Top 5 Clinical Pearls for Summer 2018
Mary Anne Jackson, MD | Interim Dean - University of Missouri - Kansas City School of Medicine | Medical Editor, The Link Newsletter
There are 12 tick-borne diseases but Rocky Mountain Spotted Fever, ehrlichiosis and tularemia are the most commonly encountered in our region. Sixty percent of RMSF cases occur in five states, and Missouri is one of them. The others include North Carolina, Oklahoma, Arkansas and Tennessee. Fever heralds the onset and headache and myalgia are notable. The maculopapular rash generally starts distally but may not appear until day three to five of illness, sometimes suggesting a viral exanthema to the clinician and often delaying diagnosis. RMSF with petechial rash is classic, but this rash does not appear until day six or later when disease has progressed to a severe form. Ehrlichiosis may manifest simply as fever with flu-like symptoms and rash may not be seen in 50 percent of cases. Obtaining a complete blood count, liver function studies and electrolytes is often helpful. Look for leukopenia and/or thrombocytopenia, and/or elevated transaminases and/or hyponatremia.
Tularemia usually presents with regional lymphadenopathy and look for a cutaneous ulcer at the tick bite site (ulceroglandular tularemia). The lymph nodes involved tend to be in the posterior cervical chain when tick bites occur on the scalp, but in some cases, the inguinal nodes are involved when tick bites occur in the abdominal region. Tularemia titers are generally diagnostic two weeks into the clinical course. The diagnosis of glandular tularemia is often delayed and in prior epidemiologic research from Children’s Mercy, multiple provider visits and multiple antibiotic prescriptions (none active against tularemia) have occurred before the correct diagnosis is made. Remember, when sending cultures in cases of suspected tularemia, the laboratory must be notified, as tularemia is a biohazard and a risk to microbiology personnel who process specimens.
Check out the CDC tick-borne disease maps for information on other tick-borne diseases that are not seen in our region, but may be seen in travelers. https://www.cdc.gov/ticks/tickbornediseases/overview.html
For travelers, dengue and chikungunya disease are the most common mosquito-borne illnesses. Both present with fever, but chikungunya manifestations classically include severe joint complaints. Yellow fever outbreaks are ongoing in Brazil, but summer is the lower season. While Zika is still a risk, there are fewer cases now than three to four years ago. However, the recommendations for avoiding travel for pregnant women or couples intending to get pregnant have not changed. DEET still ranks as best protection but must be applied (applying sunscreen first) every three to four hours.
Cryptosporidia is the common cause of summer watery diarrhea with symptoms often lasting one to two weeks. Linked to ingesting recreational water from contaminated pools, disease also may be transmitted to those playing in interactive water fountains or water play areas. Remind the parents of children you care for to take their child for routine bathroom breaks hourly during water play times. There is a high risk for protracted disease due to cryptosporidia in immunocompromised hosts, particularly solid organ transplant patients. Nitazoxanide is the recommended treatment, though disease may abate after one to two weeks in most immunocompetent hosts.
Norovirus is the most common cause of acute diarrheal illness, but most cases occur from November to April.
Salmonellosis associated with Honey Smacks™ breakfast cereal recall was announced, effective June 14, 2018. Seventy-three cases have been reported (44 hospitalized) as of 7/2 from 31 states. So far, neither Missouri nor Kansas has reported cases.
Precut melon associated salmonellosis cases were reported in the last several months; the last case reported was on 6/4/2018. Seventy have been infected in seven states and the cases have been linked to Caito Foods, LLC (Indianapolis, Ind.) pre-cut watermelon, honeydew melon, cantaloupe and fruit medley products.
Backyard poultry flocks are the latest vectors of salmonellosis with 36 states reporting cases, including Missouri and Kansas. Linked to chick or duckling exposure, most of which are sourced from a variety of hatcheries. In contrast to other food-borne salmonella cases, one-third of the backyard poultry cases have occurred in children.
Judicious use of antibiotics
Strep season is typically during the winter so testing and treatment for Group A streptococcal pharyngitis should be decreased at this time of year. Other etiologies of exudative tonsillitis to consider during summer months include enterovirus and adenoviruses.
Preparing for influenza season
The ACIP/CDC and AAP have released recommendations for the upcoming flu season, noting this last season was one of the greatest in severity in the last two decades with 172 pediatric deaths. The most common question relates to the availability this season of live attenuated vaccine, which features an H1N1 virus that appears to be improved in terms of its ability to replicate. However, there is no data on whether this will translate into vaccine effectiveness. That is why the AAP has announced preference for the inactivated vaccine, suggesting that LAIV may be considered for those for those who otherwise refuse vaccination (assuming that they are appropriate candidates for the live attenuated vaccine).