Does the length of specimen storage affect influenza testing results by real-time reverse transcription-polymerase chain reaction? an analysis of influenza surveillance specimens, 2008 to 2010.

In some influenza surveillance systems, timely transport to laboratories for reverse transcription-polymerase chain reaction (RT-PCR) testing is challenging.Guidelines suggest that samples can be stored at 4°Cfor up to 96 hours but the effect of longer storage times has not been systematically evaluated. We collected nasopharyngeal and oropharyngeal specimens from patients in Kenya and stored them in viral transport medium at 2 to 8°C before testing for influenza A and B using real-time RT-PCR. From April 2008 to November 2010, we collected 7,833 samples; 940 (12%) were positive for influenza. In multivariable analysis, specimens stored for six days were less likely to be influenza-positive compared to specimens stored between zero and one day (adjusted odds ratio (a OR): 0.49, 95%confidence interval (CI): 0.27­0.93). There was no statistically significant difference in influenza positivity of specimens stored for five days compared to zero to one day. There was no statistically significant relationship between days in refrigeration and cycle threshold(Ct) values for positive samples (p=0.31). We found that samples could remain in storage for at least five days without affecting the proportion-positive of samples,potentially increasing the feasibility of including influenza surveillance sites in remote areas.

Results from the first 30 months of national sentinel surveillance for influenza in Tanzania, 2008-2010.

Limited data exist on the burden of influenza in developing countries. In 2008, in order to better understand the epidemiology of influenza virus infection in Tanzania, the Tanzanian Ministry of Health and Social Welfare created a sentinel surveillance system for influenza. At 5 hospitals across the country, patients with influenza-like illness (ILI) and severe acute respiratory illness (SARI) had oropharyngeal and nasopharyngeal samples collected. At the National Influenza Center in Dar es Salaam, specimens were tested for influenza using real-time polymerase chain reaction tests. From May 2008 through November 2010, a total of 1794 samples were collected from 5 sentinel sites, of which 61% were from patients with ILI and 39% were from patients with SARI. Of all ILI and SARI samples, 8.0% were positive for influenza; 6.9% yielded influenza A virus, and 1.1% yielded influenza B virus. Most influenza A virus was subtype H3, which circulated in nearly every month of 2010. The proportion of influenza-positive cases was similar among ILI (8.5%) and SARI (7.3%) patients (P = .39). In multivariate logistic regression, influenza-positive SARI cases were more likely than influenza-negative SARI cases to have had rhonchi (adjusted OR [aOR], 2.31; 95% confidence interval [CI], 1.14-4.67), nasal discharge (aOR, 4.57; 95% CI, 1.30-16.10), and stridor (aOR, 2.63; 95% CI, 1.17-5.90). Influenza-positive ILI patients had a longer duration of fever on presentation, compared with influenza-negative ILI patients (median, 4 vs 3 days; P = .004). Otherwise, there was no difference in signs or symptoms among influenza-positive and influenza-negative ILI patients. During 2.5 years of surveillance for influenza at 5 geographically disbursed sites in Tanzania, we found that influenza circulated year-round. Surveillance should continue in order to fully understand the seasonality and epidemiology of influenza in Tanzania.

Correction: Temporal Patterns of Influenza A and B in Tropical and Temperate Countries: What Are the Lessons for Influenza Vaccination?

[This corrects the article DOI: 10.1371/journal.pone.0152310.].

Concurrent sexual and substance-use risk behaviours among female sex workers in Kenya's Coast Province: findings from a behavioural monitoring survey.

While many studies confirm the association between HIV, alcohol and injecting drug use by female sex workers (FSWs), little is known about their use of marijuana, khat and other substances and the association of these substances with HIV, risky sexual behaviour, and sexual violence. To better understand this association, data were analysed from a cross-sectional, behavioural survey of 297 FSWs in Mombasa, a well-known tourist destination and the second largest port in Africa and capital city of the Coast Province in Kenya. Among the FSWs, lifetime use of different substances was reported by 91% for alcohol, 71% for khat, 34% for marijuana, and 6% for heroin, cocaine, glue or petrol. The majority (79%) used more than one substance, and multiple-substance use was reported by all respondents who ever used marijuana, heroin, cocaine, glue and petrol. The risk of HIV acquisition was perceived as medium to high by 41% of respondents, 75% of whom attributed this risk to multiple partners. Sexual violence was reported by 48% of respondents, and 30% indicated that this happened several times. Despite HIV prevention programmes targeting FSWs in Mombasa, most of them continue to engage in risky sexual behaviours. This suggests that harm reduction strategies for substance use should be coupled with efforts to promote consistent condom use and partner reduction.