The Emergency campaign for smallpox eradication from Somalia (1977-1979)--revisited

The historical significance of smallpox eradication from Somalia lies in the fact that the country was the last to record the last endemic smallpox case in the world. Before 1977 the programme was mismanaged. In the mid-1970s, the programme was plagued with concealment. Confirmation of smallpox outbreak in Mogadishu in September 1976 delayed global smallpox eradication. The Government maintained that there was no ongoing smallpox transmission in the country after the Mogadishu outbreak and frustrated independent attempts to verify its claim. In February 1977 the Government allowed World Health Organization (WHO) epidemiologists to search, unhindered, for smallpox outside Mogadishu. Soon widespread smallpox transmission was detected. The Government appealed for international support. The strategy to stop the smallpox transmission was based on surveillance and containment. The WHO took the leading role of the campaign which, in spite of the Somalia/Ethiopia war of 1977/78, culminated in the eradication of smallpox from the country. Somalia was certified smallpox-free on 19 October 1979.     

Experiences with smallpox eradication in Ethiopia

The smallpox eradication campaign operated in Ethiopia from 1970 until 1977. During this time Ethiopia had only 84 hospitals, 64 health centres and fewer than 400 physicians in a country of 25 million people. In 1970 smallpox vaccination was relatively unknown in the country, and the government actually contested the fact that smallpox was present in the country. Most of the resources of the Ministry of Health were used for malaria eradication. Initial pessimism from the Ministry of Health and others was eventually overcome as the smallpox eradication campaign continued to pick up steam but many remained unenthusiastic. Ethiopia was the first country in the world to start its smallpox eradication campaign from day one with the strategy of "Surveillance and Containment". Establishing a surveillance system in a country with a limited health infrastructure was a daunting challenge. At the end of the first year of the programme in 1971, 26,000 cases of smallpox had been registered through the growing surveillance system. Throughout revolution of 1974 the smallpox campaign was the only UN program to operate in the country; in fact it expanded with the hire of many locals leading to a "nationalized" program. This development ushered in the most successful final phase of the program. As the program progressed cases were diminishing in most regions, however transmission continued in the Ogaden desert. Over the course of the campaign approximately 14.3 million US dollars was spent. Working conditions were extremely challenging and a variety of chiefs, guerrillas, landowners and governments had to be appeased. The programme was successful due to the dedicated national and international staff on the ground and by having the full support of the WHO HQ in Geneva.     

Smallpox and polio eradication in India: comparative histories and lessons for contemporary policy

This article argues that a detailed examination of factors contributing to the development of complex structures and strategies for smallpox eradication in South Asia in the 1970s can provide fruitful indications for the reformulation of the national chapters of the global polio eradication programme in this region. There is a magnificent archive in the WHO's Geneva offices, which details how smallpox eradication outbreaks were located and then contained in cities, small towns and remote rural areas in this region, by teams of international workers working closely with local officials. A systematic assessment of the global smallpox eradication efforts indicates parallels between the early stages of the global smallpox eradication programme and the present situation of the polio campaign; as we will see here, it can also provide useful indicators for future action in South Asia and beyond.     

Smallpox eradication in West and Central Africa

In 1966, a programme to eradicate smallpox and control measles began in West and Central Africa. With WHO and US bilateral technical and financial assistance, the 20 countries mounted a coordinated campaign of mass vaccination, assessment, surveillance, and maintenance activities. The last cases of smallpox occurred in May 1970. The introduction of epidemiologically directed surveillance-containment activities and their rapid success resulted in interruption of smallpox transmission much sooner than anticipated. The area has remained free of smallpox. From 1966 to 1972, over 28 000 000 children 1-6 years of age also received measles vaccination. The campaign established or strengthened structures for preventive health care services in all the countries.     

Smallpox eradication in Bangladesh, 1972-1976

Rahima Banu, the world's last endemic case of severe smallpox, Variola Major, developed rash on October 16, 1975 on Bhola Island, Bangladesh. Achieving eradication in a country destroyed by war challenged the achievement of smallpox eradication. Between January 1, 1972 and December 31, 1975, 225,000 smallpox cases and 45,000 smallpox deaths occurred. Adapting the global smallpox eradication strategies of surveillance, the detection of smallpox cases, and containment, the interruption of smallpox transmission, utilized progress toward three objectives to monitor performance: (1) surveillance - the percent of smallpox infected villages detected within 14 days of the first case of rash, (2) knowledge of the reward - public knowledge of the current amount of the reward for reporting smallpox, and (3) containment - the percent of infected villages interrupting smallpox transmission within 14 days of detection. Failures to achieve these objectives led to the identification and implementation of improved strategies that eventually achieved eradication. Essential to this success was a tripartite partnership of the citizens of Bangladesh, the Bangladesh Ministry of Health, its field staff, and staff and resources mobilized by the World Health Organization.     

Commentary: smallpox eradication in west and central Africa revisited.

In May 1980, the Thirty-third World Health Assembly adopted a resolution accepting the report of the Global Commission for the Certification of Smallpox Eradication and affirming its belief that this once-universal disease had been eradicated worldwide, 21 years after the global eradication programme had begun in 1959. A key element in the eradication effort was the surveillance-containment strategy, which was first tested in Nigeria in 1966, and which led to its adoption throughout the world. West and Central Africa became the first region of the world to be smallpox free and one by one other regions followed. One of the major lessons to be learned from the smallpox eradication programme is that interdependence is required if global results are to be achieved. Unfortunately, however, humanity has failed to learn this lesson in the long-term, and although global health has improved dramatically the gaps between the rich and poor remain vast.     

A programme of multiple-antigen childhood immunization in Yaoundé, Cameroon: first-year evaluation, 1975-1976.

The Yaoundé multiple-antigen childhood immunization programme began in November 1975, making it one of the first expanded programmes on immunization operational in Africa. During the first 9 months, more than 22 000 children were immunized against poliomyelitis, measles, tuberculosis, smallpox, whooping cough, tetanus, and diphtheria. Evaluation of the programme showed the following rates of immunization coverage in the target population; 30% for DPT (one dose or more), 27% for poliomyelitis (one dose or more), 27% for BCG, 33% for measles, and 20% for smallpox. Eighty per cent of children received the correct vaccines for their age and vaccination status. Seroconversion to measles vaccine was 89% in those over 12 months of age but only 50% in those between 6 and 11 months of age. The major factor in low immunization coverage was felt to be inadequate publicity. The cost of the programme was estimated to be US $10 920. The cost of immunizing a child completely was estimated at US $1.90. Some logistic problems encountered during this initial year of operation are discussed.     

Lessons and innovations from the West and Central African Smallpox Eradication Program

In 1966, the Centers for Disease Control began training medical officers and public health advisors for a program that would encompass 20 countries of West and Central Africa with the objective of eradicating smallpox and controlling measles. The program was funded by the US Agency for International Development with a target of smallpox eradication within 5 years and the immunization of children from 6 months to 6 years of age against measles in all areas of every country. The 40 plus field staff were directed by a Regional Office in Lagos, Nigeria and a headquarters group in Atlanta, Georgia. The teams greatly expanded the knowledge of smallpox epidemiology, helped to expand the capabilities of Ministries of Health, pioneered the use of jet injectors to provide millions of immunizations, and expanded the use of surveillance/containment to become a primary strategy for interrupting smallpox transmission. Smallpox transmission was interrupted in three and one half years, a year and a half before the time targeted and under budget. Measles transmission was interrupted in one country, The Gambia, and significantly reduced in the other 19 countries.     

Smallpox and its eradication in the Democratic Republic of Congo: lessons learned

Smallpox eradication is considered to be one of the most remarkable accomplishments of the 20th century. Lessons learned from the campaign during the 1960s and 1970s in the Democratic Republic of Congo (DRC) can provide important information for the development of other eradication programs including polio. The DRC is the third largest country in Africa; the population suffers from extreme poverty, deteriorating infrastructure and health systems, and long periods of civil strife. Despite these challenges, DRC's smallpox eradication campaign was successful, eradicating smallpox only 41 months after initiation. DRC had been polio free since 2001; however, in 2006, imported cases were identified in the country. Polio transmission has since been re-established and DRC now has the second greatest number of reported polio cases in the world. Challenges which existed during the smallpox campaign in DRC are still present today; additionally, the polio vaccine itself poses unique challenges which include requiring multiple doses to confer immunity. In the fight against polio in DRC, it will be important to draw from the smallpox eradication experience. A number of important themes emerged during the campaign that could be beneficial to eradicating polio and future eradication programs that may follow. During the smallpox campaign, a standard vaccination program was implemented, surveillance was intensified, and there were strong collaborative programs with community involvement. These successful elements of the smallpox campaign should be adapted and applied in DRC in polio eradication programs.     

Epidemiology of variola minor in Brazil based on a study of 33 outbreaks

Surveillance-containment units were established in 1969 in four States of Brazil as part of the national smallpox eradication programme. Their responsibilities included both the investigation of reported cases and the control of outbreaks, and the further extension and development of the reporting network. Altogether, 33 outbreaks of smallpox were investigated in detail, all in endemic areas not yet reached by the attack phase of the eradication programme. Official reports of 27 cases led to the discovery of an additional 1 465 cases, suggesting that reporting was not more than 2% complete in endemic areas. The total of 1 492 cases in 33 outbreaks occurred in 493 households comprising a study population of 3 088 persons: three-quarters of the cases were in children under 15 years of age. Only 5% were in individuals aged 30 years or more. The case—fatality ratio was 0.8%. The overall attack rate among unvaccinated persons (76.2%) was 23 times that among vaccinated persons (3.3%). Age-specific vaccine effectiveness ratios ranged from 94% to 100% with an overall reduction in expected cases among the vaccinated of 95%. There was no evidence to suggest waning of immunity among persons who had been successfully vaccinated. There was an inverse relationship between susceptibility and age since a greater proportion of adults had already had smallpox or a successful vaccination; 97% of pre-school-age children and 82% of school-age children had no history of smallpox and no vaccination scar. In all 33 outbreaks, more than 60% of unvaccinated persons became ill; in 5 outbreaks the attack rate for unvaccinated persons was greater than 90%.     

Eradication: lessons from the past

The declaration in 1980 that smallpox had been eradicated reawakened interest in disease eradication as a public health strategy. The smallpox programme's success derived, in part, from lessons learned from the preceding costly failure of the malaria eradication campaign. In turn, the smallpox programme offered important lessons with respect to other prospective disease control programmes, and these have been effectively applied in the two current global eradication initiatives, those against poliomyelitis and dracunculiasis. Taking this theme a step further, there are those who would now focus on the development of an inventory of diseases which might, one by one, be targeted either for eradication or elimination. This approach, while interesting, fails to recognize many of the important lessons learned and their broad implications for contemporary disease control programmes worldwide.     

Occupationally-acquired smallpox in an IgM-deficient health worker

A 21-year-old Indian who worked as a vaccinator in the smallpox programme developed an atypical case of variola major despite several previous, successful vaccinations. The clinical course of the disease was unusual, as there were two distinctly separate ”crops” of smallpox. The disease began less than one month after a successful vaccination, which therefore gave the briefest period of protection recorded for this reliable immunization. The patient was found to have a virtually complete IgM deficiency with normal levels of circulating antibody against orthopox virus.     

Eradication of contagious diseases

Based on analysis of eleven-year intense epidemiological intervention against smallpox, a number of findings and demands ensued which should be met by an infectious disease to be included into the programme of eradication or elimination. The author mentions several episodes from the programme of smallpox eradication in which he participated as a member of a WHO team. Part of the paper is a detailed explanation of the terms eradication and elimination. The main part of the article is a characteristic of infections where the global programme of eradication or elimination is underway. At present the eradication of poliomyelitis and dracunculiasis is completed and elimination of tetanus of neonates as well as leprosy, all by the year 2000. By 2010 measles, possibly German measles and mumps should be eradicated and possibly leprosy and Chagas' disease and onchocerciasis should be eliminated. Also for other infections such as lymphatic filariasis, trachoma and non-veneric treponematoses more remote terms are given or are not yet given. Depending on the decision of WHO on the programme of global eradication, under precisely defined conditions seven other infections may be included: cysticercosis (Taenia solium), diseases caused by Haemophilus influenzae b, viral hepatitis A, rotavirus enteritis, diphtheria, whooping cough and tuberculosis. In the case of viral hepatitis B only elimination is foreseen.     

Certification of smallpox eradication.

The world''s last known case of smallpox resulting from human-to-human transmission in an endemic focus occurred in Somalia in October 1977, and there remains the task of documenting the global eradication of the disease and establishing the safety of vaccination. Those countries as yet uncertified have been grouped into four categories according to the procedures recommended for their certification. An important criterion for deciding the type of procedure is how recently smallpox was endemic in a particular country. This paper is concerned with those countries in which the disease has been nonendemic for some years but which have not yet received certification of eradication. One such country is Burma, which was certified free of smallpox in 1977, some 8 years after its last reported case but 2 years after the last case in Bangladesh, with which it shares a long frontier. The procedures used in Burma and the lessons that were learnt therefrom are described.     

Assessment of vaccination coverage, vaccination scar rates, and smallpox scarring in five areas of West Africa

In 1966, nineteen countries of West and Central Africa began a regional smallpox eradication and measles control programme in cooperation with the World Health Organization. This paper summarizes sample survey data collected to assess the results of the programme in Northern Nigeria (Sokoto and Katsina Provinces), Western Nigeria, Niger, Dahomey, and Togo. These data indicate that the programme, which used mass vaccination campaigns based on a collecting-point strategy, was generally successful in reaching a high proportion of the population. Analysis of vaccination coverage and vaccination scar rates by age underlined the importance to the programme of newborn children who accumulate rapidly following the mass campaign. Of all persons without vaccination scars at the time of the surveys, 34.4% were under 5 years of age; in the absence of a maintenance programme, this figure would rise to 40% after 1 year.     

Principles and lessons from the smallpox eradication programme

The eradication of smallpox required a unique, fully collaborative international effort on the part of WHO and Member States. In the course of the programme, many lessons were learned in its organization, execution and evaluation which have implications for other international activities. Most important among these was the need to establish measurable objectives and to evaluate progress and performance in terms of these; to establish procedures for quality control both of vaccines and performance; to recruit the best possible personnel and support them; and to assure an on-going programme of problem-oriented research which can facilitate activities and resolve apparently paradoxical observations. The inherent capacities of national health services to execute their smallpox eradication programmes was gratifying. It encouraged the belief that other, more complex health measures could be undertaken. Although this would necessitate that adequate numbers of competent leaders be recruited and given delegated responsibility, such persons were usually found to be available although often inexperienced. WHO''s roles in catalysing and orchestrating this great effort were critical. Its potential for promoting other efforts in disease prevention and health promotion was apparent although still only partially realized.     

Governments,off-patent vaccines,smallpox and universal childhood vaccination

WHO is now celebrating more than 30 years of freedom from smallpox. What was originally seen as a victory over an ancient scourge can now be viewed as an epidemiologically driven programme to overcome governmental inertia and under-achievement in delivering an off-patent vaccine. Though efforts are accelerating global vaccine use, a plea is made to push the world's governments to commit to universal childhood vaccination via a proposed new programme. The latter should begin by exploiting a long list of ever more affordable off-patent vaccines, vaccines that can virtually eliminate the bulk of the world's current vaccine-preventable disease burden.     

Logistics in smallpox: the legacy

Logistics, defined as "the time-related positioning of resources" was critical to the implementation of the smallpox eradication strategy of surveillance and containment. Logistical challenges in the smallpox programme included vaccine delivery, supplies, staffing, vehicle maintenance, and financing. Ensuring mobility was essential as health workers had to travel to outbreaks to contain them. Three examples illustrate a range of logistic challenges which required imagination and innovation. Standard price lists were developed to expedite vehicle maintenance and repair in Bihar, India. Innovative staffing ensured an adequate infrastructure for vehicle maintenance in Bangladesh. The use of disaster relief mechanisms in Somalia provided airlifts, vehicles and funding within 27 days of their initiation. In contrast the Expanded Programme on Immunization (EPI) faces more complex logistical challenges.     

The Smallpox Pandemic of 1870-1874: (Section of Epidemiology and State Medicine)

The Vaccination Act of 1853 inspired by the Epidemiological Scoiety of London was the cause of the incidence and fatality of the pandemic being less in the United Kingdom than in foreign countries.Origin of pandemic in France before outbreak of Franco-Prussian War. Its spread through the country. Vaccination state of civilian population and army in France in 1870.Incidence, fatality and characteristics of the pandemic in England and Wales, London, Scotland and Ireland and foreign countries with special reference to Germany and German army. Lack of hospital accommodation for smallpox cases in London. M.A.B. hospitals opened. Absence of ambulance service. Aerial convection of smallpox. Smallpox fatality in the various Metropolitan boroughs.Incidence and fatality of smallpox heavy in civilian population in Germany as compared with the well-vaccinated army, but lower in Southern German States, where primary vaccination was compulsory, than in Prussia and Saxony which had no vaccination laws.Further statistics illustrating difference in smallpox fatality in different countries and groups of individuals according to their vaccination state.     

Poxvirus in West African nonhuman primates: serological survey results.

Ten species of nonhuman primates in West African habitat were analysed for variolavaccinia subgroup haemagglutination-inhibition (HI) and neutralization antibodies. The animals were taken in 27 different sampling zones in parts of the Ivory Coast, Mali, and Upper Volta. Of the 195 tested, 15 (8%) had elevated HI antibodies after nonspecific reactions were reduced with potassium periodate pretreatment. Positive neutralization antibodies were found in 21% (44 of 206). Antibodies were detected in serum from monkeys living near two areas where monkeypox cases in humans had occurred. Four samples were tested for monkeypox specific antibodies using an indirect immunofluorescent test; 3 were positive. Despite the prevalence of poxvirus antibodies in monkeys (and other animals) in West Africa, smallpox eradication has been maintained in the area since 1970; thus, animal reservoirs of poxvirus appear to pose no threat to the worldwide smallpox eradication programme.