This series of serologically confirmed Lyme disease is the largest reported in the UK and represents 508 patients who presented to one hospital in the South of England between 1992 and 2012. The mean rate of borreliosis throughout this period was 9·8/100 000 population, much higher than the reported national rate of 1·7/100 000. The actual rate increased each year until 2009 when it levelled off. Patients clinically presented with rash (71%), neurological symptoms (16%, of whom half had VII cranial nerve palsies), arthropathy (8%), pyrexia (5%), cardiac abnormalities (1%) or other manifestations (<1%). Twenty percent of patients had additional non-specific symptoms of fatigue, myalgia, and cognitive changes. Serological diagnosis was with a two-tiered system of ELISA and immunoblot. There was a marked seasonal presentation in the summer months and in the first and sixth decades of life. A third of patients gave a clear history of a tick bite. The median interval between tick bite and clinical symptoms was 15 days [interquartile range (IQR) 9–28 days], with a further interval of 14 days to clinical diagnosis/treatment (IQR 2–31 days). Most cases were acquired locally and only 5% abroad. Patients responded to standard antibiotic therapy and recurrence or persistence was extremely rare. A second group of patients, not included in the clinical case series, were those who believed they had Lyme disease based on a probable tick bite but were seronegative by currently available validated tests and presented with subjective symptoms. This condition is often labelled chronic Lyme disease. These patients have a different disease from Lyme disease and therefore an alternative name, chronic arthropod-borne neuropathy (CAN), and case definition for this condition is proposed. We suggest that this chronic condition needs to be distinguished from Lyme disease, as calling the chronic illness ‘Lyme disease’ causes confusion to patients and physicians. We recommend research initiatives to investigate the aetiology, diagnosis and therapy of CAN.

Objectives: To identify health care workers most at risk for H1N1 infection before vaccination and compare health outcomes after vaccination.

Methods: The indices used to gauge employee health were laboratory-confirmed H1N1 data, laboratory-confirmed influenza A data, and employee sick hours records. In phase 1 of this 2-phase study, absenteeism records for 6,093 hospital employees before vaccine administration were analyzed according to department and employee position during the spring 2009 H1N1 pandemic.

Results: Records of 123 confirmed reports of laboratory-confirmed influenza A or novel H1N1 infections in hospital employees were also analyzed. Two thirds of the H1N1 cases occurred during June (infection rates in parentheses): 34 in physicians and medical personnel (6.7%), 36 in nurses and clinical technicians (2.2%), 39 in Administrative & Support Personnel (infection rate = 1.2%), 3 in Social Workers & Counselors (infection rate = 1.0%), 8 in Housekeeping & Food Services (infection rate = 2.7%), and 3 in Security & Transportation (infection rate=3.9%). When analyzed according to department, the adult emergency department (infection rate = 28.8%) and the pediatric emergency department (infection rate = 25.0%) had the highest infection rates per department.

Conclusions: Of the reported cases of H1N1 in health care workers, 49% occurred in a population that constitutes less than 20% of the total population studied. Physicians and medical personnel had a higher infection rate than other employee positions, whereas ED personnel had the highest infection rate.

(Disaster Med Public Health Preparedness. 2010;4:47-54)

Centrocestus formosanus is a digenetic trematode from Asia that parasitizes multiple hosts and is a concern in the Comal River, Texas, USA, because of its negative effects on the endangered fountain darter Etheostoma fonticola. To determine a practical sampling method to monitor C. formosanus in the Comal River, we evaluated three sampling methods using wild-caught fish, caged fish reared in the laboratory, and cercariometry. Cercariometry detected significant spatial and temporal patterns of cercarial density in river water that were similar with metacercarial intensity in caged fish, but inconsistent with metacercarial intensity in wild-caught fish. Our results also showed a positive correlation between cercarial density in river water and metacercarial intensity in caged fish. Conversely, the relationship was not significant between cercarial density and metacercarial intensity in wild-caught fish. Because cercariometry predicted similar trends with the caged fountain darter sampling method, cercariometry was useful in predicting C. formosanus gill infections, infection rate, and longevity in infected fountain darters. Although trends from cercariometry and caged fish sampling methods were similar, we recommend cercariometry because it was less expensive to use given the amount of sampling effort required and provides trends that can be used to make pro-active management decisions in C. formosanus-infested aquatic ecosystems.

The effect of acquired immunity on the duration of Plasmodium falciparum infections is unclear, although this is an important term in models of malaria transmission. It is problematical to determine the duration of infections because of the difficulty of distinguishing persisting infections from new ones, and because parasite densities are often transiently below the limit of detection. We recently developed a dynamic model for infection incidence, clearance and detection of multiple genotype P. falciparum infections and fitted it to a panel dataset from a longitudinal study in Northern Ghana. We now extend this model to allow for seasonal and age variation in infection rates and also age dependence in clearance and in detectability of infections. These models indicate that there is seasonal variation in the infection rate, and age dependence in detectability. The best fitting models had no age dependence in infection or clearance rates, suggesting that acquired immunity mainly affects detectability.

The New Zealand cockle Austrovenus stutchburyi, whose foot is commonly infected by the digenean trematode Curtuteria australis (Echinostomatidae), is often found heavily infected and unable to burrow on the sediment surface of tidal flats. This has been interpreted as a Curtuteria-manipulation with the purpose of increasing the transmission of the parasite to shorebirds acting as final hosts. Using a field-experimental approach the alternative hypothesis was tested, that surface-dwelling cockles, caught on the surface for other reasons than parasites, accumulate larval C. australis at a higher rate than buried cockles. During the 3-month experiment, larval trematodes accumulated with a rate of approximately 0·5 metacercariae/day in both surface and buried cockles. The result strengthens the manipulation hypothesis indirectly by rejecting the alternative hypothesis. The metacercariae were unevenly distributed along the cockle-foot, with about 4 times as many cysts being found in the tip than in either the mid or hind part of the foot. In light of existing knowledge of the burrowing behaviour and apparatus in bivalves, and a negative relationship between foot mobility and infection intensity, it is suggested that C. australis manipulates its host through a mechanical obstruction of foot muscles and the dynamic hydrostatic skeleton, both necessary for successful burrowing.

Larvae, nymphs and adults of Amblyomma variegatum, and nymphs and adults of Hyalomma rufipes were infected with Dugbe virus by intracoelomic inoculation. Each developmental stage of tick was divided into three groups A, B and C and the three groups were infected respectively with a Dugbe, virus concentration of 4.5 LD50 (log10), 1.5 LD50 (log10) and 0.5 LD50 (log10). The virus multiplied to a high titre in groups A and B and reached a peak which was over 5 (log10) the infective doses of some of the larvae and nymphs.

With the exception of group B adult H. rufipes (with an infection rate of 65%), all other ticks in groups A and B have an infection rate of between 97 to 100%. The infection rate of group C ticks was below 40%.

The 1–5% infection threshold occurred with a dose higher than 0.5 log10 in larvae of A. variegatum and adults of H. rufipes, but with a dose lower than 0.5 (log10) in all other stages of the two tick species. The 50% infection threshold occurred with a dose less than 1.5 (log10) in all the developmental stages of the two tick species.

All the developmental stages of ticks transmitted Dugbe virus to rabbits during feeding.

Investigations into the vectorial capacity of wild caught Phlebotomus pedifer by feeding them on volunteer patients were carried out inside one of the caves of Mt Elgon. Female P. pedifer were fed on lesions of cutaneous leishmaniasis patients to determine the route of infection and infection rates in the flies and hence their vectorial capacity. The flies were kept for periods of 3–8 and 9–13 days before dissections were carried out. The results indicate that the longer period (9–13 days) yielded a higher infection rate. All parasite isolations from flies which were injected subcutaneously caused cutaneous lesions in the nose of the experimental hamsters. All infections were concentrated in the anterior stations of the gut of the experimental sandfly species P. pedifer.

Investigation of sandfly vectors of visceral leishmaniasis (kala-azar) was intensified after the epidemic outbreak of the latter in Machakos District, Kenya, in the early 1970s. Studies were carried out to assess the infection rate of potential vectors using human baits during the height of the 1978 epidemic outbreak. The results presented here indicated that, in Machakos District, sandflies captured when coming to human baits had higher infection rates than those collected in the natural resting sites using suction tubes.