Infectious Diseases
diagnostic testing

The recent outbreak of Corona in the world has reached the Philippines as well. In early May 2020, the number of people infected reached over 10.000, and people died almost 700. The WHO recommends large scale testing as a means to prevent the virus to spread to fast. A SARS-COV-2 infection is to be determined with RT-PCR testing, very accurately and timely, also in non-symptomatic humans. There are also serology tests to indicate if a person has been infected.

These so-called fast-testing kits are not validated yet and the non-specific tests only diagnose for a corona-virus type of infection.  In a multi-test strategy, these tests add value. Otherwise, they can do more wrong than good, as these tests may produce false-negatives (and false-positives), i.e. people are believed to be non-infected while they in fact are, and vice-versa.

HPV is the most common sexually transmitted infection (STI). HPV is so common that nearly all sexually active people get it at some point in their lives. There are many different types of HPV. Some types can cause health problems including genital warts and cancers. HPV can cause cervical and other cancers. Cervical cancer is the second most common cancer in women worldwide with an estimated 530,000 new cases and 270,000 deaths each year. The Philippines has a population of 34.30 million women ages 15 years and older who are at risk of developing cervical cancer. Current estimates indicate that every year 6670 women are diagnosed with cervical cancer and 2832 die from the disease. Cervical cancer ranks as the 2nd most frequent cancer among women in the Philippines and the 2nd most frequent cancer among women between 15 and 44 years of age. About 2.9% of women in the general population are estimated to harbor cervical HPV-16/18 infection at a given time, and 58.6% of invasive cervical cancers are attributed to HPVs 16 or 18. Cervical cancer is especially a problem in developing countries that account for over 85% of worldwide deaths. Unlike all other types of cancers, cervical carcinoma has a clearly defined causation — persistent infection with one of the high-risk HPV subtypes. In fact, over 99.7% of all cervical cancer is linked to these HPV infections, with High-Risk HPV subtypes, with HPV 16 and HPV 18 alone accounting for over 70% of cervical cancer cases.

The Pap smear (a microscopic examination of cells by a cytotechnician or pathologist) has become a valuable part of women’s healthcare since its introduction in 1940. Though specific, this method produces false-negative results about 50% of the time due to its low sensitivity. As a result, medical guidelines in many countries around the world now include HPV DNA testing as part of regular screenings to prevent cervical cancer. In fact, the World Health Organization (WHO) recommends that all women over the age of 30 should undergo routine HPV testing.

About 1 million people in the Philippines suffer from Tuberculosis, which is the third-highest prevalence rate in the world, after South-Africa and Lesotho, and the number of people infected is still rising. It is a highly curable disease, but sadly still 70 people die per day.

The WHO  urges the Philippines to run an aggressive and sustained campaign against TB. About 2-3% of the total population needs to undergo testing with rapid molecular diagnostics annually.

Dengue is a viral infection caused by four types of viruses belonging to the Flaviviridae family. The viruses are transmitted through the bite of infected Aedes aegypti and Aedes albopictus female mosquitoes that feed both indoors and outdoors during the daytime (from dawn to dusk). These mosquitoes thrive in areas with standing water, including puddles, water tanks, containers, and old tires. Lack of reliable sanitation and regular garbage collection also contribute to the spread of the mosquitoes. The number of dengue fever cases in the Philippines has grown to nearly 36,000 in the first five months of 2017, so it is a very serious problem for the country.

Efficient and accurate diagnosis of dengue is of primary importance for clinical care (i.e. early detection of severe cases, case confirmation and differential diagnosis with other infectious diseases), surveillance activities, outbreak control, pathogenesis, academic research, vaccine development, and clinical trials.

Dengue virus can be detected in the blood (serum) from patients for approximately the first 5 days of symptoms. Currently, several PCR tests are employed to detect the viral genome in serum. In addition, the virus can be isolated and sequenced for additional characterization. Molecular genetic analysis has become a primary tool to detect the virus early in the course of illness. Current tests from PHIX Genomics are highly sensitive, and more than 95% specific.