Identification of priority populations such as men who have sex with men (MSM) is important in surveillance systems to monitor trends of sexually transmitted infections (STIs). We explored using routinely collected non-behavioural data as a means to establish MSM status in surveillance by assessing anorectal swab as a marker of male-to-male sexual exposure. We used chlamydia testing data from a sexual health clinic, 2007–2012. Men reporting any male sexual partner(s) in the previous 12 months were considered MSM. The dataset was split into development and validation samples to develop a univariate predictive model and assess the model fit. The dataset included 30 358 individual men and 48 554 episodes of STI testing; 45% were among reported MSM and an anorectal swab was performed in 40% of testing episodes. Anorectal swabbing had good diagnostic performance as a marker for MSM status (sensitivity = 87%, specificity = 99%, positive predictive value = 98·6%, negative predictive value = 90·3%). The model showed good fit against the internal validation sample (area under the curve = 0·93). Anorectal swabs are a valid marker of MSM behaviour in surveillance data from sexual health clinics, and they are likely to be particularly useful for monitoring STI trends among MSM with higher risk behaviour.

Surveillance of newly acquired hepatitis C virus (HCV) infection is crucial for understanding the epidemiology of HCV and informing public health practice. However, monitoring such infections via surveillance systems is challenging because they are commonly asymptomatic. A literature review was conducted to identify methodologies used by HCV surveillance systems to identify newly acquired infections; relevant surveillance systems in 15 countries were identified. Surveillance systems used three main strategies to identify newly acquired infections: (1) asking physicians to classify cases; (2) identifying symptomatic cases or cases with elevated alanine aminotransferases; and (3) identifying cases with documented evidence of anti-HCV antibody seroconversion within a specific time-frame. Case-ascertainment methods varied with greater completeness of data in enhanced compared to passive surveillance systems. Automated systems that extract and link testing data from multiple laboratory and clinic databases may provide an opportunity for collecting testing histories for individuals that is less resource intensive than enhanced surveillance.

Investigations were carried out on the ecology of Aedes (Aedimorphus) dentatus (Theo.) in the Ngong Forest near Nairobi between 22 June and 10 September 1971. Five 24-h collections on human bait showed that Ae. dentatus is predominantly a daytime biter with a peak of activity around sunset. At the time of its greatest activity none came to bite on the 7- or 10-m platforms. Of 94 blood-meal specimens, 50 were of Bovid origin (cattle), 18 from unidentified Bovids, 13 from unidentified mammals, one from a bird, three from any primate and nine did not react with the antisera used. Resting adults were frequently found underneath leaves of Hypoestes verticillaris, a herb which grows in partly shaded areas in the forest near the forest edge. A few adults came to bite in a house outside the forest not far from the forest edge. Breeding places were not found. The evidence for Ae. dentatus being a vector of yellow fever is inconclusive. The 33 other species of mosquitoes collected are listed.