Infectious diseases continue to pose “substantial challenges” to US public health, despite efforts and advances in control, according to a report by Centers for Disease Control and Prevention (CDC), published online July 2 in the Lancet.
The second in a new CDC series about the health of Americans, the report describes the following priority areas.
Endemic diseases affect millions of Americans, with racial and ethnic minorities disproportionately affected. High-burden diseases include:
- Chronic hepatitis: 75% of chronic hepatitis C virus cases and hepatitis C virus deaths occur among baby boomers.
- HIV: Incidence has remained stable. People in urban areas, blacks, Latinos, and men who have sex with men (MSM) remain most affected. New infections have climbed among young MSM. About 16% of HIV-positive people are unaware of their status, and 75% of HIV-positive people are not virally suppressed.
- Sexually transmitted infections: About half occur in young people. Rates of gonorrhoea and chlamydia are highest among blacks. Syphilis rates are rising, especially among young MSM. Antibiotic-resistant gonorrhoea remains particularly concerning.
- Tuberculosis: Although at “record lows,” tuberculosis disproportionately affects foreign-born individuals, minorities, drug users, and the homeless, with an estimated 11 million cases of latent tuberculosis.
An estimated 20 million vaccine-preventable illnesses, causing more than 40,000 deaths, could be avoided if each birth cohort received proper childhood immunizations, the authors point out. Gains have been made in combatting pneumococcus and rotavirus. Challenges remain for human papillomavirus, for which vaccine uptake has been slow; pertussis, with resurgence linked to waning immunity; and measles, mumps, and rubella, with outbreaks linked to travel. Parental decision against immunization also plays a role in this category.
Emerging and Reemerging Diseases
West Nile Virus causes the majority of arboviral diseases in the United States, with Lyme disease the most common vector-borne disease. Notable pathogens include Sin Nombre Virus, swine flu variants, Middle East Respiratory Syndrome coronavirus, Rocky Mountain Spotted fever, dengue fever, and Chikungunya fever. The influenza strain that caused the 2009-2010 H1N1 pandemic was first isolated in the United States and was a genetic reassortment of swine, avian, and human influenza viruses.
Each year, about 48 million foodborne illnesses cause 128,000 hospital admissions and 3000 deaths, according to background information in the article. Major pathogens include norovirus, Salmonella spp, Clostridium perfringens, and Campylobacter. Rates of Escherichia coli 0157 illness have declined, but Salmonella illness remains stable. From 1998 to 2008, more than half of foodborne illness outbreaks were linked to produce, although meat and poultry caused most deaths.
About 1 in 5 patients contracts healthcare-associated infections in hospitals, amounting to $26 to $33 billion in extra medical costs and roughly 99,000 deaths, according to background information in the article. Causes include unsafe medical practices and contaminated products.
“However, these estimates do not include the substantial burden and consequences of [healthcare-associated infections] in non-hospital settings such as long-term care facilities, dialysis settings, and outpatient clinics, where an increasing number of invasive practices are done,” the authors write.
Antimicrobial resistance, the authors note, is a “global health crisis.” Rates of central blood line infections, surgical site infections, and catheter-associated urinary tract infections have declined. Rates of Clostridium difficile infections, however, have climbed, only recently beginning to plateau. Gram-negative drug-resistant bacterial infections are particularly concerning.
New technologies, the authors mention, will likely play important roles in the control of infectious diseases. These include health communication via social media as well as new laboratory tests and increased understanding of the human microbiome.
“An important priority of control of infectious disease is to ensure that scientific and technological advances in molecular diagnostics and bioinformatics are well integrated into public health,” the authors emphasize. “Broad and diverse partnerships across governments, health care, academia, and industry, and with the public, are essential to effectively reduce the burden of infectious diseases.”