Tag: microbiology

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Shingles Vaccine may be Viewed as a Quality of Life Vaccine

An example of shingles. (iStockphoto/Thinkstock)
An example of shingles. (iStockphoto/Thinkstock)


A man with shingles of the face.

Shingles is caused by chickenpox virus called varicella zoster virus. The first indications that chickenpox and shingles were caused by the same virus were noticed at the beginning of the 20th century.

The incidence of shingles is mainly in adults. There are approximately four cases per 1000 population per year and a lifetime risk of 20 to 30 per cent.

Chickenpox generally occurs in children. Once the child gets over the illness the virus does not disappear from the body. Virus can settle down in one of the nerve cell bodies and lay dormant for many years.

When your resistance is low and this can be due to any reason, the virus may break out of the nerve cell and travel down the nerve causing viral infection of the skin in the area supplied by that nerve. This can happen decades after the chickenpox infection. Exactly how the virus remains latent in the body, and subsequently re-activates is not understood.

Shingles starts with burning pain, itching and tingling followed by painful rash and blisters in the area supplied by the affected nerve. The pain and rash most commonly occurs on the torso, but can appear on the face, eyes or other parts of the body. If the nerve to the eye is involved then a person may suffer loss of vision. It usually affects one nerve on one side of the body.

The rash and blisters heal within two to four weeks but some sufferers experience residual nerve pain for months or years. This condition is known as postherpetic neuralgia. About 20 per cent of patients with shingles suffer from this.

If the diagnosis of shingles is made early then it helps to start antiviral medications within 72 hours of the appearance of the rash. This reduces the severity and duration of the illness. The antiviral medications should be used for seven to ten days. The blisters crust over within seven to ten days, and usually the crusts fall off and the skin heals. But sometimes after severe blistering, scarring and discolored skin remains.

Until the rash has developed crusts, a person is extremely contagious. During the blister phase, direct contact with the rash can spread the virus to a person who has no immunity to the virus. This newly infected individual may then develop chickenpox, but will not immediately develop shingles.

Since 2008-2009, a vaccine for shingles is available for adults age 60 and over. The vaccine is used to boost the waning immunity to the virus that occurs with aging. The effectiveness of the vaccine is about 60 per cent. It is kind of a “quality of life” vaccine. It does not prevent death from shingles (an extremely rare event) but does help with postherpetic neuralgia (pain).

Booster doses of the vaccine are not recommended for healthy individuals. The efficacy of protection has not been assessed beyond four years and it is not known whether booster doses of vaccine are beneficial. This recommendation may need to be revisited as further information becomes available.

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C. difficile-Associated Diarrhea In Pregnancy – A Complex Clinical Challenge

A pregnant woman touching her belly. (Jupiterimages)
A pregnant woman touching her belly. (Jupiterimages)

Photograph shows colon acutely inflamed - red, swollen with white patches of psuedo membranes. An extreme case of C.difficile colitis - also known as pseudomembranous colitis.
Photograph shows colon acutely inflamed – red, swollen with white patches of psuedo membranes. An extreme case of C.difficile colitis – also known as pseudomembranous colitis.

In 1935, Hall and O’Toole first isolated a bacterium from the stool of healthy newborns. They named it Bacillus difficilis to reflect the difficulties they encountered in its isolation and culture. Now, after 77 years, we are unable to contain the growth and spread of the same bacterium, renamed as Clostridium difficile.

C. difficile is a frequent cause of infectious colitis, usually occurring as a complication of antibiotic therapy. Elderly hospitalized patients and other vulnerable patients are easy victims. Then there is community acquired disease in people who have not taken antibiotics.

This is not surprising, since C. difficile has been cultured from the stool of three per cent of healthy adults and up to 80 per cent of healthy newborns and infants. Patients who are discharged from the hospital or the visitors to the hospitals and nursing homes can pick up these bugs and spread it in the community. Hand hygiene plays an important role in prevention.

There is not much information out there on C. difficile-associated diarrhea (CDAD) in pregnancy. I did find one article: Clostridium difficile-associated diarrhea: an emerging threat to pregnant women (American Journal of Obstetrics and Gynecology – June 2008). The article says that largely due to their young age and overall good health, pregnant women have historically been at low risk for developing CDAD.

In a retrospective study of 74,120 admissions to an obstetrics and gynecology service over 10 years, only 18 women (0.02 per cent) developed CDAD. However, a Morbidity and Mortality Weekly Report reported 10 cases of peripartum (occurring during the last month of pregnancy or the first few months after delivery) disease from four states. Among these women, 40 per cent required hospitalization, 50 per cent experienced relapse, and one died.

Since CDAD is not a reportable disease, it is difficult to know the exact incidence of the problem and its complications in pregnant patients. It is a serious problem and CDAD should be taken seriously in this particular population and to raise the level of concern and vigilance among physicians.

Patients with CDAD can have a broad range of symptoms. Patient may be asymptomatic carrier or in an extreme situation may have life-threatening colitis.

Approximately, three per cent of adults and 80 per cent of neonates are infected with C difficile and most remain without symptoms. About 25 to 30 per cent of hospitalized adults are also C difficile carriers. These patients do not require any treatment.

Some patients have mild-to-moderate diarrhea, usually not bloody. At the other extreme, patients can be very seriously sick and have pseudomembranous colitis (see photograph). This is a serious condition and is a systemic illness. Patients have abdominal pain and tenderness, fever, and severe diarrhea that may be bloody. Marked elevations of the white blood count can be observed and may serve as a diagnostic clue. Bowel perforation is a very serious complication.

Oral metronidazole or oral vancomycin remains first-line therapy. Use of metronidazole in pregnancy remains controversial. Oral vancomycin is the only FDA-approved medication for the treatment of CDAD and can be used in pregnancy. Probiotics, to replace the good bugs in the gut, helps. Questran powder can be used to slow down the frequency of bowel movements. For intractable cases, stool transplant is an option.

Regardless, 12 to 24 per cent of patients develop a second episode of CDAD within two months of the initial diagnosis. If a patient has two or more episodes of CDAD, the risk for recurrences increases to 50 to 65 per cent.

Clearly, CDAD and C difficile infection pose a complex clinical challenge to the physician – whether the patient is pregnant or not.

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Chlamydia, Gonorrhea and Syphilis on the Rise

Recent memo from Alberta Health Services’ South Zone office warns physicians about the significant rise of sexually transmitted diseases (STD) in Southern Alberta. In 2009, Alberta reported the highest STD rates across the country. Most significant is the increase in syphilis.

In 2008, a report in the Canadian Medical Association Journal (CMAJ August 12, 2008) said that Alberta launched a $2 million campaign to combat the rise of sexually transmitted disease a day after releasing figures indicating skyrocketing rates of gonorrhea and chlamydia among young people in the province. The ads were meant to encourage condom use and regular testing for the disease. But the incidence of STD continues to rise.

STD is also on the rise in other western countries. In the United Kingdom, cases of syphilis among people aged 45 to 64 increased 139 per cent between 2002 and 2006. Cases of chlamydia rose 51 per cent.

In March 2008, U.S. Centers for Disease Control and Prevention reported that one in four teenage girls in the U.S. has a STD. An estimated 3.2 million teenage girls in that country are at risk for health problems such as infertility and cervical cancer because they have chlamydia, trichomoniasis, herpes simplex virus or human papillomavirus (causes genital warts).

Cases of syphilis have particularly increased among men having sex with men. In this group, there is also a high incidence of HIV. If a person has sex with someone who has STD then the risk of contracting the disease is extremely high. It does not matter whether a person is heterosexual or homosexual.

You are at risk of having STD if you ever had sex, if you had many sex partners, if you had sex with someone who has had many sex partners and/or you had sex without using condom.

Long term consequences of STD can be serious and sometime life threatening. Chlamydia and gonorrhea can cause pelvic inflammatory disease in women and infection of testicular area in men. This may render a person sterile. Viral warts can cause cancer of the cervix or penis. Syphilis can cause infection of the nervous system, mental problems, blindness and death. Other illnesses related to STD are hepatitis, genital herpes and AIDS.

You can lower the risk of STD by having sex with someone who is not having sex with anyone else – a monogamous relationship, who does not have STD and by always using a condom until your relationship has been established with your partner.

Primary prevention of STD can be achieved by preventing exposure by identifying at-risk individuals, performing a thorough assessment accompanied by patient-centred counselling and education and immunization when appropriate, says one of the CMAJ articles.

Secondary prevention is aimed at preventing or limiting further spread by decreasing the prevalence of STDs through detection in at-risk populations, counselling, conducting partner notification and treating infected individuals and contacts.

Practicing safe sex is the best way to stay out of trouble. Same rules apply to men and women, whether they are homosexual or heterosexual.

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Role of Probiotics in Health and Disease

About a month ago, I wrote that there is some evidence to advise patients to take probiotics when they are on antibiotics. This is to prevent antibiotic-associated colitis. The probiotic suggested was Bio-K. I understand patients are having trouble finding Bio-K. My pharmacist tells me that they can order one if the patient can wait for a day or so. So talk to your pharmacist and I am sure they can get one for you.

Bacterial content of Bio-K are Lactobacillus acidophilus CL 1285 and Lactobacillus casei LBC80R. Research has shown that these bacteria reduce the incidence of antibiotic-associated diarrhoea.

There is increasing trend towards the use of probiotics by patients suffering from certain kinds of illnesses and by the public in general. In fact, Ipsos Reid poll conducted this year revealed that 72 per cent of Canadians believe that probiotics improve their health.

Probiotics are bacteria that help maintain the natural balance of bacteria in the intestine. The normal human digestive tract contains about 400 types of probiotic bacteria that reduce the growth of harmful bacteria and promote a healthy digestive system.

The word probiotics is a compound of a Latin and a Greek word. It means “favourable to life.” Probiotics, as defined by the Food and Agricultural Organization of the United Nations (FAO), are live microorganisms administered in adequate amounts which confer a beneficial health effect on the host.

The largest group of probiotic bacteria in the intestine is lactic acid bacteria, of which Lactobacillus acidophilus, found in yogurt, is the best known. Probiotic yogurt was first launched in Canada in 2004. Yeast is also a probiotic substance. Probiotics are also available as dietary supplements.

There are a number of products available in the market. It is difficult to know which one to use. An article in the Medical Post (April 19, 2011) provides some guidelines and I will try and summarize that here.

For diarrhoea, try Danone’s Activia and DanActive. Bio-k has been mentioned earlier. DanActive has also been shown to reduce the duration of respiratory infection. Bio-K and DanActive should be routinely used in the hospitals where the incidence of diarrhoea and respiratory infection is high.

It would be nice to find a probiotic which will help two fairly common conditions affecting our gut – inflammatory bowel disease and irritable bowel syndrome. But there are no solid recommendations in the Medical Post article. That means more research is required. Probiotics in the form of chewing gum and lozenges are being investigated for oral hygiene.

So, don’t spend your money on probiotics just because your friend or neighbour says it is a good idea. Probiotics do not fix all your problems. Do your own research. Go on the internet. Check Health Canada website. Eat yogurt regularly – it has many other benefits – before you spend your precious dollar.

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