Occupational allergy in laboratory workers caused by the African migratory grasshopper Locusta migratoria.

BACKGROUND: Recent reports of fatal asthma cases associated with swarms of locusts affecting African countries have highlighted the importance of this insect in causing asthma morbidity and mortality. However, only limited information is available about the allergic health outcomes such as asthma and its determinants in exposed individuals. In this study, workers exposed to the African migratory locust Locusta migratoria were evaluated for allergic health outcomes as well as the nature of the offending allergens. METHODS: Ten scientists and technicians exposed to locusts in a laboratory were investigated for locust-related allergy using questionnaires and immunological tests. The presence of allergy was determined by quantification of specific IgE and IgG to L. migratoria using the UniCAP system and via skin-prick testing (SPT). The allergens were characterized by Western blot and ImmunoCAP inhibition assays. RESULTS: Six of the 10 workers experienced symptoms ranging from urticaria and rhinoconjuctivitis to asthma. Seven individuals demonstrated sensitivity on SPT and five had specific IgE antibodies to L. migratoria. Significant cross-reactivity was demonstrated for allergens in the locust faeces, body and wings but not to cockroach allergens. Novel allergens with molecular weights of approximately 70 kDa were identified in locust wings, which are distinctly different from other known allergen sources from locusts. CONCLUSION: Exposure to L. migratoria allergens is a potential sensitizer in exposed individuals. Raised levels of locust-specific IgE can be readily quantified. The wings of this insect species have been identified as a novel allergen source.

The association between idiopathic spontaneous preterm delivery, an infected intra-uterine environment and hyaline membrane disease.

A total of 110 preterm infants delivered as a result of the spontaneous onset of labour in the absence of obvious maternal and/or neonatal lesions and without premature rupture of the membranes was examined prospectively. Thirty per cent had more than 5 pus cells per high-power field in the gastric aspirate at birth. This finding correlated significantly with a lower incidence of hyaline membrane disease (HMD). All infants who developed HMD had negative or intermediate foam test results. There was no consistent relationship between either the pus cell count or the foam test result and the development of the wet lung syndrome. Data from our community suggest that many spontaneous deliveries occur in association with an infected itra-uterine environment.

The gastric aspirate foam test in the prediction of hyaline membrane disease.

The gastric aspirate foam test was performed on 99 infants of low birth weight. In 59 of 61 infants with no respiratory distress, the test was positive. All infants who developed hyaline membrane disease (HMD) had negative or intermediate foam test results. There was no consistent relationship between the foam test result and the development of wet lung syndrome. Infants who were small for gestational age had a significantly lower incidence of HMD, as did infants with amniotic fluid infection syndrome. These data indicate that the gastric aspirate foam test is a reliable index of neonatal lung maturity.