Tinytags monitor environmental conditions at the medical research facility during evaluation of insecticides and vector control tools.

Tinytag data loggers are used by Dr Matt Kirby and the team at the Kilimanjaro Christian Medical University College (KCMUCo) in Moshi, Tanzania. Dr Kirby is a Lecturer in Medical Entomology at London School of Hygiene and Tropical Medicine, and Study Director for PAMVERC (Pan African Malaria Vector Research Consortium) at the KCMUCo. PAMVERC is an alliance of African research institutes and trial sites for evaluation of insecticides and vector control tools. (Vector control is the method to limit or eradicate the organisms - vectors - which transmit disease pathogens, frequently mosquitos.) The individual trial sites have unique expertise in vector control product evaluation and have historical collaboration with the London School of Hygiene and Tropical Medicine.

KCMUCo is situated in the shadow of Mount Kilimanjaro and shares the site with a regional hospital, a school of pharmacy and a biotechnology laboratory. There are currently 72 ongoing projects in malaria, HIV/AIDS, TB, non-communicable diseases, reproductive health, dermatology and disabilities. The PAMVERC facilities specifically comprise an Insecticide Testing Facility, an insectary, an animal house, a molecular laboratory and three field stations where insecticide-treated products are tested in a community setting.

Environmental conditions, including water temperatures, air temperatures and humidity are being monitored in several locations with a variety of Tinytag data loggers. Tinytag Aquatic 2 data loggers monitor the range of water temperatures experienced by mosquito larvae in the insectary in larval breeding bowls. It is important to optimise the conditions the larvae experience in order to maximise productivity of adults, for testing against insecticides. Larval development is strongly influenced by temperature - at low temperatures they develop very slowly and at very high temperatures they either die or do not accumulate enough energy reserve so the adults that emerge are not suitable for testing.

When conducting assays of insecticide-treated bed nets and other insecticide-treated surfaces, this must also be done under carefully controlled conditions in the laboratory. For this, 12 Tinytag View 2 temp/RH data loggers are used to check conditions on benchtops, in fridges, in chemical storerooms, and in incubators. The aim is to demonstrate how quickly and effectively insecticides can kill mosquitoes, and a control group which is not exposed to the insecticides is required as a reference. It is important that the assays are run under conditions that are suitable for the control group i.e. that none or very few of them die. Mosquitoes are naturally quite sensitive to low humidity as they do not have much water reserve and desiccate quickly. So assays are run typically at a narrow range: 27°C ±2 and 75%RH±10. In addition, the efficacy of some insecticides that impact on respiratory pathways is influenced by temperature.

Trials of vector control tools (bed nets, insecticide sprayed on walls) are run in the local community, and temperature is recorded using four Tinytag Plus 2 temp/RH data loggers located inside and outside houses. Mosquito nightly activity and behaviour is strongly influenced by environmental conditions, and it is important to analyse the data and make allowances/adjustments for changes in the environment from week to week.

Two hand-held thermohygrometers are used in the field insectaries. Hand held units are needed as there are no computers in these locations (no reliable electricity) to which the data could be uploaded from alternative types of logger. The handheld units have proved useful as they give rapid readings and adjust quickly to being moved around. Readings are taken from the screen and recorded on paper record sheets.

In addition to the stand-alone units, 12 Tinytag Ultra Radio temp/RH data loggers are mounted on the wall in each room in the laboratory, in the insectary, the animal house and the store of insecticide-treated bed nets. PAMVERC at KCMUCo is undergoing an internationally-recognised audit of Good Laboratory Practice. Under this scheme they are required to conduct experiments under carefully controlled, pre-defined, repeatable and reliable conditions. Monitoring environmental conditions is a critical component of this.

The Ultra Radio loggers have proved particularly useful in this respect as they have been set up in these various locations, communicating back to a centrally located receiver linked to a laptop dedicated to running the Tinytag Explorer software. This laptop is accessible (it is hosted on a server with a global IP) to office desktops, so all the senior management can check the data from the Ultra Radio loggers in real-time and take corrective action immediately if any reading is out of range. All the facilities are equipped with thermostatically-controlled heater units, hygrostatically-controlled humidifiers and A/C units and these can be moved or adjusted as necessary to quickly return the environment to within the acceptable range.

Temperature sensitive chemicals and other test items in fridges and freezers are also monitored. If there is a power cut and the fridges go out of acceptable range, this must be reported to the trial sponsor and a decision made as to whether this has had a negative impact on the trial i.e. should the results from those test items be discarded, the test repeated, or the entire protocol restarted.

Dr Kirby chose Tinytags because of their good reputation. Various loggers had been used previously by several of the team's project managers and by Dr Kirby himself in other trial sites in Africa. The Radio System is a personal favourite not only because of the instant access to data, but also the ability to group the units in the output display (there are separate facilities each with several units), to bring up and project graphs of the data easily, and most importantly, to set the alarm ranges for each unit independently and to have those flash on laptop screens. This allows problems to be seen easily and corrective action to be taken immediately. This potentially saves repeating dozens of experiments each month that would otherwise have been conducted under sub-optimal environmental conditions.

Dr Kirby concludes, "The various Tinytag loggers used by PAMVERC have been easy to install and operate, and are suited to a wide range of situations. They are appropriate for laboratories requiring calibrated, accurate and reliable environmental monitoring. We are highly satisfied with them and will continue to purchase more units as our facility expands."

Photographs:

Top: Tinytag Aquatic 2 data logger in larval bowl.

Right: Insectary Facility Supervisor using Tinytag Hand-held thermohygrometer in adult mosquito room.

Listing image: Tinytag View 2 data logger in the chemical store cabinet.