Risk factors for diphtheria: a prospective case-control study in the Republic of Georgia, 1995-1996.
J Infect Dis
- To get diphtheria from another person, the distance to that person should be less than 1 meter. If the distance is greater, the risk of infection is significantly reduced.
- 40-78% of unvaccinated children in Afghanistan, Burma and Nigeria developed natural immunity by the age of 5.
- Socioeconomic factors, such as cramped quarters, poverty, alcoholism and low level of hygiene contribute to the spread of diphtheria.
A study of 218 cases of diphtheria in Georgia in 1995-1996. Fatality rate was 10%.
- Among children, elementary level education of the mother was associated with a 4 times higher risk of getting diphtheria, as compared to those, whose mothers had academic education.
- Among adults, people with elementary level education got sick with diphtheria 5 times more often than those, who got a university degree.
- Chronic illnesses were associated with a 3 times higher risk of getting diphtheria. Unemployed got sick twice as often. Taking a shower less than once a week was associated with a two times higher risk of infection.
- Unvaccinated people got sick 19 times more often than those who have been vaccinated. However, only those who received all doses and boosters, and have been vaccinated in the last 10 years, were considered as vaccinated. The rest were considered as unvaccinated. The authors write that perhaps the patients did not remember well whether they have been vaccinated or not.
- Among the 181 cases: 9% were unvaccinated, 48% had a chronic illness, 21% took showers less than once a week. The authors conclude that vaccination is the most important tool in the control of diphtheria, but do not overly emphasize that people should wash themselves more often than once a week.
Also, the authors write that diphtheria is not very contagious and that it takes a prolonged contact with a patient to contract it.
Visiting crowded places was not a risk factor.
Compared to the previous epidemics in Europe and USA, which occurred mainly among alcoholics, the authors did not find an increased risk in alcoholism in this study. They conclude that low socioeconomic status, and not alcoholism, is likely a risk factor.