Recreational Bugs

From the 2008 Update on Infectious Diseases, sponsored by the University of Wisconsin
School of Medicine and Public Health, Madison

Educational Objectives

The goals of this program are to improve management of medical risks associated with travel and to improve the di­agnosis and treatment of sexually transmitted infections. After hearing and assimilating this program, the clinician will be better able to:

   Advise patients on preventing mosquito-transmitted diseases.

   Select appropriate malaria prophylaxis.

   Describe common presentations of malaria, South African tick bite fever, and babesiosis.

   Provide effective treatment for gonococcal and chlamydial infections and syphilis.

   List indications for hospitalization of women with pelvic inflammatory disease.

Faculty Disclosure

In adherence to ACCME Standards for Commercial Support, Audio-Digest requires all faculty and members of the planning committee to disclose relevant financial relationships within the past 12 months that might create any per­sonal conflicts of interest. Any identified conflicts were resolved to ensure that this educational activity promotes quality in health care and not a proprietary business or commercial interest. For this program, the faculty and plan­ning committee reported nothing to disclose.

Acknowledgements

Drs. Reich and Mejicano spoke in Madison, WI, at 2008 Update on Infectious Diseases, sponsored by the Uni­versity of Wisconsin School of Medicine and Public Health. The Audio-Digest Foundation thanks the speakers and the University of Wisconsin School of Medicine and Public Health for their cooperation in the production of this program.

Travel Medicine

Richard M. Reich, MD, Clinical Associate Professor of Medicine, University of Wisconsin School of Medicine and Public Health, Madison

Pretravel evaluation: physical examination; ask about underlying immunosuppression (eg, HIV), renal disease, liver disease, history of splenectomy, drug allergies, medications (consider interaction with travel prophylaxis), preg­nancy and nursing status, age, weight, risk for glucose-6-phosphate dehydrogenase (G6PDH) deficiency, destina­tion, conditions of accommodations, and travel duration

Travel advice: advise patients to consider purchasing separate insurance policy for air evacuation, trip cancellation, and medical coverage; ask about activities (eg, swimming); discuss personal safety (eg, warn patients about sexual tourism) and rabies avoidance; advise patients to prepare travel medical kits; provide information about finding English-speaking physicians; State Department advisories about dangerous areas to visit change frequently, as does advice on immunizations and prophylactic drugs

Mosquito-transmitted diseases: malaria; dengue fever common in Caribbean; yellow fever; other insect-borne dis­eases include Chagas’ disease, trypanosomiasis, and tick-borne illnesses; primary prevention  —  avoid outdoors during primary mosquito feeding times (dawn and dusk); remain in screened areas; use mosquito netting and per­methrin-treated clothing; cover skin with clothing; apply insect repellant (eg, diethyltoluamide [DEET] or picari­din); malaria may be acquired without traveling to malaria-endemic zones; Centers for Disease Control and Prevention (CDC) guidelines  —  higher concentrations of DEET provide longer protection (concentrations of 30%-50% may last ³5 hr); picaridin does not last as long as DEET and requires more frequent applications; apply sun­screen before insect repellant; mosquitos that transmit dengue fever bite during day

Transportation issues: motion sickness (offer prophylaxis); deep venous thrombosis (advise patients about walking around airplane, pumping calves, and use of compression stockings); altitude sickness  —  slow ascent and acclimati­zation recommended; acetazolamide effective for prevention (consider sulfonamide allergy); alternatives with less documentation include nifedipine and dexamethasone; barotrauma (instruct patients on diver’s maneuver and using decongestants); jet lag

Other travel risks: crime (scam awareness; advise making 2 copies of passport and medical records, [one to take, and other to leave with trusted person]); homicide; vehicular accidents common; use of drugs and alcohol; food and water precautions  — bottled and boiled beverages (eg, tea, coffee, colas) generally safer; avoid street vendors, raw vegetables, vegetables that cannot be peeled, and ice; use bottled water, mouthwash, or diet soda to brush teeth

Treatment of travelers’ diarrhea: fluoroquinolones  —  most effective; single dose or use for £3 days usually effec­tive; contraindications include pregnancy or nursing and quinolone allergy; concomitant steroid use increases risk for tendinopathy; alternatives include rifaximin or azithromycin; bismuth subsalicylate less effective; prophylactic antibiotics generally not recommended

Immunizations for adults: routine immunizations should be up-to-date; travel-related immunizations  —  hepatitis A and B; typhoid; rabies; meningococcal disease; polio; Japanese encephalitis; yellow fever; some vaccines (for, eg, Japanese encephalitis and yellow fever) available only at certain centers

Malaria prophylaxis for chloroquine-sensitive areas: eg, South America and Central America; chloroquine, 500 mg/wk (first dose given 1 wk before departure, then once weekly while in risk area, and for 4 wk after leaving risk area); generally well tolerated and believed safe in pregnancy; may cause nausea and vomiting; can worsen psoria­sis; contraindicated in patients with seizure disorder and G6PDH deficiency

Malaria prophylaxis for chloroquine-resistant areas: most third-world countries; doxycycline; mefloquine (Lar­iam); atovaquone and proguanil (Malarone)  —  1 tablet daily (starting 1-2 days before travel, then for 1 wk after re­turn); may cause nausea, vomiting, headache, and abdominal pain; generally well tolerated; contraindicated in renal failure, pregnancy, small children, and nursing mothers; doxycycline  —  should be taken with food to prevent nausea and vomiting; may cause photosensitive rashes; contraindicated in young children, pregnancy, and breast­feeding; mefloquine  —  taken once weekly (starting 1 wk before travel, then during travel, and for 4 wk after return); side effects similar to (or slightly more severe than) chloroquine; may cause serious psychiatric side effects (rare) and seizures; relatively contraindicated in patients with history of psychiatric disorder; pregnancy category C; me­floquine-resistant Plasmodium falciparum seen in Myanmar, Thailand, and Cambodia (atovaquone and proguanil or doxycycline recommended)

Malaria case presentation: man, 27 yr of age; returned from 2-mo stay on western coast of Africa and South Africa and presented with nausea, vomiting, headache, vertigo, malaise, and jaundice; found to have acute hepatitis B in­fection; patient given antiemetics and discharged; shortly after, patient became febrile, with chills and right upper quadrant pain; many ring forms consistent with P falciparum malaria seen on blood film; man had severe malaria with severe parasitemia with clinical mild cerebral malaria; treatment  —  intravenous (IV) doxycycline and IV quin­idine; artesunate (available from CDC); complications  —  acute respiratory distress syndrome (ARDS); some re­ports of improvement of ARDS with IV corticosteroids (eg, high-dose dexamethasone); artesunate  —drug of choice for severe malaria; more effective and safer than quinine

Case presentation: South African tick bite fever  —  man, 56 yr of age, complained of sore ankle; no history of trauma; man febrile, with crusted lesion on ankle and morbilliform rash on limbs; diagnosis confirmed by rickettsial serol­ogy and skin biopsy; treated with doxycycline

Babesiosis: symptoms  —  rigors; malaise; fever; fatigue; severe frontal headache; nausea; can present with mild ane­mia, moderate thrombocytopenia, elevated erythrocyte sedimentation rate and C-reactive protein, and mild hypona­tremia; in United States, babesiosis caused by Babesia microti; red blood cells with 2 intracellular ring forms; treat with atovaquone and azithromycin (slightly less effective than older regimen of clindamycin and quinine, but better tolerated); in patients with severe disease, clindamycin and quinine regimen recommended, due to greater efficacy, and should be given to patients returning from Europe; may take £3 mo for blood clear; follow-up blood smears re­quired; confirm positive blood smear with antibody testing or polymerase chain reaction (PCR) testing; patient with positive PCR test and negative blood smear may not need treatment (monitor patient)

Sexually Transmitted Infections

George C. Mejicano, MD, MS, Associate Professor and Associate Dean, University of Wisconsin School of Medicine and Public Health, Madison

Urethritis: primarily occurs in men but can occur in women; gonococcal urethritis  —  caused by Neisseria gonor­rhoeae; discharge purulent, green, and profuse, with redness and erythema; associated with severe dysuria; painful when symptomatic; incubation period short (£4 days); nonspecific urethritis (NSU)  —  incubation period longer; dysuria often intermediate and mild; discharge gray or cloudy; no erythema around urethral meatus; diagnosis in men  —  Gram stain of urethral secretions shows ³5 white blood cells (WBCs) per oil immersion field; dipstick test of first void urine (leukocyte esterase or ³10 WBCs per high power field); NSU caused by many organisms (eg, Chlamydia trachomatis); consider viral etiology of NSU (eg, adenovirus; more common in men with oral sexual contact and male partners) and Mycoplasma genitalium

Mucopurulent cervicitis: caused by N gonorrhoeae and C trachomatis; clinical diagnosis  —  yellow exudate; occa­sional bleeding; increased neutrophils on Gram stain

C trachomatis: number one bacterial sexually transmitted infection (STI) in North America; in 2006, >1 million new cases reported (may be underreported by factor of 3); 50% of men have symptoms; 75% of women with cervicitis have no symptoms (women can become reservoir); more women have chlamydia than men; complications  — neonatal eye and lung infections; pelvic inflammatory disease (PID) and sequelae; certain serotypes (L1, L2, and L3) associated with lymphogranuloma venereum; study suggested (independent of human papillomavirus [HPV]), C trachomatis may be oncogenic, and certain serotypes might be risk for cervical cancer; screening recommendations  —  annual screening for all sexually active women £24 yr of age; annual screening of women ³ 25 yr of age with other risk factors; insufficient evidence to recommend screening asymptomatic men; therapy  —  efficacy of azithromycin or doxycycline, 90%; azithromycin typically first-line therapy (single-dose regimen im­proves adherence); doxycycline, 100-mg tablets taken bid for 1 wk; azithromycin drug of choice in pregnant women; management of sex partners  —  refer all sex partners within last 2 mo for evaluation and treatment; patients should be counseled to avoid sexual contact until therapy (for patient and partner) complete; after taking azithromy­cin, patients should avoid sexual contact for ³1 wk, starting from time treatment of partner initiated

N gonorrhoeae: »360  000 new cases in 2006 (may be underreported by factor of 2 or 3); transmission rate through one-time sexual contact, 20% to 35%; reinfection rate high (counseling important); higher incidence in black men; most men develop symptoms quickly; most women asymptomatic; coinfection with Chlamydia occurs; chlamydia occurs 3 times more than gonorrhea (in patients with gonorrhea, evaluate and/or treat for chlamydia); since oral sex and passive anal intercourse becoming more common, incidence of pharyngeal gonorrhea and proctitis from gonor­rhea increasing; can cause eye infection in neonates, PID, abscesses, disseminated infection, and Fitz-Hugh Curtis syndrome

Testing: single intravaginal swab (SIS)  —  sample collected by patient and mailed to laboratory; can screen for multi­ple STIs; sensitivity and specificity “quite good”; review of 29 studies looking at different amplification assays found that for C trachomatis, results of test did not depend on symptoms or sample site; however, for N gonor­rhoeae, sensitivity decreased, depending on sample site (in women, sampling urine not recommended)

Treatment of gonorrhea: 2006 data show resistance to fluoroquinolones nearly 16%; ciprofloxacin cannot be used; use intramuscular (IM) ceftriaxone or cefixime (may be difficult to obtain); treat empirically with azithromycin or doxycycline to cover Chlamydia, or rule out chlamydia; pharyngeal involvement  —ceftriaxone; in pregnant women, use ceftriaxone or cefixime; spectinomycin indicated for pregnant women who have anaphylactic reactions to b-lactams (eg, penicillin)

Disseminated gonococcal infection: occurs in »2% of patients (predominantly women); risk factors include men­struation and pregnancy; classic presentations  —  1) chills; polyarthralgia; fever; distinct skin rash (pustules with red rim and black necrotic area); blood cultures often positive; 2) monoarticular septic arthritis (typically of knee); blood cultures often negative, but culture of joint fluid positive; management  — hospitalization; ceftriaxone, 7-day course required (can switch from IV to oral formulation after 2 days); treat for possible chlamydial coinfection

Pelvic inflammatory disease: infection of fallopian tubes and adnexal tissues; usually polymicrobial (treat empiri­cally); complications include infertility, ectopic pregnancy, chronic pain, and pelvic abscesses; diagnosis  —  uterine tenderness; cervical motion tenderness; purulent material from cervical os; friable mucosa; pressing on cervix causes pain; indications for hospitalization  —  surgical emergency cannot be excluded; abscess; pregnancy; inability to take oral medications; vomiting; toxic appearance; counsel sex partners; if sexual contact within last 60 days, treat presumptively; inpatient regimens  —  A) second-generation cephalosporins (eg, cefotetan, cefoxitin) and doxy­cycline; B) preferred for patients with abscesses; high-dose clindamycin and gentamicin; outpatient regimen  —  single dose of ceftriaxone or cefoxitin and probenecid, plus doxycycline, with or without metronidazole (speaker recommends using metronidazole)

Genital ulcers: not all ulcers caused by STIs; can be due to fixed-drug eruptions or trauma; chancroid and genital herpes painful; syphilis, lymphogranuloma venereum, and granuloma inguinale painless; evaluation  —  serologic testing for syphilis; direct fluorescence assay (DFA) for Treponema pallidum; obtain culture for herpes simplex vi­rus (HSV) and for Haemophilus ducreyi (causes chancroid)

HSV infection: after initial infection, lives in neurons and can cause symptomatic outbreaks or asymptomatic viral shedding; herpes simplex virus 2 (HSV-2) prevalent in United States (affects 25% of women in United States); greater number of lifetime sex partners correlates with higher likelihood of seropositivity; 70% of genital herpes le­sions due to HSV-2, 30% due to HSV-1; typical case  —  painful crop of vesicles form ulcers, crust over, and heal without scarring; initial infection can cause fever, lymphadenopathy, myalgias, and malaise; epidemiology  —  changing as result of oral sex (genital HSV-1 becoming more common); recurrences  —  »90% of patients with HSV-2; precipitated by stress, menstrual cycle, fever, or sunlight; viral shedding common; diagnosis  —  viral cul­ture; type-specific serologic testing; Tzanck preparation of ulcer scrapings helpful but not confirmatory; pregnancy  —  if genital lesions visible at time of delivery, cesarean delivery indicated (regardless of membrane rup­ture status); vertical transmission of HSV-2 can lead to severe disabilities and death; treatment  —  acyclovir, 400 mg tid for 7 days, effective for primary infection; recurrences  —diminish further out from primary infection; »25% of patients have more recurrences in fifth year than first year; 7 regimens available (equally efficacious; eg, acyclovir, 800 mg tid for 2 days); median number of recurrences in first year of infection, 6 (1 yr of suppression therapy rec­ommended with initial therapy);  antiviral therapy (eg, valacyclovir) for positive partner diminishes likelihood of transmission; in cases in which HSV-negative woman wants to become pregnant with positive partner, speaker treats woman with antiviral drug

Syphilis: diagnosis  —  fluorescent antibody testing on ulcer scraping; screen with nontreponemal test, ie, VDRL or rapid plasma reagin (RPR); also used to follow response to treatment; confirm with treponemal test; primary syphilis  —solitary painless chancre; can occur 1 wk to 3 mo after infection; spontaneously heals 4 to 6 wk after on­set of symptoms; secondary syphilis  —  systemic; seen after 3 to 8 wk; rash; fever; malaise; pharyngitis; weight loss; lymphadenopathy; highly contagious; latent syphilis  —  patients asymptomatic; early latency (infection known to have occurred within 1 yr; late latency, >1 yr); can progress to tertiary syphilis and/or neurosyphilis; treatment of primary, secondary, or early latency syphilis  —  single dose of IM benzathine penicillin, 2.4 million U; use doxycy­cline if patient allergic to penicillin; for late latency syphilis or if duration unknown, give 3 doses (1 dose/wk); monitor patients; screen for HIV

Suggested Reading

[No author]: Standing up to syphilis. Nursing 39:66, 2009; Carroll B et al: Travel health Part 1 preparing the tropical travel­ler. Br J Nurs 17:1046, 2008, Devi KM et al: Co-infection of herpes simplex virus (HSV) with human immunodeficiency vi­rus (HIV) in women with reproductive tract infections (RTI). J Commun Dis 40:193, 2008; Drew WL: Valacyclovir to reduce transmission of genital herpes simplex virus infection. J Infect Dis 199:916, 2009; Haggerty CL et al: Diagnosis and treat­ment of pelvic inflammatory disease. Womens Health (Lond Engl) 4:383, 2008; Maeda S et al: Azithromycin treatment for nongonococcal urethritis negative for Chlamydia trachomatis, Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma parvum, and Ureaplasma urealyticum. Int J Urol 16:215, 2009; Nicosia V et al: Assessment of acceptability and ease of use of atovaquone/proguanil medication in subjects undergoing malaria prophylaxis. Ther Clin Risk Manag 4:1105, 2008; Short VL et al: Clinical presentation of Mycoplasma genitalium Infection versus Neisseria gonorrhoeae infection among women with pelvic inflammatory disease. Clin Infect Dis 48:41, 2009; Steichen CT et al: Gonococcal cervicitis: a role for biofilm in pathogenesis. J Infect Dis 198:1856, 2008; Wang SA et al: Antimicrobial resistance for Neisseria gonorrhoeae in the United States, 1988 to 2003: the spread of fluoroquinolone resistance. Ann Intern Med 147:81, 2007.