F lu A Major Concern for Pregnant Women

Transcription

1 c i m e d n a P F lu A Major Concern for Pregnant Women Nurses caring for pregnant women and infants are on the front lines to mitigate serious consequences that may occur with an influenza pandemic. To assist nurses in becoming prepared for a pandemic, this article will address various types of influenza viruses, effects of influenza on pregnant women, diagnosis, treatment and ways to protect pregnant women and newborns. Amy Labant, PhD, RNC Julia A. Greenawalt, PhD, RNC

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3 Overview of Influenza Viruses Influenza is a RNA virus of the orthomyxovirus family that causes acute respiratory illness. There are three types of influenza viruses and they are classified as type A, B or C. Types A and B pose a concern to human health and are associated with seasonal flu; type C may produce mild or no symptoms. Only type A viruses can cause pandemics (World Health Organization [WHO], 2005). Influenza A virus is further classified based on two surface proteins, hemagglutinin (H) and neuraminidase (N). The hemagglutinin (H) protein allows the influenza virus to attach to host cells by binding to specific receptors. The neuraminidase (N) protein helps newly formed viral particles to be released from the cell surface to provide the capability to infect other cells (Gorby, 2009). Influenza viruses are continually evolving, causing mutations that can occur gradually or suddenly. When a slight mutation occurs it is identified as an antigenic drift. Because of antigenic drift, seasonal influenza vaccines must be updated annually. When a significant mutation occurs it s called an antigenic shift. The antigenic shift can occur through mutations of nonhuman (e.g., avian or swine) viruses or reassortment of human and nonhuman viruses. Mutations and reassortments form novel subtypes. When novel subtypes develop that can Bottom Line Pregnant women and newborns are particularly vulnerable during an influenza pandemic. There are several precautions that can be taken to reduce transmission of a novel virus. Health care providers must stay abreast of the latest information on the H1N1 virus. be easily transmitted among humans, an influenza pandemic can develop (U.S. Department of Health and Human Services, 2005). There are 16 different hemagglutinins and nine different neuraminidase subtypes (Centers for Disease Control and Prevention [CDC], 2007). Thus, there are many different arrangements that may evolve. An influenza pandemic arises when a new influenza virus Editor s note: The content in this article was up-to-date at the time this article went to press in mid-july. However, given the highly evolving nature of information on the H1N1 virus, readers are urged to check the Web site of the Centers for Disease Control and Prevention (CDC) at for new information. Amy Labant, PhD, RNC, and Julia A. Greenawalt, PhD, RNC, are assistant professors at Indiana University of Pennsylvania in Indiana, PA. Address correspondence to: alabant@iup.edu. DOI: /j X x subtype appears, against which no one is immune (WHO, 2005). Global transportation and urbanization will make new influenza viruses likely to occur rapidly worldwide. Historically, pandemic influenzas have taken place in waves lasting 6 to 8 weeks and reoccurring in several months. Pandemics occur infrequently, whereas seasonal flu is annual. The differences between pandemics and seasonal influenza include the severity of symptoms and complications (see Box 1). Annually, there are approximately 36,000 deaths from seasonal influenza (CDC, 2009a). The first influenza pandemic was reported in 1580 (Potter, 2001). During the 20th century, there were three pandemics worldwide. The 1918 Spanish Flu (H1N1) was the most devastating and killed more than 675,000 people in the United States (Gorby, 2009). The mortality was highest among healthy adults between 20 and 50 years old. Pregnant women were among the most vulnerable. The second pandemic was reported in 1957 and was called the Asian Flu (H2N2). The highest infection rates were seen among school children, young adults and pregnant women (Ray & Walker-Jenkins, 2006). An estimated 69,800 people died in the United States from the Asian Flu. The third pandemic was the 1968 Hong Kong Flu (H3N2) and was the mildest pandemic in the 20th century with a mortality figure of 34,000 (Gorby). H1N1 Virus On April 26, 2009, the U.S. Department of Health and Human Services declared a national health emergency regarding novel influenza A (H1N1), formerly referred to as swine influenza A virus. The novel influenza A (H1N1) is a genetic mixture of swine, bird and human viruses. As of June 11, 2009, the WHO issued a pandemic period phase 6. Box 2 identifies the WHO pandemic phases and compares them to the U.S. Federal Government response stages. Swine influenza is a common respiratory disease in pigs and was first isolated in There are currently four main influenza type A virus subtypes in pigs (CDC, 2009c). Swine flu mutates and changes constantly. Pigs can be infected by swine influenza, avian influenza, and human influenza viruses. When influenza viruses from different species infect pigs, the viruses can reassort (i.e., swap genes) and new viruses that are a mix of swine, human and/or avian can emerge. Before March 18, 2009, when Mexico first reported swine flu (H1N1) in humans, H1N1 rarely infected humans. From 2005 until January 2009, 12 human cases of swine flu were reported in the United States and none were fatal (CDC, 2009c). However, it was reported in September 1988 that a previously healthy 32-year-old pregnant woman was hospitalized for pneumonia and died 8 days later. A swine H1N1 flu virus was detected. Four days before becoming ill, the patient attended a county fair swine exhibition where there was influenza-like illness among the swine. It was also reported that 76 percent of the swine exhibitors at the fair and several health care personnel who , AWHONN

4 Box 1 Comparison of Seasonal Influenza Versus Pandemic Influenza Seasonal Influenza Caused by influenza A and B viruses that have previously infected people Pandemic Influenza Caused by new influenza A virus to which people have not been previously exposed Vaccine available No vaccine available initially Symptoms include cough, fever, headache, malaise, myalgia, rhinitis and sore throat Symptoms are similar to seasonal flu but may be more severe with serious complications. More people may be affected and have higher risk of morbidity and mortality. Healthy adults usually are not at risk for serious complications Healthy adults may be at increased risk for serious complications Generally causes modest impact on society Patterns of daily life could change for some time. Schools and business could be closed. People could be quarantined to prevent the spread of the virus. Travel and public gatherings could be limited. Basic services and access to supplies could be disrupted. Sources: U.S. Department of Health and Human Services (2006) and CDC (2009b) had contact with the patient had antibodies of swine flu infection, but no serious illness was detected (CDC, 2009c). Influenza and Pregnancy Pregnancy alters the immune system, which may cause pregnant women to be more susceptible to influenza and may enhance the severity of the illness, thereby increasing mortality rates in this vulnerable population (Jamieson, Theiler, & Rasmussen, 2006). Pregnant women have been classified as a high-risk group (Brauser, 2009). Physiological factors during pregnancy in the cardiovascular and respiratory systems, in- cluding increased heart rate, stroke volume and oxygen consumption, and decreased lung capacity may also increase the woman s risk factor (Jamieson et al.). It has been reported that pregnant women are at risk for acquiring influenza both during interpandemic and pandemic periods. A large-scale study that encompassed 19 interpandemic influenza seasons was conducted by Neuzil, Reed, Mitchel, Simmonsen, and Griffin (1998). Pregnant women were compared with postpartum women. The results revealed that pregnant women were significantly more likely to be hospitalized for a cardiopulmonary event during the influenza season. Hos- Influenza viruses are continually evolving, causing mutations that can occur gradually or suddenly October November 2009 Nursing for Women s Health 377

5 Sneezing into one s sleeve is recommended rather than sneezing into one s hands pitalizations of pregnant women with respiratory illnesses during seasonal influenza have been reported to be 3.4 per 1,000 during the 1998 to 2002 influenza season (Cox et al., 2006). During the 1918 Spanish Flu pandemic, the death rate for pregnant women ranged from 23 percent to 71 percent (Barry, 2005). Death rates for pregnant women were also reported to be high during the Asian Flu, accounting for 20 percent of deaths associated with pregnancy during the pandemic period in Minnesota (Freeman & Barno, 1959). Overall, novel influenza A (H1N1) has been mild in the United States, but viruses are unpredictable. Historically, pandemics come in waves; therefore, the worst may not be over. The CDC expects that more H1N1 cases, more hospitalizations and more deaths will occur over the coming days and months. The symptoms of novel influenza (H1N1) include fever, cough, sore throat, runny or stuffy nose, body aches, headache, chills and fatigue (CDC, 2009b). In addition, vomiting and diarrhea have been reported in some cases. As of May 10, 2009, a total of 20 cases of novel influenza A (H1N1) virus had been reported among pregnant women in the United States. Three women were hospitalized, one of whom died (CDC, 2009d). The impact of maternal influenza infections on the fetus is not well understood (Rasmussen, Jamieson, & Bresee, 2008). Previous pandemics have shown high incidence of spontaneous abortions and preterm births. A major concern is hyperthermia. Past studies have shown that maternal hyperthermia early in pregnancy can increase the risk for neural tube defects (Moretti, Bar-Oz, Fried, & Koren, 2005). Maternal fever during labor has been shown to be a risk factor for adverse neonatal and developmental outcomes, including neonatal seizures, encephalopathy, cerebral palsy and neonatal death (CDC, 2009e). chain reaction (RT-PCR) is the recommended test for confirmation of novel influenza A (H1N1) virus. The CDC (2009e) states that pregnant women with influenza-like illnesses should receive antiviral treatment for 5 days. Oseltamivir (Tamiflu) is the preferred treatment for pregnant women, and the drug regimen should be initiated within 48 hours of symptom onset. Pregnant women who are in close contact with a person with confirmed or suspected novel influenza A (H1N1) infection should receive a 10-day course of chemoprophylaxis with zanamivir (Relenza) or oseltamivir (Tamiflu) (CDC, 2009e). The CDC antiviral recommendations for pregnant women may change during the course of the pandemic. Influenza vaccines are ideal in preventing influenza. The U.S. Department of Health and Human Services Secretary Kathleen Sebelius is directing nearly $1 billion in existing preparedness funds to manufacture a vaccine for the novel influenza A (H1N1) virus (U.S. Department of Health and Human Services, 2009). Diagnosis and Treatment of H1N1 Preventing Influenza Among Pregnant Women and Newborns The diagnosis of individuals suspected of novel influenza A (H1N1) is done by obtaining an upper respiratory specimen (CDC, 2009f). Swab specimens should be collected using swabs with a synthetic tip (e.g., polyester or Dacron) and an aluminum or plastic shaft. Swabs with cotton tips and wooden shafts are not recommended. All specimens should be kept at 4 C for no longer than 4 days. Real-time reverse-transcription polymerase To prevent seasonal flu, it s recommended that pregnant women receive the inactivated vaccine (Fiore et al., 2008). A blinded randomized control study was conducted on 340 mothers to evaluate the effectiveness of maternal seasonal influenza immunizations in mothers and infants. Maternal influenza immunizations significantly reduced the rate of laboratory-confirmed influenza in the infant (Zaman et al., 2008). 378 Nursing for Women s Health Volume 13 Issue 5

6 Influenza viruses are most commonly spread via liquid droplet projected into the air as one sneezes or coughs. The goal is to limit transmission of a new influenza strain. Therefore, it is recommended to employ cough etiquette; that is, sneezing into one s sleeve is recommended rather than sneezing into one s hands. Wash hands frequently, and avoid touching membranous areas such as the nose and eyes. Additional measures may include home quarantine of members with confirmed or probable influenza cases, reducing social contacts and avoiding crowds. During a pandemic, hospitals can become a site for increased risk of morbidity and mortality for pregnant women and newborns. The Association of Maternal and Child Health Programs Box 2 Federal Response Stages WHO Phases Federal Government Response Stages INTER-PANDEMIC PERIOD 1 No new influenza virus subtypes have been detected in humans. An influenza virus subtype that has caused human infection may be present in animals. If present in animals, the risk of human disease is considered to be low. 2 No new influenza virus subtypes have been detected in humans. However, a circulating animal influenza virus subtype poses a substantial risk of human disease. 0 New domestic animal outbreak in at-risk country PANDEMIC ALERT PERIOD 3 Human infection(s) with a new subtype, but no human-to-human spread, or at most rare instances of spread to a close contact. 4 Small cluster(s) with limited human-tohuman transmission but spread is highly localized, suggesting that the virus is not well adapted to humans. 5 Larger cluster(s) but human-to-human spread still localized, suggesting that the virus is becoming increasingly better adapted to humans, but may not yet be fully transmissible (substantial pandemic risk). 0 New domestic animal outbreak in at-risk country. 1 Suspected human outbreak overseas 2 Confirmed human outbreak overseas PANDEMIC PERIOD 3 Widespread human outbreaks in multiple locations overseas 6 Pandemic phase: increased and sustained transmission in general population. 4 First human case in North America 5 Spread throughout United States 6 Recovery and preparation for subsequent waves October November 2009 Nursing for Women s Health 379

7 (2007) provides recommendations for the care of women and infants during labor, birth and postpartum in the event of a pandemic of a new type A viral strain. The main goal is to prevent contact between infected individuals and pregnant women and newborns. An option is to isolate the delivery suites from other areas of the hospital. Entry to the unit would be restricted to essential hospital staff who are not ill. If possible, a separate entrance to the maternity unit would be used to prevent contact within lobbies, corridors and elevators. Visitors would be restricted to only one healthy significant other, and discharge would be as soon as possible. All mothers should be encouraged to breastfeed early and frequently, so that the newborn can receive as many maternal antibodies as possible. If a mother or newborn should become ill with novel influenza A (H1N1), the CDC (2009e) recommends continuing breastfeeding. If the mother becomes too ill to breastfeed and pumping is not an option, offering human donor milk from a certified breast milk bank may be an alternative (CDC, 2009e). Additional measures for protecting infants from respiratory illness are described in Box 3. Care of In-Patient Pregnant Women and Newborns Box 3 Measures to Protect Infants from Respiratory Illness Wash adults and infants hands frequently with soap and water. Keep the infant away from people who are ill and keep the infant out of crowded areas. Limit sharing of toys and other items that have been in infants mouths. Wash thoroughly with soap and water any items that have been in infants mouths. Keep pacifiers and other items out of mouths of adults or other infants prior to giving to infant. Practice cough and sneeze etiquette. Encourage breastfeeding. Source: CDC (2009e) All health care personnel caring for patients being evaluated or in isolation for novel H1N1 should take standard and contact precautions plus eye protection (CDC, 2009g). When caring for a pregnant woman who has confirmed, probable or suspected novel H1N1, the nurse must check the most current information from the CDC on caring for these patients. As of July 6, 2009, the CDC (2009h) recommends the following: Initiate appropriate antiviral treatment as soon as possible. Isolate the ill mother from healthy pregnant women. Place a surgical mask on the ill mother during labor and delivery, if tolerable, in order to decrease exposure of the newborn, health care personnel and other labor and delivery patients to potentially infectious respiratory secretions. Place the ill mother in isolation after delivery. The mother who has influenza-like-illness at delivery should consider avoiding close contact with her infant until the following conditions have been met: She has received antiviral medications for 48 hours, her fever has fully resolved and she can control coughs and secretions. Meeting these conditions may reduce, but not eliminate, the risk of transmitting influenza to the baby. Before these conditions are met, the newborn should be cared for in a separate room by another person who is well, and the mother should be encouraged and assisted to express her milk. Breast milk is not thought to be a potential source of influenza virus infections. As soon as all conditions are met, the mother should be encouraged to wear a facemask, change to a clean gown or clothing, adhere to strict hand hygiene and cough etiquette when in contact with her infant, and begin breastfeeding (or if not able to breastfeed, bottle feeding). She should continue these protective measures both in the hospital setting and at home, for at least 7 days after the onset of influenza symptoms. If symptoms last more than 7 days, she should discuss the symptoms with her doctor. Protective measures might need to be continued until she is symptom-free for 24 hours. People who are once again well 7 days after getting sick are thought to be at low risk for transmitting the virus to others. The risk for transmission of novel H1N1 from mother to fetus is unknown; therefore, the newborn should be considered to be potentially infected if delivery occurs during the 2 days before through 7 days after illness onset in the mother. Infection control procedures developed for H1N1 flu should be used for the newborn throughout the hospital stay. Health care workers should don nonsterile gown, mask and protective eye equipment upon entering the room of a patient being screened for influenza or caring for the patient in isolation. If the patient is a confirmed, suspected or probable novel H1N1 influenza patient, health care workers should wear a N95 or higher filtering face piece respirator certified by the CDC/ National Institute for Occupational Safety and Health (NI- OSH). According to NIOSH, there are ratings for respirators. A rating of N, R or O can be assigned. An N rating means that the respirator is not oil resistant, whereas R designates that it is oil resistant, and O means that the respirator is oil proof. The numeral after the oil resistant status designates the mask 380 Nursing for Women s Health Volume 13 Issue 5

8 Pregnant women and newborns are very vulnerable during a pandemic be distributed to pregnant women. Pandemic education can be incorporated into childbirth classes, prenatal visits and postpartum teaching. Additionally, providing information and encouraging pregnant women to receive an annual seasonal influenza vaccine is vital. Promoting and supporting breastfeeding is also essential. Secondly, based on previous pandemics, the impact on maternity services could possibly be overwhelming. Pandemic disaster drills need to be conducted for inpatient and out-patient facilities. Finally, continuously monitoring information on novel influenza A (H1N1) as it evolves is highly recommended to stay abreast of the latest information, possibly mitigating the consequences of a pandemic. NWH References American Red Cross (2006, October). Pandemic Flu Family Preparedness Guide. Retrieved July 20, 2009, from fam_prepared_fs.pdf will filter out 95 percent of airborne particles. Better masks are certified to filter up to percent of the airborne particles. This conservative approach is recommended by the CDC until more is known about the specific transmission of this unique virus. Isolation precautions should stay in effect for 7 days from symptom onset or until the resolution of symptoms, whichever is longer. Exposure to the patient should be reserved for necessary health care interventions. Visitors should be limited and their movement within the facility should be restricted. Visitors will need to be educated on isolation precaution concepts, such as frequent hand hygiene, limiting surfaces touched while in the patient s room, how to don the recommended equipment nonsterile gown, N95 mask, gloves and protective eye gear as well as how to properly dispose of it. It s imperative that vigilant respiratory infection control measures be followed (CDC, 2009g). Nursing Implications Pregnant women and newborns are very vulnerable during a pandemic. The goal of the nurse is to provide optimal care for pregnant women and newborns during a pandemic. Taking a proactive approach and planning is imperative. First, nurses can assist pregnant women in planning and preparing for a pandemic through education. The American Red Cross (2006) provides a brochure entitle Pandemic Flu: Family Preparedness Guide and the CDC offers public information that can October November 2009 Association of Maternal and Child Health Programs (2007). State emergency planning and preparedness recommendations for maternal and child health populations. Washington, DC: Author. Barry, J. M. (2005). The great influenza. New York: Penguin Books. Brauser, D. (2009, May 4). Treatment of H1N1 influenza A (swine flu) in high-risk populations: Guidance for clinicians. Medscape Infectious Diseases. Retrieved May 20, 2009, from medscape.com/viewarticle/702292_print Centers for Disease Control and Prevention. (2007, December 20). Types of influenza viruses. Retrieved May 29, 2009, from Centers for Disease Control and Prevention. (2009a). Questions and answers regarding estimating deaths from influenza in the United States. Retrieved May 29, 2009, from about/disease/us_flu-related_deaths.htm Centers for Disease Control and Prevention. (2009b). Clinical signs and symptoms of influenza. Retrieved May 29, 2009, from Centers for Disease Control and Prevention. (2009c). Key facts about swine influenza. Retrieved May 2, 2009, from cdc.gov/h1n1flu/key_facts.htm Centers for Disease Control and Prevention. (2009d). Novel Influenza A (H1N1) virus infections in three pregnant women United States, April May Morbidity and Mortality Weekly Report. Retrieved May 20, 2009, from preview/mmwrhtml/mm5818a3.htm Centers for Disease Control and Prevention. (2009e). Pregnant women and novel influenza A (H1N1) considerations for clinicians. Retrieved June 30, 2009, from Nursing for Women s Health 381

9 Centers for Disease Control and Prevention. (2009f). Interim guidance on specimen collection, processing, and testing for patients with suspected novel influenza A (H1N1) virus infection. Retrieved May 29, 2009, from Centers for Disease Control and Prevention. (2009g). Interim guidance for infection control for care of patients with confirmed or suspected novel influenza A (H1N1) virus infection in a healthcare setting. Retrieved May 20, 2009, from 1flu/guidelines_infection_control.htm Centers for Disease Control and Prevention. (2009h). Considerations regarding novel H1N1 flu virus in obstetric settings. Retrieved July 17, 2009, from Cox, S., Posner, S. F., McPheeters, M., Jamieson, D. J., Kourtis, A. P., & Meikle, S. (2006). Hospitalization with respiratory illness among pregnant women during influenza season. Obstetrics and Gynecology, 107, Fiore, A. E., Shay, D. K., Broder, K., Iskander, J. K., Uyeki, T. M., & Mootrey G., et al. (2008). Prevention and control of influenza: Recommendations of the advisory committee on immunization practices (ACIP). Morbidity and Mortality Weekly Report. Retrieved May 20, 2009, from mmwrhtml/rr57e717a1.htm Freeman, D. W., & Barno, A. (1959). Deaths from Asian influenza associated with pregnancy. American Journal of Obstetrics and Gynecology, 78, Gorby, G. L. (2009). What do I need to know about the new H1N1 flu that everyone is concerned about? Retrieved May 10, 2009, from Jamieson, D. J., Theiler, R. N., & Rasmussen, S. A. (2006). Emerging infections and pregnancy. Emerging Infectious Disease, 12(11). Retrieved May 24, 2009, from vol12no11/ htm Moretti, M. E., Bar-Oz, B., Fried, S., & Koren, G. (2005). Maternal hyperthermia and the risk for neural tube defects in offspring: Systematic review and meta-analysis. Epidemiology, 16(2), Neuzil, K. M., Reed, G. W., Mitchel, E. F., Simmonsen, L., & Griffin, M. R. (1998). Impact of influenza on acute cardiopulmonary hospitalizations in pregnant women. American Journal of Epidemiology, 148, Potter, C. W. (2001). A history of influenza. Journal of Applied Microbiology, 91, Rasmussen, S. A., Jamieson, D. J., & Bresee, J. S. (2008). Pandemic influenza and pregnant women. Emerging and Infectious Diseases, 14, Retrieved May 29, 2009, from gov/eid/content/14/1/95.htm Ray, M. M. & Walker-Jenkins, A. (2006). Confronting bird flu. AWHONN Lifelines, 10, U.S. Department of Health and Human Services. (2005). HHS pandemic influenza plan. Retrieved December 12, 2008, from Get the Facts American Red Cross Association of Maternal and Child Health Programs AWHONN CDC Flu.gov U.S. Department of Health and Human Services. (2006). A guide for individuals and families. Retrieved July 28, 2008, from U.S. Department of Health and Human Services. (n.d.) Federal response stages. Retrieved May 29, 2009, from U.S. Department of Health and Human Services. (2009). HHS takes additional steps toward development of vaccine for novel influenza A (H1N1). Retrieved May 22, 2009, from news/press/2009pres/05/ b.html World Health Organization. (2005). WHO checklist for influenza pandemic preparedness Planning. Department of Communicable Disease Surveillance and Response Global Influenza Programme. Retrieved May 28, 2009, from publications/influenza/who_cds_csr_gip_2005_4/en/ Zaman, K., Roy, E., Arifeen, S. E., Rahman, M., Raqib, R., & Wilson, E., et al. (2008). Effectiveness of maternal influenza immunization in mothers and infants. New England Journal of Medicine, 359, Nursing for Women s Health Volume 13 Issue 5