Immunization, Vaccines and Biologicals

WHO-recommended surveillance standard of neonatal tetanus

Rationale for surveillance

Neonatal tetanus (NT) is targeted by UNICEF, UNFPA and WHO for elimination as a major public health burden along with maternal tetanus. Elimination is defined as less than one NT case per 1000 live births at district level per year. High coverage with tetanus toxoid among pregnant women and in high-risk areas among all childbearing aged women (CBAW) , as well as improved access to clean delivery services are primary strategies for achieving this goal. Effective surveillance is critical for identifying areas or populations at high risk for NT and for monitoring the impact of interventions. However, in the absence of reliable surveillance data, actions aimed at reducing the incidence of NT should not be postponed until the establishment or improvement of surveillance systems. In this situation, elimination strategies should be targeted at areas with high neonatal mortality to which NT is likely to be a major contributor

Recommended case definition

Clinical case definition and case classification

Suspected case:
  • Any neonatal death between 3 and 28 days of age in which the cause of death is unknown; or
  • Any neonate reported as having suffered from neonatal tetanus between 3 and 28 days of age and not investigated
Confirmed case:

Any neonate with normal ability to suck and cry during the first 2 days of life and
- who, between 3 and 28 days of age, cannot suck normally and
- becomes stiff or has spasms (i.e. jerking of the muscles)

Note: The basis for case classification is entirely clinical and does not depend on laboratory confirmation. NT cases reported by physicians are considered to be confirmed. However, investigators should examine NT case records during annual hospital record reviews

Recommended types of surveillance
  • Routine monthly surveillance: the number of confirmed NT cases should be included in all routine reports and should be reported separately from other (non-neonatal) tetanus
  • Zero reporting: designated reporting sites at all levels should report at a specified frequency (e.g. weekly or monthly) even if there are zero cases (often referred to as "zero reporting")
  • Active surveillance: major health facilities should be visited regularly (at least monthly) to identify any NT case admitted or diagnosed in them. Such visits should preferably be made by staff not attached to the health facilities concerned. During these visits, hospital inpatient and outpatient registers should be checked and key clinical staff (e.g. in paediatric and emergency wards) should be asked whether any new NT case has been identified in the hospital since the previous visit
  • Retrospective record review: hospital records should be reviewed for NT cases at least once annually in major hospitals to identify previously unreported NT cases

For all of the above it is recommended that, at least in the short term, NT surveillance be linked to AFP surveillance. Forms and databases should be adapted and standardized so as to enable easy reporting of NT (and, as appropriate, measles) cases when AFP surveillance is carried out

  • Community sensitization: in "silent areas" areas (i.e. where routine reporting is not functional but where other indicators suggest that neonatal tetanus could be a problem) the community should be sensitized about NT and the need to bring suspect cases/deaths to the attention of the health authorities
  • Case investigation and case response:
    - To optimize available resources, case investigations should be conducted first in areas considered at low risk, since cases are not expected here and therefore the response should be tailored to the specific cause. Low-risk areas are those with a clean delivery rate 3 70% and/or TT2 coverage 3 80% (from routine or supplementary immunization activities (SIAs)) or as specified by country-specific criteria
    - In areas already known to be at high risk the focus should firstly be on implementing SIAs to increase immunity to tetanus, rather than on investigating every case and mounting case-response activities around each one. An NT case often represents a sentinel event indicating a more systematic problem. The findings from the case investigation should therefore help to guide the nature and extent of the immunization response. The latter should attempt to immunize all women in the area who are not adequately protected against tetanus or who are eligible for a TT dose. The NT patient should be treated in accordance with local treatment protocols and the mother of the NT case should be immunized immediately against tetanus

Recommended minimum data elements

Aggregated data

  • Number of cases
  • Number of doses of TT administered during routine immunization to pregnant women or number of neonates protected at birth (PAB) (see special aspects section)
  • Number of doses of TT administered during SIAs (such doses should be recorded by dose rather than by round)
    Note: Doses given during routine immunization and during SIAs should be recorded separately on tally sheets and reported separately
  • Completeness/timeliness of monthly zero reports

Case-based data (to be obtained through case-investigation)

  • Unique identifier
  • Date of case investigation
  • Geographical area, name of place of birth (e.g. village, district and province)
  • Date of birth of baby
  • Age (in days) of baby at onset of symptoms (or date of onset)
  • Sex: 1 = male; 2 = female; 9 = unknown
  • Number of live births delivered (including this most recent one) by the mother
  • Number of past neonatal deaths with similar symptoms
  • Number of contacts the mother had with a midwife or trained health worker during this last pregnancy
  • Protection at birth (PAB) status of the last baby born based on the number of tetanus toxoid doses received, interval between doses, and time since last dose (using card or verbal history):
  • Place of birth: 1 = hospital; 2 = health centre; 3 = home; 4 = other; 9 = unknown
  • Assistance during childbirth:* 1 = health staff; 2 = traditional birth attendant; 3 = family member or alone; 4 = other; 9 = unknown
  • Tool(s) used to cut umbilical cord
  • Material used as dressing for cord stump
  • Final outcome of childís health: 1 = alive; 2 = dead; 9 = unknown
  • Final classification: 1 = confirmed; 2 = suspected; 3 = discarded (i.e. not an NT case); 9 = unknown
  • Active case search for additional NT cases done in the locality of birth:* 1 = yes; 2 = no; 9 = unknown
    If yes, number of previously unreported suspected cases detected as having occurred in the previous 12 months
  • If available at the time of investigation:
    Mother given protective TT dose(s) within three months after the report of an NT case: 1 = yes; 2 = no; 9 = unknown
  • If given a protective dose, date of dose
    Note: All mothers whose children are admitted for NT should be immunized immediately on admission to hospital Supplemental immunization conducted within same locality as the case: 1 = yes; 2 = no; 9 = unknown

*Health workers may have to be interviewed to obtain correct and detailed information on these topics

Recommended data analyses, presentations, reports

Aggregated data (i.e. routine monthly reporting)

  • Number of cases and incidence rates by month, year and geographical area
  • District-specific, sex-specific, incidence rates per 1000 live births by year
  • TT2+ coverage (or PAB) by year and geographical area among pregnant women
  • If TT doses are being administered to all women of childbearing age, TT2+ coverage among CBAWs;
  • For SIAs, TT1, TT2, and TT3 coverage among child-bearing women targeted
  • Completeness/timeliness of monthly and zero reporting

Case-based data (i.e. from case investigations only)

as for aggregated data plus the following:

  • Number, and rate of confirmed NT cases by sex, geographical location of birth, month year Percentage of confirmed NT cases by place of birth (health facility or home delivery), protection status at birth, type of birth assistance, type of cord-cutting tools used, type of umbilical stump dressing used, age group of mother, and parity of mother Percentage of confirmed NT cases whose mother received antenatal care
  • Case-fatality ratio among confirmed NT cases
  • Percentage of confirmed NT cases whosemother received a protective TT dose(s) subsequent to the onset of tetanus in the baby
  • Percentage of confirmed NT cases which triggered an active search in the community Percentage of confirmed NT cases which triggered an immunization response
  • Number of unreported cases found through active searches
  • TT2+ coverage (or PAB) by year and geographical area among pregnant women (if TT doses are being administered to all women of childbearing age (CBAW), TT2+ coverage among CBAWs);
  • For Supplemental Immunization Activities (SIAs): TT1, TT2, and TT3 coverage among child-bearing women targeted
  • Completeness/timeliness of monthly and zero reporting

Principal use of data for decision-making
  • Monitor progress towards achieving and sustaining high routine TT2+ (or PAB) coverage in all geographical areas Monitor progress towards maternal and neonatal tetanus elimination in every geographical area (progress towards neonatal tetanus elimination is a proxy for maternal tetanus elimination)
  • Investigate suspect NT cases in areas not considered at risk for NT to identify risk factors
  • Identify high-risk geographical areas and conduct supplemental immunization activities
  • Identify missed opportunities for tetanus toxoid immunization through antenatal care Monitor whether corrective actions were taken in those areas considered to be at high risk. Periodically verify the sensitivity of NT reporting by comparing the number of reported cases with cases identified through active surveillance, hospital record reviews, and active searches
  • Periodically profile risk factors for NT (e.g. place of birth, assistance during delivery, cord care, immunization status, age and parity of mother)to target messages and actions appropriately Monitor risk levels in areas considered at low risk and take corrective action accordingly Monitor specificity of reporting through analysis of age of death, risk factors

Special aspects

Protection at birth

% protected at birth (PAB) is a supplemental method of determining coverage protection (particularly where TT2+ is unreliable and where DTP1 coverage is high). To monitor PAB during DTP1 visits, health workers record whether infants were protected at birth by the motherís TT status. % PAB is then estimated as: number of infants protected divide by the total number of births. If a child was unprotected the mother should receive a dose of TT during the same visit and should be followed up with a subsequent TT dose if needed for protection. The same applies for mothers whose children were protected at birth but who remain eligible for another TT dose

Serological investigations

Simple serological test kits for measuring antibody titres in a survey setting have been developed and are being further refined. The role of serological investigations, however, should always be complementary to other surveillance or assessment methods and the expected outcome should be well defined for each setting

School-based immunization

Where tetanus toxoid is given in a school setting, coverage of this approach should be monitored.
To monitor the proportion of children receiving school-based TT, the recommended method for monitoring coverage is:
TT (grade X) = number of children in grade X who received a dose of tetanus toxoid in the school immunization service in a given year divided by the total number of children living in the schoolís catchment area who were born in the same year as the children in grade X
To monitor school-based TT immunization, the calculation above would be used except that the denominator would be the total number of children enrolled in grade X