Meningitis due to Listeria monocytogenes : (a case report).
Meningitis or meningoencephalitis is perhaps the commonest manifestation of human listeriosis. Genital tract infection in the gravid female with infection of the offspring is the most characteristic of infections caused by Listeria monocytogenes. Neonatal listeriosis can manifest either early within the first 2 days after birth or late, where the disease appears after a few days or weeks or even at times after a few months.
According to the Communicable Disease Surveillance Centre, in 1978, the incidence of perinatal listeriosis in England and Wales was 1 in 37,0,00 births (assuming mother and child to be a single case).
Most cases of listeriosis are sporadic. though two epidemics from East Germany,  and one from New Zealand are reported.
Very few reports are available from India,,, and hence the present case is reported.
A two month old male child was admitted to the hospital with a history of fever, vomiting and loose motions for 2-3 days. The patient also had convulsions twice before admission. The mother's history was unremarkable and this child was born of a full term normal delivery. The general examination of the patient was noncontributory except for hydrocephalus. Central nervous system examination findings were suggestive of meningitis.
Cerebrospinal fluid was blood-stained and hazy. Proteins were 200 mg%, globulins were increased; sugar was 55 mg%. Gram stained smear examination showed presence of RBCs, occasional pus cells but no organisms were seen. CSF culture was sterile. CSF examination was repeated after 2 days and from this sample Listeria monocytogenes were grown.
The patient was subjected to ventriculogram followed by construction of a V.A. shunt. The ventricular fluid collected at this time also grew L. monocytogenes. Simultaneously blood for culture, throat swab, nasal swab and ear swabs were collected. The throat swab and nasal swab cultures also revealed L. monocytogenes but not the ear swab culture. Blood culture incubated at 37°C did not show growth upto the 10th day but the sample kept in the refrigerator grew L. monocytogenes on the 5th day. The mother's vaginal swab was also cultured which showed a growth of L. monocytogenes. Serology was not done.
Following the construction of a V.A. shunt, the patient's condition deteriorated and he expired on the 8th day of admission.
Autopsy on the child revealed marked congestion and oedema of the brain and an exudate covering the left occipital lobe. CSF sample collected at the time of autopsy grew L. monocytogenes.
Listeria monocytogenes has a world wide distribution and has been found in over 50 species of animals including mammals, birds and fish. In most human cases, the mode of infection is unknown, though it probably involves ingestion of infected soil or foodstuffs or contact with infected animals. Listeria can be harboured in the genital tract for a considerable period which has suggested a possible veneral route of infection. In the present case, the organisms were isolated from the mother as well as from the child, though the manifestation of the disease was late. The late form of the disease is characterised by meningitis, sometimes presenting as slow hydrocephalus as is seen in the present case.
In different studies reported by Krishna et al from Bombay and Bhujwala et al,  from Delhi, the incidence of listeriosis has been reported as 14% and 1.4% respectively. Both the studies were done in females with bad obstetric history Thomas et al have reported isolation of Listeria monocytogenes from 3 cases out of 135 meconium stained babies.
Besides epidemics some sporadic case reports are available in literature., 
Other than meningitis and encephalitis, septicemia, pneumonia, conjunctivits are other manifestations of human listeriosis McEnery and Chattopadhyay, in their report, were able to isolate the organisms from the infant's blood, eye swab, umbilicus, nose and also from mother's vaginal swab.
L. monocytogenes has four serotypes but serological reactions are not of much value as cross reactions are known to occur with other bacteria.
The authors thank the Dean, L.T.M. Medical College and L.T.M.G. Hospital, Bomb-ay, for permission, to publish this paper.