How we wish to be cited:
Hedström SÅ. The culture of AIDS – smallpox out,
AIDS in [culture]? Rondel 2003; 16. URL: http://www.rondellen.net
The culture of AIDS
Smallpox out, AIDS in?
Background
Around 1980 a new mysterious disease appeared in USA, later named AIDS and shown to be caused by the nowadays well known microorganism HIV. AIDS in humans is caused by two lentiviruses, HIV-1 and HIV-2, seemingly derived from mutations of one type of SIV (Simian Immunodeficency Virus) from chimpanzees from central and eastern equatorial Africa, coinciding with the region that seems to be the origin of the HIV-1 pandemic, and the other type of SIV from the sooty mangabey monkey from western Africa, respectively [1]. Thus, two similar virus diseases popped up simultaneously in two African regions lying apart.
Serial passages of the virus from man to man could explain progressive evolution from SIV to HIV and this process may have been initiated already in the 1910s [2]. Especially the HIV-1 has been object to a variety of genetic diversity including independent cross-species transmission events resulting in three groups (M, N and O) and sub-types [1]. Genetic analyses place the last common ancestor of the M group prior to 1940, and there are indications that the virus jumped from chimpanzees to humans before that year [1].
Personal observations
During the last 3-4 years I have worked as a general practitioner in many small villages in Kenya. Mainly heterosexually HIV/AIDS was an obvious problem besides the classical sexually transmitted diseases (STD). When I visited some medical institutions in Tanzania and Kenya in 1974 HIV/AIDS was of course unknown but STD was nearly as common as today. Recently, when I read my notes from 1974, I was struck by my repressed description of a lot of meagre patients with Kaposi sarcoma, whom I saw in a Tanzanian hospital. My colleagues there had no explanation to the great number and I do not know anything about their fate. If they were HIV infected as we see patients with Kaposi sarcoma are today the virus must have been spread in Africa. Saved African blood samples from 1960s were found to contain antibodies against HIV [3].
Smallpox out – AIDS in
In western and central Africa a successive reduction of reported cases of smallpox occurred from around 17500 in 1961 to zero in 1971. A similar development was seen in Tanzania where reported cases were on the level of 3000 in the middle of the 1960s and fell to 32 in 1970 [4]. The last noted smallpox case in Tanzania dated from September 1970.
A model scenario might be this: SIV had since many years been transmitted to humans. A progressive evolution from SIV to HIV was probable during several decades since the 1910s [2]. Seventeen years old sera from Africans were stored in a laboratory in which antibodies against HIV later were detected [3]. An inexplicable gathering of Kaposi sarcoma was noted in an East African Hospital 6 years before.
Thus, there are many grounds for believing that HIV-infection was low endemic before 1980. Why did we notice such a rapid increase from 1980 and during the 1980s and not before, as the viruses obviously were present for decades? One explanation could be a mutation increasing the virulence but it is unlikely that a mutation could happen simultaneously in two viruses geographically apart from each other. Another explanation is that the human lifestyle changed but that is nothing that comes suddenly. Is there a further reason?
Both HIV-1 and HIV-2 affects the immune system but the resulting diseases differ in severity. The most spread infection and cause – at that time HTLV-III - was detected and described in 1981-83, mainly in USA where the scientific resources were better than in Africa. Both HIV infections have a latency period and until the diseases manifested themselves in various countries the dissemination of virus could have been going on insidiously due to human behaviour such as expanding travelling, promiscuity, use of intravenous drugs.
The last case of smallpox was seen in October 1977 in Somalia and on 9th of December 1979 the world was declared free of smallpox after a gigantic vaccination campaign [4]. After that an explosive global dissemination of the HIV/AIDS followed. Had the eradication of smallpox an influence on the increasing number of HIV/AIDS cases?
The HIV infection affects the immune system to a degree comparable to the congenital condition of a combined immunodeficiency. Children with that disease are very susceptible to microorganisms, including those with low virulence, and unprotected they die at low age. It is described that even vaccination with attenuated smallpox virus killed the children with that kind of immunodeficiency [5].
In the same way, patients with affected immunity by HIV hypothetically could be very susceptible to smallpox, even low endemic, and may die before they have an opportunity to spread HIV to a high degree.
Summary
There is a time relation between the disappearance of smallpox and the appearance of HIV/AIDS. During a short period smallpox disappeared and HIV appeared and then increased rapidly. There is also a hypothetically possibility that smallpox may have killed HIV-infected persons in Africa, because of the immunodeficiency, resulting in only a slow spreading of HIV, a low endemic period. After HIV-patients were not threatened by smallpox and instead survived there might be no impediment for HIV disease to increase locally in number and geographic dispersion and after that a dissemination all over the world was possible due to human lifestyles.
Sven Åke Hedström
MD, PhD, associate professor, specialist in infectious diseases
Arvid Carlsons v. 1, SE-311 92 Falkenberg, Sweden
E-mail: sah.creatus@sydpost.nu
References
Published August 20, 2003