Updates
By Carol A. Kemper, MD, FACP, Clinical Associate Professor of Medicine, Stanford University, Division of Infectious Diseases; Santa Clara Valley Medical Center, Section Editor, Updates; Section Editor, HIV, is Associate Editor for Infectious Disease Alert.
Furry Friends in Hospitals
DiSalvo H, et al. Am J Infect Control. 2006;34:301-307.
The introduction of therapy animals and pets in the health care setting has created unique opportunities and challenges for infection control personnel—problems that DiSalvo and colleagues point out can be blurred by confusion between various animal programs. For example, the "Furry Friends Foundation" at Santa Clara Valley Medical Center (SCVMC) allows pet visitation in certain areas of the hospital, a program which is distinct from other animals allowed in the facility.
There are 3 categories of animals allowed at our hospital: service animals, therapy animals, and pet visitation animals, each of which has their own purpose, restrictions and policies. Only service animals (generally trained dogs) are regulated by Federal and State laws. Service animals are defined by the American with Disabilities Act as "an animal individually trained to perform (essential) tasks for people with disabilities." An organization such as a hospital cannot require proof of a person's disability or proof of the service animal's training. As such, service animals can go anywhere in the facility.
In contrast, hospitals can define policies and restrictions for therapy pets (also generally dogs) and pet visitation animals. Therapy dogs are used for specific purposes, eg, to stimulate physical or mental rehabilitation, and are used in certain areas of the facility, eg, the burn unit, physica l therapy, etc. Pet visitation is just what it sounds like; volunteers bring their own pets to the hospital for recreation and entertainment. While SCVMC only allows pet visitation in the day rooms of their facility, a neighboring hospital has elected to allow them on the medical and surgical floors but restricts them from ICUs and isolation rooms. Infection Control programs can require animals in both of these latter categories to pass certain physical and behavioral evaluations. Specific clearance may be required for stool ova and parasites, vaccinations, and a physical and behavioral evaluation by a licensed vet. The owner may be required to take basic animal training classes or exhibit knowledge about good infection control practices, such as (enthusiastic) hand washing.
Pet programs are a positive addition to the hospital and should be associated with minimal risk, as long as IC programs adopt good policies and regulations, and make clear the differences between animal groups.
Culture Conversion Key Measure in MDR-TB
Source: Holtz TH, et al. Ann Intern Med. 2006;144:650-659.
Sputum culture conversion for patients with multidrug resistant tuberculosis (MDR-TB) is generally believed to be the simplest marker of treatment success, and is especially useful in areas with limited resources and access to specialized radiographic techniques. However, medical correlates of sputum conversion and outcome have not been well-defined in clinical trails.
Holtz and colleagues examined the time to sputum mycobacterial conversion in Latvian patients with pulmonary MDR-TB. This retrospective cohort analysis assessed 167 civilians with pulmonary MDR-TB, or at least with combined resistance to INH and rifampin, each of whom received individualized therapy through a DOTS-Plus Strategy. DOTS-Plus was introduced in 1998, and provides directly observed therapy with second line TB drugs tailored to the individual's isolate. Patients first receive empirical, individualized regimens, using anywhere from 4 to 8 agents, including the use of at least one injectable, taking into consideration any previous therapy. Once the results of susceptibility studies are available in 3 to 8 weeks, the therapy is modified as appropriate to include at least 5 or more drugs to which the patient's isolate is susceptible. When appropriate, the injectable agent (generally an aminoglycoside) is continued until culture conversion, at which time it is continued for another 2 to 3 months. The remaining oral regimen is continued for another 12 to 18 months, depending on the patient's status. Adjuvant surgical management was done for patients with advanced disease not responding to therapy.
During this study, sputum cultures were obtained monthly, and culture conversion was defined as the date of the first of 2 consecutive negative cultures. Patients frequently missed obtaining monthly sputum cultures, although generally this was fewer than 5.
At baseline, 78% of the patients were men; the median age was 43 years for men and 39 years for women. The majority (74%) had received first or second line therapy for TB in the past and were resistant to a median of 5 agents (range, 2 to 10). One-third had bilateral cavitary disease, and 53% were smear positive. Sputum culture conversion was achieved in 129 of 167 (77%), with a median time of 60 days (range, 4 to 462 days). Among those who converted, 16% converted by one month of treatment, 39% by 2 months, and 60% by 4 months. Treatment outcome was best for patients who attained sputum conversion by the second month of therapy.
Fourteen patients had initial sputum conversion, followed by positive cultures; 2 of these patients had 7 or more sequential positive monthly cultures, although 13 of these ultimately responded to treatment. The ability to tolerate and comply with the regimen was important; 76% of patients adherent to a full course of treatment had culture conversion. Fourteen patients had initial sputum conversion, followed by positive cultures. Two of these patients had 7 or more positive monthly cultures, although 13 of these ultimately responded to treatment. Of the 129 patients who achieved sputum conversion, 14 (11%) were subsequently lost to follow-up, 5 (4%) died, and 2 (1%) had treatment failure.
Failure of treatment was associated with prior treatment for TB, a history of incarceration, high initial colony counts (4+ smears), bilateral cavitary disease, resistance to 6 or more drugs, and specific resistance to pyrazinamide or kanamycin. Of the 38 patients who failed to respond, 8 (21%) died. Although cavitary disease was considered a poor prognostic factor, 67% of patients who completed a full course of therapy were ultimately cured.
A limitation of this project was the lack of information on how many patients required modifications in their regimens and how often resistance to agents that were initially susceptible was detected in follow-up specimens. However, this study shows that aggressive and individualized intervention using the DOTS-Plus Strategy with multiple antituberculous agents was successful in this hard-to-treat cohort of patients with MDR-TB (with resistance to a median number of 5 drugs!). Three-fourths (77%) of patients responded to treatment, and 65% were considered cured. In those who did respond, sputum culture conversion occurred at a median of 60 days, not much longer than that described for patients with a fully susceptible organism. Monthly sputum cultures were a simple and effective method for monitoring response to therapy.
Investigation of MDR-HIV in NYC
CDC. MMWR Morb Mortal Wkly Rep. 2006;55:793-796.
You may recall reports of the 46-year-old NYC man with rapidly progressive HIV/AIDS who was infected with a strain of multi-drug resistant, dual tropic HIV (meaning, it utilized both CCR5 and CXCR4 co-receptors for entry in to CD4 lymphocytes). The man developed acute primary HIV infection in December 2004, with rapid progression to AIDS within one month of infection.
A broad public health investigation was conducted to identify sexual contacts of the index case and to define the prevalence of this strain of HIV in the New York area. The investigation was focused in 3 different directions: contact investigation; examination of newly diagnosed MDR HIV cases in NYC; and attempts to match the index case genotype with laboratory sequences. The first problem encountered was the patient's lifestyle. He reported multiple partners, many of whom were anonymous. Fourteen names were provided, 10 of whom were known to be HIV+ before 2004; none of the 10 had a genotype matching the index case. The remaining 4 persons refused testing or could not be located.
A second effort was made to alert physicians and laboratories in the NYC area to report all newly diagnosed cases of MDR-HIV. A total of 189 MDR HIV-1 isolates belonging to 134 patients were identified. An attempt to match persons in the registry with their isolate was made, and the medical records of 121 individuals were examined for date of infection, previous genotype data, and treatment history. Five persons had MDR-HIV and had been infected between 2002 to 2004, 2 of whom had never received therapy.
A third and broader attempt to identify the prevalence of this strain of MDR HIV was also made by comparing the index case's pol gene against sequence libraries at the CDC, the NY State Department of Health, and 3 large commercial laboratories in the United States, 2 in Canada, and one in Europe. In addition, 28 labs conducting HIV genotyping on NYC residents were alerted to match the index pol genotype against sequences in their databases. Isolates belonging to 3 men with > 90% homology to the index case isolate were identified (one in Connecticut and 2 in NYC). The men were contacted, and all reported sexual activity at the same time and at similar venues as the index case. Unfortunately, there was insufficient data to determine the aggressiveness of their disease, although all 3 were reportedly stable on antiretroviral therapy.
It is quite remarkable that despite an extensive and labor-intensive effort by numerous public health departments, the CDC, the Aaron Diamond Research Center, and dozens of laboratories, only a handful of cases with MDR-HIV similar to the index case were identified in the NYC area, and none of these appear to have resulted in rapidly progressive disease. But the MMWR points out that at least 6400 MSM in NYC have never been tested for HIV, and many more may be at risk. Many HIV+ individuals have not been genotyped, at least not before initiating HIV therapy. Therefore, the actual prevalence of this particular strain of MDR-HIV in NYC is unknown. This case reinforces current recommendations to obtain baseline genotype testing in any newly diagnosed or treatment-naïve HIV+ individual.
The introduction of therapy animals and pets in the health care setting has created unique opportunities and challenges for infection control personnelproblems that DiSalvo and colleagues point out can be blurred by confusion between various animal programs.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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