but Sin Nombre virus is present in the non-grassland area as well. We request physician collaboration in detection and reporting of HPS cases and present brief recommendations for prevention.

Creutzfeldt-Jakob disease in unusually young patients who consumed venison.

BACKGROUND: Creutzfeldt-Jakob disease (CJD) in humans and chronic wasting disease (CWD) in deer and elk occur in the United States. Recent reports of 3 unusually young patients with CJD who regularly consumed deer or elk meat created concern about the possible zoonotic transmission of CWD. OBJECTIVE: To examine the possible transmission of CWD to humans. PATIENTS: Three unusually young patients (aged 28, 28, and 30 years) with CJD in the United States during 1997-2000. METHODS: We reviewed medical records and interviewed family members and state wildlife and agriculture officials. Brain tissue samples were tested using histopathologic, immunohistochemical, immunoblot, or prion protein gene analyses. MAIN OUTCOME MEASURES: Presence or absence of established CJD risk factors, deer and elk hunting in CWD-endemic areas, and comparison of the evidence for the 3 patients with that of a zoonotic link between new variant CJD and bovine spongiform encephalopathy. RESULTS: None of the patients had established CJD risk factors or a history of travel to Europe. Two patients hunted game animals and 1 was a daughter of a hunter. Unlike patients with new variant CJD, the 3 patients did not have a unique neuropathologic manifestation, clinicopathologic homogeneity, uniformity in the codon 129 of the prion protein gene, or prion characteristics different from those of classic variants. CONCLUSIONS: Although the occurrence of 3 unusually young patients with CJD who consumed venison suggested a possible relationship with CWD, our follow-up investigation found no strong evidence for a causal link. Ongoing CJD surveillance remains important for continuing to assess the risk, if any, of CWD transmission to humans.

Improving the health of Oklahomans through clinical prevention, part II: Screening to identify early-stage disease and risk factors.

The purpose of screening is to identify asymptomatic disease, or risk factors for disease, so that interventions can occur as early as possible in the disease process. The primary goal is to decrease the morbidity the patient experiences from the disease. For infectious diseases, screening can benefit not only the individual with the disease but also the community, since infectious persons can be identified and treated prior to transmitting the disease to others. Although screening can be very beneficial to the individual and to the community, it can also have adverse outcomes if not used appropriately. In this article we will discuss current recommendations for the use of screening tests and their role in addressing the leading causes of morbidity and mortality in Oklahoma. In general, physicians should consistently screen for the risk factors for cardiovascular disease and stroke (hypertension, high cholesterol, obesity and diabetes) and for early-stage cancers of the colon, breast, and cervix. They should also consider screening Native Americans for diabetes and persons at increased risk for certain infectious diseases, particularly sexually transmitted diseases.

Medical response to bioterrorism: are we prepared?

The 1995 bombing of the Federal Building in Oklahoma City made terrorism a shocking reality for all Oklahomans. The fact that such an event could happen here, far from foreign political and ethnic conflicts and from large coastal cities, made us realize that no one is immune from the terrorist threat. But as horrific as that event and other terrorist incidents have been, the present threat of the use of infectious agents in acts of terrorism has the potential to cause far greater human death and suffering than any previously used terrorist weapon. Although health care professionals have not historically participated in terrorist planning and response activities, the addition of infectious agents to the terrorists' arsenal makes medical and public health professionals critical players in these efforts. Indeed, physicians have the ability to first recognize and report such an event and thereby diminish the impact. To meet the bioterrorism responsibility, physicians must be knowledgeable of this type of threat. In this article we present an overview of bioterrorism and review the organisms most likely to be used in a terrorist event.

High prevalence of penicillin-nonsusceptible Streptococcus pneumoniae at a community hospital in Oklahoma.

During 1997, Oklahoma City's Hospital A reported penicillin-nonsusceptible Streptococcus pneumoniae in almost 67% of isolates. To confirm this finding, all Hospital A S. pneumoniae isolates from October 23, 1997, through February 19, 1998, were tested for antibiotic susceptibility and repeat-tested at two other hospital laboratories. Medical records of Hospital A patients with invasive S. pneumoniae infections during 1994 through 1997 were also reviewed. These data were compared with 1998 statewide sentinel hospital surveillance data for invasive S. pneumoniae. Of 48 S. pneumoniae isolates from Hospital A during October 23, 1997, through February 19, 1998, 31 (65%) were penicillin-nonsusceptible S. pneumoniae, and 23 (48%) were highly penicillin resistant. Similar prevalences were confirmed at the other hospital laboratories; however, significant interlaboratory differences were noted in the determination of third-generation cephalosporin susceptibility. During 1994 through 1997, a trend toward increasing penicillin nonsusceptibility (p <0.05) was noted among S. pneumoniae isolates from nursing home patients. During 1998, 85 (30%) of 282 invasive isolates reported to the state surveillance system were penicillin-nonsusceptible S. pneumoniae; 33 (12%) were highly resistant. The increase in resistance observed is notable; the interlaboratory discrepancies are unexplained. To respond, a vaccination program was implemented at Hospital A, and vaccination efforts were initiated at nursing homes.

A prolonged outbreak of Pseudomonas aeruginosa in a neonatal intensive care unit: did staff fingernails play a role in disease transmission?

OBJECTIVES: To describe an outbreak of Pseudomonas aeruginosa bloodstream infection (BSI) and endotracheal tube (ETT) colonization in a neonatal intensive care unit (NICU), determine risk factors for infection, and make preventive recommendations. DESIGN: A 15-month cohort study followed by a case-control study with an environmental survey and molecular typing of available isolates using pulsed-field gel electrophoresis. SETTING AND PATIENTS: Neonates in the NICU of a university-affiliated children's hospital. INTERVENTIONS: Improved hand washing and restriction of use of long or artificial fingernails. RESULTS: Of 439 neonates admitted during the study period, 46 (10.5%) acquired P aeruginosa; 16 (35%) of those died. Fifteen (75%) of 20 patients for whom isolates were genotyped had genotype A, and 3 (15%) had genotype B. Of 104 healthcare workers (HCWs) from whom hand cultures were obtained, P aeruginosa was isolated from three nurses. Cultures from nurses A-1 and A-2 grew genotype A, and cultures from nurse B grew genotype B. Nurse A-1 had long natural fingernails, nurse B had long artificial fingernails, and nurse A-2 had short natural fingernails. On multivariate logistic regression analysis, exposure to nurse A-1 and exposure to nurse B were each independently associated with acquiring a BSI or ETT colonization with P aeruginosa, but other variables, including exposure to nurse A-2, were not. CONCLUSION: Epidemiological evidence demonstrated an association between acquiring P aeruginosa and exposure to two nurses. Genetic and environmental evidence supported that association and suggested, but did not prove, a possible role for long or artificial fingernails in the colonization of HCWs' hands with P aeruginosa. Requiring short natural fingernails in NICUs is a reasonable policy that might reduce the incidence of hospital-acquired infections.

Improving the health of Oklahomans through clinical prevention. Part 1: Counseling to decrease major risk factors.

Compared to other states, Oklahomans suffer higher levels of morbidity and mortality from several common conditions--coronary heart disease, chronic lung disease, stroke and injury. Unhealthy personal behaviors contribute significantly to each of these conditions, thus rendering them at least partially preventable by changing those behaviors. Research has shown that many patients will modify unhealthy behaviors as a result of services provided by physicians or staff in their offices, often with briefly delivered messages. In this report we will discuss the most common preventable illnesses suffered by Oklahomans and the risk factors associated with those illnesses. Physicians should make maximum use of their ability to promote healthy behaviors by their patients, with emphasis on the risk factors associated with significant morbidity in the state. They should also focus on those risk factors patients are likely to change following physician counseling, as determined by prevention research and described in the U.S. Preventive Services Task Force document Guide to Clinical Preventive Services. In general, physicians should consistently deliver messages that address tobacco products, alcohol and other drugs, the use of seat belts, and diet and exercise. Also, they should recommend that all women of childbearing age who are capable of becoming pregnant take a multivitamin containing folic acid daily.

Improving the health of Oklahomans through clinical prevention, Part III: Immunizations and chemoprophylaxis.

Vaccines are one of the greatest achievements of biomedical science and public health and are clearly one of the most effective tools of clinical prevention. Diseases that once caused significant morbidity and mortality in Americans--particularly children--have been virtually eliminated from the population through effective immunization programs. But until these diseases have been eradicated globally we must continue to maintain high immunization levels to prevent their return; a 90% coverage rate has been set as the national goal for recommended vaccines in preschool age children. In Oklahoma we have only achieved that goal for two vaccines (measles and polio) and for the last several years we have ranked near the bottom in vaccine coverage rates compared to other states. Although achieving high vaccination rates in children involves numerous partners, private physicians must play a major role in that effort since they are the primary vaccine providers in the state. Physicians should also be alert to the vaccine needs of their adolescent and adult patients, particularly for pneumococcal disease, influenza, hepatitis A and B, and tetanus. This article describes current vaccination levels in Oklahoma children and adults for several routine and newly recommended vaccines and discusses the role of private physicians in maintaining and improving immunization coverage.

Prevalence of American trypanosomiasis (Chagas disease) among dogs in Oklahoma.

OBJECTIVE: To determine the prevalence of Trypanosoma cruzi infection among dogs in Oklahoma. DESIGN: Cross-sectional study. ANIMALS: 301 owned or impounded dogs related by ownership or general geographic location to 3 dogs determined to have trypanosomiasis. PROCEDURES: Blood samples were obtained from dogs between November 1996 and September 1997. Infection status was determined by use of a radioimmunoprecipitation assay. Second blood samples were obtained from some of the seropositive dogs for study by hemoculture and polymerase chain reaction (PCR) assay. Sites where infected dogs were found were inspected for triatomine insects, and light traps were used for vector trapping. RESULTS: 11(3.6%) dogs were seropositive for T. cruzi infection. Ten of the 11 were owned rural hunting dogs. Protozoal organisms isolated from the blood of 1 seropositive dog were identified as T. cruzi by PCR testing. Only 1 adult Triatoma sanguisuga was captured in a light trap at a site near infected dogs; this insect was not infected. CONCLUSIONS AND CLINICAL RELEVANCE: Our findings suggest that T. cruzi is enzootic in eastern Oklahoma. Measures that would reduce the risk of dogs acquiring T. cruzi infection are unlikely to be acceptable to their owners, and no effective drugs are available for treatment. The presence of T. cruzi-infected dogs poses a threat of transmission to persons at risk of exposure to contaminated blood Veterinarians who practice in the southern United States should be cognizant of this blood borne zoonosis and educate all personnel about appropriate precautions.

Oklahoma notes decline in Haemophilus influenzae: invasive Haemophilus influenzae disease among children aged < 5 years--Oklahoma, 1990-1997.

Haemophilus influenzae (Hi) causes many clinical illnesses such as meningitis, bacteremia, epiglottitis, pneumonia, otitis media, sinusitis and tracheobronchitis. Before the introduction of the Haemophilus influenzae type b (Hib) conjugate vaccine in 1988, Hib caused more than 95 percent of invasive Hi disease in developed countries. Conjugate vaccines were licensed for use in children > or = 15 months of age in 1989 and for use in children > or = 2 months of age in 1990. During 1987-1995, the incidence of invasive Hi disease among children < 5 years of age decreased 96 percent in the United States. This report summarizes the trend in invasive disease caused by Hi among Oklahoma children < 5 years of age. The data represents cases reported to the OSDH as part of the infectious disease surveillance system. Invasive Hi disease has been reportable by law in Oklahoma since 1983.

Ticks and tick-borne diseases in Oklahoma.

Tick-borne diseases are common in Oklahoma, especially the eastern part of the state where tick prevalence is highest. Three species of hard ticks are present in Oklahoma that are known vectors of human disease--the American dog tick (Rocky Mountain spotted fever; RMSF), the lone star tick (ehrlichiosis) and the black-legged tick (Lyme disease). Oklahoma consistently ranks among the top states in numbers of reported RMSF cases, and Ehrlichiosis may be as prevalent as RMSF. Although Lyme disease is frequently reported in Oklahoma, over-diagnosing of this disease due to false-positive test results is common; positive or equivocal screening tests should be confirmed by Western immunoblot. At present, it is unclear whether the disease seen here is Lyme disease or another Lyme-like disease. If true Lyme disease is present in the state, it is probably rare. Physicians should be aware of the most recent recommendations for diagnosis, therapy and prevention of tick-borne diseases.

First reported case of hantavirus pulmonary syndrome in Oklahoma.

Hantavirus Pulmonary Syndrome (HPS) is a condition of rapidly progressive pulmonary failure with a case-fatality rate of almost 50 percent. Rodents serve as the reservoir for hantaviruses and human infection occurs primarily via aerosolized virus in rodent excreta. The rodent reservoir for the disease is widespread across Oklahoma and the first case of HPS has recently been confirmed in an Oklahoma resident. Physicians should suspect HPS in a previously healthy person who develops a febrile illness and respiratory insufficiency and has potentially been exposed to the virus. Common laboratory findings include a left-shifted neutrophilic leukocytosis, elevated hematocrit and thrombocytopenia. Therapy is supportive. If HPS is suspected, the patient should be immediately transferred to a facility that can provide aggressive supportive care.

An outbreak of multidrug-resistant pneumococcal pneumonia and bacteremia among unvaccinated nursing home residents.

BACKGROUND: Outbreaks of pneumococcal disease are uncommon and have occurred mainly in institutional settings. Epidemic, invasive, drug-resistant pneumococcal disease has not been seen among adults in the United States. In February 1996, there was an outbreak of multidrug-resistant pneumococcal pneumonia among the residents of a nursing home in rural Oklahoma. METHODS: We obtained nasopharyngeal swabs for culture from residents and employees. Streptococcus pneumoniae isolates were serotyped and compared by pulsed-field gel electrophoresis. A retrospective cohort study was conducted to identify factors associated with colonization and disease. RESULTS: Pneumonia developed in 11 of 84 residents (13 percent), 3 of whom died. Multidrug-resistant S. pneumoniae, serotype 23F, was isolated from blood and sputum from 7 of the 11 residents with pneumonia (64 percent) and from nasopharygeal specimens from 17 of the 74 residents tested (23 percent) and 2 of the 69 employees tested (3 percent). All the serotype 23F isolates were identical according to pulsed-field gel electrophoresis. Recent use of antibiotics was associated with both colonization (relative risk, 2.3; 95 percent confidence interval, 1.3 to 4.2) and disease (relative risk, 3.6; 95 percent confidence interval, 1.2 to 10.8). Only three residents (4 percent) had undergone pneumococcal vaccination. After residents received pneumococcal vaccine and prophylactic antibiotics, there were no additional cases of pneumonia, and the rates of carriage decreased substantially. CONCLUSIONS: In this outbreak a single pneumococcal strain was disseminated among the residents and employees of a nursing home. The high prevalence of colonization with a virulent organism in an unvaccinated population contributed to the high attack rate. Clusters of pneumococcal disease may be underrecognized in nursing homes, and wider use of pneumococcal vaccine is important to prevent institutional outbreaks of drug-resistant S. pneumoniae infection.

Phase I/IIa safety, immunogenicity, and efficacy trial of NYVAC-Pf7, a pox-vectored, multiantigen, multistage vaccine candidate for Plasmodium falciparum malaria.

Candidate malaria vaccines have failed to elicit consistently protective immune responses against challenge with Plasmodium falciparum. NYVAC-Pf7, a highly attenuated vaccinia virus with 7 P. falciparum genes inserted into its genome, was tested in a phase I/IIa safety, immunogenicity, and efficacy vaccine trial in human volunteers. Malaria genes inserted into the NYVAC genome encoded proteins from all stages of the parasite's life cycle. Volunteers received three immunizations of two different dosages of NYVAC-Pf7. The vaccine was safe and well tolerated but variably immunogenic. While antibody responses were generally poor, cellular immune responses were detected in >90% of the volunteers. Of the 35 volunteers challenged with the bite of 5 P. falciparum-infected Anopheles mosquitoes, 1 was completely protected, and there was a significant delay in time to parasite patency in the groups of volunteers who received either the low or high dose of vaccine compared with control volunteers.

Sterile protection of monkeys against malaria after administration of interleukin-12.

An estimated 300-500 million new infections and 1.5-2.7 million deaths attributed to malaria occur annually in the developing world, and every year tens of millions of travelers from countries where malaria is not transmitted visit countries with malaria. Because the parasites that cause malaria have developed resistance to many antimalarial drugs, new methods for prevention are required. Intraperitoneal injection into mice of one dose of 150 ng (approximately 7.5 micrograms per kg body weight) recombinant mouse interleukin-12 (rmIL-12) 2 days before challenge with Plasmodium yoelii sporozoites protects 100% of mice against malaria. We report that one subcutaneous injection of 10 micrograms/kg recombinant human IL-12 (rhIL-12) 2 days before challenge with P. cynomolgi sporozoites protected seven of seven rhesus monkeys. Protection was associated with marked increases in plasma levels of interferon-gamma (IFN-gamma), and relative increases of lymphoid cell messenger RNA coding for IFN-gamma and several other cytokines. We speculate that rIL-12 protects monkeys through IFN-gamma-dependent elimination of P. cynomolgi-infected hepatocytes. This first report of rIL-12-induced protection of primates against an infectious agent supports assessment of rhIL-12 for immunoprophylaxis of human malaria.

Case report: locally acquired trichinosis in an immigrant from Southeast Asia.

The authors report a case of trichinosis acquired in Oklahoma City by an immigrant from Southeast Asia. The 49-year-old female reported having abdominal discomfort, nausea, and vomiting, and had purchased and eaten lightly cooked pork. She also complained of fatigue, anorexia, and muscle aches for several months. An immigrant from Laos, she stated that she regularly eats pork and prefers it rare or mildly cooked. The authors caution local physicians to be aware of the increased risk of trichinosis among Southeast Asian immigrants in the area, particularly those from Laos and Cambodia. Continued emphasis on the need to thoroughly cook all pork products is necessary if the incidence of trichinosis in the U.S. is to be controlled.