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Biomedical subjects

B L Rao

Publications and source records attributed to B L Rao.

32 records · Page 2Linked to original sources

Epidemiological, clinical, and virological features of influenza outbreaks in Pune, India, 1980.

During the course of continuous surveillance of influenza in 1980 in Pune, India, which has a tropical monsoon climate, three outbreaks of acute respiratory infection (ARI) were investigated in March (hot season), in July-September (rainy season), and in November (cold season); sporadic cases during the interepidemic months were also studied. The first outbreak was associated with influenza A virus (H3N2), the second with influenza A viruses (H3N2) and (H1N1) and influenza B virus, but fewer influenza viruses were isolated during the third outbreak. The illnesses affected all age groups including infants and adults over 60 years of age, although the paediatric age group was mainly affected. The ARI outbreaks associated with the hot and cold seasons commenced at about the time the weather changed whereas the mixed influenza A (H3N2) and A(H1N1) outbreaks occurred in the middle of the rainy season.

Adolescent↗

A large outbreak of acute encephalitis with high fatality rate in children in Andhra Pradesh, India, in 2003, associated with Chandipura virus.

BACKGROUND: An outbreak of acute encephalitis of unknown origin with high case fatality (183 of 329 cases) was reported in children from Andhra Pradesh state in southern India during 2003. We investigated the causative agent. METHODS: Cell lines and peripheral blood lymphocyte co-cultures were used to isolate the causative agent from clinical samples. Identity of the agent was established by electron microscopy and serological and molecular assays. FINDINGS: Clinical samples tested negative for IgM antibodies to Japanese encephalitis, West Nile, dengue, and measles viruses, and for RNA of coronavirus, paramyxovirus, enterovirus, and influenza viruses. Virus was isolated from six patients with encephalitis and was identified as Chandipura virus by electron microscopy, complement fixation, and neutralisation tests. Chandipura virus RNA was detected in clinical samples from nine patients. Sequencing of five of these RNA samples showed 96.7-97.5% identity with the reference strain of 1965. Chandipura viral antigen and RNA were detected in brain tissue of a deceased child by immunofluorescent antibody test and PCR. Neutralising, IgG, and IgM antibodies to Chandipura virus were present in some patients' serum samples. Serum samples obtained after 4 days of illness were more frequently positive for IgM to Chandipura virus than were those obtained earlier (p<0.001). A similar trend was noted for neutralising antibodies. INTERPRETATION: Our findings suggest that this outbreak of acute encephalitis in Andhra Pradesh was associated with Chandipura virus, adding to the evidence suggesting that this virus should be considered as an important emerging pathogen.

Acute Disease↗

Epidemiology and control of influenza.

Influenza causes frequent epidemics and periodic pandemics, and is a major public health problem. Pandemics occurred in 1918 (swine influenza), 1957 (Asian influenza), 1968 (Hong Kong influenza) and 1977 (Russian influenza) due to major antigenic variation of the type A influenza virus. Frequent epidemics occur after pandemics as a result of minor antigenic variation of the pandemic virus strains. Minor antigenic variant strains of type A (H1N1), A (H3N2) and type B influenza viruses are currently circulating globally, causing frequent epidemics. The World Health Organization (WHO) has established a network of National Influenza Centres all over the world to study the epidemiology and ecology of influenza, and collaborating centres for updating the influenza vaccines and other research activities. As a part of this programme, it has set up the WHO Flunet for disseminating updates on the global influenza situation, current vaccines and antiviral drugs. Some National Influenza Centres in India have investigated and reported pandemics and epidemics caused by global influenza virus strains during the past 50 years. There is a need to expand influenza surveillance in our country, as only a few centres are conducting these studies.

Animals↗