Febrile Illnesses During the Summer and Fall:  Consider Tick-borne Infections in the Differential Diagnosis

 Summary

While Lyme disease (LD) is by far and away the most common tick-borne illness in Maine, two other such infections[1] occur here in much smaller numbers: babesiosis and human granulocytic ehrlichiosis (HGE).  For these illnesses, early diagnosis and treatment are potentially lifesaving. Most of Maine’s reported cases have occurred among persons whose tick exposures occurred in south coastal Maine. 

Clinicians seeing patients with unexplained “summer fevers” and history of tick bites or of outdoor exposures in tick-infested areas, should consider these infections in the differential diagnosis.  Basic laboratory studies (including CBC with peripheral smear, platelet count, and ALT/AST levels) provide valuable supportive information in screening for these illnesses.  Following is a brief summary of epidemiologic and clinical features of babesiosis and HGE:

 Babesiosis

Babesiosis is a malaria-like disease caused by the protozoan parasite Babesia microti.  It is most likely to result in significant medical problems among the elderly and the immunocompromised, and especially among asplenic individuals.  Like LD and HGE, it is transmitted by the bite of the deer tick and is maintained in an ecologic cycle that includes small rodent and deer populations.

 Clinical Manifestations

Most cases of babesiosis are asymptomatic and resolve spontaneously.  Among those persons who become ill, onset of illness follows an incubation period of 1-4 weeks after tick bite.  Principal manifestations are fever, chills, and fatigue.  Additionally, patients may have severe headache, myalgias and arthralgias, and nausea and vomiting.  Profuse malaria-like sweats also occur. There is no rash. The physical examination is usually unremarkable.  Deaths are uncommon among persons with normal splenic function.  (Note: Patients with babesiosis are often co-infected with Lyme disease.  Diagnostic testing for Lyme disease should be considered in all patients with babesiosis.)

 Laboratory Findings

 In clinically ill persons, hemolytic anemia is common, and thrombocytopenia and mild elevations of ALT and AST may also occur.  The diagnostic hallmark of babesiosis, however, is the presence of intraerythrocytic forms of the parasite, best seen on multiple Giemsa-stained thick and thin smears of peripheral blood.  The degree of parasitemia is usually less than 10%, but may be much higher in asplenic individuals.  For illnesses with clinical and epidemiologic features suggestive of babesiosis but without detectable parasitemia, indirect immunofluorescent antibody (IFA) testing can be diagnostic. For more detailed information go to:  http://www.dpd.cdc.gov/dpdx/HTML/Babesiosis.htm

 Treatment

For persons with severe clinical illness, a course of quinine plus clindamycin or of atrovaquone plus azithromycin may be given. Other drug combinations may also be useful.  Consultation with an infectious disease specialist should be obtained.

 Epidemiology

Most of the several hundred reported cases of babesiosis in the past two decades have been reported from islands off the coast of Massachusetts (Nantucket and Martha’s Vineyard) and from Long Island, N.Y, but babesiosis may occur sporadically in other areas of the Northeast.  Most cases have their onset during the warmer months of spring, summer, and fall.  In Maine, locally-acquired babesiosis was first confirmed during 2001 in a York county resident.  During 2004, five cases of babesiosis were reported in Maine.

 Prevention

Preventive measures for babesiosis include the same measures for avoiding deer tick bites as apply for Lyme disease (i.e., use insect repellents, wear long sleeve shirts and long pants, avoid overgrown areas likely to be infested with ticks, and examine your clothes and skin for ticks after being outside).

 Human Granulocytic Ehrlichiosis (HGE)

Ehrlichiae are small gram-negative cocci, members of the Rickettsia family that cause a number of diseases in humans and animals around the world.  In the United States, canine, ruminant, and equine illnesses can result from infections with several Ehrlichia species.  In humans, clinical illnesses occur in two distinct epidemiologic patterns in this country: Human Monocytic Ehrlichiosis (HME) is seen in southeastern and midwestern states; Human Granulocytic Ehrlichiosis (HGE), which is clinically very similar to HME, is seen the Northeast and in parts of the upper Midwest. The etiologic agent of HGE is Anaplasma phagocytophilum. (note: HGE is now referred to in some literature as “Anaplasmosis”)

 Clinical Manifestations

After an incubation period averaging 5-10 days, most patients with HGE will have a nonspecific constitutional illness (fever, headache, malaise, myalgias) and, may also experience vomiting and diarrhea, cough, confusion and arthralgias.  Rash occurs rarely.  Serious complications of illness (especially in untreated patients) may include seizures, encephalitis, renal failure, disseminated intravascular coagulation (DIC), and adult respiratory distress syndrome (ARDS). One-half of all diagnosed patients require hospitalization and the severity of illness is greater among immunocompromised persons. The rate of subclinical HGE infection is unknown.  Most, but not all, diagnosed patients will recall a history of a tick bite, or outdoor exposures in tick-inhabited areas.

 Laboratory Findings

Basic laboratory findings suggestive of HGE include leukocytopenia, thrombocytopenia, and elevated serum aminotransferase levels. In addition, Giemsa or Diff-Quik stains of peripheral blood may identify intragranulocytic organisms.  Confirmation of HGE can be challenging.  Reference laboratory methods include indirect immunofluorescent assay (IFA), and serum antibody titers (IgM and IgG ), which should be performed on both acute and convalescent specimens.  Other methods, including DNA amplification by polymerase chain reaction (PCR) are available through some research laboratories.

 Treatment

When HGE is strongly suspected, the initiation of treatment should not be delayed for laboratory confirmation.  Doxycycline (adult dosage: 100 mg. b.i.d. for a minimum of 5-7 days and until fever has resolved and clinical improvement has been evident for at least 3 days) is the drug of choice for treatment.  Fever will generally subside within 24-72 hours after treatment with a tetracycline begins, and failure to do so argues against the diagnosis of HGE.

 Ecology and Epidemiology

The agent of HGE is maintained in rodent and deer populations, and is transmitted by the bite of the deer tick (Ixodes scapularis), the same tick that transmits Lyme disease.  Incidence rates of HGE are highest in states that also have high rates of Lyme disease; the greatest numbers of reported cases have come from New York, Connecticut, Wisconsin, and Minnesota.  Like Lyme disease, the great majority of cases (80%) occur between April and September, with peak incidence during midsummer. In contrast to Lyme disease, case rates of HGE are highest in older adults, with most patients over age 40.

 HGE in Maine

In Maine, the first case was reported in a Franklin county resident in 2000.  During 2004, one HGE case was reported in a resident of Cumberland County.  This year, several reported cases are currently being investigated.

 Prevention

HGE prevention strategies involve measures to prevent deer tick bites, as for Lyme disease and babesiosis (i.e., use insect repellents, wear long sleeve shirts and long pants, avoid overgrown areas likely to be infested with ticks, and examine your clothes and skin for ticks after being outside).

Reporting and Consultation: To report suspect cases and/or to discuss with a medical epidemiologist, call 1-800-821-5821

For more information on babesiosis go to:  http://www.cdc.gov/ncidod/dpd/parasites/babesia/default.htm

For more information on HGE go to: http://www.cdc.gov/ncidod/dvrd/ehrlichia/Index.htm

Summer Is Here: Think RWI  (Recreational Water Illnesses)

Selected excerpts from American Academy of Pediatrics Newsletter, May 2004

One of the many reasons Maine is known as “Vacationland” is the wide array of opportunities to participate in recreational water activities.  From a local community pool to state beaches, rivers, and lakes, Maine offers both tourists and locals endless swimming options.  

While swimming is a pleasurable activity it can also be a vehicle for the transmission of infection.  According to surveillance conducted by the Centers for Disease Control and Prevention (CDC), outbreaks of gastrointestinal illness associated with recreational water venues are on the rise.  While the Maine Department of Health and Human Services, Bureau of Health receives sporadic reports of Recreational Water Illnesses (RWI),  it is difficult to adequately characterize the full spectrum of such outbreaks in the state due to underreporting.  It is only through increased vigilance by health professionals to take stool samples and test for RWI, that we will have a better understanding of this issue. 

RWI refer to illnesses associated with the use of recreational water venues, including swimming pools, hot tubs, and water parks as well as untreated or naturally occurring bodies of water such as lakes, rivers, and oceans.

RWI include a broad spectrum of illnesses including infections of the skin, eye, ear, respiratory, neurologic, and gastrointestinal systems.  Bacteria, viruses and small parasites that enter recreational water cause RWI.  Norwalk-like viruses, Escherichia coli 0157:H7, and the parasites Cryptosporidium and Giardia have been increasingly linked with RWI, however other infectious diseases, including salmonella, shigella, hepatitis A, legionella, and trematode cercariae have also been detected.  As with all infectious diseases, groups at particularly high-risk for having serious and life-threatening consequences from infection with certain waterborne pathogens include the immunosuppressed, pregnant women, the elderly, and the young.

There are several factors contributing to RWI.  Although many waterborne pathogens such as Giardia are commonly found in the environment, some such as Cryptosporidium, display chlorine resistance and therefore may survive for days in swimming pools despite adequate chlorination.  Many of the pathogens have low infectious doses and can be shed for weeks even after diarrhea ends.  Hence the continued propagation of infection can continue by young children to other family members and within group settings, such as day care facilities, as these young persons are not known for their careful attention to personal hygiene. 

In the summer, when beaches are heavily used, shallow and warm, bacteria and viruses can flourish and the beach may become a health risk, particularly when there is little new water or current to dilute and refresh the beach. Children and adults can contract a RWI if they swallow, breath in or come in contact with  water that has been contaminated. Natural water venues may be contaminated by infected animals defecating in watershed areas or by point source contamination (e.g. sewage effluent).   Also, boat sewage and storm water overflow are potential sources.  In all recreational water settings, fecal accidents as well as swimmers bodies serve as potential sources of contamination.  

Medical providers should consider evaluating patients who present with diarrheal symptoms for a possible RWI and submit stool specimens for enteric testing. Patients presenting with fever and chills, signs of dehydration, pain or unusual discharge from the eyes and ears, unusual skin eruptions or difficulty breathing should also be evaluated for a possible RWI. 

Medical providers or members of the public who identify illness related to water activity, or become aware of persons getting sick from water activity, should call the Maine Bureau of Health at 1- 800-821-5821 to report the illness. 

The key message is to practice healthy swimming habits (not stop swimming).   Information about healthy swimming tips (including information for health professionals, the general public, and aquatic staff) is available at: www.cdc.gov/healthyswimming 

To learn more about what Maine is doing to keep our beaches and pools safe visit: www.MaineHealthyBeaches.org  /  www.maine.gov/dep/blwq/beach.htm  /  http://www.maine.gov/dhhs/eng/el/index.html

Contributed by Mary Kate Appicelli and Megan Kelley

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West Nile Virus: Update for Maine Clinicians, July 2005 

In Maine, West Nile Virus (WNV) was first detected in tested dead birds during the summer of 2001. In each of the subsequent three years, active surveillance efforts in the state identified WNV in birds and/or mosquito pools, but not among humans tested because of clinically compatible illnesses. To date, Maine is one of only two states in which human cases of WNV infection have not been reported. 

While we have yet to see WNV-associated illnesses in Maine, the course of this epidemic in North America is unpredictable and the potential for a disease outbreak remains real. The DHHS Bureau of Health will continue to track deaths among corvids (crows, bluejays, ravens)  to document any evidence of WNV activity in local ecosystems. The Bureau is also collecting data on the distribution and density of Maine mosquitoes associated with WNV risk. 

The Bureau of Health continues to recommend that residents and visitors take basic measures to decrease the risk of exposure to mosquito bites, including the use of appropriate insect repellents and efforts to reduce standing water. More detailed information is available at the Maine WNV Information Center: http://www.maine.gov/dhhs/boh/ddc/westnile.htm 

Following, is a brief summary of West Nile Virus information of specific interest to clinicians. Much of this information has been adapted from current CDC fact sheets. For further questions or concerns, please contact the Division of Disease Control medical epidemiologist on call at: 1-800-821-5821. 

 Clinical Features of WNV Infection 
 Mild Disease (West Nile Fever)

Most WNV infections are asymptomatic and often clinically inapparent. Approximately 20% of those infected develop a generally mild illness, that is termed West Nile Fever. After an incubation period of 2 –14 days, symptoms last from 3 to 6 days. Reports from earlier outbreaks describe West Nile Fever as febrile illness of sudden onset often accompanied by:

 Neuroinvasive Disease:  Meningitis, Encephalitis, and West Nile Poliomyelitis

When the central nervous system (CNS) is affected, clinical syndromes ranging from febrile headaches to aseptic meningitis and encephalitis may occur, and these are usually indistinguishable from similar syndromes caused by other viruses. Approximately 1 in 150 WNV infections will result in neuroinvasive disease, with encephalitis (70%) being more commonly reported than meningitis (30%). 

West Nile meningitis usually involves fever, headache and stiff neck, accompanied by the typical findings of viral meningitis in the CSF (pleocytosis with a predominance of lymphocytes, elevated protein, normal glucose). Changes in consciousness are not usually seen, and are mild when present. 

West Nile encephalitis is characterized by headache and fever complicated by more severe global neurologic signs and symptoms (alteration in consciousness that may progress to confusion and coma) and possible focal neurologic deficits including limb paralysis and cranial nerve palsies. Tremors and movement disorders have also been noted. 

West Nile poliomyelitis, a flaccid paralysis syndrome is less common than WNV meningitis or encephalitis. This syndrome is generally characterized by the acute onset of asymmetric limb weakness or paralysis in the absence of sensory loss. Pain sometimes precedes the paralysis. The paralysis can occur in the absence of fever, headache, or other common symptoms associated with WNV infection. Involvement of respiratory muscles can sometimes lead to acute respiratory failure.

 The most significant risk factor for severe neurological disease is advanced age. Other clinical features sometimes associated with severe disease include:

 Common Laboratory Findings of Severe Disease:

•  Total leukocyte count in peripheral blood is usually normal but may be elevated, with lymphocytopenia and anemia also occurring.
• Hyponatremia is sometimes present, particularly among patients with encephalitis.
• Examination of the cerebrospinal fluid (CSF) shows pleocytosis, usually with a predominance of lymphocytes. Protein is universally elevated. Glucose is normal.
• Computed tomography is not useful in the diagnosis of WNV infection, but may help to rule out other etiologies of acute meningoencephalitis. Brain MRI is often normal, but will sometimes display leptomeningeal enhancement or parenchymal signal changes.

 Diagnostic Tests for WNV Infection

Clinical Suspicion: WNV infection can be suspected in a person based on clinical symptoms and patient history. Diagnosis relies on a high index of suspicion and on results of specific laboratory tests. WNV or other arboviral infections should be seriously considered in any individual – but especially in adults 50 years of age or older - who has onset of unexplained encephalitis or meningitis in the late summer or early fall.

The local presence of WNV enzootic activity (i.e., WNV positive birds and/or mosquitoes ) should further raise the index of suspicion. Severe neurologic disease due to WNV infection has occurred in persons of all ages, and because year-round transmission is possible in southern states, WNV should always be considered in persons with unexplained meningitis and encephalitis. WNV testing for persons with signs and symptoms of milder illness (West Nile Fever – see above) may also be considered. WNV infection may occur during pregnancy, and should be considered in the differential diagnosis of persistent unexplained fever among pregnant women. 

Laboratory Tests:  Laboratory testing is required for a confirmed diagnosis.  The most efficient diagnostic methods are:

• Detection of IgM antibody to WNV in serum collected 3-10 days after onset of illness (note: if a specimen collected less than 10 days after onset of illness is negative, a convalescent serum should be collected and tested for IgM antibody 2-3 weeks after the first collection date).  

• Detection of  IgM antibody to WNV in  CSF collected within 8 days of illness onset (for persons with neuroinvasive disease).

Most public health laboratories utilize the IgM antibody-capture, enzyme-linked immunosorbent assay (MAC-ELISA). Testing is available free-of-charge in Maine through the DHHS Health and Environmental Testing Laboratory (see details below).

Because some other arboviral infections [1] can cause indistinguishable clinical presentations, public health testing for WNV infection in Maine is accompanied by testing for  St. Louis Encephalitis (SLE), Eastern Equine Encephalitis (EEE), and Powassan Encephalitis (POW) virus infections. Confirmatory testing of IgM ELISA – positive specimens is performed using the plaque-reduction neutralization test (PRNT) at the Centers for Disease Control and Prevention. The PRNT is useful in ruling out possible false positive results and in distinguishing cross-reactions that can occur between different arboviral infections.

Imaging: The CT scan has not been effective in identifying any signs that are consistent or unique for WNV encephalitis. MRI is more effective but will yield abnormal results in only 25% to 35% of cases, and the MRI abnormalities are nonspecific.

 Treatment of WNV Infection

No specific treatment is currently available for WNV disease. In severe cases treatment consists of supportive care that often involves hospitalization, intravenous fluids, respiratory support, and prevention of secondary infections.  Several clinical trials are ongoing. Those that meet specific criteria are listed by CDC in Clinical Trials for Treating WNV Disease. (http://www.cdc.gov/ncidod/dvbid/westnile/clinicalTrials.htm)

 Transmission and Risk Factors for Disease

WNV is maintained in nature through a cycle that primarily involves mosquitoes and birds. The main route of human infection is through the bite of an infected mosquito. There is no documented transmission to humans from infected animals. In the northeastern United States, most human cases have had onset of illness between July and October.

Alternative modes of transmission are very uncommon, and include: organ transplantation, blood transfusion, breast milk, transplacental transmission, and occupational transmission (to laboratory workers).

Risk Factors for Severe Disease: Age is by far the most important risk factor for developing neuroinvasive disease. The CDC chart below presents U.S. data from 2002 for median age of persons reported with mild disease (West Nile Fever), for meningitis, for encephalitis, and for death. As noted, mortality and severe morbidity are most common in persons > 60 years of age.

 WNV Prevention

• No human vaccine against West Nile virus (WNV) is currently available.
• Education about reducing the risk of infection is important for all persons in transmission areas, but especially in the higher-risk populations (persons more than 50 years old and persons who are immunocompromised).

• The primary prevention step recommended is the use of mosquito repellent when outdoors. Mosquitoes may bite through thin clothing, so spraying clothes with repellent containing permethrin or DEET will give extra protection. These repellents are highly effective and are the most studied.

• In April, 2005, the CDC provided updated information suggesting that repellent compounds containing Picaridin, provide protection of equivalent duration to that of commonly-used DEET-containing products. Products containing Oil of lemon eucalyptus are also effective, but for shorter durations. (http://www.cdc.gov/ncidod/dvbid/westnile/RepellentUpdates.htm)

• The more DEET a repellent contains the longer time it can protect from mosquito bites, but DEET concentrations higher than 50% do not increase the length of protection.

• Repellents containing permethrin are not approved for direct application on the skin. Repellent containing DEET should not be sprayed on the skin under clothing. For detailed information about using repellents, see Insect Repellent Use and Safety.

• Other options include wearing protective clothing (long sleeves, socks, and long pants) when outdoors.

• The primary mosquito-biting hours for many of the species that are important vectors of WNV are from dusk to dawn. It is advisable to either stay indoors during these hours or use protective clothing and repellent.

• Household mosquito-source reduction is also important. Standing water should be removed from outdoor receptacles in the periresidential environment.

• Integrated mosquito management can be another important factor in controlling mosquito populations. (See Q & A: Pesticides Used in Mosquito Control.)

 Specimen Submission and Reporting in Maine

Diagnostic testing of serum and cerebrospinal fluid for West Nile Virus infection (and related arboviral infections) is available free of charge through the Maine Health and Environmental Testing Laboratory.  For technical and logistical information on obtaining and submitting specimens for diagnostic testing call the number below or go to: http://www.maine.gov/dhhs/boh/ddc/wnvclinical.htm 

For consultation on diagnostic questions and to report suspect WNV cases, call the 24-hour Disease Reporting and Consultation line at 1-800-821-5821.

Contributed by Geoff Beckett

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Lymphogranuloma Venereum (LGV) Update 

An overview of LGV and its resurgence among men who have sex with men (MSM) in the Netherlands and in the United States was provided in the April 2005 edition of the Epi-Gram (http://www.maine.gov/dhhs/boh/ddc/April.pdf).  Through June 2005, the U.S. Centers for Disease Control and Prevention (CDC) confirmed 14 cases of LGV.  All positive cases were among MSM with the majority of cases among HIV positive MSM.  Ten of the men presented with proctocolitis, and one had buboes.  Several of the men were concurrently diagnosed with at least one other STD at the time they were evaluated for LGV.  Individual states have confirmed cases of LGV based on the existing published case definition, which requires clinical compatibility and serologic or culture test results suggestive of LGV. In the New England region, Massachusetts has reported ten cases of LGV using this case definition. 

In May 2005, the CDC updated previously distributed materials on LGV, including specimen collection, shipping, and the clinical information form for patients with suspected LGV.  These updated materials as well as a flow diagram of specimen collection and testing procedures are available at www.cdc.gov/std/lgv.  The CDC will continue to revise the LGV website as more information becomes available or is updated.  

Most clinicians and public health labs, including Maine’s Health and Environmental Testing Laboratory, are unable to diagnose rectal chlamydia or LGV because nucleic acid amplification tests for chlamydia detection have not been approved for rectal specimens.  Therefore, since November 2004, specimens have been sent to the CDC for assistance with diagnostic testing. 

Clinicians, especially those who see men who have sex with men, should be knowledgeable about the clinical presentations of LGV and maintain a heightened index of suspicion for this disease.  The following key points should be kept in mind for any suspect cases:  

• Site-specific (e.g. rectal, urine, urethral) specimens should accompany serology specimens; CDC will not test serum specimens submitted alone for LGV. 
• Clinicians of patients with suspected LGV should contact the Maine STD Program (287-2046) to:
• Report the suspected case of LGV to the STD Program.
• Arrange for specimen submission through the Maine Health and Environmental Testing Laboratory (HETL) to CDC  because CDC will only accept specimens from state health departments and federal agencies.  When submitting a specimen, label the specimen “Hold for possible LGV testing at CDC” and notify the STD Program when you submit it.
• Ensure that the clinical information form, available on the CDC LGV website, for patients with suspected LGV is completed and submitted with the specimen. 

• Patients suspected of having LGV should be treated presumptively with doxycycline 100mg orally twice a day for 21 days.  Treatment information is available in the 2002 STD Treatment Guidelines (http://www.cdc.gov/STD/treatment/).   

The Bureau of Health is available to help clinicians answer questions regarding suspected cases of LGV, including procedural questions on specimen collection and the process of sending specimens to CDC for diagnostic testing.  Collaboration between the Bureau of Health and healthcare providers is essential to ensure the prompt identification and control of LGV.  For more information or assistance, please contact the STD Program at 287-2046. 

Contributed by Bethany Sanborn

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Prevention and Control of Meningococcal Disease   

Neisseria meningitidis is a leading cause of bacterial meningitis and sepsis among older children and young adults in the United States. This report describes the clinical manifestations of meningococcal disease and the epidemiology of meningococcal infection in the United States and Maine.  A confirmed case of meningococcal infection is also described as an example of a timely provider report that triggered public health action.  Additionally, the recently released CDC Advisory Committee on Immunization Practices (ACIP) recommendations on prevention and control of meningococcal disease are discussed. 

 Background

N. meningitidis colonizes mucosal surfaces of the nasopharynx and is transmitted through respiratory tract droplets from patients or asymptomatic carriers.  Meningococcal infection usually results in meningococcemia, meningitis, or both.  Onset with meningococcemia is often abrupt with fever, chills, malaise, prostration and a rash that initially may be macular, maculopapular, or petechial.  The presentation of meningococcal meningitis is clinically indistinguishable from signs and symptoms of acute meningitis caused by Streptococcus pneumoniae or other meningeal pathogens.  

Most cases of meningococcal disease are sporadic, however, outbreaks have been documented in childcare centers, schools, colleges, and military recruit camps.  US surveillance data indicate that the overall rate of meningococcal disease among undergraduate college students was lower than the rate among persons aged 18-23 years who were not enrolled in college, though rates were somewhat higher among freshmen.  When compared to other students, college freshmen living in dormitories were at higher risk for meningococcal disease.  Other risk factors for meningococcal disease include active and passive smoking, recent respiratory illness, corticosteroid use, new residence, new school, Medicaid insurance, and household crowding.  These groups might benefit from prevention efforts. 

Close contacts of patients with meningococcal disease, including household members, childcare or nursery school contacts, and those persons having direct exposure to the index patient’s nasopharynx secretions (e.g. by kissing, mouth-to-mouth resuscitation, endotracheal intubation, or endotracheal tube management) during the 7-10 days before the onset of illness, are at increased risk of developing infection and should receive prophylaxis ideally within 24 hours of diagnosis of the primary case.

 Meningococcal Disease in the United States

N. meningitidis is a gram-negative diplococcus with at least 13 serogroups. The majority of meningococcal cases in the United States are caused by serogroups B, C, and Y, though this varies by age group.  Among infants less than 1 year of age, >50% of cases are caused by serogroup B, for which no vaccine is licensed or available in the United States.  Of all cases of meningococcal disease among persons greater than 11 years of age, 75% are caused by serogroups C, Y, or W-135, which are included in vaccines available in the United States.

 Meningococcal Disease in Maine

Approximately 14% of infections were fatal.  For the 21 cases of which a serogroup was known, the majority were serogroups C (33%), B (29%), and Y (24%).  Of the 34 cases of which a primary infection was identified during 2000-2004, the majority were identified as primary bacteremia (71%).  

 Case Report

On May 13, 2005, a southern Maine infant aged 9 months presented to the emergency department of hospital A with a petechial rash, poor oxygenation, decreased urine output, and fever.  Symptom onset began during the early morning hours of May 13, and the child was referred to the ED after being seen in a primary care practice.  A lumbar puncture was performed, revealing cerebral spinal fluid (CSF) cloudy in appearance with red blood cell count of 63 and white blood cell count of 22,000 with 100% neutrophils.  A gram stain of blood showed gram-negative diplococci.  The patient was transferred to Hospital B and treated with ceftriaxone for 7 days.  A health care provider from Hospital B alerted the Bureau of Health to this case of meningococcal disease in the evening of May 13. The epidemiologist on call contacted the patient’s family to identify close contacts, including household members, childcare or nursery school contacts, and those persons having direct exposure to the case patient’s nasopharyngeal secretions during the 7-10 days before the onset of illness.  A total of 26 people received prophylaxis: four children, 10 adults, and 12 health care workers.  Clinical specimens were sent to the state Health and Environmental Testing Laboratory, where CSF culture results were positive for N. meningitidis group B on May 19.  The patient was discharged on May 19 and referred for follow up consultation to screen for hearing loss.

 Discussion

While the incidence of meningococcal disease in Maine remains relatively low compared to national estimates, a substantial number of infections result in mortality.  The prevention and control of meningococcal infections rely on early recognition, reporting, and follow up of cases and contacts to limit secondary transmission and outbreaks.  This report documents a case of meningococcal disease in an infant that was recognized by health care providers within hours of symptom onset and who initiated treatment and infection control measures immediately.  Bureau of Health epidemiologists worked with health care providers to identify and prophylax close contacts.  The public health action that resulted from this sporadic case demonstrates the importance of collaboration among public health and clinical medicine professionals.

 CDC Advisory Committee on Immunization Practices Recommendations

The new tetravalent A, C, Y, W-135 conjugate vaccine licensed for persons aged 11-55 years should become a key addition to existing meningococcal disease prevention measures.  Routine vaccination of young adolescents (persons aged 11-12 years) with a tetravalent meningococcal polysaccharide-protein conjugate vaccine (MCV4) is now recommended at the preadolescent health-care visit (at age 11-12 years).  For those who have not previously received MCV4, ACIP recommends vaccination before high school entry (at approximately age 15 years).  Increasing MCV4 vaccination rates among adolescents is an effective strategy to reduce the incidence of meningococcal disease among adolescents and young adults.   

Routine vaccination is also recommended for certain persons who have increased risk for meningococcal disease.  Use of MCV4 is preferred among persons aged 11-55 years; however, use of the tetravalent meningococcal polysaccharide vaccine (MPSV4) is recommended among children aged 2-10 years and persons aged >55 years.  If MCV4 is unavailable, MPSV4 is an acceptable alternative for persons aged 11-55 years.   

The following populations are at increased risk for meningococcal disease:

• College freshmen living in dormitories;

• Microbiologists who are routinely exposed to isolates of N. meningitidis;

• Military recruits;

• Persons who travel to or reside in countries in which N. meningitidis is hyperendemic or epidemic, particularly if contact with local populations will be prolonged;

• Persons who have terminal complement component deficiencies; and

• Persons who have anatomic or functional asplenia. 

The Bureau of Health and Maine Immunization Program are working with partners to develop a strategy to obtain and distribute MCV4, so Maine children and young adults can receive vaccine.  

Background, US surveillance data, and ACIP recommendations included in this report are taken largely from the recently published Prevention and Control of Meningococcal Disease: Recommendations of the Advisory Committee on Immunization Practices (ACIP).  MMWR 2005; 54(No. RR-7).  http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5407a1.htm 

Contributed by Anne R. Redmond

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Selected Reportable Diseases in Maine Year-to-Date through June 2005

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Contributed by Andrew Pelletier