Annual report on the Medical Research Institute / 1909-.

  • Nigeria. Medical Research Institute.
Date:
[1923]
Catalogue details

Licence: Public Domain Mark

Credit: Annual report on the Medical Research Institute / 1909-. Source: Wellcome Collection.

    24/34 page 22
    There was also one specimen of Glossins tachinoides. A search was made in all for the larvae of Pilaria, but the result was uniformly negative. As noted elsewhere in this report, many bugs and lice were dissected in a search for the spironema of relapsing fever, and also a number of Mansonioides africana after having fed on a patient in whose blood there were embryos of Acanthoclieilonema perstans. Most of the year however, lias been taken up with the systematic dissection of mosquitoes brought in by the labourers from the native houses in the vicinity of Yaba. Every Saturday evening each labourer was provided with several plugged test, tubes and told to collect mosquitoes from his house, particularly those which had bitten him. This lessened the likelihood of his filling the test tube with male specimens. A bribe was offered for the largest collection each Monday morning. As it was quite impossible, on account of the presence of blood in the stomach to dissect the whole collection in one day, the weaker specimens were worked on first and the others fed on sugar-water. It was somewhat of a surprise to find that Mansonioides africana greatly outnumbered all the other mosquitoes brought in. The actual number was 4,027 of which 3,064 wTere dissected, the others having died before their blood feed was digested. Larvae of Filaria were found in the proboscis of one, and in the muscles of the head and thorax of another. Small nematodes were found in the stomach of two, and in a third, two much larger nematodes were noted, one extending from the thorax into the abdomen and the other coiled at the tip of the abdomen. Spironemata were observed in the stomach of five individuals but their numbers were small. On one occasion the stomach contents, in a little saline were injected into the peritoneum of a rat, but the inocula¬ tion was unproductive. Amoebae and other protozoa were occasionally found in the stomach, most probably derived from the water in which the insect hatched, but none was of known pathogenic importance. Herpetomonas were noted in the stomach contents on one occasion. In ten specimens however there were structures resembling developmental forms of Proteosoma or Plasmodium. There were bodies resembling oocysts in the stomach wall of seven, and structures similar to sporozoites in the salivary glands of four, one insect showing both types of structures. 298 Anonheles costalis were collected of which 198 were dissected : of these, forty were found to be infected with malaria, and twelve with filaria. . Eleven showed sporozoites in the glands but nothing, in the stomach. Twenty-one showed oocysts in the stomach but nothing in the glands. Eight had the parasitic both in the glands and in the stomach. Three of the insects with the stomach only infected contained also filaria and two mosquitoes with a malarial infection of both stomach and glands showed also very numerous filariae in the head and thorax. The other mosquitoes dissected were :— Culiciomyia nebulosa, fourteen, all negative. Culex rima, eight, one with Herpetomonas in stomach, seven, negative.
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