Q fever in the Southern California desert: epidemiology, clinical presentation and treatment

Despite the absence of a natural reservoir for Q fever in the desert of Southern California, six cases have been identified during the past 32 years. During that period of time, two areas have been used by northern sheep ranchers from Idaho and Wyoming to import sheep to an area in the Coachella Valley through 1985. Thereafter, because of housing development, the sheep area was moved to Blythe along the Colorado River. All but two of these patients probably acquired infection by Coxiella burnetii by living or working in close proximity to these grazing areas but not directly involved with the sheep. The shift of infected patients from the Coachella Valley to Blythe (100 miles distant) seems to support that supposition. All patients with acute Q fever developed antibodies primarily to phase II antigen, whereas the only person with chronic Q fever developed phase I antibodies. All patients presented with granulomatous hepatitis. One also had a pulmonary infiltrate, and the single individual with chronic Q fever also had a mitral valve prosthesis, although echocardiography could not define endocarditis. All patients with acute infections responded to 3-5 weeks of therapy with doxycycline, whereas the patient with chronic disease failed 3 years of therapy with combination regimens. Further studies at the Eisenhower Medical Center on the prevalence of infection in Blythe, CA, and elsewhere are anticipated.     

Molecular epidemiology of yellow fever in Bolivia from 1999 to 2008

Yellow fever (YF) is a serious public health problem in Bolivia since at least the 19th century. Surprisingly, very limited information has been made available to date regarding the genetic characterisation and epidemiology of Bolivian YF virus (YFV) strains. Here, we conducted the genetic characterization of 12 human isolates of YFV collected in Bolivia between 1999 and 2008, by sequencing and analysis of two regions of the viral genome: a fragment encoding structural proteins "PrM" (premembrane and envelope) and a distal region "EMF," spanning the end of the virus genome. Our study reveals a high genetic diversity of YFV strains circulating in Bolivia during the last decade: we identified not only "Peruvian-like" genotype II viruses (related to previously characterized Bolivian strains), but also, for the fist time, "Brazilian-like" genotype I viruses. During the complete period of the study, only cases of "jungle" YF were detected (i.e., circulation of YFV via a sylvatic cycle) with no cluster of urban cases. However, the very significant spread of the Aedes aegypti mosquito across Bolivian cities threatens the country with the reappearance of an urban YFV transmission cycle and thus is required a sustained epidemiological surveillance.     

Lower respiratory tract infections due to adenovirus in hospitalized Korean children: epidemiology, clinical features, and prognosis.

On occasion, outbreaks of infection with adenovirus types 3, 7, and 21 cause severe lower respiratory tract infections (LRTIs) in children. From 1990 to 1998, all cases of LRTI due to adenovirus at the Seoul National University Children's Hospital, Seoul, Korea, were reviewed. Adenoviruses were recovered from nasal aspirate specimens of 87 (5.9%) of 1472 children with LRTI. The principal adenovirus serotypes were type 2 (13 [15%] of 87 strains), type 3 (13 [15%]), and type 7 (36 [41%]). Of the 87 infections, 62 (71%) occurred in children <2 years of age, and 81 (94%) occurred in children <5 years of age. Infections due to types 3 and 7 occurred during epidemics, whereas infections due to type 2 occurred sporadically. For patients who were infected with types 3 and 7, extrapulmonary abnormalities were more common and homogeneous consolidation and pleural effusion were frequently identified on radiographs. The mortality rate was 12% overall and 19% among patients who were infected with type 7. Residual sequelae were identified in 6 (50%) of 12 patients who were infected with type 3 and in 9 (25%) of 36 who were infected with type 7. The data confirm that adenovirus types 3 and 7 can cause epidemics of severe LRTI in young children. Epidemics of LRTIs caused by adenovirus types 3 and 7 in Korea have not been described in reports published elsewhere.     

Epidemiologic features and clinical presentation of acute Q fever in hospitalized patients: 323 French cases.

PURPOSE: To contribute to the knowledge of epidemiologic and clinical features of patients hospitalized with Q fever in France. METHODS: We conducted a retrospective analysis of 22,496 sera submitted between 1982 and 1990 to the French National Reference Center for Rickettsial Diseases (NRC). The diagnosis of acute Q fever was based on an IgG titer greater than or equal to 1:200 and an IgM titer greater than or equal to 1:25 against phase II Coxiella burnetii antigen on an indirect immunofluorescence test (IFA). Fifteen cases prior to 1985 were diagnosed on the basis of a complement fixation titer greater than or equal to 1:8. A serosurvey of blood donors from Marseille was also conducted in 1988 on 924 sera, using IFA with a cutoff titer of 1:25. RESULTS: The serosurvey conducted in 1988 showed a seroprevalence of 4.03%, without age or sex prediction. The incidence rate of acute Q fever detection at the NRC was 0.58 per 100,000 inhabitants over the 9-year period. Three hundred twenty-three clinical cases were diagnosed, rising from 1 in 1982 to 107 in 1990. In patients hospitalized for acute Q fever, there was a significantly higher sex ratio of males to females (2.3), which, coupled with the age distribution, indicated that elder males, who are overrepresented due to our recruitment bias, are more susceptible to C. burnetii infections. The mean age of the patients was 45.5 years, while the risk was increased in the 30 to 39 age group as well as in the 60 to 69 age group. Usual epidemiologic risk factors were found in 20.1% of the cases. Hepatitis (61.9%) was a more common clinical presentation in our patients with Q fever than pneumonia (45.8%). This might reflect differences in strains of C. burnetii or the biology of the host. However, French farmers and stock breeders commonly drink unpasteurized raw milk from their cattle, which might indicate a relationship between hepatitis and infection via the digestive tract. CONCLUSION: Our results indicate that many cases of acute Q fever are undiagnosed. A greater awareness of the disease and more extensive serologic testing of patients with symptoms compatible with Q fever may improve the situation.     

Q fever in Spain: acute and chronic cases, 1981-1985

Two hundred forty-nine cases of Q fever were documented at the laboratories of the Centro Nacional de Microbiología, Virología e Inmunología Sanitarias (CNMVIS) during the 5-year period 1981-1985. Two hundred thirty-four cases corresponded to acute infections, mostly sporadic but including two epidemics. The clinical presentation was respiratory in 74% of the cases and febrile in 18%. Fifteen cases, all but one of which were endocarditis, were categorized as chronic. The cases studied were referred from almost every region of Spain. The clinical and epidemiologic analyses and the number of cases reported permit only an approximation of the true incidence and characteristics of Q fever in Spain.     

Pneumococcal pneumonia: epidemiology and clinical features.

Pneumoccal pneumonia is a common illness; the highest incidence occurs at the extremes of age. The rate of pneumococcal bacteremic pneumonia is higher in blacks than in whites and 41 times higher in those with human immunodeficiency virus (HIV) infection than in individuals of the same age who are not HIV infected. Risk factors for pneumococcal pneumonia include dementia, seizure disorders, cigarette smoking, congestive heart failure, cerebrovascular disease, institutionalization, and chronic obstructive pulmonary disease. Outbreaks of pneumococcal pneumonia occur in situations of overcrowding such as in jails or in shelters for the homeless. Streptococcus pneumoniae is the most common cause of community acquired pneumonia requiring hospitalization, accounting for up to 50% of all such cases. The mortality rate from this infection varies considerably in reported studies ranging from 7% to 36%. Bacteremic pneumococcal pneumonia often has a complicated course. Respiratory failure, meningitis, pleural effusion, and empyema are the most common complications. The radiographic manifestations of pneumococcal pneumonia vary, but in general lobar consolidation is more likely to be associated with bacteremia. Cavitation is unusual.     

Bichat guidelines for the clinical management of Q fever and bioterrorism-related Q fever

Q fever is a zoonotic disease caused by Coxiella burnetii. Its interest as a potential biological weapon stems from the fact that an aerosol of very few organisms could infect humans. Another route of transmission of C. burnetii could be through adding it to the food supply. Nevertheless, C. burnetii is considered to be one of the less suitable candidate agents for use in a bioterrorist attack; the incubation is long, many infections are inapparent and the mortality is low. In the case of an intentional release of C. burnetii by a terrorist, clinical presentation would be similar to naturally occurring disease. It may be asymptomatic, acute, normally accompanied by pneumonia or hepatitis, or chronic, usually manifested as endocarditis. Most cases of acute Q fever are asymptomatic and resolve spontaneously without specific treatment. Nevertheless, treatment can shorten the duration of illness and decrease the risk of complications such as endocarditis. Post-exposure prophylaxis is recommended after the exposure in the case of a bioterrorist attack.     

A community-based study of the epidemiology of asthma. Incidence rates, 1964-1983.

To determine whether the incidence of asthma had increased in Rochester, Minnesota, from January 1, 1964 through December 31, 1983, we used a population-based computer-linked medical diagnosis system to identify individual medical records with diagnosis of asthma or other conditions mimicking asthma. All records were reviewed using explicit predetermined diagnostic criteria; we identified 3,622 incident cases of asthma, including definite asthma (n = 1,547), probable asthma (n = 952), and single wheezing episodes (n = 1,123). The annual age- and sex-adjusted incidence of definite + probable asthma rose from 183 per 100,000 in 1964 to 284 per 100,000 in 1983. This rise was entirely accounted for by increased incidence rates in children and adolescents (age range, 1 to 14 yr); incidence rates for infants younger than 1 yr of age and for adults remained constant. For definite + probable asthma cases, the incidence rates for males were higher than for females from infancy through 9 yr of age and for persons older than 50; incidence rates for females were higher than for males from 15 through 49 yr of age. The median age at onset was 3 yr for males and 8 yr for females. We conclude that asthma begins in early childhood, with a higher incidence and earlier onset in males, and that the increase in incidence rates seen from 1964 to 1983 occurred only in children and in adolescents.     

Lymphoid interstitial pneumonia: clinical features, associations and prognosis.

Lymphoid interstitial pneumonia (LIP) is rare and its clinical course incompletely described. The aim of this study was to examine the clinical features, associations and prognosis of surgical lung biopsy-proven LIP. The study group consisted of 15 subjects encountered over a 14-yr period. The majority of subjects were females (n = 11) and the mean age was 47 yrs (range 17-78 yrs). Underlying systemic immune disorders were frequent, including Sj?gren's syndrome (n = 8), rheumatoid arthritis, systemic lupus erythematosus, polymyositis, common variable immunodeficiency and dysproteinaemia. Only three patients were classified as "idiopathic". Presenting symptoms were dominated by dyspnoea and cough. Restrictive physiology, reduced diffusion capacity (62.5+/-18.4% predicted) and bronchoalveolar lavage lymphocytosis (30.5+/-29.1% pred) were noted. Thirteen patients received corticosteroid therapy. Of the nine whose response could be assessed, four showed clinical improvement and four were stable. Overall, median survival was 11.5 yrs. Of the seven patients who died, respiratory problems were the primary cause of death in three. Conversion to lymphoma was not identified. In conclusion, histopathological lymphoid interstitial pneumonia is commonly associated with immune system dysregulation, with idiopathic lymphoid interstitial pneumonia being extremely rare. Clinical stability or improvement with corticosteroids can be expected; however, survival remains impaired.     

A seriological investigation of Q fever in clinical patients

Results of a serological survey of 507 patients, 301 males and 206 females at the Ahmadu Bello University Teaching Hospital indicated a total 20.5 per cent, or 21.3 per cent in males and 19.4 per cent females, had been exposed to Q fever agent and had circulating antibody against Coxiella burnetii. Most of the positive sera were from patients whose clinical diagnoses were typhoid and pyrexia of unknown origin though these generally are the commonest clinical diagnoses in the hospital. Titres varied from 1:4 to 1:1028 indicating old infections in some patients and acute in others. The results of normal blood donors also showed a 22 per cent positive. It is suggested that the presumptive evidence of the serological tests results be substantiated by isolation of the agent so that a correlation between clinical signs and evidence of Q fever infection be established.     

Influenza: epidemiology, clinical features, therapy, and prevention

Influenza A and B are important causes of respiratory illness in all age groups. Influenza causes seasonal outbreaks globally and, less commonly, pandemics. In the United States, seasonal influenza epidemics account for >200,000 hospitalizations and >30,000 deaths annually. More than 90% of deaths occur in the elderly population. Interestingly, in the novel 2009 H1N1 influenza pandemic, attack rates were highest among children and young adults. Fewer than 10% of cases occurred in adults >60 years old, likely because preexisting antibodies against other H1N1 viruses afforded protection. Despite concerns about a high lethality rate with the novel 2009 H1N1 strain, most illnesses caused by the 2009 H1N1 viruses were mild (overall case fatality rate <0.5%). Clinical features of influenza infection overlap with other respiratory pathogens (particularly viruses). The diagnosis is often delayed due to low suspicion and the limited use of specific diagnostic tests. Rapid diagnostic tests are widely available and allow detection of influenza antigen in respiratory secretions within 1 hour; however, sensitivity ranges from 50 to 90%. Neuraminidase inhibitors (NAIs) (eg, oseltamivir and zanamivir) are effective for treating influenza A or B and for prophylaxis in selected adults and children. Resistance to NAIs is rare, but influenza strains resistant to oseltamivir have been detected. Vaccines are the cornerstone of influenza control. Currently, trivalent inactivated vaccine (TIV) and live attenuated influenza vaccine (LAIV) are available. These agents reduce mortality and morbidity in high-risk patients (i.e., the elderly or patients with comorbidities), and expanding the use of vaccines to healthy children and adults reduces the incidence of influenza, pneumonia, and hospitalizations due to respiratory illnesses in the community.     

Psoriasis: epidemiology, clinical features, and quality of life

Psoriasis is a common chronic, recurrent, immune mediated disease of the skin and joints. It can have a significant negative impact on the physical, emotional, and, psychosocial wellbeing of affected patients. Psoriasis is found worldwide but the prevalence varies among different ethnic groups. It has a strong genetic component but environmental factors such as infections can play an important role in the presentation of disease. There are several clinical cutaneous manifestations of psoriasis but most commonly the disease presents as chronic, symmetrical, erythematous, scaling papules and plaques. The epidemiology, clinical features, and impact on quality of life of psoriasis are reviewed.     

HIV-TB: epidemiology, clinical features and diagnosis of smear-negativeTB

TB remains an important public health problem in the world that has been exacerbated by the HIV epidemic. In 2000, while 9% of new TB infections worldwide were attributable to HIV, in Sub-Saharan Africa--a region with higher HIV prevalence--about 31% of new TB cases were attributable to HIV. Clinical presentation of TB in HIV-infected individuals depends on the severity of the suppression of immunological functions. In patients in early stages of HIV infection, TB clinical presentation resembles that of HIV-negative individuals with more pulmonary involvement and localized lesions. With the progressive suppression of immunological functions, TB tends to be more generalized affecting more than one organ. Classic TB symptoms are non-specific and may result in delayed diagnosis or misdiagnosis. Diagnosis of smear negative pulmonary TB is based on clinical and radiological features. Sputum culture and rapid diagnostic tests based on polymerase chain reaction can be used where available.