The low down on rotavirus in the United States

The following article provides some interesting insight into the statistics for the rotavirus illness in children. It also goes into detail about the vaccines which have been developed for this illness. It is a very interesting read, especially if you have children who fall in the age range for the childhood immunization schedule.

Rotavirus: Death by Diarrhea?

February 4, 2008 by generic
Filed under: Vaccine/Disease Analysis

Rotavirus is reported to be the leading cause of diarrhea among children, causing upwards of 55,000 hospitalizations per year in the US. Symptoms consist of vomiting and diarrhea, usually lasting between 3-8 days. Subsequent bouts of rotavirus are usually milder.

When this vaccine made its debute in 1998, I’ll admit to some skepticism. I laughed and said,“Really? Now it’s death by diarrhea!” When the first Rotavirus vaccine (RotaShield) was recalled in 1999, for causing intussusception, I felt justified in my stance. Especially when I found out that intussusception caused by this vaccine is a “compensable injury” and is paid for out of the National Vaccine Injury Compensation Program. (1) (Intussusception is a serious and potentially life-threatening condition that occurs when the intestine gets blocked or twisted. One portion of the intestine telescopes into a nearby portion, causing the intestinal obstruction. The most common site is where the small intestine joins the large intestine.)

In 2006, a new rotavirus vaccine (RotaTeq) was approved by the FDA. My family doctor and most of those around me were all strongly recommending the new vaccine, so I turned my attention towards some research.

 First, the numbers of hospitalizations and deaths. The epidemiology of rotavirus diarrhea in the United States: surveillance and estimates of disease burden (2) was published in the Journal of Infectious Diseases in 1996 and the statistics look similar to the CDC’s. 55,000 children per year hospitalized due to Rotavirus. Alas, if you look a little closer you’ll notice some details you might otherwise have missed.

According to said article:

“From 1968 to 1985, diarrhea-related deaths among US children <5 years old declined from 1100 to 300/year. This decline was associated with the disappearance of winter peaks for diarrhea-related deaths previously associated with rotavirus infection among children 4-23 months old. From 1979 to 1992, however, hospitalizations for diarrhea averaged 186,000/year and retained their winter peaks, which have been linked to rotavirus infections. Each year an estimated 54,000-55,000 US children are hospitalized for diarrhea, but <40 die with rotavirus.”

So, deaths went down but hospitalizations went up. Less than 40 deaths a year didn’t seem “vaccine-worthy” either. Strange. Still, this didn’t give me an ACTUAL number for hospitalizations or deaths. There are averages, estimations, and less than. I needed more. There must be more, right? Additionally, what did the numbers look like between 1992-1998 when the first rotavirus vaccine was released?

I couldn’t seem to pin the numbers down!

I found Global Illness and Deaths Caused by Rotavirus Disease in Children (3) on the CDC website, but its description of the method of estimation left me with even more questions. Here’s an excerpt:

“Rotavirus-Associated Deaths

To estimate the total number of child deaths from diarrhea, we plotted (for each country with available data) the fraction of deaths of children <5 years of age attributable to diarrhea against per capita gross national product (GNP). Countries were classified on the basis of GNP per capita into World Bank Income Groups (low[<U.S. $756], low-middle [U.S. $756-$2,295], high-middle [U.S. $2,2996-$9,265], high [>U.S. $9,265]) (9). For each income group, we calculated the median proportion of deaths of children <5 years of age attributable to diarrhea. We then multiplied the median proportion for each income group by the total number of deaths of children <5 years of age for each country in that income group to yield country-specific estimates of the mortality rate from diarrhea. These country-specific estimates were added to calculate the global mortality rate from diarrhea.

To estimate the fraction of diarrhea deaths attributable to rotavirus, we plotted the proportion of rotavirus infection detected in children hospitalized for diarrhea that was, by virtue of the need for hospitalization, presumed to be severe. These figures were again plotted against per capita GNP for each country to yield median rotavirus detection rates for countries in the four World Bank income groups. Previously estimated diarrhea mortality rates for each country in an income group was multiplied by the median rotavirus detection rate for that income group to yield the estimated number of rotavirus deaths by country. These figures were added to yield the number of global deaths from rotavirus diarrhea. For each income strata and overall, the risk of death from rotavirus diarrhea by 5 years of age was calculated by dividing the total number of live births by the total number of deaths from rotavirus.”

Estimations based on presumptions and more estimations. Yet, still no death statistics for the US. Why couldn’t I find any definite answers?

I abandoned my search to pinpoint exact numbers. Instead, I turned my attention to the question: Why create a vaccine for a population in which lightening strikes (<62 per year) are a more likely cause of death than rotavirus (<40 per year)?

The Journal of Pediatrics from February 2004 (Volume 144 Issue 2) article, Safety, efficacy, and immunogenicity of a live, quadrivalent human-bovine reassortant rotavirus vaccine in healthy infants, (4) served up more than I’d expected. Down at the very bottom of the page I found:

Drs H. Fred Clark, David I. Bernstein, Penelope H. Dennehy, Paul Offit, Michael Pichichero, John Treanor, and Richard L. Ward received funding for research or for clinical investigation from Merck & Co, Inc. Drs Clark and Offit are coholders of the patent on the human reassortant rotavirus vaccine. Dr Dennehy also is a member of Merck’s Speakers Bureau. Drs David L. Krah, Alan Shaw, Michael J. Dallas, Karen M. Kaplan, and Penny Heaton are current employees and Drs Joseph J. Eiden and Nathalie Ivanoff are former employees of Merck & Co, Inc.

What’s so important about this name? Dr. Paul Offit was a member of the CDC’s Advisory Committee of Immunization Practices. This means his job was to recommend or reject vaccines for use in the routine immunization program. I understand Dr. Offit stood down from the official vote on this vaccine, however, here we see an example of him holding a patent for RotaTeq, participating in the study (paid for by Merck) demonstrating that RotaTeq is safe and it works AND amazingly it is recommended for use through the CDC. Conflict of interest? Maybe? What other reasons could I find for the rotavirus vaccine’s recommended use?

I found my answer in the Journal of the American Medical Association (JAMA). Cost-effectiveness Analysis of a Rotavirus Immunization Program for the United States (5) was published in 1998 discussing the merits of implementing the rotavirus vaccine into the current immunization program.

“Context.— Rotavirus is the most common cause of severe diarrhea in children, and a live, oral vaccine may soon be licensed for prevention.

Results.— A routine, universal rotavirus immunization program would prevent 1.08 million cases of diarrhea, avoiding 34000 hospitalizations, 95000 emergency department visits, and 227000 physician visits in the first 5 years of life. At $20 per dose, the program would cost $289 million and realize a net loss of $107 million to the health care system—$103 per case prevented. The program would provide a net savings of $296 million to society. Threshold analysis identified a break-even price per dose of $9 for the health care system and $51 for the societal perspective. Greater disease burden and greater vaccine efficacy and lower vaccine price increased cost-effectiveness.”

This study was written to demonstrate how much money this vaccine will save our economy. Also from this study, I was served up a little nugget of heaven. At last, I’d found a cumulative incidence of deaths due to rotavirus among children.

Finally, about 20 deaths occur each year due to rotavirus diarrhea among children younger than 5 years,1, 6 for a cumulative incidence by age 5 years of 0.000005 (1 in 195000 children).

Armed with the knowledge that only about 20 children die per year due to rotavirus, I was off to investigate the vaccine itself.

What most people don’t know is that the rotavirus vaccine contains live viral cells. These cells can ‘shed’ from the body for days (even weeks) after vaccination, and consequently give people rotavirus disease. Rotavirus in particular is well known for shedding, specifically in fecal matter. It is imperative that the utmost attention be paid to hygiene during the shedding period so that cross-contamination/infection does not occur.

Another interesting tidbit was found in the study titled Serum antibody as a marker of protection against natural rotavirus infection and disease (6) which was published in the Journal of Infectious Disease in 2000. Apparently, children are gaining natural immunity from rotavirus after 2 consecutive infections whether or not they demonstrated symptoms.

“Protective antibody titers were achieved after 2 consecutive symptomatic or asymptomatic rotavirus infections. These findings indicate that serum anti-rotavirus antibody, especially IgA, was a marker of protection against rotavirus infection and moderate-to-severe diarrhea.”

This is supported by documents at the CDC showing that 95% of children have had rotavirus by age 5 and that after just one natural infection, 87% of children are protected against severe diarrhea. (7) Additionally, complications from severe rotavirus infection and rotavirus vaccination are compared. Allow me to share:

Rotavirus complications:

severe diarrhea
dehydration
electrolyte imbalance
metabolic acidosis
Immunodeficient children may have more severe or persistent disease

          Vaccine complications:

Vomiting
Diarrhea
Nasopharyngitis
fever

As for treatment, even the the CDC believes that acute gastroenteritis can be properly cared for at home (8):

Home Management of Acute Diarrhea

Treatment with ORS is simple and enables management of uncomplicated cases of diarrhea at home, regardless of etiologic agent. As long as caregivers are instructed properly regarding signs of dehydration or are able to determine when children appear markedly ill or appear not to be responding to treatment, therapy should begin at home. Early intervention can reduce such complications as dehydration and malnutrition. Early administration of ORS leads to fewer office, clinic, and emergency department (ED) visits (37) and to potentially fewer hospitalizations and deaths.

*ORS being oral rehydration solutions such as pedialyte.  Breastfed infants should continue nursing on demand.

To summarize, less than 20 children per year die from rotavirus. Rotavirus is manageable with at-home care. We gain natural immunity from repeated exposure to infection, whether or not we show symptoms, and the side effects caused by the vaccine are remarkably similar to actual rotavirus infection.

Why are we vaccinating for this, again? Death by diarrhea indeed.

Original article can be found here.

1)Rotavirus Vaccine Coverage Under VICP
2)Epidemiology of Rotavirus in the US
3)Global Illness and Deaths caused by Rotavirus Disease in Children
4)The Journal of Pediatrics, Volume 144, Issue 2, February 2004, Pages 184-190
5)Cost Effectiveness Analysis
6)Serum antibody as a marker of protection against natural rotavirus infection and disease
7)CDC’s Rotavirus Pinkbook, Page 1-2
8.) Managing Acute Gastroenteritis Among Children