Surgical presentation of melioidosis in India

BACKGROUND

Melioidosis, the disease caused by Burkholderia pseudomallei, is common in Southeast Asia. It has also been reported from India, where some investigators feel it is under-diagnosed and under-reported. We report our experience with melioidosis presenting as abscesses at unusual sites.

METHODS

All consecutive patients with culture proven B. pseudomallei, who presented to a single surgical unit between 1995 and 1998, were evaluated.

RESULTS

Three patients presented with splenic abscesses and one with a soft tissue abscess in the neck. One patient developed septicaemia. All patients responded favourably to ceftazidime and/or co-trimoxazole which was started as soon as the diagnosis was confirmed.

CONCLUSION

Melioidosis is under-diagnosed in India, probably due to a low index of suspicion of this disease among clinicians. It should be considered as a possibility when abscesses are encountered at unusual sites. The pus must then be cultured to identify the causative agent.

An epidemic of dengue haemorrhagic fever/dengue shock syndrome in tropical India

An epidemic of dengue haemorrhagic fever/dengue shock syndrome occurred in Chennai, South India in 1989 during and following the rainy season. Sixty-nine infants and children admitted to the Institute of Child Health and Hospital for Children with a brief febrile illness associated with skin and mucous membrane bleeds and/or shock were studied. Forty-nine had antibodies to dengue viruses. The specific serotype of the virus responsible could not be identified owing to cross-reacting antibodies. Primary infection occurred in 11 cases, secondary infection in 17 cases, antibodily titres were indicative of 'probable' dengue infection in 16 and were uninterpretable in five. In 11 cases, serology could not be done. The pattern of disease in these 60 cases was similar, with a high mortality. Haemoconcentration was not a feature in the majority and the Hess test was negative in all those tested. Nine cases with a similar but milder illness tested negative for dengue.

Cell-to-cell spread of poliovirus in the spinal cord of bonnet monkeys (Macaca radiata)

In order to study the spread of poliovirus in the spinal cord of bonnet monkeys, 10(8) TCID50 Mahoney strain of poliovirus was inoculated into the ulnar nerves of monkeys that were subsequently autopsied on days 1, 2, 3, 6, 9, 12, 14, 15 and 16 postinoculation (p.i.). Virus spread in the spinal cord, the accompanying histopathological changes and paralysis occurred in a cervico-thoraco-lumbar direction. Virus reached the cervical region of the spinal cord within the first 3 days and subsequently spread to all segments of the spinal cord. In situ hybridization demonstrated viral RNA initially in the cervical neurons on day 3 p.i. and in the anterior horn neurons of lumbar segments of the spinal cord by day 6 p.i. Loss of Nissl substance in some of the anterior horn neurons was apparent on day 3 p.i. in the cervical and thoracic regions and by day 6 p.i. in the lumbar region. In the lumbar region, neuronophagia was a consistent feature which was observed on days 6-9 p.i., followed by neuronal dropouts on day 12 p.i. and thereafter. In the cervical and thoracic region, reappearance of Nissl substance was apparent from day 12 p.i. Upper limb paralysis preceded lower limb paralysis (5.5+/-1.73 vs 8.18+/-2.18, P = 0.046), further suggesting that virus spread within the spinal cord was via an intraneural route despite persistent viraemia detectable from day 2 p.i. onwards. The temporal distribution of the virus spread, distribution of viral RNA, histopathological and clinical changes indicate a cell-to-cell spread of poliovirus in the CNS, having gained access to the CNS from the peripheral nerve.

Haemophilus influenzae disease in children in India: a hospital perspective

We review and summarize published information on diseases caused by Haemophilus influenzae in India and unpublished data from our center covering more than three decades. Since the mid-1950s H. influenzae has been the most common cause of pyogenic meningitis in children admitted to our hospital, accounting for one-third to one-half of cases. Information from other centers in India has been scanty; the lower frequency of isolation of Haemophilus in studies in some centers may be caused by unsatisfactory media and culture methods. The annual numbers of admissions for pyogenic meningitis in our hospital have been quite similar to the numbers of cases of poliomyelitis. Assuming that the similar numbers of children hospitalized with these two diseases indicate similar incidence rates in the community and taking into account the frequency of Haemophilus isolations in pyogenic meningitis, we estimate that there may be as many as 75 to 100 cases of meningitis caused by this organism per year per 100000 children <5 years of age. Although pneumonia caused by H. influenzae has been recognized in a few studies, information is too scanty to attempt the estimation of incidence. Pus-producing infections caused by Haemophilus are rare. Epiglottitis caused by Haemophilus does not seem to occur in India. In recent years we have found that most invasive Haemophilus infections are caused by H. influenzae type b (Hib); other types or untypable strains are infrequent. An increasing prevalence of resistance to chloramphenicol and ampicillin has been recognized in our center and elsewhere. Thus from a hospital perspective, primary prevention by using Hib vaccine seems to be a rational and beneficial intervention. Community-based studies to measure the disease burden of Hib are urgently needed for a more satisfactory assessment of the need for, and cost benefit of, Hib immunization of all infants.

Increasing prevalence of HIV antibody among blood donors monitored over 9 years in one blood bank

To determine the time trend of HIV infection among non-professional blood donors at the Christian Medical College and Hospital, Vellore, the annual HIV prevalence among them for the years 1993-1997 was compared with that of the previous 5 yr. Since confirmed number of HIV positive blood donors is required for calculation of prevalence, the serum samples which were reactive for HIV 1/2 antibody by ELISA, were confirmed by Western blot. The annual prevalence of HIV antibody gradually increased from 1.6 per 1000 in 1988-1989, to 3.8 per 1000 in 1996-1997. The mean tri-annual prevalences for the years 1988-91, 1991-94 and 1994-97 were 1.3, 2.7 and 3.6 per 1000 respectively, suggesting a slow but steady increase in HIV prevalence over time. Our findings provide an insight into the dynamics of HIV infection in the general population of our country, whom the nonprofessional blood donors at our hospital represent.

A primate model of respiratory syncytial virus infection

To determine whether bonnet monkeys are susceptible to infection and disease due to respiratory syncytial virus (RSV), 4 juvenile bonnet monkeys (Macaca radiata) were inoculated with RSV intratracheally and sacrificed at 3, 5, 7 and 9 days post infection. RSV was cultured from pre-autopsy broncheoalveolar lavage fluid from all 4 animals with a peak titre of virus on day 9. Serum RSV neutralizing antibody was present by day 7. Animals developed tachypnoea and chest retractions by 5th day post infection and 2 animals had lobular pneumonia on chest radiography. The pathological changes were of a bronchovascular inflammation, interstitial pneumonia and alveolitis, akin to that seen in humans. These findings show that bonnet monkeys can be infected with RSV, and can develop immune response and clinical and pathological changes similar to those seen in human infants with RSV disease. Thus intractracheal RSV inoculation of juvenile bonnet monkeys appears to be a good model to study pathogenesis of RSV disease.

Disease surveillance at district level: a model for developing countries

For over a decade we have maintained within a district of 5 million people, a system of prompt reporting of cases of childhood vaccine-preventable diseases, encephalitis, meningitis, hepatitis, and rabies; together with a sentinel laboratory surveillance of cholera, typhoid fever, malaria, HIV infection and antimicrobial-resistance patterns of selected pathogens. The system combined government and private sectors, with every hospital enrolled and participating. Reports were scanned daily on a computer for any clustering of cases. Interventions included investigations, immunisation, antimicrobial treatment, health education, and physical rehabilitation of children with paralysis. All vaccine-preventable diseases have declined markedly, whilst malaria and HIV infections have increased steadily. Annual expense was less than one US cent per head. The reasons for the success and sustainability of this model include simplicity or reporting procedure, low budget, private-sector participation, personal rapport with people in the network, regular feedback of information through a monthly bulletin, and the visible interventions consequent upon reporting. This district-level disease surveillance model is replicable in developing countries for evaluating polio eradication efforts, monitoring immunisation programmes, detecting outbreaks of old or new diseases, and for evaluating control measures.

Immune response of infants to fractional doses of intradermally administered inactivated poliovirus vaccine

Seventy eight infants aged 6-8 weeks received either two doses of 0.1 ml of inactivated poliovirus vaccine (IPV) intradermally 8 weeks apart (group A) or three doses 4 weeks apart (group B). Pre- and 4 weeks post-immunization serum samples were tested for the presence and titer of neutralizing antibody to poliovirus types 1, 2 and 3. The seroconversion rates to poliovirus types 1, 2 and 3 were 90, 70 and 97%, respectively, among infants in group A and 90, 80 and 98%, respectively, in group B; in children without pre-existing maternal antibody, seroconversion rates were 100% to all three poliovirus serotypes in both groups. These rates were comparable to those in children receiving five doses of OPV or two doses of intramuscular IPV. Intradermal administration of fractional doses of IPV may be a less expensive alternative for use in developing countries.

Diagnosis of typhoid fever by the detection of anti-LPS & anti-flagellin antibodies by ELISA

In a developing country like ours where typhoid fever is endemic and there are very few microbiology laboratories to provide diagnosis by culture, a search for non culture techniques for rapid and reliable diagnosis continues. The Widal test has a low sensitivity. We have attempted to adapt the well established enzyme linked immunosorbent assay (ELISA) technique to provide a serological test of better sensitivity and specificity. The ELISA described here to detect anti-LPS antibodies was found to have a sensitivity of 89.4 per cent and a specificity of 94.9 per cent. The sensitivity for the antiflagellin ELISA was 68.1 per cent and specificity was 97.4 per cent. The likelihood ratio was 17.5 for anti-LPS ELISA and 26.2 for the anti-flagellin ELISA. Considering the positivity of either one ELISA as diagnostic, the sensitivity was 93.6 per cent and specificity was 94.9 per cent.