IV. INVESTIGATION OF C. DIPHTHERIAE
165
sporadic cases, and their contacts, as well as from healthy carriers of
non-epidemic communities from all over the country.
(b) Thus the distribution of biotypes and phage types of C. diphtheriae
in each geographical region of the country is well known, and the penetration of a new phage type can easily be detected.
2. Results
Valuable general conclusions have been drawn from past results. For
instance, a striking parallelism could be observed between the incidence of
the gravis toxigenic biotype and diphtheria morbidity during the whole
epidemic period. Thus, the occurrence of gravis toxigenic strains always
represented an epidemic indicator and an alarm signal for epidemiologists,
necessitating immediate prophylactic measures. Phage typing provided
the origin and spread of a certain type in a region or in the country, the
origin and extent of an epidemic, the filiation of the cases, and relationships
between the outbreaks even when distant in space and time. It also helped
us to establish the right epidemiological relationships and prognosis, to
arrest the spread of infection and to elucidate the role and right attitude
to be adopted today towards non-toxigenic healthy carriers.
C. Scheme of intervention in a diphtheria outbreak
biological and immunological (Fig. 44).
1. Epidemiological methods
(a) Outline of a common plan developed together with or solely by the
local Health Authorities involving epidemiologists, bacteriologists, pediatricians, physicians and medical officers.
Three categories of methods are applied, i.e. epidemiological, micro(b) Identification and hospitalisation of the cases.
(c) Epidemiological inquiries.
(d) Delimitation of the area of epidemic spread by investigating all
(e) Clinical and bacteriological examination of contacts.
(f) Study of the recorded vaccinations of the whole community.
(g) Diagnosis, isolation and treatment of contacts (treatment by anti(h) Follow-up and control of the area after specific intervals of time:
contacts.
biotics).
3, 6, 12 months.
2. Microbiological methods
(a) Swabbing of all cases, suspects, or contacts established by the
165
sporadic cases, and their contacts, as well as from healthy carriers of
non-epidemic communities from all over the country.
(b) Thus the distribution of biotypes and phage types of C. diphtheriae
in each geographical region of the country is well known, and the penetration of a new phage type can easily be detected.
2. Results
Valuable general conclusions have been drawn from past results. For
instance, a striking parallelism could be observed between the incidence of
the gravis toxigenic biotype and diphtheria morbidity during the whole
epidemic period. Thus, the occurrence of gravis toxigenic strains always
represented an epidemic indicator and an alarm signal for epidemiologists,
necessitating immediate prophylactic measures. Phage typing provided
the origin and spread of a certain type in a region or in the country, the
origin and extent of an epidemic, the filiation of the cases, and relationships
between the outbreaks even when distant in space and time. It also helped
us to establish the right epidemiological relationships and prognosis, to
arrest the spread of infection and to elucidate the role and right attitude
to be adopted today towards non-toxigenic healthy carriers.
C. Scheme of intervention in a diphtheria outbreak
biological and immunological (Fig. 44).
1. Epidemiological methods
(a) Outline of a common plan developed together with or solely by the
local Health Authorities involving epidemiologists, bacteriologists, pediatricians, physicians and medical officers.
Three categories of methods are applied, i.e. epidemiological, micro(b) Identification and hospitalisation of the cases.
(c) Epidemiological inquiries.
(d) Delimitation of the area of epidemic spread by investigating all
(e) Clinical and bacteriological examination of contacts.
(f) Study of the recorded vaccinations of the whole community.
(g) Diagnosis, isolation and treatment of contacts (treatment by anti(h) Follow-up and control of the area after specific intervals of time:
contacts.
biotics).
3, 6, 12 months.
2. Microbiological methods
(a) Swabbing of all cases, suspects, or contacts established by the