Epidemiology of respiratory syncytial virus infection in rural and urban Kenya

BACKGROUND

Information on the epidemiology of respiratory syncytial virus (RSV) infection in Africa is limited for crowded urban areas and for rural areas where the prevalence of malaria is high.

METHODS

At referral facilities in rural western Kenya and a Nairobi slum, we collected nasopharyngeal/oropharyngeal (NP/OP) swab specimens from patients with influenza-like illness (ILI) or severe acute respiratory illness (SARI) and from asymptomatic controls. Polymerase chain reaction assays were used for detection of viral pathogens. We calculated age-specific ratios of the odds of RSV detection among patients versus the odds among controls. Incidence was expressed as the number of episodes per 1000 person-years of observation.

RESULTS

Between March 2007 and February 2011, RSV was detected in 501 of 4012 NP/OP swab specimens (12.5%) from children and adults in the rural site and in 321 of 2744 NP/OP swab specimens (11.7%) from those in the urban site. Among children aged <5 years, RSV was detected more commonly among rural children with SARI (odds ratio [OR], 2.0; 95% confidence interval [CI], 1.2-3.3), urban children with SARI (OR, 8.5; 95% CI, 3.1-23.6), and urban children with ILI (OR, 3.4; 95% CI, 1.2-9.6), compared with controls. The incidence of RSV disease was highest among infants with SARI aged <1 year (86.9 and 62.8 episodes per 1000 person-years of observation in rural and urban sites, respectively).

CONCLUSIONS

An effective RSV vaccine would likely substantially reduce the burden of respiratory illness among children in rural and urban areas in Africa.

Demographic, socio-economic and geographic determinants of seasonal influenza vaccine uptake in rural western Kenya, 2011

Influenza-associated acute lower respiratory infections cause a considerable burden of disease in rural and urban sub-Saharan Africa communities with the greatest burden among children. Currently, vaccination is the best way to prevent influenza infection and accompanying morbidities. We examined geographic, socio-economic and demographic factors that contributed to acceptance of childhood seasonal influenza vaccination among children living in a population-based morbidity surveillance system in rural western Kenya, where influenza vaccine was offered free-of-charge to children 6 months-10 years old from April to June, 2011. We evaluated associations between maternal and household demographic variables, socio-economic status, and distance from home to vaccination clinics with family vaccination status. 7249 children from 3735 households were eligible for vaccination. Of these, 2675 (36.9%) were fully vaccinated, 506 (7.0%) were partially vaccinated and 4068 (56.1%) were not vaccinated. Children living in households located >5km radius from the vaccination facilities were significantly less likely to be vaccinated (aOR=0.70; 95% CI 0.54-0.91; p=0.007). Children with mothers aged 25-34 and 35-44 years were more likely to be vaccinated than children with mothers less than 25 years of age (aOR=1.36; 95% CI 1.15-1.62; p<0.001; and aOR=1.35; 95% CI 1.10-1.64; p=0.003, respectively). Finally, children aged 2-5 years and >5 years of age (aOR=1.38; 95% CI 1.20-1.59; p<0.001; and aOR=1.41; 95% CI 1.23-1.63; p<0.001, respectively) and who had a sibling hospitalized within the past year (aOR=1.73; 95% CI 1.40-2.14; p<0.001) were more likely to be vaccinated. Shorter distance from the vaccination center, older maternal and child age, household administrator's occupation that did not require them to be away from the home, and having a sibling hospitalized during the past year were associated with increased likelihood of vaccination against influenza in western Kenya. These findings should inform the design of future childhood seasonal influenza vaccination campaigns in rural Kenya, and perhaps elsewhere in Africa.

Hospitalizations and deaths caused by diarrhea in children five years old and younger at four hospitals in Haiti, 2010-2012

Worldwide, diarrhea is a major contributor to morbidity and mortality in children; however, there are few data on the burden of diarrheal disease in Haiti. We conducted a retrospective review of hospital discharge registries from 2010 to 2012 in the pediatric wards of four Haitian hospitals and recorded the number of all-cause hospitalizations and deaths as well as diarrheal hospitalizations and deaths by age (≤ 2 and 3-5 years) and epidemiological week. Diarrhea was associated with 3,582 (33.7%) of 10,621 hospitalizations and 62 (11.5%) of 540 in-hospital deaths in children ≤ 5 years old. Of these children, 88.5% and 96.8%, respectively, were among children ≤ 2 years old. The highest proportions of diarrhea-associated hospitalizations occurred from January to April. At four Haitian hospitals over a 3-year period, during which time a major epidemic of cholera occurred, diarrheal disease in children ≤ 5 years was a major contributor to pediatric hospitalizations and mortality.

Laboratory-confirmed cholera and rotavirus among patients with acute diarrhea in four hospitals in Haiti, 2012-2013

An outbreak of cholera began in Haiti in October of 2010. To understand the progression of epidemic cholera in Haiti, in April of 2012, we initiated laboratory-enhanced surveillance for diarrheal disease in four Haitian hospitals in three departments. At each site, we sampled up to 10 hospitalized patients each week with acute watery diarrhea. We tested 1,616 specimens collected from April 2, 2012 to March 28, 2013; 1,030 (63.7%) specimens yielded Vibrio cholerae, 13 (0.8%) specimens yielded Shigella, 6 (0.4%) specimens yielded Salmonella, and 63 (3.9%) specimens tested positive for rotavirus. Additionally, 13.5% of children < 5 years old tested positive for rotavirus. Of 1,030 V. cholerae isolates, 1,020 (99.0%) isolates were serotype Ogawa, 9 (0.9%) isolates were serotype Inaba, and 1 isolate was non-toxigenic V. cholerae O139. During 1 year of surveillance, toxigenic cholera continued to be the main cause of acute diarrhea in hospitalized patients, and rotavirus was an important cause of diarrhea-related hospitalizations in children.

Uptake and effectiveness of monovalent influenza A (H1N1) pandemic 2009 vaccine among healthcare personnel in Kenya, 2010

INTRODUCTION

During April-June 2010, the Kenya Ministry of Public Health and Sanitation distributed free monovalent influenza A(H1N1)pdm09 vaccines to health care personnel (HCP) and other vulnerable groups. We conducted a prospective, cohort study among HCP to characterize influenza A(H1N1)pdm09 vaccine uptake, and to assess influenza A(H1N1)pdm09 vaccine effectiveness.

METHODS

We enrolled HCP from 5 hospitals and followed them for 6 months. At enrollment, we asked HCP if they had received the influenza A(H1N1)pdm09 vaccine and their reasons for their decision. We administered weekly questionnaires to participants about respiratory symptoms suffered during the previous week. Participants who had acute respiratory illness were asked to contact our surveillance clinician, and nasopharyngeal and oropharyngeal specimens were collected and later tested for influenza by real-time reverse-transcriptase polymerase-chain-reaction. Vaccine effectiveness was estimated by comparing the incidence of acute respiratory illness, absenteeism from work due to respiratory illness and laboratory-confirmed influenza among vaccinated and unvaccinated HCP.

RESULTS

We enrolled 3803 HCP from the five hospitals; 64% received influenza vaccine. Vaccinated HCP were more likely to develop acute respiratory illness (ARI) and more likely to report missed days of work due to respiratory illness compared to non-vaccinated HCP (adjusted incidence rate ratio (aIRR) 1.50, 95% confidence intervals (CI): 1.33-1.70) and (aIRR 2.02, 95% CI: 1.41-2.88), respectively. Of 531 samples collected from vaccinated and non-vaccinated HCP, 30 were influenza A and 3 were influenza B. Two influenza A(H1N1)pdm09 subtypes were isolated; one from vaccinated and the other from non-vaccinated HCP.

DISCUSSION AND CONCLUSIONS

A majority of Kenyan HCP surveyed reported receiving the influenza A(H1N1)pdm09 vaccine. Because of low circulation of influenza A(H1N1)pdm09 virus during the study period, vaccine effectiveness could not be determined. The findings of increased ARI events and missed days of work among vaccinated HCP were likely confounded by vaccine-seeking behavioral factors.

Assessing parents' knowledge and attitudes towards seasonal influenza vaccination of children before and after a seasonal influenza vaccination effectiveness study in low-income urban and rural Kenya, 2010-2011

Background

Influenza vaccine is rarely used in Kenya, and little is known about attitudes towards the vaccine. From June-September 2010, free seasonal influenza vaccine was offered to children between 6 months and 10 years old in two Population-Based Infectious Disease Surveillance (PBIDS) sites. This survey assessed attitudes about influenza, uptake of the vaccine and experiences with childhood influenza vaccination.

Methods

We administered a questionnaire and held focus group discussions with parents of children of enrollment age in the two sites before and after first year of the vaccine campaign. For pre-vaccination focus group discussions, we randomly selected mothers and fathers who had an eligible child from the PBIDS database to participate. For the post-vaccination focus group discussions we stratified parents whose children were eligible for vaccination into fully vaccinated, partially vaccinated and non-vaccinated groups.

Results

Overall, 5284 and 5755 people completed pre and post-vaccination questionnaires, respectively, in Kibera and Lwak. From pre-vaccination questionnaire results, among parents who were planning on vaccinating their children, 2219 (77.6%) in Kibera and 1780 (89.6%) in Lwak said the main reason was to protect the children from seasonal influenza. In the pre-vaccination discussions, no parent had heard of the seasonal influenza vaccine. At the end of the vaccine campaign, of 18,652 eligible children, 5,817 (31.2%) were fully vaccinated, 2,073 (11.1%) were partially vaccinated and, 10,762 (57.7%) were not vaccinated. In focus group discussions, parents who declined vaccine were concerned about vaccine safety or believed seasonal influenza illness was not severe enough to warrant vaccination. Parents who declined the vaccine were mainly too busy [251(25%) in Kibera and 95 (10.5%) in Lwak], or their child was away during the vaccination period [199(19.8%) in Kibera; 94(10.4%) in Lwak].

Conclusion

If influenza vaccine were to be introduced more broadly in Kenya, effective health messaging will be needed on vaccine side effects and frequency and potential severity of influenza infection.

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.

Epidemiology, seasonality, and burden of influenza and influenza-like illness in urban and rural Kenya, 2007-2010

BACKGROUND

The epidemiology and burden of influenza remain poorly defined in sub-Saharan Africa. Since 2005, the Kenya Medical Research Institute and Centers for Disease Control and Prevention-Kenya have conducted population-based infectious disease surveillance in Kibera, an urban informal settlement in Nairobi, and in Lwak, a rural community in western Kenya.

METHODS

Nasopharyngeal and oropharyngeal swab specimens were obtained from patients who attended the study clinic and had acute lower respiratory tract (LRT) illness. Specimens were tested for influenza virus by real-time reverse-transcription polymerase chain reaction. We adjusted the incidence of influenza-associated acute LRT illness to account for patients with acute LRT illness who attended the clinic but were not sampled.

RESULTS

From March 2007 through February 2010, 4140 cases of acute LRT illness were evaluated in Kibera, and specimens were collected from 1197 (27%); 319 (27%) were positive for influenza virus. In Lwak, there were 6733 cases of acute LRT illness, and specimens were collected from 1641 (24%); 359 (22%) were positive for influenza virus. The crude and adjusted rates of medically attended influenza-associated acute LRT illness were 6.9 and 13.6 cases per 1000 person-years, respectively, in Kibera, and 5.6 and 23.0 cases per 1000 person-years, respectively, in Lwak. In both sites, rates of influenza-associated acute LRT illness were highest among children <2 years old and lowest among adults ≥50 years old.

CONCLUSION

In Kenya, the incidence of influenza-associated acute LRT illness was high in both rural and urban settings, particularly among the most vulnerable age groups.

Influenza surveillance in 15 countries in Africa, 2006-2010

BACKGROUND

In response to the potential threat of an influenza pandemic, several international institutions and governments, in partnership with African countries, invested in the development of epidemiologic and laboratory influenza surveillance capacity in Africa and the African Network of Influenza Surveillance and Epidemiology (ANISE) was formed.

METHODS

We used a standardized form to collect information on influenza surveillance system characteristics, the number and percent of influenza-positive patients with influenza-like illness (ILI), or severe acute respiratory infection (SARI) and virologic data from countries participating in ANISE.

RESULTS

Between 2006 and 2010, the number of ILI and SARI sites in 15 African countries increased from 21 to 127 and from 2 to 98, respectively. Children 0-4 years accounted for 48% of all ILI and SARI cases of which 22% and 10%, respectively, were positive for influenza. Influenza peaks were generally discernible in North and South Africa. Substantial cocirculation of influenza A and B occurred most years.

CONCLUSIONS

Influenza is a major cause of respiratory illness in Africa, especially in children. Further strengthening influenza surveillance, along with conducting special studies on influenza burden, cost of illness, and role of other respiratory pathogens will help detect novel influenza viruses and inform and develop targeted influenza prevention policy decisions in the region.

Clinic- and hospital-based sentinel influenza surveillance, Uganda 2007-2010

BACKGROUND

To assess the epidemiology and seasonality of influenza in Uganda, we established a sentinel surveillance system for influenza in 5 hospitals and 5 outpatient clinics in 4 geographically distinct regions, using standard case definitions for influenzalike illness (ILI) and severe acute respiratory illness (SARI).

METHODS

Nasopharyngeal and oropharyngeal specimens were collected from April 2007 through September 2010 from patients with ILI and SARI aged ≥ 2 months, tested for influenza A and B with real-time reverse-transcription polymerase chain reaction, and subtyped for seasonal A/H1, A/H3, A/H5, and 2009 pandemic influenza A (pH1N1).

RESULTS

Among the 2758 patients sampled, 2656 (96%) enrolled with ILI and 101 (4%) with SARI. Specimens from 359 (13.0%) were positive for influenza; 267 (74.4%) were influenza A, and 92 (25.6%) were influenza B. The median age of both patients with ILI and patients with SARI was 4 years (range, 2 months to 67 years); patients aged 5-14 years had the highest influenza-positive percentage (19.6%), and patients aged 0-4 years had the lowest percentage (9.1%). Influenza circulated throughout the year, but the percentage of influenza-positive specimens peaked during June-November, coinciding with the second rainy season.

CONCLUSIONS

Continued and increased surveillance is needed to better understand the morbidity and mortality of influenza in Uganda.

Pandemic H1N1 influenza surveillance in Haiti, July-December 2009

Please cite this paper as: Fitter et al. (2012) Pandemic H1N1 influenza surveillance in Haiti, July–December 2009. Influenza and Other Respiratory Viruses DOI: 10.1111/irv.12060.

From June 2009 through December 2009, Haiti conducted sentinel surveillance for influenza. 499 samples were collected and tested using real‐time RT‐PCR. 197 (39.5%) were positive for influenza, including 95 (48%) pandemic (H1N1) 2009, 57 (29%) seasonal influenza A and 45 (23%) influenza B. The median age of pandemic (H1N1) 2009 cases was 21.7; two‐thirds of pandemic (H1N1) 2009 cases were in patients aged 6 years – 35 years. Pandemic activity peaked in September and co‐circulated with other influenza subtypes. The age distribution and seasonality of pandemic (H1N1) 2009 in Haiti were similar to other countries in the Caribbean region.

Influenza and malaria coinfection among young children in western Kenya, 2009-2011

BACKGROUND

Although children <5 years old in sub-Saharan Africa are vulnerable to both malaria and influenza, little is known about coinfection.

METHODS

This retrospective, cross-sectional study in rural western Kenya examined outpatient visits and hospitalizations associated with febrile acute respiratory illness (ARI) during a 2-year period (July 2009-June 2011) in children <5 years old.

RESULTS

Across sites, 45% (149/331) of influenza-positive patients were coinfected with malaria, whereas only 6% (149/2408) of malaria-positive patients were coinfected with influenza. Depending on age, coinfection was present in 4%-8% of outpatient visits and 1%-3% of inpatient admissions for febrile ARI. Children with influenza were less likely than those without to have malaria (risk ratio [RR], 0.57-0.76 across sites and ages), and children with malaria were less likely than those without to have influenza (RR, 0.36-0.63). Among coinfected children aged 24-59 months, hospital length of stay was 2.7 and 2.8 days longer than influenza-only-infected children at the 2 sites, and 1.3 and 3.1 days longer than those with malaria only (all P < .01).

CONCLUSIONS

Coinfection with malaria and influenza was uncommon but associated with longer hospitalization than single infections among children 24-59 months of age.

Etiology and Incidence of viral and bacterial acute respiratory illness among older children and adults in rural western Kenya, 2007-2010

BACKGROUND

Few comprehensive data exist on disease incidence for specific etiologies of acute respiratory illness (ARI) in older children and adults in Africa.

METHODOLOGY/PRINCIPAL FINDINGS

From March 1, 2007, to February 28, 2010, among a surveillance population of 21,420 persons >5 years old in rural western Kenya, we collected blood for culture and malaria smears, nasopharyngeal and oropharyngeal swabs for quantitative real-time PCR for ten viruses and three atypical bacteria, and urine for pneumococcal antigen testing on outpatients and inpatients meeting a ARI case definition (cough or difficulty breathing or chest pain and temperature >38.0 °C or oxygen saturation <90% or hospitalization). We also collected swabs from asymptomatic controls, from which we calculated pathogen-attributable fractions, adjusting for age, season, and HIV-status, in logistic regression. We calculated incidence by pathogen, adjusting for health-seeking for ARI and pathogen-attributable fractions. Among 3,406 ARI patients >5 years old (adjusted annual incidence 12.0 per 100 person-years), influenza A virus was the most common virus (22% overall; 11% inpatients, 27% outpatients) and Streptococcus pneumoniae was the most common bacteria (16% overall; 23% inpatients, 14% outpatients), yielding annual incidences of 2.6 and 1.7 episodes per 100 person-years, respectively. Influenza A virus, influenza B virus, respiratory syncytial virus (RSV) and human metapneumovirus were more prevalent in swabs among cases (22%, 6%, 8% and 5%, respectively) than controls. Adenovirus, parainfluenza viruses, rhinovirus/enterovirus, parechovirus, and Mycoplasma pneumoniae were not more prevalent among cases than controls. Pneumococcus and non-typhi Salmonella were more prevalent among HIV-infected adults, but prevalence of viruses was similar among HIV-infected and HIV-negative individuals. ARI incidence was highest during peak malaria season.

CONCLUSIONS/SIGNIFICANCE

Vaccination against influenza and pneumococcus (by potential herd immunity from childhood vaccination or of HIV-infected adults) might prevent much of the substantial ARI incidence among persons >5 years old in similar rural African settings.

Estimated global mortality associated with the first 12 months of 2009 pandemic influenza A H1N1 virus circulation: a modelling study

BACKGROUND

18,500 laboratory-confirmed deaths caused by the 2009 pandemic influenza A H1N1 were reported worldwide for the period April, 2009, to August, 2010. This number is likely to be only a fraction of the true number of the deaths associated with 2009 pandemic influenza A H1N1. We aimed to estimate the global number of deaths during the first 12 months of virus circulation in each country.

METHODS

We calculated crude respiratory mortality rates associated with the 2009 pandemic influenza A H1N1 strain by age (0-17 years, 18-64 years, and >64 years) using the cumulative (12 months) virus-associated symptomatic attack rates from 12 countries and symptomatic case fatality ratios (sCFR) from five high-income countries. To adjust crude mortality rates for differences between countries in risk of death from influenza, we developed a respiratory mortality multiplier equal to the ratio of the median lower respiratory tract infection mortality rate in each WHO region mortality stratum to the median in countries with very low mortality. We calculated cardiovascular disease mortality rates associated with 2009 pandemic influenza A H1N1 infection with the ratio of excess deaths from cardiovascular and respiratory diseases during the pandemic in five countries and multiplied these values by the crude respiratory disease mortality rate associated with the virus. Respiratory and cardiovascular mortality rates associated with 2009 pandemic influenza A H1N1 were multiplied by age to calculate the number of associated deaths.

FINDINGS

We estimate that globally there were 201,200 respiratory deaths (range 105,700-395,600) with an additional 83,300 cardiovascular deaths (46,000-179,900) associated with 2009 pandemic influenza A H1N1. 80% of the respiratory and cardiovascular deaths were in people younger than 65 years and 51% occurred in southeast Asia and Africa.

INTERPRETATION

Our estimate of respiratory and cardiovascular mortality associated with the 2009 pandemic influenza A H1N1 was 15 times higher than reported laboratory-confirmed deaths. Although no estimates of sCFRs were available from Africa and southeast Asia, a disproportionate number of estimated pandemic deaths might have occurred in these regions. Therefore, efforts to prevent influenza need to effectively target these regions in future pandemics.

FUNDING

None.

Detection of influenza A virus in live bird markets in Kenya, 2009-2011

Please cite this paper as: Munyua et al. (2013) Detection of influenza A virus in live bird markets in Kenya, 2009–2011. Influenza and Other Respiratory Viruses 7(2), 113–119.

Background  Surveillance for influenza viruses within live bird markets (LBMs) has been recognized as an effective tool for detecting circulating avian influenza viruses (AIVs). In Sub‐Saharan Africa, limited data exist on AIVs in animal hosts, and in Kenya the presence of influenza virus in animal hosts has not been described.

Objectives  This surveillance project aimed to detect influenza A virus in poultry traded in five LBMs in Kenya.

Methods  We visited each market monthly and collected oropharyngeal and cloacal specimens from poultry and environmental specimens for virological testing for influenza A by real time RT‐PCR. On each visit, we collected information on the number and types of birds in each market, health status of the birds, and market practices.

Results  During March 24, 2009–February 28, 2011, we collected 5221 cloacal and oropharyngeal swabs. Of the 5199 (99·6%) specimens tested, influenza A virus was detected in 42 (0·8%), including 35/4166 (0·8%) specimens from chickens, 3/381 (0·8%) from turkeys, and 4/335 (1·2%) from geese. None of the 317 duck specimens were positive. Influenza was more commonly detected in oropharyngeal [33 (1·3%)] than in cloacal [9 (0·4%)] specimens. None of the 485 environmental specimens were positive. Virus was detected in all five markets during most (14/22) of the months. Ducks and geese were kept longer at the market (median 30 days) than chickens (median 2 days).

Conclusions  Influenza A was detected in a small percentage of poultry traded in LBMs in Kenya. Efforts should be made to promote practices that could limit the maintenance and transmission of AIVs in LBMs.

Hospitalized patients with pandemic (H1N1) 2009, Kenya

To describe the epidemiology and clinical course of patients hospitalized with pandemic (H1N1) 2009 in Kenya, we reviewed medical records of 49 such patients hospitalized during July–November 2009. The median age (7 years) was lower than that in industrialized countries. More patients had HIV than the general Kenyan population.

Outbreak of beriberi among African Union troops in Mogadishu, Somalia

Context and Objectives

In July 2009, WHO and partners were notified of a large outbreak of unknown illness, including deaths, among African Union (AU) soldiers in Mogadishu. Illnesses were characterized by peripheral edema, dyspnea, palpitations, and fever. Our objectives were to determine the cause of the outbreak, and to design and recommend control strategies.

Design, Setting, and Participants

The illness was defined as acute onset of lower limb edema, with dyspnea, chest pain, palpitations, nausea, vomiting, abdominal pain, or headache. Investigations in Nairobi and Mogadishu included clinical, epidemiologic, environmental, and laboratory studies. A case-control study was performed to identify risk factors for illness.

Results

From April 26, 2009 to May 1, 2010, 241 AU soldiers had lower limb edema and at least one additional symptom; four patients died. At least 52 soldiers were airlifted to hospitals in Kenya and Uganda. Four of 31 hospitalized patients in Kenya had right-sided heart failure with pulmonary hypertension. Initial laboratory investigations did not reveal hematologic, metabolic, infectious or toxicological abnormalities. Illness was associated with exclusive consumption of food provided to troops (not eating locally acquired foods) and a high level of insecurity (e.g., being exposed to enemy fire on a daily basis). Because the syndrome was clinically compatible with wet beriberi, thiamine was administered to ill soldiers, resulting in rapid and dramatic resolution. Blood samples taken from 16 cases prior to treatment showed increased levels of erythrocyte transketolase activation coefficient, consistent with thiamine deficiency. With mass thiamine supplementation for healthy troops, the number of subsequent beriberi cases decreased with no further deaths reported.

Conclusions

An outbreak of wet beriberi caused by thiamine deficiency due to restricted diet occurred among soldiers in a modern, well-equipped army. Vigilance to ensure adequate micronutrient intake must be a priority in populations completely dependent upon nutritional support from external sources.

Comparison of nasopharyngeal and oropharyngeal swabs for the diagnosis of eight respiratory viruses by real-time reverse transcription-PCR assays

Background

Many acute respiratory illness surveillance systems collect and test nasopharyngeal (NP) and/or oropharyngeal (OP) swab specimens, yet there are few studies assessing the relative measures of performance for NP versus OP specimens.

Methods

We collected paired NP and OP swabs separately from pediatric and adult patients with influenza-like illness or severe acute respiratory illness at two respiratory surveillance sites in Kenya. The specimens were tested for eight respiratory viruses by real-time reverse transcription-polymerase chain reaction (qRT-PCR). Positivity for a specific virus was defined as detection of viral nucleic acid in either swab.

Results

Of 2,331 paired NP/OP specimens, 1,402 (60.1%) were positive for at least one virus, and 393 (16.9%) were positive for more than one virus. Overall, OP swabs were significantly more sensitive than NP swabs for adenovirus (72.4% vs. 57.6%, p<0.01) and 2009 pandemic influenza A (H1N1) virus (91.2% vs. 70.4%, p<0.01). NP specimens were more sensitive for influenza B virus (83.3% vs. 61.5%, p = 0.02), parainfluenza virus 2 (85.7%, vs. 39.3%, p<0.01), and parainfluenza virus 3 (83.9% vs. 67.4%, p<0.01). The two methods did not differ significantly for human metapneumovirus, influenza A (H3N2) virus, parainfluenza virus 1, or respiratory syncytial virus.

Conclusions

The sensitivities were variable among the eight viruses tested; neither specimen was consistently more effective than the other. For respiratory disease surveillance programs using qRT-PCR that aim to maximize sensitivity for a large number of viruses, collecting combined NP and OP specimens would be the most effective approach.

Viral shedding in patients infected with pandemic influenza A (H1N1) virus in Kenya, 2009

Background

Understanding shedding patterns of 2009 pandemic influenza A (H1N1) (pH1N1) can inform recommendations about infection control measures. We evaluated the duration of pH1N1 virus shedding in patients in Nairobi, Kenya.

Methods

Nasopharyngeal (NP) and oropharyngeal (OP) specimens were collected from consenting laboratory-confirmed pH1N1 cases every 2 days during October 14–November 25, 2009, and tested at the Centers for Diseases Control and Prevention-Kenya by real time reverse transcriptase polymerase chain reaction (rRT-PCR). A subset of rRT-PCR-positive samples was cultured.

Results

Of 285 NP/OP specimens from patients with acute respiratory illness, 140 (49%) tested positive for pH1N1 by rRT-PCR; 106 (76%) patients consented and were enrolled. The median age was 6 years (Range: 4 months–41 years); only two patients, both asthmatic, received oseltamivir. The median duration of pH1N1 detection after illness onset was 8 days (95% CI: 7–10 days) for rRT-PCR and 3 days (Range: 0–13 days) for viral isolation. Viable pH1N1 virus was isolated from 132/162 (81%) of rRT-PCR-positive specimens, which included 118/125 (94%) rRT-PCR-positive specimens collected on day 0–7 after symptoms onset. Viral RNA was detectable in 18 (17%) and virus isolated in 7/18 (39%) of specimens collected from patients after all their symptoms had resolved.

Conclusions

In this cohort, pH1N1 was detected by rRT-PCR for a median of 8 days. There was a strong correlation between rRT-PCR results and virus isolation in the first week of illness. In some patients, pH1N1 virus was detectable after all their symptoms had resolved.

Risk factors for hospitalized seasonal influenza in rural western Kenya

Background

Risk factors for influenza hospitalization in Africa are unknown, including the role of HIV.

Methods

We conducted a case-control study of risk factors for hospitalized seasonal influenza among persons in rural western Kenya, a high HIV prevalence area, from March 2006- August 2008. Eligible cases were ≥five years old, admitted to health facilities with respiratory symptoms, and had nasopharyngeal/oropharyngeal swab specimens that tested positive for influenza A or B by real-time reverse transcription-PCR. Three randomly selected age-, sex- and neighborhood-matched controls were enrolled per case. A structured questionnaire was administered and home-based HIV testing was performed. Risk factors were evaluated using conditional logistic regression.

Results

A total of 64 cases (38 with influenza A and 26 with influenza B) and 190 controls were enrolled. The median age was 16 years (range 5–69 years). Among cases, 24.5% were HIV-infected versus 12.5% of controls (p = 0.004). Among persons ≥18 years old, 13 (59%) of 22 tested cases were HIV-positive compared with 15 (24%) of 62 tested controls (p = 0.005). In multivariable analysis, HIV-infection was associated with hospitalization due to influenza [adjusted Odds Ratio (aOR) 3.56, 95% CI 1.25–10.1]. The mean CD4 count among HIV-infected cases and controls was similar (399 vs. 387, respectively, p = 0.89). Chronic lung disease (aOR 6.83, 95% CI 1.37–34.0) was also associated with influenza hospitalization in multivariable analysis. Active pulmonary tuberculosis was associated with influenza hospitalization in bivariate, but not multivariable, analysis.

Conclusions

People with HIV infection and chronic lung disease were at increased risk of hospitalized influenza in rural Kenya. HIV infection is common in many parts of sub-Saharan Africa. Influenza vaccine might prevent severe influenza in these risk groups.

Are Kenyan healthcare workers willing to receive the pandemic influenza vaccine? Results from a cross-sectional survey of healthcare workers in Kenya about knowledge, attitudes and practices concerning infection with and vaccination against 2009 pandemic influenza A (H1N1), 2010

Over 1200 cases of 2009 pandemic influenza A H1N1 (pH1N1) have been identified in Kenya since the first case in June 2009. In April 2010 the Kenyan government launched a program to immunize high-risk groups and healthcare workers (HCWs) with pH1N1 vaccines donated by the World Health Organization. To characterize HCWs' knowledge, attitudes and practices regarding pH1N1 vaccination, we conducted a quantitative and qualitative survey in 20 healthcare facilities across Kenya between January 11 and 26, 2010. Of 659 HCWs interviewed, 55% thought there was a vaccine against pH1N1, and 89% indicated that they would receive pH1N1 vaccine if it became available. In focus group discussions, many HCWs said that pH1N1 virus infection did not cause severe disease in Kenyans and questioned the need for vaccination. However, most were willing to accept vaccination if they had adequate information on safety and efficacy. In order for the influenza vaccination campaign to be successful, HCWs must understand that pH1N1 can cause severe disease in Kenyans, that pH1N1 vaccination can prevent HCWs from transmitting influenza to their patients, and that the vaccine has been widely used globally with few recognized adverse events.

Afriflu--international conference on influenza disease burden in Africa, 1-2 June 2010, Marrakech, Morocco

The burden of influenza disease is to a large extent unknown for the African continent. Moreover, the interaction of influenza with common infectious diseases in Africa remains poorly described. Solid scientific evidence on the influenza disease burden in Africa is critical for the development of effective influenza vaccine policies. On 1st and 2nd June 2010 in Marrakech, Morocco, over eighty surveillance and influenza experts from 22 African countries as well as Europe and America met at the 'Afriflu' conference to discuss influenza challenges and solutions for the continent. During the meeting, participants exchanged their experiences and discussed a wide variety of topics related to influenza in Africa, including diagnosis, surveillance, epidemiology, and interventions. The meeting concluded with a pledge to improve influenza knowledge and awareness in Africa, with an emphasis on accurate determination of disease burden to help orient public health policies.

Type IV FDP avulsion: lessons learned clinically and through review of the literature

The type IV flexor digitorum profundus avulsion is a rare injury involving fracture of the volar base of the distal phalanx and separation of the tendon from the fracture fragment. Recommendations for management are sparse and are substantiated only by a few isolated case reports. We recently encountered two of these injuries, both of which proved challenging, particularly with regard to joint incongruity and tendon adhesions. In reviewing the literature, it is apparent that no consensus exists regarding surgical strategies. However, based on our experience and that of other authors, we can suggest the following: (1) high index of suspicion of this potentially deceptive injury, with use of magnetic resonance imaging or ultrasound if preoperative confirmation is needed; (2) rigid bony fixation that prevents dorsal subluxation of the distal phalanx; (3) tendon repair that is independent of the bony fixation; and (4) early range of motion therapy.

Use of rapid tests and antiviral medications for influenza among primary care providers in the United States

Limited data are available about how physicians diagnose and treat influenza. We conducted an internet-based survey of primary care and emergency physicians to evaluate the use of influenza testing and antiviral medications for diagnosis and treatment of influenza. In April 2005, an electronic link to a 33-question, web-based survey was emailed to members of the American College of Physicians, American Academy of Pediatrics, American Academy of Family Physicians, and American College of Emergency Physicians. Of the 157,674 physician members of the four medical societies, 2649 surveys were completed (1.7%). The majority of participants were internists (59%). Sixty percent of respondents reported using rapid tests to diagnose influenza. Factors associated with using rapid influenza tests included physician specialty, type of patient insurance, and practice setting. After controlling for insurance and community setting, emergency physicians and pediatricians were more likely to use rapid influenza tests than internists [odds ratio (OR) 3.7, confidence interval (CI): 2.3-6.1; and OR 1.7, CI: 1.4-2.1, respectively]. Eighty-six percent of respondents reported prescribing influenza antiviral medications. Reasons for not prescribing antivirals included: patients do not usually present for clinical care within 48 hours of symptom onset (53.0%), cost of antivirals (42.6%) and skepticism about antiviral drug effectiveness (21.7%). The use of rapid tests and antiviral medications for influenza varied by medical specialty. Educating physicians about the utility and limitations of rapid influenza tests and antivirals, and educating patients about seeking prompt medical care for influenza-like illness during influenza season could lead to more rapid diagnosis and improved management of influenza.