Challenges of cold chain quality for routine EPI in south-west Burkina-Faso: An assessment using automated temperature recording devices.

BACKGROUND: Abnormal temperatures are a major issue for vaccines within the Expanded Program of Immunization in tropical climates. Prolonged exposure to temperatures outside the standard +2 °C/+8 °C range can impact vaccine potency. METHODS: The current study used automatic temperature recording devices (Testostore 171-1©) to monitor cold chain in remote areas of Western Burkina Faso. A series of 25 randomly selected health centers representing 33% of the existing 176 EPI facilities in Western Burkina Faso were prospectively assessed for eight months in 2015. Automatic measurements were compared to routine temperature loggers and vaccine vial monitors (VVM). RESULTS: The median age for all refrigerators was 9 years with 10/25 (42%) older than 10 years. Adverse temperatures were recorded in 20/24 (83%) refrigerators and ranged from -18.5 °C to +34.2 °C with 12,958/128,905 (10%) abnormal hourly records below +2 °C and 7357/128,905 (5.7%) above +8 °C. Time of day significantly affected the rate of temperature excursions, with higher rates from 00 am to 06 am (p < 0.001) for low temperatures and 10-12 am (p < 0.001) and 13-16 pm (p < 0.001) for high temperatures. Abnormal temperatures lasted from 1 h to 24 h below +2 °C and 13-24 h above +8 °C. Standard manual registers reported only 182/2761 (7%) inadequate temperatures and VVM color change detected only 133/2465 (5%) disruptions. Reliability of the refrigerators ranged from 48% to 98.7% with a median of 70%. Risk factors for excursions were old age of the refrigerators, the months of April and May, hours of high activity during the day, and health staff-associated factors such as inappropriate actions or insufficient knowledge. CONCLUSION: Important cold chain reliability issues reported in the current study in Western Burkina Faso raise concern about vaccine potency. In the absence of systematic renewal of the cold chain infrastructure or improved staff training and monitoring, antibody response assessment is recommended to study levels of effective immunization coverage.

[Computerized temperature monitoring of the vaccine cold chain in a tropical climate, Chad]. / Surveillance informatisée de la chaîne du froid en milieu tropical (Tchad).

Because new EPI liquid vaccines are highly sensitive to freezing and overheating, close monitoring of the cold chain is mandatory. The new Testostore 171-1 electronic thermometer (Testo) provides more reliable monitoring of cold chain temperature than freezer indicators, vaccine vial monitors and color strips that only indicate if vaccines are out-of-date. The Testo thermometer uses a probe placed in refrigeration units to periodically measure and store temperature readings. Temperature curves are displayed via a USB connection on a laptop computer running special software (Comfort software light). Testo temperature data can easily be communicated to all management levels by e-mail. The first experience using the Testo system in Africa involved regional EPI supervision in Mondou, Logone Occidental, Chad. After a preliminary mission in Chad in 2006 showed the feasibility of using this method to manage the national cold chain at all levels, a nurse was appointed as EPI supervisor and given a refresher course in Chad's capital Ndjamena in March 2009. In April-May 2009, the supervisor was sent back to the Logone Occidental Region to monitor, by himself, refrigeration units making up the regional and district cold chain for vaccine storage in five health centers (rural and urban). Temperature curve readings were performed on site in the presence of the medical staff and results were compared to those recorded twice a day on conventional temperature charts using lamellar thermometers installed in refrigerators doors. Testo curves showed that liquid vaccine storage temperatures fell below freezing too frequently and that temperatures readings of door thermometers were often inaccurate. Testo readings also detected power outages in refrigeration units used in urban settings and flame extinctions in kerosene lamp refrigerators due to refrigerator breakdown or windy weather conditions before the rainy season. The main advantage of this monitoring method is to provide reliable data as a basis not only for detection of possible freezing of liquid vaccines but also for discussion of cold chain management and improvement with medical staff.

[Inclusion of hepatitis B vaccination in the Expanded Program of Immunization: feasibility study in the medical region of Kolda (Senegal)]. / Inclusion de la vaccination contre l'hépatite B dans le programme élargi de vaccination: étude de faisabilité dans la région médicale de Kolda (Sénégal).

Hepatitis B is highly endemic in Senegal. The prevalence of hepatitis B antigens in the population was estimated to be 10 to 12% in 1982. According to the WHO recommendations, a hepatitis B vaccination program (HBV) was launched in 10 medical centers in the Kolda medical region to assess the feasibility of including HBV in the EPI. The epidemiological impact of HBV was also investigated by comparison of the vaccinated zone (VZ) to a control non vaccinated zone (NVZ). HBV coverage had a pattern similar to that of DPT-IPV, but at a lower level: the overall coverage with HBV was only 37.5%, and the drop out rate for HBV1-3 was only 34.4%. In addition, the coverage of the under one year age group was insufficient: 45% for HBV3 as compared to 78% for DPT3 (p < 0.0001). Routine vaccination records in the medical centers in the VZ were consistent with the findings of cluster surveys. Hepatitis B markers were less prevalent among vaccinated that non vaccinated children (8 versus 18.5%, p < 0.001). HB antigenemia was significantly less frequent in the VZ than the NVZ (3.9 versus 10.9, p < 0.0001), and the difference was even larger for all hepatitis markers (7.4 versus 23.7%, p < 0.0001). This study therefore suggests that the inclusion of HBV in the EPI should be continued and strengthened in less accessible regions by an adapted social mobilization program. HBV could then be extended to the whole medical district of Kolda in association with regular epidemiological and serological surveillance.