Marine researcher starts pox outbreak
(Editor’s note: The following is a summarized excerpt from an epidemiological analysis of the 1971 smallpox outbreak in Aralsk, Kazakhstan, in the former Soviet Union by Alan Zelicoff, MD.1 The complete analysis and the official Soviet report of the incident can be found at http://cns.miis.edu/pubs/opapers/op9/index.htm.)
During the summer of 1971, a previously unreported outbreak of smallpox occurred in Aralsk, a city of approximately 50,000 people on the northern shore of the Aral Sea in the Soviet republic of Kazakhstan. It is now clear that senior Soviet leaders, starting with KGB chief Yuri Andropov, suppressed the reporting of this outbreak, possibly to protect the top-secret Soviet biological warfare program.
Bakyt B. Atshabar, director of the Mosgut Aikim-baev Kazakh, a Scientific Center of Quarantine and Zoonotic Infections in Almaty, Kazakhstan, gave a copy of a previously secret Soviet medical report describing the 1971 smallpox outbreak to Center for Nonproliferation Studies of the Monterey (CA) Institute of International Studies. The official report states that on or about July 15, 1971, a biological research vessel called the Lev Berg set sail from Aralsk on an extended voyage to assess the ecological damage to the Aral Sea. On board the Lev Berg was a young fisheries expert, Patient 1, who was responsible for, among other things, casting nets and collecting various species of fish and plants for archiving. The official report states that on Aug. 6, as the research vessel headed back to Aralsk at the northern end of the Aral Sea, Patient 1 became ill with fever, headache, and muscle aches. Shortly thereafter, a rash appeared on her back, face, and scalp and her fever broke. She recovered quickly. On Aug. 27, however, her 9-year-old brother, Patient 2, came down with a fever and a skin rash. Over the ensuing weeks eight additional cases of smallpox appeared in six adults and two children. Overall, seven of the 10 cases — including the index case and her brother — had been immunized for smallpox. The three people who were not immunized developed the rare and highly lethal hemorrhagic form of smallpox and died. Nearly 50,000 residents of Aralsk were vaccinated in less than two weeks, and hundreds of people were quarantined in a facility on the outskirts of town. Transportation into and out of Aralsk was almost completely halted.
The data suggest that the variola virus strain involved in the epidemic may have been somewhat vaccine-resistant. This hypothesis is strengthened by a statistical comparison of the transmissivity of smallpox in the Aralsk outbreak with that in other well-documented outbreaks. In addition, the household quarantining, the halting of all transportation into and out of the city, and the isolation of infected or exposed individuals in a separate observation hospital for as long as three to four weeks may have been as important as mass vaccination in preventing further spread.
How did the index case in the 1971 Aralsk outbreak become infected with smallpox? The official report does not offer a conclusive explanation but one of the suggested hypotheses is that the patient contracted smallpox when she went ashore at one of the ports of call to do some shopping. According to this scenario, On May 25, 2002, the author (Zelicoff) contacted the index case, Patient 1, by telephone and conducted an extensive interview. Patient 1 is currently living in Kazakhstan, is married, and consistent with the official report, is now 54 years of age. She insists that she did not disembark from the Lev Berg at any of the ports of call along its route. Official policy allowed only the male members of the crew to leave the ship, and that this rule was strictly enforced. She noted in the interview that, as the youngest member of the crew, she was the one working most frequently on deck. She spent most of her time casting nets to catch fish.
It is clear that Patient 2 became ill as a result of contact with his sister, Patient 1, the index case. Because it is certain that Patient 2’s illness began during the last week of August 1971, it is most likely that his sister, Patient 1, became ill on or about Aug. 11, roughly 13 days earlier. This is precisely in line with her oral history and at variance with the official report, where the date of onset of her illness is given as Aug. 6. It is extremely unusual for patients with smallpox to transmit the disease after the first week of clinical illness, further discrediting the official report. It is therefore most likely that she became infected with small- pox during the last days of July 1971.
It is now known that beginning in 1936, the Soviet Ministry of Defense used Vozrozhdeniye Island in the Aral Sea as a site for bioweapons field testing. The island offered a number of advantages: it was isolated and surrounded by water, making security relatively easy. The wind blew predictably from north to south, providing an upwind "safe haven" on the northern end of the island that was used for housing troops. Reportedly, it was used for the offensive and defensive testing of aerosols of various biological agents, including the pathogens that cause anthrax, tularemia, and Q-fever. Some sources have also claimed that smallpox virus strains were stored and tested on the island. The Lev Berg was probably south of Vozrozhdeniye Island on or about July 30. Could an open-air test or a laboratory accident involving a virulent strain of variola virus have resulted in the inadvertent contamination of the research vessel?
Plotter Burgos, a former chief sanitary physician of the Soviet Union, was interviewed in the Russian press in November 2001. He was quoted as having said:
"On Vozrozhdeniye Island in the Aral Sea, the strongest formulations of smallpox were tested. Suddenly, I was informed that there were mysterious cases of disease in Aralsk. A research ship of the Aral fleet came 15 km away from the island. (It was forbidden to come any closer than 40 km.) The laboratory technician of this ship took samples of plankton twice a day from the top deck. The smallpox formulation — 400 g of which was exploded on the island — got her,’ and she became infected. . . . I called Andropov, who at that time was chief of the KGB, and informed him of the exclusive recipe of smallpox in use on Vozrozhdeniye Island. He ordered that not another word be said about it. This is a real biological weapon! The minimum radius of contamination was 15 km. One could imagine what would have happened if instead of one laboratory technician, there had been 100 to 200 people."3
For the first time, there is clear circumstantial evidence that the Soviets not only "weaponized" smallpox but also succeeded in aerosolizing it and, it appears, "hardening" the virus so that it maintained its infectivity as it traveled downwind over a distance of at least 15 km. What strain of variola virus was tested on Vozrozhdeniye Island? Does the apparently high prevalence in the Aralsk smallpox outbreak of hemorrhagic manifestations and, perhaps, of vaccine resistance indicate that Soviet military scientists chose an especially virulent strain of variola as a candidate biological weapon? Are clinical or laboratory samples of the weaponized strain still stored in one or more Russian laboratories?
The answers to these and many other questions will almost certainly have a profound effect on civilian and military biodefense efforts in the United States and elsewhere. In the immediate term, our complete reliance on a single vaccine (unmodified vaccinia) represents a serious potential vulnerability.
References
1. Zelicoff AP. "An Epidemiological Analysis of the 1971 Smallpox Outbreak in Aralsk, Kazakhstan." In: Tucker JB, Zilinskas RA, eds. The 1971 Smallpox Epidemic in Aralsk, Kazakhstan, and the Soviet Biological Warfare Program. The Center for Nonproliferation Studies (CNS) of the Monterey (CA) Institute of International Studies. Occasional Papers: #9: 2002.
2. Alibek K. Testimony before the Committee on International Relations, U.S. House of Representatives, 107th Congress. First Session; Dec. 21, 2001.
3. Kvitko E. Smallpox: As bad a weapon: An interview with General Pyotr Burgasov (in Russian). Moskovskie Novosti, Nov. 13, 2001.
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