Studies highlight outbreaks in India and Philippines

Three studies have been published describing water and foodborne outbreaks in India and the Philippines.

The articles, in a supplement of the International Journal of Infectious Diseases, involve Salmonella, Hepatitis A and suspected anthrax. They are accepted conference abstracts that were to be presented at the International Congress on Infectious Diseases in September 2020 in Kuala Lumpur, Malaysia. However, the event was cancelled because of the coronavirus pandemic.

The first is an outbreak of ceftriaxone-resistant Salmonella Typhi attributed to eating chicken at a hotel in Tiruchirappalli, India in 2018.

Link to hotel
In May 2018, India’s National Centre for Disease Control’s antimicrobial resistance surveillance network was notified by the Tamil Nadu State Surveillance Unit about ceftriaxone-resistant Salmonella Typhi cases in Tiruchirappalli city, central Tamil Nadu.

Researchers defined a case as occurrence of culture positive Salmonella Typhi with ceftriaxone-resistance in a resident of Tiruchirappalli city, during January to June 2018. They were identified by reviewing records of hospitals and laboratories.

Based on descriptive epidemiology and a few patient interviews, scientists hypothesized that eating at a hotel could be a potential exposure and tested this with a case-control study. A second such study was done to identify the food caused the outbreak.

Seven of 51 typhoid case-patients had ceftriaxone-resistance. The age range was 12 to 42 years old and five were men. All seven had fever and hospital stays ranged from four to 23 days.

Five of the seven cases reported eating food at a hotel prior to illness. Incidence of ceftriaxone-resistant typhoid was higher among patients who ate at this hotel than controls. Incidence of ceftriaxone-resistant typhoid were higher among cases who ate chicken gravy at the hotel than controls. Food handlers did not have typhoid carrier status.

“The cluster of ceftriaxone-resistant Salmonella Typhi was due to eating chicken gravy at a hotel in central Tamil Nadu. We recommended proper processing of chicken and continuing surveillance for ceftriaxone-resistance,” said researchers.

Hepatitis A infections
The second study reported a Hepatitis A outbreak with Salmonella Typhi and Salmonella Poona infection in south India. The outbreak of Hepatitis A with salmonellosis occurred in an urban settlement of Vellore, India between July and August 2019.

In June 2019, researchers observed clustering of jaundice cases in a pre-established cohort, and conducted an outbreak investigation, interviewing children and adults, from clusters of identified cases.

Between April and August 2019, they identified 58 cases of jaundice. Of these, 57 were children younger than age of 15, with one aged 19 years old. A total of 24 children with jaundice received a blood culture. Two of the cultures grew Salmonella Typhi, and one Salmonella Poona.

“Our findings highlight that hepatitis A infection can present as sporadic outbreaks in communities with sub-standard water and sewage systems, along with the co-infection of other enteric infections such as invasive salmonellosis,” said researchers.

They also said population-based surveillance for hepatitis A is required in India, to identify people and geographical regions at risk, and potentially plan strategies for vaccination.

Water buffalo meat
Finally, in March 2017, a field investigating team was sent to Cayapa Village, Abra, Philippines because of increasing reports of foodborne illness.

Twenty-nine suspected cases were identified with an age range from 6 to 77 years old and 15 were males. All ate water buffalo meat. Clinical manifestations were abdominal pain, fever and diarrhea. Interviews revealed that a water buffalo was butchered and sold amongst the villagers. All 11 serum specimens and five soil samples were negative for Bacillus anthracis.

Researchers said findings indicate a point source outbreak of gastrointestinal Anthrax.

“Though, bacterial isolation were both negative for human specimen and environmental sample, all clinical manifestations were consistent with Bacillus anthracis rather than other foodborne bacterial pathogens,” they said.

An educational campaign was conducted with information that sick or dead animal by-products should not be sold or eaten and need to be properly handled and disposed of.

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