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H H NAJARIAN

Publications and source records attributed to H H NAJARIAN.

17 recordsLinked to original sources
PubMed1961

Studies on bilharziasis endemicity in the vicinity of Basra, Iraq.

This paper reports on investigations into the distribution of snail genera and possible limiting environmental factors in the endemic and non-endemic areas of human bilharziasis in and near Basra, carried out in 1958 by the WHO Bilharziasis Control Project staff in Iraq. These investigations confirmed the existence of an abrupt line of demarcation between these areas immediately south of Basra.During June and October 1958, the known intermediate snail host, Bulinus truncatus, was not found in canals bordering on areas of either infected or non-infected human populations. From these findings and the evidence of previous investigations it is concluded that in southern Iraq, and particularly in Basra, B. truncatus has been demonstrated with difficulty, if at all. Nevertheless, transmission has continued to take place. Explanations of this apparent phenomenon are discussed and it is concluded that populations of B. truncatus may be completely absent for several years and that other snail genera may play a role in transmitting the disease.A study of environmental factors indicates that water velocities, salinity, turbidity, and pH in the endemic and non-endemic areas showed no significant differences, but that the continuous change in water flow may be a factor limiting B. truncatus colonization.It is also concluded that the salinity in the Shatt al Arab River originates from Lake Hammar and is not introduced from the Persian Gulf by tidal wave, as has been previously believed.

Animals↗
PubMed1961

Biological studies on the snail, Bulinus truncatus, in Central Iraq.

This paper presents some results of field and laboratory studies on Bulinus truncatus, the snail intermediate host of urinary bilharziasis in Iraq, made in 1958 as part of the work of the WHO Bilharziasis Control Project in that country.Observations on the linear distribution and size composition of Bulinus populations in the canals of central Iraq indicate that molluscicides might most suitably be applied in May before the entire snail population reaches breeding size, or early in November when most snails are juveniles. However, laboratory experiments appear to show that isolation of individual bulinid snails does not diminish, but may actually increase, their egg-laying capacity in comparison with that of grouped snails; this suggests that, even if the snail population were drastically reduced by treatment of the canals and all further importation of snails rendered impossible, the snail population would nevertheless soon renew itself from the few individuals remaining.Results are also given of laboratory experiments on egg masses, hatching and growth of B. truncatus and on the egg-laying of random populations of that snail.

Animals↗