The distribution of ticks of the Ornithodoros moubata complex in different habitats in Malawi, particularly pigsties and houses, was established from a four-phase survey undertaken between 1982 and 1985. The first phase consisted of preliminary interviews, the second phase consisted of a questionnaire to Veterinary Assistants (VAs) in rural areas, the third involved tick collections by VAs and the fourth involved both interviews and tick collections by members of the Central Veterinary Laboratory, Lilongwe. The area in which O. moubata is found in pigsties includes much of the African swine fever (ASF) enzootic area, and it seems likely that the enzootic area could become larger in future. The occurrence of O. moubata in warthog habitats was also investigated.

In an attempt to determine the frequency of virus infections of the gastrointestinal tract, the duration of virus shedding in faeces and its relation to outbreaks of illness of any kind, faecal samples were collected from children attending a day nursery at a Lisbon institution.

In this study, ten children were surveyed from their enrolment at the nursery, weekly specimens of faeces being collected over a period of 1 year. A total of 459 samples were obtained. In addition four of these children were also followed-up from their first week of life to their enrolment at the nursery, 79 samples being collected during this period.

Viruses were detected in a high percentage (44·4%) of these stools, including strains of oral vaccine polioviruses together with viruses isolated in routine cell cultures and by electron microscopy (EM). These viruses were detected in both healthy and ill babies.

The possible association between viruses isolated in cell cultures or detected by EM and illness was examined and the results show that the asymptomatic excretion of viruses is frequent, particularly in children within this age group.

An outbreak of keratoconjunctivitis is described which involved at least 186 people; adenovirus type 8 was identified in 50 of the cases. Topical human fibroblast interferon was assessed in a double-blind, placebo-controlled study in which 34 patients participated. Seventeen of the 34 trial patients yielded adenovirus type 8; three were infected with adenovirus type 7. The outbreak was curtailed by control of infection measures: principally careful hand-washing by medical personnel between cases and by discouraging attendance of new cases at the Eye Infirmary. Consequently the trial numbers are small. In addition there was a wide interpatient variation in the severity of infection. Therefore it was not possible to make any statistically valid conclusions concerning the recovery rate of patients receiving interferon or placebo.