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ABSTRACT:Haemorrhagic septicaemia (HS) is an endemic disease in most countries of Asia and sub-Saharan Africa. Within the Asian Region, countries can be classified into three categories, on the basis of incidence and distribution of the disease; these are respectively countries where the disease is endemic or sporadic, clinically suspected but not confirmed, or free. Economic losses due to HS are not only confined to losses to the animal industry, but also rice production on account of its high prevalence among draught animals used in rice fields. Only a few attempts have been made to estimate economic losses, the methodologies used in different countries have varied, and many are not based on active surveillance, and a consideration of all components of direct and indirect losses. Most Asian countries rank HS as the most important contagious disease or the most important bacterial disease in cattle and buffaloes. Resource allocation for prevention and control of HS nationally or internationally will evidently depend on a correct estimate of its economic impact. e key factors in prevention and control would be timely and correct reporting, accurate and rapid diagnosis, strategic use of vaccines with the attainment of a high coverage where necessary with a high quality vaccine. National level activities geared towards attainment of these objectives may be with advantage supported and strengthened by international organisations involved in animal health. e present paper attempts to review aspects related to the epidemiology, control and containment of HS in Asia and, proposes some key issues on which a regional programme for HS control in this continent should be centred.

Fifty-seven young buffaloes were experimentally infected or naturally exposed to haemorrhagic septicaemia (HS). Of these animals 32 became immune carriers. They were observed in groups for periods up to 360 days to monitor the appearance of pasteurellae in the nasopharynx and antibody status. In most animals pasteurellae appeared in the nasopharynx for a short period initially and disappeared. The organism reappeared intermittently and the longest observed period of reappearance was 215 days after exposure. All animals showed rising antibody titres with a peak lasting for 150 to 180 days and declining thereafter. Pasteurellae persisted in the tonsils and were isolated from 20 out of 27 carriers after slaughter. The longest period when isolation was made after slaughter was 229 days. The organism lodged in the tonsils was unaffected by antibacterial therapy using drugs to which the organism displayed in vitro sensitivity. It is concluded that in HS, carrier animals exist in an active as well as a latent state, the former appearing for short intermittent periods between long latent periods, when pasteurellae continue to remain in the tonsils which constitute a long-term reservoir.

Data on the mortality of cattle and buffaloes in 62 epizootics of haemorrhagic septicaemia (HS) in the HS enzootic and non-enzootic regions of Sri Lanka was collected and subjected to statistical analysis. It was found that the overall mortality for buffaloes was higher than for cattle (45.2 and 15.8% respectively, P less than 0.001). For buffaloes in enzootic areas only the overall mortality was 29% whilst in non-enzootic areas it was 64.5% (P less than 0.05). In the enzootic areas deaths were mainly confined to young animals whereas in the non-enzootic areas when sporadic outbreaks of HS occurred deaths were scattered over all age groups. The vaccines used, vaccination schedules adopted and the coverage of vaccination in these herds did not appear to influence the mortality among buffaloes in enzootic areas to a statistically significant degree.

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