The risk of meningococcal infection in a child under 18 years of age, increases by 3.8 times if their mother smokes.
Smoking increases the risk of meningococcal infection in adults by 2.4 times, passive smoking by 2.5 times, and chronic disease by 10.8 times.
Passive smoking increases the risk of meningococcal infection by 2.2 times. When both parents smoke, the risk increases by 8 times. More:   
In Ghana, where meningococcal meningitis is much more common than in developed countries, cooking in wood-burning ovens is associated with a 9-fold higher risk of infection.
When parents only smoke outside of the house, it does not decrease the level of nicotine in the children’s hair, which might indicate that the smokers continue to exhale nicotine after smoking. This hints at that the risk of meningococcal infection will not decrease if smoking is prohibited only in certain places, like homes, cars and hospitals, but a full ban is needed. It is known, however, that a relatively small number of people quit smoking, so vaccinating children will probably be more effective. Moreover, there’s hope that children will be able to protect their smoking parents from meningococcus through collective immunity.
Active and passive smoking is associated with a doubling of the risk of tuberculosis. In past and present smokers, the risk of infection with the tuberculosis bacterium, the risk of developing tuberculosis, the risk of complications, and the risk of death from tuberculosis are increased.
The risk of recurrent tuberculosis was 2 times higher in those who smoked more than 10 cigarettes a day than non-smokers. In addition:    
Passive smoking is associated with a 40% increase in the risk of Hib. Daycare – with 3-fold increase in the risk. Breastfeeding decreases the risk by 50%. African Americans got infected 4 times more often.
Analysis of all the Hib cases in Los Angeles in 1988-9 (8.7 million population, 750 thousand of them – children under the age of 5 years). 88 cases were registered among children during the year. Mortality rate was 4.5%.
The risk of Hib in children living in homes with more than two smokers was 6 times higher.
Six or more people living in one hearth is associated with a 3.7-fold increase in the risk of Hib. African Americans get infected 3.5 times more often. Chronic illness and low income also increase the risk.
Vaccination and breastfeeding decrease the risk of Hib (for white people). Vaccination with polysaccharide vaccine increases the risk of Hib.
Another study found that a smoking parent increases the risk of Hib by 2.4 times.
In infants whose mothers smoked during pregnancy, the risk of death was 4 times higher compared to non-smoking mothers. SIDS risk was also increased if mothers continued to smoke after birth. The more mother smoked, the higher was the SIDS prevalence. Father's smoking also increased the risk of SIDS. More: 
In infants of alcoholic mothers, the prevalence of SIDS was increased by 7-8-fold, and the risk of death from other causes was 2.3 times higher. More: 
Smoking is associated with a 4.1-fold increase in the risk of invasive pneumococcal infection in adults, passive smoking – with a 2.5-fold increase.
Chronic disease is associated with a 2.6-fold increase in risk. People with incomplete secondary education get the disease 2.8 times more often, and people with secondary education twice as often than people with higher education.