Invasive Salmonella virchow infection in childhood.

Salmonella virchow is generally considered to be one of the less invasive non-typhoidal Salmonellae species; however, several invasive cases have previously been reported. We report 3 cases of otherwise healthy children with S. virchow bacteraemia, monoarthritis and prevertebral abscess, only 1 of whom had previously had gastroenteritis. All 3 children responded to antibiotic regimens consisting of cefotaxime for 10 d, ceftriaxone for 3 weeks and ceftriaxone plus clindamycin for 4 weeks, respectively. In conclusion, S. virchow may be a more invasive serotype in immunocompetent children and present with a wider spectrum of manifestations than considered previously.     

Nontyphoid Salmonella bacteremia: age-related differences in clinical presentation, bacteriology, and outcome.

In a retrospective study, 80 episodes of nontyphoid salmonella (NTS) bacteremia in children were compared with 55 episodes in adults over a 10-year period. The study disclosed major differences in the predisposition, clinical presentation, and outcome as well as the microbiology of NTS bacteremia in relation to age. Adults were more likely than children to have predisposing diseases (95% vs. 15%, respectively; P < .0001) and to receive prior medications (95% vs. 23%, respectively; P < .0001), particularly immunosuppressive agents (58% vs. 5%, respectively; P < .0001). In most adults (67%), NTS infection presented as a primary bacteremia and was associated with a high incidence of extraintestinal organ involvement (34%) and a high mortality rate (33%). In children, NTS bacteremia was usually secondary to gastroenteritis (75%) and caused no fatalities. Although group D Salmonella (78%) and the serovar Salmonella enteritidis were the predominant isolates from adults, the emergence of infections due to group C Salmonella (46%) and the serovar Salmonella virchow in children was noted.     

Risk factors for mortality caused by nontyphoidal Salmonella sp. in children.

OBJECTIVE: To identify the risk factors for mortality in extraintestinal nontyphoidal Salmonella (NTS) infections in infants and children. METHODS: We performed a retrospective analysis of 107 patients with at least one nonfecal culture for NTS seen from January 1988 to December 1995. RESULTS: The median age was 12 (range 1-216) months. Malnutrition was found in 55 patients (51%), and 22 (20%) displayed severe features (weight loss >40%). Seventy-two patients (67%) had previously been hospitalized, and 59 (55%) had received antibiotics during the month before admission. Fever (85%) and diarrhea (56%) were the most frequent clinical manifestations. Nineteen children (18%) had leukopenia. Forty-nine patients (46%) had only bacteremia, 33 (31%) bacteremia with focal infections, and 25 (23%) focal infections with negative blood cultures. Forty-seven strains (44%) were multiresistant, and 40 of them were nosocomially acquired. Eight patients (7%) had received inappropriate antibiotic treatment, and two of them died. Thirteen (12%) children died. Age, underlying disease, previous admission, previous antibiotic therapy, type of infection, susceptibility of the strains and inappropriate antibiotic treatment were not statistically significant risk factors for mortality. A logistic regression analysis selected the following variables as independently influencing outcome: malnutrition (P<0.01), leukopenia (P<0.002) and presence of diarrhea (P<0.02). CONCLUSIONS: Children with extraintestinal infections by NTS with leukopenia, malnutrition and presence of diarrhea have a higher risk of death.     

Invasive non-typhoidal salmonella disease: an emerging and neglected tropical disease in Africa

Invasive strains of non-typhoidal salmonellae have emerged as a prominent cause of bloodstream infection in African adults and children, with an associated case fatality of 20-25%. The clinical presentation of invasive non-typhoidal salmonella disease in Africa is diverse: fever, hepatosplenomegaly, and respiratory symptoms are common, and features of enterocolitis are often absent. The most important risk factors are HIV infection in adults, and malaria, HIV, and malnutrition in children. A distinct genotype of Salmonella enterica var Typhimurium, ST313, has emerged as a new pathogenic clade in sub-Saharan Africa, and might have adapted to cause invasive disease in human beings. Multidrug-resistant ST313 has caused epidemics in several African countries, and has driven the use of expensive antimicrobial drugs in the poorest health services in the world. Studies of systemic cellular and humoral immune responses in adults infected with HIV have revealed key host immune defects contributing to invasive non-typhoidal salmonella disease. This emerging pathogen might therefore have adapted to occupy an ecological and immunological niche provided by HIV, malaria, and malnutrition in Africa. A good understanding of the epidemiology of this neglected disease will open new avenues for development and implementation of vaccine and public health strategies to prevent infections and interrupt transmission.     

Five cases of non-typhoidal Salmonella endovascular infection

The incidence of human non-typhoidal Salmonella (NTS) infection has increased in many countries. Endovascular infection is one of the most serious forms of extraintestinal infection. Five patients with NTS endovascular infection treated at Middlemore Hospital, Auckland, New Zealand, are presented here. All persons with NTS bacteraemia who are older than 50 years and have a risk of atherosclerosis should be evaluated for possible endovascular infection.     

Are intestinal helminths a risk factor for non-typhoidal Salmonella bacteraemia in adults in Africa who are seropositive for HIV? A case-control study

In Africa, invasive, non-typhoidal Salmonella (NTS) infections are a common but life-threatening complication in adults who are seropositive for HIV. The high prevalence of human infection with intestinal helminths which penetrate the gut could explain the greater importance of NTS bacteraemia in Africa compared with that in industrialized countries. If helminth infection is a major risk factor for NTS it would provide a locally relevant, public-health target. Intestinal helminth carriage in 57 HIV-positive patients with NTS bacteraemia (the cases) was compared with that in 162 HIV-positive controls who were similar to the cases in terms of age, sex, urban dwelling and socio-economic factors. The prevalence of helminth infection, 29% overall, was lower among the cases (18%) than among the controls (33%), giving a crude odds ratio of 0.40 [with a 95% confidence interval (CI) of 0.21-0.9] and an adjusted odds ratio (aOR) of 0.79 (CI = 0.4-1.8). Five (9%) of the cases and 12 (7%) of the controls were infected with nematodes which penetrate the gut (Ascaris lumbricoides and/or Strongyloides stercoralis). The aOR for infection with these penetrating worms, corrected for age, sex, urban dwelling and phase of study, was 1.40 (CI = 0.4-4.5). The present results do not exclude the possibility that helminths play a role in invasive NTS infections, but are not consistent with helminths being a sufficient risk factor in this population to be a public-health target. Anthelmintics are unlikely to have a major impact on preventing NTS bacteraemia in patients diagnosed HIV-positive in Africa.     

Hepcidin regulation in Kenyan children with severe malaria and non-typhoidal Salmonella bacteremia

Malaria and invasive non-typhoidal Salmonella (NTS) are life-threatening infections that often co-exist in African children. The iron-regulatory hormone hepcidin is highly upregulated during malaria and controls the availability of iron, a critical nutrient for bacterial growth. We investigated the relationship between Plasmodium falciparum malaria and NTS bacteremia in all pediatric admissions aged <5 years between August 1998 and October 2019 (n=75,034). We then assayed hepcidin and measures of iron status in five groups: (1) children with concomitant severe malarial anemia (SMA) and NTS (SMA+NTS, n=16); and in matched children with (2) SMA (n=33); (3) NTS (n=33); (4) cerebral malaria (CM, n=34); and (5) community-based children. SMA and severe anemia without malaria were associated with a 2-fold or more increased risk of NTS bacteremia, while other malaria phenotypes were not associated with increased NTS risk. Children with SMA had lower hepcidin/ferritin ratios (0.10; interquartile range [IQR]: 0.03-0.19) than those with CM (0.24; IQR: 0.14-0.69; P=0.006) or asymptomatic malaria (0.19; IQR: 0.09-0.46; P=0.01) indicating suppressed hepcidin levels. Children with SMA+NTS had lower hepcidin levels (9.3 ng/mL; IQR: 4.7-49.8) and hepcidin/ferritin ratios (0.03; IQR: 0.01-0.22) than those with NTS alone (105.8 ng/mL; IQR: 17.3-233.3; P=0.02 and 0.31; IQR: 0.06-0.66; P=0.007, respectively). Since hepcidin degrades ferroportin on the Salmonella-containing vacuole, we hypothesize that reduced hepcidin in children with SMA might contribute to NTS growth by modulating iron availability for bacterial growth. Further studies are needed to understand how the hepcidin-ferroportin axis might mediate susceptibility to NTS in severely anemic children.     

Salmonella infections in immunocompromised adults

Clinical syndromes caused by Salmonella infection in humans are divided into typhoid fever, caused by Salmonella typhi and Salmonella paratyphi, and a range of clinical syndromes, including diarrhoeal disease, caused by a large number of non-typhoidal salmonella serovars (NTS). Typhoid is a human-restricted and highly adapted invasive disease, but shows little association with immunocompromise. In contrast, NTS have a broad vertebrate host range, epidemiology that often involves food animals, and have a dramatically more severe and invasive presentation in immunocompromised adults, in particular in the context of HIV. Immunocompromise among adults, including underlying severe or progressive disease, chronic granulomatous disease, defects or blockade of specific cytokines (particularly IL-12/IL-23/IL-17 and TNF), and HIV, is associated with suppurative foci and with primary bacteraemic disease, which may be recurrent. These patients have markedly increased mortality. Worldwide, invasive recurrent NTS bacteraemia associated with advanced HIV disease is a huge problem, and the epidemiology in this context may be more human-restricted than in other settings. This review will describe the presentation and pathogenesis of NTS in different categories of immunocompromised adults, contrasted to typhoid fever.     

Invasive non-typhoidal Salmonella in Mozambican children

Objective  To describe the epidemiology and clinical presentation of invasive non-typhoidal Salmonella (NTS) in Mozambique.
Methodology  We analysed the epidemiology, clinical presentation and serotype distribution of invasive NTS among Mozambican children admitted to the Manhiça District Hospital between May 2001 and April 2006.
Results  A total of 401 NTS cases were analysed; the median age was 16 months [interquartile range (IQR): 10–24]. Fever, cough and increased respiratory rate were the most common symptoms reported, while diarrhoea was present in only 29%. In the univariate analysis, invasive NTS was associated with age, fever, diarrhoea, increased respiratory rate, splenomegaly, hepatomegaly, severe malnutrition, and severe anaemia. Young age, severe malnutrition, diarrhoea and pneumonia were independent risk factors of death. S. typhimurium (66%), and S. enteritidis (25%) were the most frequent serotypes, with incidence rates of 240.4 and 108.6 per 100 000 child years among infants for S. typhimurium and S. enteritidis , respectively; and no significant differences were found regarding their clinical presentation. Resistance to ampicillin, chloramphenicol and trimethoprim-sulfamethoxazole was high for both S. typhimurium and S. enteritidis .
Conclusions  Clinical presentation of invasive NTS was non-specific and similar to that of other infections, with some factors being associated with NTS. Antibiotic resistance was very common to currently recommended and available antibiotics for suspected sepsis.     

Airway centered invasive pulmonary aspergillosis in an immunocompetent patient: case report and literature review

Invasive pulmonary aspergillosis is a major problem that occurs in severely immunocompromised patients. Airway centered invasive pulmonary aspergillosis is rare in patients with normal immunity or those without critical illness. Computed tomography (CT) is a very useful diagnostic modality, yielding characteristic imaging findings for early diagnosis of this infection in immunocompromised and immunocompetent patients. We describe the case of an immunocompetent patient with airway centered invasive aspergillosis, who was successfully treated with voriconazole.     

Rhodococcus equi infections in immunocompetent hosts: case report and review.

Rhodococcus equi is an unusual cause of infection in humans. Infection in immunocompetent patients is extremely rare-only 19 cases in immunocompetent hosts have been reported. Localized infections represent nearly 50% of reported cases. Pulmonary infections account for only 42% of infections in immunocompetent hosts, compared with 84% of infections in immunocompromised hosts. The mortality rate among immunocompetent patients is approximately 11%, compared with rates of 50%-55% among human immunodeficiency virus (HIV)-infected patients and 20%-25% among non-HIV-infected immunocompromised patients. Treatment of infections in immunocompetent hosts depends on the site of infection. Serious infections need to be treated with combinations of parenteral antibiotics, followed by combinations of oral antibiotics. Surgical treatment is necessary for certain types of local infections. We report a pulmonary infection due to R. equi in an immunocompetent patient, and we review all reported cases of R. equi infection in immunocompetent hosts.     

Focal non-typhoidal Salmonella infections from a single center in Malaysia

A retrospective review of patients with focal non-typhoidal Salmonella (NTS) infection was performed to determine its features and outcome. All patients with focal NTS infection admitted to the University of Malaya Medical Center, Malaysia, from 1993 to 2002 were studied. More than half (58%) of the 35 cases (54% male, median age 39 years, range 1.5 months to 79 years) were immunocompromized or had chronic medical conditions. One-third of the patients (34%) had superficial infections (lymphadenitis or subcutaneous tissue infection) and all recovered with antimicrobial therapy alone. Deep infections (66%) noted were: meningitis (9%), osteomyelitis or arthritis (26%), abscesses of the gastrointestinal tract or adjacent organs (20%), and others (11%). Deep infections were more likely to occur in the extremes of age (<6 months or >60 years, p< 0.04), associated with adverse outcomes with an overall mortality rate of 9%, or required major surgery (15%).     

Invasive aspergillosis in an immunocompetent host

Invasive aspergillosis is an uncommon opportunistic infection usually seen in immunocompromised patients. Despite extensive therapeutic measures the outcome is usually unfavourable. We report a case of invasive aspergillosis in an immunocompetent individual.     

Myonecrosis caused by Edwardsiella tarda: a case report and case series of extraintestinal E. tarda infections.

Edwardsiella tarda is an unusual human pathogen. It is primarily associated with gastrointestinal disease, although recent reports of extraintestinal disease are broadening the current understanding of the clinical spectrum of E. tarda. A series of 11 cases of extraintestinal E. tarda infection is presented, including the first reported case of myonecrosis in an immunocompetent patient. Wound infections were the most common manifestation, and 3 of 5 patients with infected wounds had been exposed to a marine environment. One patient had bacteremia, and the remaining 5 patients developed abscesses that required surgical drainage. Four patients had E. tarda isolated in pure culture, including the patient with myonecrosis. Although it is often difficult to ascertain the contribution of E. tarda to infection when it is isolated as part of a mixed culture, this case series suggests that E. tarda is singularly capable of causing limb- and life-threatening infections.     

Systematic review of invasive Acinetobacter infections in children

INTRODUCTION:

Clinicians are generally familiar with Acinetobacter as an etiological agent for serious nosocomial infections in intensive care units. However, there are no previous reviews of the full spectrum of invasive infections in children.

METHODS:

A systematic review of the literature was completed up to December 2008 for reports of invasive Acinetobacter infections in children.

RESULTS:

There were 101 studies that met the inclusion criteria including 18 possible outbreaks, 33 case series and 49 case reports. Suspected outbreaks were concentrated in neonatal intensive care units (16 of 18 outbreaks) and involved bacteremia or meningitis. Proof of isolate clonality or identification of the source of the outbreak was seldom established. Case series were primarily of children younger than five years of age presenting with bacteremia (sometimes multiresistant), meningitis, endocarditis or endophthalmitis, with many community-acquired infections being reported from India. Case reports consisted of unique presentations of disease or the use of novel therapies. Attributable mortality in the outbreaks and case series combined was 68 of 469 (14.5%).

DISCUSSION:

Invasive Acinetobacter infections in children usually manifest as bacteremia, meningitis or both, but can result in a wide variety of clinical presentations. Outbreaks are primarily a problem in newborns with underlying medical conditions. Most reports of community-acquired infections are from tropical countries. The study of the mechanism of colonization and infection of children in intensive care units and of neonates in tropical countries may provide some insight into prevention of invasive infections.     

Capnocytophaga species: infections in nonimmunocompromised and immunocompromised hosts

Retrospective review of isolates of Capnocytophaga, a genus of capnophilic gram-negative bacilli, referred to the Massachusetts State Laboratory Institute in Boston revealed 31 patients with infection due to Capnocytophaga, 16 in nonimmunocompromised hosts. These infections included empyema (three patients), lung abscess (one), sinusitis (one), conjunctivitis (three), subphrenic abscess (one), wound (three), osteomyelitis (one), and bacteremia (three). Two of the wound infections were closed-fist injuries involving bone or soft tissue. Capnocytophaga was frequently isolated as part of a polymicrobial infection with other oral flora. There was only one death in the nonimmunocompromised group. In contrast, of 15 immunocompromised patients with 16 episodes of bacteremia due to Capnocytophaga, 87% had leukopenia and 73% had significant oral pathology such as gingivitis, mucositis, or ulceration. Five immunocompromised patients died. Thus, Capnocytophaga species may cause disease in both nonimmunocompromised and immunocompromised hosts. Isolation of this organism should suggest an oral source for infection.     

Non-tuberculous mycobacterial osteomyelitis: an unusual cause of hip pain in immunocompetent children

Non-tuberculous mycobacteria (NTM) are an unusual cause of osteomyelitis in immunocompetent children. Diagnosis is often difficult due to the paucity of clinical symptoms and a subtle course of the disease. NTM comprise a group of about 91 identified species of environmental mycobacteria that cause infections most frequently in immunocompromised individuals or in patients with predisposing factors. Cervical lymphadenitis is the most common presentation of NTM infection in children. Invasive and recurrent infections with these organisms have been associated with a genetic defect of the interferon γ-receptor. We report a 3-year-old immunocompetent girl who presented a NTM osteomyelitis of the left femur. Four months before she had been treated with medical and surgical therapy for a mycobacterium avium complex cervical lymphadenitis. Polymerase chain reaction assay on bone aspirate specimens confirmed the diagnosis of mycobacterium avium osteomyelitis. The patient was treated successfully with clarithromycin and rifampicin for 6 months.     

Non-Typhoidal Salmonella Gastroenteritis at a Diarrheal Hospital in Dhaka,Bangladesh, 1996–2011

Data on non-typhoidal Salmonella (NTS) infection in South Asia are limited. We used data gathered prospectively from 1996 to 2011 as part of a hospital surveillance system in Dhaka, Bangladesh, to identify diarrheal patients with NTS isolated from stool. NTS was isolated in 1.3% (468 of 37,439) of diarrheal patients; 47% of total cases of NTS were in children < 5 years of age, although older adults (≥ 60 years) had the highest isolation rates. NTS isolation peaked in the monsoon months of July and August. Over the study period, rates of multidrug resistance decreased, whereas rates of decreased susceptibility to ciprofloxacin increased. Compared with control patients, NTS patients were older and wealthier; however, no differences in type of housing or exposure to animals were found. NTS patients had increased inflammatory cells in stool and required more fluid resuscitation.     

Bacteremia in Malawian children with severe malaria: prevalence, etiology, HIV coinfection, and outcome

BACKGROUND: Previous prospective studies of bacteremia in African children with severe malaria have mainly included children with cerebral malaria, and no study has examined the impact of human immunodeficiency virus (HIV) infection. We examined the prevalence and etiology of bacteremia and the impact of HIV infection on bacteremia in Malawian children with severe malaria, as well as the impact of bacteremia and HIV infection on outcome. METHODS: From 1996 until 2005, blood for culture was obtained on admission from all children admitted with severe malaria during the rainy season to the Paediatric Research Ward at the Queen Elizabeth Central Hospital in Blantyre, Malawi. HIV testing was performed prospectively from 2001 to 2005 and retrospectively for those admitted from 1996 to 2000. Multivariate regression analysis examined independent risk factors for bacteremia and death. RESULTS: Sixty-four (4.6%) of 1388 children with severe malaria had bacteremia; nontyphoidal Salmonellae (NTS) accounted for 58% of all bacteremias. The prevalence of any bacteremia and of NTS bacteremia was highest in children with severe malarial anemia (11.7% and 7.6%), compared with the prevalence in children with cerebral malaria and severe anemia (4.7% and 3.8%) and in those with cerebral malaria alone (3.0% and 0.9%). HIV infection status was determined in 1119 patients. HIV prevalence was 16% (and was highest in those with severe malaria anemia, at 20.4%), but HIV infection was not significantly associated with bacteremia. Neither bacteremia nor HIV infection was associated with death. CONCLUSIONS: Antibiotics are not routinely indicated for children with severe malaria in this region, in which HIV is endemic. However, antibiotic therapy should be used to treat NTS infection if bacteremia is suspected in children with severe malarial anemia.     

Cryptococcoma unresponsive to antifungal treatment in a 63-year-old non-HIV-infected male

Cryptococcosis is an invasive fungal infection mainly due to Cryptococcus neoformans which has become increasingly prevalent in immunocompromised patients. The majority of patients with disseminated infection are immunocompromised due to AIDS, prolonged treatment with corticosteroids, organ transplantation, or malignancy. Invasive cryptococcal infection is rare in healthy immunocompetent individuals. We present a case of cerebral cryptococcoma in a previously healthy individual with development of meningitis and multiple intracerebral lesions in spite of persistently negative cultures and refractory to conventional antifungal therapy. The diagnosis was confirmed by two independent anatomopathological examinations.