Epidemiology of Prevention of Communicable Diseases

Function

Four major patterns of HAV infections worldwide are divided into areas of high, intermediate, low, or very low prevalence. Endemic areas of high prevalence include parts of Africa, Asia, and Latin America. Most infections in these areas occur in early childhood. Areas of low and very low prevalence include North America and Western Europe, with few infections during childhood, and most of the population is susceptible throughout adulthood.

In the United States, HAV is one of the most reported diseases among vaccine-preventable diseases. Over 30,000 cases were reported in 1997. An estimated 270,000 HAV infections are said to have occurred each year between 1980 and 1999. A total of 1390 cases of hepatitis A were reported from 50 states to the Centers for Disease Control and Prevention (CDC) in 2015. There was a 12.2% increase in reported cases of HAV in 2014. Of note, the overall incidence in 2015 was 0.4 cases per 100,000 population, the same as in 2014 (CDC, 2017). Since 1996, the declining incidence in the United States has been attributed to the widespread use of HAV vaccination for high-risk populations. An incidence of 1 case per 10,000 was notably the lowest recorded in 2007. States with routine vaccination for children also noticeably made the most noticeable difference (Epocrartes, 2017). Overall, there has been a 95% decline in HAV in the United States since the vaccine for HAV became available in 1995.

Globally, HAV's epidemiology is evolving, partly attributed to improved sanitation standards and living conditions, mostly noticeable in developing countries. This has undoubtedly contributed to the decline in infected children globally. However, the incidence among adults has increased due to the larger population lacking antibodies that are protective against HAV.[7][8]

Issues of Concern

Recently, the Division of Disease Control and Health Protection issued a Healthcare Provider Advisory note on HAV in Florida, indicating that 217 cases have been reported in Florida alone since January 2017, a significant increase compared to the past 5-year average of 94 cases. Of note was that most HAV cases did not have international travel exposure. Southeast Florida (eg, Broward and Miami-Dade counties) had the most cases of HAV, with 69% among males (most had male sexual contact). The median age of reported cases was 38 years, with the highest rates of Hepatitis A disease recorded among people ages 25 to 44 years. About 60% of the cases of HAV in Florida required hospitalization.

Also of note is the fact that nearly 1200 outbreaks of HAV were recorded among individuals who are homeless, use intravenous (IV) drugs, men who have sex with men, and their close or direct contacts, as investigated by the health departments in Arizona, California, Colorado, Michigan, New York and Utah (DOH, Florida 2017).

Clinical Significance

History and Physical Examination

• Acute onset fever
• Fatigue
• Malaise
• Nausea and vomiting
• Jaundice
• Hepatomegaly
• Right upper quadrant pain
• Joint pain
• Clay-colored bowel movements

Other Clinical Factors

• Headache
• Fatigue
• Dark urine
• Pruritus
• Rash
• Arthralgias and myalgias
• Cough
• Bradycardia
• Diarrhea
• Constipation
• Splenomegaly
• Posterior cervical lymphadenopathy

Diagnostic Tests

• Serum aminotransferases
• Serum bilirubin
• BUN
• Serum Creatinine
• Prothrombin time
• IgM anti-hepatitis A virus (HAV)
• IgG anti-hepatitis A virus (HAV)
• Stool and body fluid electron microscopy
• Hepatitis A virus RNA

Treatment Options

Presumptive: If unvaccinated with recent exposure to HAV less than 2 weeks: HAV or immune globulin

Acute presentation HAV infection

• Confirmed HAV: Supportive and conservative management
• Worsening jaundice and encephalopathy: liver transplant

Recommendations of the Advisory Committee on Immunization Practices: DOH Florida, 2017.

• All children at age 1 year
• Persons who are at increased risk for infection
• Persons who are at increased risk for complications from HAV
• Any person wishing to obtain immunity

Other Issues

Recommendation for two-dose HAV vaccine, 6 to 12 months apart, for the following persons:

• Men who have sex with men
• Injection and non-injection drug users
• Persons with chronic liver disease
• Persons traveling to or working in countries with high or intermediate endemicity of hepatitis A
• Persons with clotting-factor disorders
• Household members and other close personal contacts of adopted children newly arriving from countries with high or intermediate hepatitis A endemicity
• Persons with direct contact with persons who have hepatitis A

Enhancing Healthcare Team Outcomes

Communicable diseases are illnesses caused by viruses or bacteria that people spread to one another through contact with contaminated surfaces, bodily fluids, blood products, insect bites, or the air. There are many examples of communicable diseases. Health professionals must be aware that some require reporting to appropriate health departments or government agencies in the locality of the outbreak. Some examples of reportable communicable diseases include HIV, hepatitis A, B, and C, measles, salmonella, measles, and blood-borne illnesses. The most common forms of spread include fecal-oral, food, sexual intercourse, insect bites, contact with contaminated fomites, droplets, or skin contact. Improving health professionals' understanding of communicable diseases that must be reported can lead to better patient outcomes.

Nurse educators and infectious disease nurses are crucial in educating clinicians and nurses to avoid spreading communicable diseases in the hospital setting. Further, the infectious disease nurse assists in identifying concerns and reporting issues to the interprofessional team managing a patient's care. Often, this involves more stringent infection prevention precautions and guiding the interprofessional team caring for the patient to avoid further spread of disease and obtain the best outcomes.