Hurricanes Irma, Maria pose threat of infectious diseases in US
The aftermath of Hurricanes Irma and Maria have displaced an estimated 100,000 to 200,000 Puerto Rican citizens, with many people from the island and other Caribbean areas traveling to the United States for refuge.
The conditions these people have been exposed to may leave them and other individuals vulnerable to diseases not typically seen within the U.S., according to a presentation at the Infectious Diseases in Children Symposium by Joseph A. Bocchini Jr., MD, professor and chair of pediatrics at Louisiana State University, Shreveport. The CDC has issued a health warning that includes the possibility of increased infection rates from this travel through March 2018. Bocchini said that the majority of these people may be traveling to Florida and New York.
“Not only did [these hurricanes] disrupt the normal life of the individuals who were affected, but they increased the likelihood for us to see infections that we would not routinely see in our practices in the U.S.,” he said in his presentation. “There are a couple of illnesses that may appear in the patients you serve that the CDC is concerned may have been transmitted in the affected Caribbean areas after the hurricanes.”
A combination of circumstances — including compromised drinking water and sanitation, decreased access to safe food and shelter, increased amounts of standing water and the interruption of previous mosquito control efforts — have amplified the possibility of spreading infectious diseases such as leptospirosis, hepatitis A and mosquito-borne illnesses such as dengue and Zika.
“It will be a number of months before we know whether outbreaks of these infections will occur in the hurricane affected areas and whether travelers from these areas have been infected,” Bocchini said in an interview with Infectious Diseases in Children.
According to Bocchini, leptospirosis, an infection caused by the spirochete Leptospira, is the most common worldwide zoonosis. Only 100 to 150 cases are reported within the U.S. annually, however, nearly 50% of these cases occur in Puerto Rico. Following the hurricanes, through October, the Commonwealth reported 18 cases and four deaths related to the disease.
The reservoirs are wild and domestic animals, including rats, dogs and livestock such as cattle and pigs; however, animals are frequently asymptomatic. These animals shed the spirochete in urine and other bodily fluids, excluding saliva, for months to years after infection. Leptospira is viable in most soil, mud and water for weeks to months in warm climates.
Patients with leptospirosis are most likely exposed to the organism through direct contact with bodily fluid from these animals or through recreational exposure, including wading, swimming and boating in contaminated water. These patients likely have a history of being submerged or swallowing this water or have experienced flooding after hurricanes or monsoons.
“This is where there is concern related to hurricanes,” Bocchini said. “Heavy rainfall allows water to run off from areas in which the organism may be in the soil or that are contaminated by livestock into areas that people are forced to walk or wade without skin protection and often with small injuries that allow the spirochete to enter and produce disease.”
Although about 90% of leptospirosis cases are self-limited or asymptomatic, severe or life-threatening symptoms, including liver disease with jaundice and renal dysfunction or failure, may be experienced. Additional effects include myocarditis, acute respiratory distress syndrome, pulmonary hemorrhage or shock. More common side effects include conjunctival suffusion without purulent discharge (30%-99%) and myalgia of calf and lumbar areas (40%-100%). The incubation period, according to Bocchini, lasts between 5 and 14 days (range = 2-30 days).
“Treatment should be started as soon as the diagnosis is considered, and the treatment of choice continues to be intravenous penicillin,” he said. “For those who have severe disease, it is important to remember that when you initiate penicillin therapy — just like with syphilis — the patient may experience a Jarisch-Herxheimer reaction, which may make the patient appear much worse for a 24- to 36-hour period after antibiotics are started.”
Alternative therapies that are equally as effective include cefotaxime, ceftriaxone and doxycycline. For those with mild disease, Bocchini suggests doxycycline, ampicillin, amoxicillin or azithromycin.
He also noted that although pediatricians do not typically see many cases of HAV infection today, the hurricanes have provided an opportunity for this disease to spread and should cause concern. Nearly 30% of children infected with the virus are younger than 6 years of age infected with the virus will present with nonspecific, viral-like symptoms such as fever, malaise, anorexia, nausea and vomiting. Few present with jaundice.
Older children and adults are more likely to be symptomatic, with approximately 70% of patients developing jaundice. Infection typically resolves in 1 to 2 months, but 10% to 15% of patients may experience a more prolonged or relapsing illness for up to 6 months. Chronic infection is not a risk, and fulminant hepatitis is rare.
Diagnosing HAV includes testing for anti-HAV IgG and IgM antibodies.
“A single test is often what you need,” Bocchini said. “Virtually everybody who has an acute infection will have a positive anti-HAV IgM during the acute phase.”
Vaccination is available in both hurricane-affected areas and within the U.S. In Puerto Rico, 86% of children between the ages of 19 and 35 months have received both doses of hepatitis A vaccine, and 70% have received both doses in the U.S. Virgin Islands. However, immunization rates within the U.S. are lower, with 61% in this age group having received 2 doses. In addition, only 57% of U.S. adolescents have received both doses.
“One thing that is a real warning is that if HAV is reintroduced, we have the chance for older individuals who were not immunized to become infected,” Bocchini said. “The CDC has shown that the rate of HAV infections in older age groups has actually increased in the U.S. in recent years, and there have been some outbreaks throughout the country. As we have improved the immunization rates of children, there has been a reduced spread of disease, leaving more unimmunized adults at risk for HAV infection.”
Different prophylaxis regimens against HAV are suggested for different age groups. According to Bocchini, individuals between the ages of 12 months and 40 years who have been exposed to the virus for less than 2 weeks should receive the HAV vaccine rather than immune globulin. Children younger than 12 months and those who are immunocompromised, have liver disease or a contraindication to vaccination should receive serum immune globulin, 0. 02 mL/kg. If a patient has been exposed for more than 2 weeks, “it is really too late to prevent the infection with either immune serum globulin or a vaccine but vaccine can be given for ongoing exposure.”
Mosquito-borne illnesses may also be a true threat for people traveling from hurricane-affected areas, with an increased possibility of Zika and other mosquito borne infections.
“The standing water resulting from the flooding and the disruption of mosquito abatement activities have led to opportunities for mosquitos to breed and grow,” Bocchini said. “The possibility of new outbreaks of [these diseases] truly exist. We need to consider in patients who come from affected areas who have febrile illnesses the possibility that they may have a mosquito-borne illness.”
Symptoms of Zika virus infection include fever, maculopapular rash, joint pain, conjunctivitis, myalgia and headache; however, these symptoms are also observed in dengue and chikungunya. Bocchini suggests ordering specific antibody testing for the three conditions. He also notes that nonsteroidal anti-inflammatory drugs should not be prescribed to these patients until dengue is ruled out to prevent the likelihood of developing a more severe infection.
“It is important to ask patients about recent travel from, or exposure to persons from, areas affected by the hurricanes,” he said. “Pediatricians should consider less common infectious disease etiologies in patients who have traveled from Puerto Rico, the U.S. Virgin Islands and other Caribbean areas. They should also contact public health authorities for advice on diagnostic tests [for these diseases].” – by Katherine Bortz
- Bocchini JA. Hot topics and emerging infections in 2017-18. Presented at: IDC Symposium. Nov.18-19, 2017; New York, NY.
Disclosure: Bocchini reports no relevant financial disclosures.