Prolonged delay for controlling KPC-2-producing Klebsiella pneumoniae outbreak: the role of clinical management

BACKGROUND

Carbapenemase-producing Enterobacteriaceae (CPE) are becoming of immediate concern for infection control policies. Prompt detection of CPE on health care setting admission is crucial to halt the spread of an outbreak. We report a cluster of 13 Klebsiella pneumoniae carbapenemase (KPC)-2-producing K pneumoniae cases in a tertiary care hospital.The objective of this study was to identify contributing factors originating the outbreak.

METHODS

An outbreak investigation was conducted using descriptive epidemiology, observation of health care practices, and interviews of management staff. A root cause analysis was performed to identify patent and latent failures of infection control measures using the association of litigation and risk management method.

RESULTS

The main patent failure was the delay in identifying KPC-2-producing K pneumoniae carriers. Contributing factors were work and environmental factors: understaffing, lack of predefined protocols, staff members' characteristics, and underlying patients' characteristics. Latent failures were as follows: no promotion of the national guidelines for prevention of CPE transmission, no clear procedure for the management of patients hospitalized abroad, no clear initiative for promoting a culture of quality in the hospital, biologic activity recently outsourced to a private laboratory, and poor communication among hospital members.

CONCLUSION

Clinical management should be better promoted to control hospital outbreaks and should include team work and safety culture.

Benefits of task-shifting HIV care to nurses in terms of health-related quality of life in patients initiating antiretroviral therapy in rural district hospitals in Cameroon [Stratall Agence Nationale de Recherche sur le SIDA (ANRS) 12110/Ensemble pour une Solidarité Thérapeutique Hospitalière en Réseau (ESTHER) substudy]

OBJECTIVES

The World Health Organization (WHO) recommends task-shifting HIV care to nurses in low-resource settings with limited numbers of physicians. However, the effect of such task-shifting on the health-related quality of life (HRQL) of people living with HIV (PLHIV) has seldom been evaluated. We aimed to investigate the effect of task-shifting HIV care to nurses on HRQL outcomes in PLHIV initiating antiretroviral therapy (ART) in rural district hospitals in Cameroon.

METHODS

Outcomes in PLHIV were longitudinally collected in the 2006-2010 Stratall trial. PLHIV were followed up for 24 months by nurses and/or physicians. Six HRQL dimensions were assessed during face-to-face interviews using the WHO Quality of Life (WHOQOL)-HIV BREF scale: physical health; psychological health; independence level; social relationships; environment; and spirituality/religion/personal beliefs. The degree of task-shifting was estimated using a consultant ratio (i.e. the ratio of nurse-led to physician-led visits). The effect of task-shifting and other potential correlates on HRQL dimensions was explored using a Heckman two-stage approach based on linear mixed models to adjust for the potential bias caused by missing data in the outcomes.

RESULTS

Of 1424 visits in 440 PLHIV (70.5% female; median age 36 years; median CD4 count 188 cells/μL at enrolment), 423 (29.7%) were task-shifted to nurses. After multiple adjustment, task-shifting was associated with higher HRQL level for four dimensions: physical health [coefficient 0.7; 95% confidence interval (CI) 0.1-1.2; P = 0.01], psychological health (coefficient 0.5; 95% CI 0.0-1.0; P = 0.05), independence level (coefficient 0.6; 95% CI 0.1-1.1; P = 0.01) and environment (coefficient 0.6; 95% CI 0.1-1.0; P = 0.02).

CONCLUSIONS

Task-shifting HIV care to nurses benefits the HRQL of PLHIV. Together with the previously demonstrated comparable clinical effectiveness of physician-based and nurse-based models of HIV care, our results support the WHO recommendation for task-shifting.

Patterns of adherence to antiretroviral therapy and HIV drug resistance over time in the Stratall ANRS 12110/ESTHER trial in Cameroon

OBJECTIVES

The emergence of HIV drug resistance is a crucial issue in Africa, where second-line antiretroviral therapy (ART) is limited, expensive and complex. We assessed the association between adherence patterns and resistance emergence over time, using an adherence measure that distinguishes low adherence from treatment interruptions, in rural Cameroon.

METHODS

We performed a cohort study among patients receiving nonnucleoside reverse transcriptase inhibitor (NNRTI)-based ART in nine district hospitals, using data from the Stratall trial (2006-2010). Genotypic mutations associated with antiretroviral drug resistance were assessed when 6-monthly HIV viral loads were > 5000 HIV-1 RNA copies/mL. ART adherence data were collected using face-to-face questionnaires. Combined indicators of early (1-3 months) and late (6 months to t - 1; t is the time point when the resistance had been detected) adherence were constructed. Multivariate logistic regression and Cox models were used to assess the association between adherence patterns and early (at 6 months) and late (after 6 months) resistance emergence, respectively.

RESULTS

Among 456 participants (71% women; median age 37 years), 45 developed HIV drug resistance (18 early and 27 late). Early low adherence (< 80%) and treatment interruptions (> 2 days) were associated with early resistance [adjusted odds ratio (95% confidence interval) 8.51 (1.30-55.61) and 5.25 (1.45-18.95), respectively]. Early treatment interruptions were also associated with late resistance [adjusted hazard ratio (95% confidence interval) 3.72 (1.27-10.92)].

CONCLUSIONS

The emergence of HIV drug resistance on first-line NNRTI-based regimens was associated with different patterns of adherence over time. Ensuring optimal early adherence through specific interventions, adequate management of drug stocks, and viral load monitoring is a clinical and public health priority in Africa.

Nationwide inventory of mosquito biodiversity (Diptera: Culicidae) in Belgium, Europe

To advance our restricted knowledge on mosquito biodiversity and distribution in Belgium, a national inventory started in 2007 (MODIRISK) based on a random selection of 936 collection points in three main environmental types: urban, rural and natural areas. Additionally, 64 sites were selected because of the risk of importing a vector or pathogen in these sites. Each site was sampled once between May and October 2007 and once in 2008 using Mosquito Magnet Liberty Plus traps. Diversity in pre-defined habitat types was calculated using three indices. The association between species and environmental types was assessed using a correspondence analysis. Twenty-three mosquito species belonging to traditionally recognized genera were found, including 21 indigenous and two exotic species. Highest species diversity (Simpson 0.765) and species richness (20 species) was observed in natural areas, although urban sites scored also well (Simpson 0.476, 16 species). Four clusters could be distinguished based on the correspondence analysis. The first one is related to human modified landscapes (such as urban, rural and industrial sites). A second is composed of species not associated with a specific habitat type, including the now widely distributed Anopheles plumbeus. A third group includes species commonly found in restored natural or bird migration areas, and a fourth cluster is composed of forest species. Outcomes of this study demonstrate the effectiveness of the designed sampling scheme and support the choice of the trap type. Obtained results of this first country-wide inventory of the Culicidae in Belgium may serve as a basis for risk assessment of emerging mosquito-borne diseases.

Diel activity patterns of male Aedes albopictus in the laboratory

This study was conducted to investigate the flight and dispersal behavior of male Aedes albopictus under laboratory conditions. Two different methods, the Observer and Ethovision software devices, were used to determine the total duration, the mean and maximum flight speed, and the distance covered by these mosquitoes. During 24 h, mosquitoes were more active from 0800 to 1200 h and from 1700 to 2100 h than during the rest of the day. Male Ae. albopictus displayed different activities at different times. The flight activity was 47 min and 57 sec over 24 h. During this period, sugar-fed males flew an average distance of 236.20 m at an average speed of 8.5 cm/sec. The unfed males flew significantly faster than recently fed males, with maximum flight speeds of 44.9 cm/sec and 33.6 cm/sec, respectively. The time used for resting (22 h 2 min +/- 13 min) was significantly higher (P < 0.0001) than walking and flying times (68 min +/- 10 sec and 49 min +/- 5 min, respectively). Overall, both methods allowed observations on flight activity, and the camera recordings allowed these activities to be quantified.

A review of control methods and resistance mechanisms in stored-product insects

This review describes the major stored-product insect species and their resistance to insecticides. The economic importance of the control of those pests is highlighted with a loss of more than one billion US dollars per year worldwide. A detailed common description of species resistance throughout the world has been developed, and we observed 28 recurrent studied species involved in resistance cases disseminated on the five continents. The different mechanisms, including behavioral resistance, were studied particularly on Oryzaephilus surinamensis. The role of detoxifying enzymes and studies on the genetic resistance, involving the kdr mutation mechanisms and the transmission of the genes of resistance, are also described. A chapter clarifying definitions on cross and multiple resistance is enclosed.

[Sterile insect technique: targeted control without insecticide]

Sterile insect technique (SIT) is a method of disease vector control technique that consists of releasing overwhelming numbers of sterile males. This method provides an environmentally friendly alternative to insecticides. Another advantage of SIT in comparison with other methods is to provide a targeted species-specific approach. In Reunion Island, SIT has been proposed as a basis for developing a viable method of vector control against Aedes albopictus and Anopheles arabiensis. The technique has already been successfully tested on fly and mosquito species for more than 40 years. The CRVOI (Centre de Recherche et de Veille sur les Maladies Emergentes dans l'Océan Indien) is carrying out studies to determine the feasibility of SIT for control of Anopheles arabiensis (vector of malaria) and Aedes albopictus (vector of chikungunya and dengue) on Reunion Island and other islands in the Indian Ocean region.

Noninvasive molecular methods to identify live scarab larvae: an example of sympatric pest and nonpest species in New Zealand

Despite the negative impact that many scarab larvae have on agro-ecosystems, very little attention has been paid to their taxonomy. Their often extremely similar morphological characteristics have probably contributed to this impediment, which has also meant that they are very difficult to identify in the field. Molecular methods can overcome this challenge and are particularly useful for the identification of larvae to enable management of pest species occurring sympatrically with nonpest species. However, the invasive collection of DNA samples for such molecular methods is not compatible with subsequent behavioural, developmental or fitness studies. Two noninvasive DNA sampling and DNA analysis methods suitable for the identification of larvae from closely related scarab species were developed here. Using the frass and larval exuviae as sources of DNA, field-collected larvae of Costelytra zealandica (White) and Costelytra brunneum (Broun) (Scarabaeidae: Melolonthinae) were identified by multiplex PCR based on the difference in size of the resulting PCR products. This study also showed that small quantities of frass can be used reliably even 7 days after excretion. This stability of the DNA is of major importance in ecological studies where timeframes rarely allow daily monitoring. The approach developed here is readily transferable to the study of any holometabolous insect species for which morphological identification of larval stages is difficult.

Sexual performance of male mosquito Aedes albopictus

Issues of male fertility must be addressed to support the development of a sterile insect technique (SIT) programme for the control of Aedes albopictus Skuse (Diptera: Culicidae) populations on Reunion Island in the Indian Ocean. The mating ability of a local strain of Ae. albopictus was tested using several batches of females and different cage sizes under laboratory conditions. Individual males were able to inseminate up to 14 females at an average of 9.5 females per male when exposed to 20 females over 7 days. Males filled between three and 27 spermathecal capsules at an average of 15.5 capsules per male. The average number of females inseminated per male was 5.3 when two virgin females were introduced to one male and replaced every day for 12 days, and 8.6 when 10 virgin females were introduced to one male and replaced every day for 14 days. A continuous decrease in the number of both inseminated females and filled spermathecal capsules was observed over time, until no mating occurred after 14 days. The high number of females inseminated by one male and the duration of male activity may have strong implications for SIT control of mosquitoes.