# 6158
Forty-three years ago (1969), Surgeon General of the United States William H. Stewart, famously (and as it turned out, prematurely) declared, "The war against diseases has been won."
And for a time, it seemed he might be right.
With the advent of the Salk Vaccine in 1955, we finally had the tool with which to eradicate the last great childhood scourge in this country; Polio. By 1963, an early measles vaccine had been developed, and in the late 1970s significant improvements had been made in the existing mumps vaccine.
And the tremendous victory over smallpox – now vanquished from the planet for more than 3 decades – seemed only to prove the point.
A telling graphic from the MMWR of Dec 1999, Achievements in Public Health, 1900-1999: Control of Infectious Diseases shows the progress made during the 20th century in the battle against infectious diseases.
But this victory was short-lived. By 1996 you can begin to see the uptick in infectious disease deaths, after reaching its nadir in 1980.
Since Stewart’s pronouncement we’ve seen a Swine Flu pandemic, a SARS epidemic, the return of the H1N1 virus in 1977 plus the emergence of previously unknown pathogens like HIV, Lyme Disease, Nipah, Hanta and Hendra (among others).
We’ve watched the global spread of MRSA, along with the recent arrival of of NDM-1 and other Carbapenemases that threaten the viability of our antibiotic arsenal. Even Gonorrhea, once easily cured, threatens with new drug resistant strains.
And we’ve seen an explosion in dengue and chikungunya cases, the global persistence of malaria, along with outbreaks of Ebola, CCHF, and other exotic diseases.
Even old scourges, once thought on the way out, are showing new signs of life . . . like Pertussis, measles, and polio. Perhaps most troubling of all has been the emergence of increasingly drug resistant strains of tuberculosis.
On average – researchers have discovered one new zoonotic threat a year over the past three decades.
Admittedly a lot of these emerging infectious diseases are predominantly found in developing, or under-developed countries.
Non-communicable diseases – like cancer, coronary artery disease, diabetes, and tobacco-related illnesses – are generally thought of as being the primary health threats in developed countries.
And in terms of total numbers, that holds true.
But infectious diseases are on the rise in the developed world, as is once again confirmed by the following report on a nationwide epidemiological survey of New Zealand from The Lancet.
The Lancet, Early Online Publication, 20 February 2012
doi:10.1016/S0140-6736(11)61780-7
Increasing incidence of serious infectious diseases and inequalities in New Zealand: a national epidemiological study
Dr Michael G Baker MBChB a, Lucy Telfar Barnard PhD a, Amanda Kvalsvig MBChB a, Ayesha Verrall MBChB a, Jane Zhang MSc a, Michael Keall PhD a, Nick Wilson MBChB a, Teresa Wall DPH b, Prof Philippa Howden-Chapman PhD a
Findings
Infectious diseases made the largest contribution to hospital admissions of any cause. Their contribution increased from 20·5% of acute admissions in 1989—93, to 26·6% in 2004—08. We noted clear ethnic and social inequalities in infectious disease risk. In 2004—08, the age-standardised rate ratio was 2·15 (95% CI 2·14—2·16) for Māori (indigenous New Zealanders) and 2·35 (2·34—2·37) for Pacific peoples compared with the European and other group. The ratio was 2·81 (2·80—2·83) for the most socioeconomically deprived quintile compared with the least deprived quintile. These inequalities have increased substantially in the past 20 years, particularly for Māori and Pacific peoples in the most deprived quintile.
Interpretation
These findings support the need for stronger prevention efforts for infectious diseases, and reinforce the need to reduce ethnic and social inequalities and to address disparities in broad social determinants such as income levels, housing conditions, and access to health services. Our method could be adapted for infectious disease surveillance in other countries.
Retrospective epidemiological analyses such as this one are always subject to a certain degree of error.
As this study is based on hospital admissions, it is likely that milder infections are under-represented. Coding errors, or the re-evaluation of original diagnosis codes based on the judgment of the reviewers, may further complicate matters.
The authors cite economic and social disparities as prime factors in the increase in infectious diseases.
Problems that are hardly unique to New Zealand.
While almost 75% of their hospitalizations still come as the result of non-communicable diseases, the trend over the past two decades shows that infectious diseases are gaining ground.
Up by roughly 30% since 1989.
In the discussion section, the authors write:
The large increase in admissions for infectious diseases has important health and economic implications, and challenges prevailing views about the waning importance of infectious diseases. New Zealand seems to have the dual burden of rising non-infectious diseases, without having controlled the incidence of infectious disease.
The increase is equivalent to an additional 17 000 hospital admissions per year compared with the expected incidence, had the proportion of admissions caused by infectious diseases in 1989—93 continued to the present.
For more on this apparent pendulum swing back towards emerging infectious diseases, you may wish to revisit a blog I wrote more than a year ago called:
The Third Epidemiological Transition
