Tetanus seroprevalence among farmers: a preliminary study

Immunization Coverage Surveys and Linked Biomarker Serosurveys in Three Regions in Ethiopia

Objective

Demographic and health surveys, immunization coverage surveys and administrative data often divergently estimate vaccination coverage, which hinders pinpointing districts where immunization services require strengthening. We assayed vaccination coverage in three regions in Ethiopia by coverage surveys and linked serosurveys.

Methods

Households with children aged 12–23 (N = 300) or 6–8 months (N = 100) in each of three districts (woredas) were randomly selected for immunization coverage surveys (inspection of vaccination cards and immunization clinic records and maternal recall) and linked serosurveys. IgG-ELISA serologic biomarkers included tetanus antitoxin ≥ 0.15 IU/ml in toddlers (receipt of tetanus toxoid) and Haemophilus influenzae type b (Hib) anti-capsular titers ≥ 1.0 mcg/ml in infants (timely receipt of Hib vaccine).

Findings

Coverage surveys enrolled 1,181 children across three woredas; 1,023 (87%) also enrolled in linked serosurveys. Administrative data over-estimated coverage compared to surveys, while maternal recall was unreliable. Serologic biomarkers documented a hierarchy among the districts. Biomarker measurement in infants provided insight on timeliness of vaccination not deducible from toddler results.

Conclusion

Neither administrative projections, vaccination card or EPI register inspections, nor parental recall, substitute for objective serological biomarker measurement. Including infants in serosurveys informs on vaccination timeliness.

A cross-sectional study of tetanus and diphtheria antibody concentrations post vaccination among lung transplant patients compared with healthy individuals

BACKGROUND

Lung transplant (LuTx) patients are routinely immunized against tetanus and diphtheria. However, few studies have been done to measure serologic immunity in the transplant population.

OBJECTIVES

The primary objective of this study was to compare tetanus and diphtheria antibody concentrations in LuTx vs. healthy subjects.

METHODS

Serum was used from an available sample of 111 total individuals (n = 36 healthy; n = 75 LuTx). Tetanus and diphtheria antibody concentrations were measured using an enzyme-linked immunosorbant assay method.

RESULTS

A statistically significant difference in both tetanus and diphtheria antibody concentrations was found between the groups. The median concentration of tetanus antibody was higher for healthy individuals compared with the LuTx group (3.2 IU/mL [1.2-5.2 interquartile range {IQR}] vs. 1.3 IU/mL [0.4-2.6 IQR], respectively; P = 0.0001). No difference in time was found since the last tetanus-diphtheria vaccine or tetanus-diphtheria-pertussis vaccine dose between the groups (healthy 76.5 months [16-114 IQR] vs. LuTx 74.5 months [45-118 IQR]; P = 0.44).

CONCLUSIONS

Tetanus and diphtheria immunizations are recommended for LuTx patients to reduce the risk of infection. Because the LuTx group has lower antibody concentrations, further studies should investigate the possible need for more frequent tetanus and diphtheria boosters.

The seroepidemiology of tetanus in Catalonia, Spain

Titres of anti-tetanus toxin antibodies > or = 0.1 IU/ml were determined using an enzyme linked immunosorbent assay in representative samples of the juvenile and adult population of Catalonia. The prevalence obtained in 1,316 juveniles and 1,296 adults was 99.4 and 68.3%, respectively. In adults, the prevalence in males (76.5%) was higher (P < 0.001) than in females (61.7%), fell with increasing age and was higher in subjects born in Catalonia (72.5%) than in those born outside Catalonia (57.9%) (P < 0.001). These results show that routine vaccination of children is successful. In adults aged > or = 45 years, the prevalence is inadequate and efforts should be made to increase vaccination.

Measurement of tetanus antitoxin in oral fluid: a tool to conduct serosurveys

BACKGROUND

Serosurveys that measure tetanus antitoxin can complement immunization coverage surveys to allow evaluation of immunization services in developing countries. Measurement of IgG tetanus antitoxin in oral fluid was investigated as a practical and noninvasive alternative to and correlate of serum antibodies.

METHODS

Serum and oral fluid were collected from Malian infants, toddlers and adults (males without a history of tetanus vaccination). Specific IgG tetanus antitoxin was measured by enzyme-linked immunosorbent assay in serum (S-ELISA) and oral fluid (OF-ELISA).

RESULTS

One hundred forty-two pairs of serum and oral fluid samples were collected from infants, 35 pairs from toddlers and 35 pairs from adults. IgG tetanus antitoxin titers measured by OF-ELISA were 100-fold lower than those measured by S-ELISA but they correlated strongly (r = 0.90, P < 0.001). All 35 toddlers who had received 2 or 3 doses of diphtheria-tetanus-pertussis (DTP) vaccine (100%) had serum tetanus antitoxin levels >or=0.15 IU/mL and 28 of 35 (80%) had oral fluid values >or=0.0015 IU/mL. Among adults lacking a history of tetanus immunization, only 6 of 35 (17.1%) had serum titers >or=0.15 IU/mL and 4 of 35 (11%) had oral fluid titers >or=0.0015 IU/mL in oral fluid.

CONCLUSIONS

IgG tetanus antitoxin in oral fluid correlates well with levels in serum. OF-ELISA values >or=0.0015 IU/mL constitute protection against tetanus and in subjects >12 months of age imply multiple prior contacts with immunization services. IgG tetanus antitoxin measured by OF-ELISA provides a logistically practical alternative for performing seroprevalence surveys.

Vaccinations for waste-handling workers. A review of the literature

A review of the literature relating to the need for vaccination against infectious disease in the solid waste industry was conducted, focusing on hepatitis A, hepatitis B and tetanus. Databases (Medline, PreMedline, EMBASE, CINAHL, Current Contents, Cochrane Database, HTA Database, DARE, OSHROM) were searched up to and including August 2003. Articles were included in the review if they reported the prevalence of immunity to hepatitis A, hepatitis B or tetanus in solid waste workers or the incidence of clinical infection with any of these diseases. Papers about hazardous or medical waste, incineration or other infectious diseases were excluded. Forty-four papers constituted the evidence database. Only one paper studied the prevalence of antibodies to hepatitis A and hepatitis B in solid waste workers compared with sewage plant workers and office workers, and no difference was found between these groups of workers. There was some evidence to support a theoretical risk of infection with hepatitis A, B and tetanus; however, no studies could be found of the risk of these diseases in solid waste workers. No single cases of these diseases being acquired occupationally in solid waste management were identified in the literature. Workers in the solid waste industry may theoretically be at increased risk of acquiring infectious diseases occupationally. However, at present no studies could be found which have documented this risk.